Mounting a RACI finderscope on a collapsible tabletop telescope

I recently bought a Sky-Watcher Virtuoso GTi 150P tabletop 150mm (6-inch) telescope. This is a slightly larger variation, with a go-to mount, of a popular design sold by Astronomers Without Borders as the OneSky, a 130mm (5-inch) altitude-azimuth mounted collapsible tabletop telescope, shown at left.

These telescopes have a Vixen-style dovetail bar attached to the solid part of the tube—the green thing in the pictures of my telescope below. This is how the tube attaches to the mount, which has a Dobsonian style groundboard for the azimuth (side to side) axis and a half-fork with dovetail saddle for the altitude (up and down) axis. The tube can be removed from the saddle and clamped back on with a single threaded knob, the knob sticking up from the blue tube in the picture of the OneSky, making this portable design even more portable.

The problem

For finding objects, or in the case of the go-to model, aligning the mount or finding objects when the go-to isn't cutting it, the scopes are equipped with a straight-through red dot finder that projects a red dot on a window in front of the stars. A clever design with many variations, but like some people, I have trouble—no, make that pain—bending my neck enough to comfortably look through one, especially at objects high in the sky. 

On my other two scopes I have added azimuth circles and a digital angle gauge to find objects by looking up their alt-az coordinates in an app like Sky Safari Pro, moving the scope so that the coordinates are set on the azimuth circle and the gauge, and then using a right angle correct image (RACI) finderscope to zero in on the target. A RACI finder doesn’t require neck contortions and shows a correctly oriented view like you would see in binoculars.

I wanted to add a RACI finder to the Sky-Watcher tabletop telescope, but the problem is that the front ring that holds the secondary mirror and focuser is extended out on two truss tubes so that the whole front half can collapse into the solid rear half that holds the primary mirror, making it quite compact. There is no good place to add a finder on the front ring and it would make the scope quite front-heavy, requiring some sort of counterweight for manual operation. Others have added reinforcement to the front plastic ring or have drilled holes in the tube to add a finderscope, but I didn’t want to do either of these things. 

The solution

I added a universal dovetail shoe (base) to a block of wood attached to the scope's dovetail bar (the green thing) and swap my RACI finder between my 4.5-inch and this telescope. Looking at the design, the long dovetail bar attached to the telescope tube has two channels that run its length and a single 1/4-20 threaded hole close to the front end of the bar. The hole is presumably for mounting on a tripod, but it’s at a very poor location for balance. I had seen others mount a laser pointer and finder on that part of the dovetail bar, so I experimented with mounting a Svbony SV182 6x30 RACI finder that I have on my 4.5-inch reflector. I zip tied it in place to see how it worked. The problem was that, sticking out straight from the dovetail bar, the finder was too far from the observer’s position and I had to get up and either lean over or walk around the back of the scope to the other side to use it.

If I were to fasten a block of wood to the end of the dovetail bar at a 90 degree angle, then I could mount the RACI finder on the end of it, bringing the eyepiece to a much better position, even better than if I had drilled a couple of holes in the solid tube to mount it. After doing just that, I noted a post on the OneSky megathread on Cloudy Nights that did something similar, but by drilling and tapping a dovetail clamp instead of using a block of wood. Same end result.

Here’s how to do it

I cut all the pieces using a basic mitre box and a hand saw.

I cut a 5” piece of 2x2 baluster (vertical railing piece) that I had left over from making the legs for the telescope’s table mount. I cut a 45 degree corner on one end so I wouldn’t have a sharp corner sticking out. These balusters tend to vary slightly in cross section width, so I checked a few pieces before I found one where the dovetail finder shoe, or base, fits tightly in one direction—one more way to make it even more solid. Note: I used balusters rather than the 8’ lengths of 2x2 that they have because the balusters tend not to be as warped as the long pieces and they were actually cheaper per foot.

I glued and screwed two small pieces of wood to the block to sit in the bar channels and keep the block from rotating on the single bolt. I cut the two little pieces from a large size paint stirring stick (1/4” thick). The pieces are 7/16” wide and 2-1/4” long. I sanded them so they fit tightly into the bar channels.

This side will face the observer sitting at the telescope.

I dry fit the block and the two channel pieces to make sure they fit tightly in the dovetail bar. There are two screws in the dovetail bar at the bottom of each channel 1/8” from the front end of the bar. The block would need to sit behind these screws with the channel pieces butting up against them to add stability. I marked where the bolt would go through the block into the dovetail bar and also where I would need to glue the small channel pieces that would fit snugly into the two channels in the bar. I had cut them a little long just to give a bit more twist resistance in the channel.

Where the bolt would go through the block and screw into the dovetail bar, I countersank a 3/4” diameter hole about 3/16” deep, enough so the bolt head, with a 5/8” outer diameter - 1/4” inner diameter washer, would be flush or nearly flush with the surface, using a 3/4” Forstner bit. (3/4” because my wrench socket would fit in it so I could tighten the bolt.) You must do this before drilling the hole for the bolt so that the bit can center properly. It’s not essential to countersink the bolt head, but I thought it would be better than having it sticking out, and I recently got the Forstner bit set, so I’m eager to find reasons to use it! I then drilled a 1/4” hole all the way through the block, centered in the 3/4” countersunk hole.

I inserted the two little channel pieces into the channels and pushed them tight up against the screws in the bar channels. I inserted the bolt and tightened it to make sure the fit was good. Then I removed the bolt, put wood glue on the two channel pieces where they would join the block and bolted the block into place. Once the glue had dried for about 45 minutes, I removed the assembly and cleaned off some glue that got on the dovetail bar. It removes easily.

The dovetail shoe for the finder has four slots for screws. I screwed it into the top of the block with four 1-1/4” #6 wood screws. Everything looked good, so I took the shoe off the block assembly, painted the block assembly black, reattached the shoe, and attached the whole assembly to the dovetail bar. The shoe stays on the bar and the finderscope is removed for transport. This modification is also entirely reversible with no alteration to the telescope.

The finished mount. Note the four screws added to the channel bars. I found glue alone did not hold. Make sure you recess the screw heads into the wood with a countersink bit so they don't scrape the dovetail bar.

The finder is at a more comfortable, although still not optimum, location. I can also fit my head in there to use the red dot if necessary. The scope can rotate through the entire range of altitude motion without anything bumping or binding, but be careful when pointing above 50 degrees, as the additional weight of the finder will want to flip the tube backwards.

Packed up, the finder mount is out of the way and adds very little weight or volume to the overall package. Just loosen the two thumbscrews, slide the finderscope on, and tighten the thumbscrews. 

View from above when collapsed. The finderscope mount does not stick out beyond the round baseboard of the telescope mount. The dovetail shoe is mounted so that the thumbscrews point inward and are less likely to catch on a cover or other item.

Now I can use the RACI finder more easily and swap it between the two telescopes. It's still not an optimum viewing position especially at higher altitudes, although being able to rotate the diagonal on the finderscope helps. But for these collapsible telescopes, this makes a useful addition or alternative to the red dot finder.

Recording your observations

 

Jupiter-Venus conjunction, March 2023

 

July 3, 1990 (Miami, Florida)

Picked out major stars: Vega, Altair, Deneb, Arcturus, Spica, and Antares (near Moon). Found the “Teapot” and figured that was Saturn to the left (west) of it. Mosquitoes were fierce and it’s only July! Looked for M19- too washed out to spot it. Also M4. Traced out some of the constellations. Moon is gibbous—some good crater action on the “tan line”.

That was the first observation I ever recorded. I didn't even have celestial east and west sorted out yet. Not that I hadn't observed the sky with a variety of telescopes, binoculars, or the unaided eye before that. But this was my first year of "getting serious" with amateur astronomy.

But how serious are you about Sirius?

It's what you make it. It's a hobby. For some people it's a passion. But it's still a hobby. Most of your observations matter only to you, so consider that, when and if you record them. I do strongly suggest you keep some kind of observing log, for the following reasons:

• It will jog your memory to bring back specific nights and events
• You can compare observations made at different times, in different skies, through different instruments
• It's interesting to see your progress in the hobby, and your failures
• It will tell you if you've observed something before or if it's new to you
• You'll remember people (and critters) you would otherwise have forgotten

That's just a few, and it really varies depending upon the person.

I can only tell you how I log my observations. I don't always log details, especially for objects I've seen many times, unless I see something new in them. I like to keep it conversational and not too technical. I like to have fun. I don't like to be bothered recording the seeing, transparency, exact eyepieces and powers I was using, data from a sky quality meter, etc. for every observation. I'll note the sky conditions at the beginning of a session and if they change, as they often do. I keep it simple- who, what, where, and when. I already know the why. See my post on the Comet Shoemaker-Levy 9 impacts on Jupiter log entries to get an idea of what I put in there and how a log makes a great memento of a memorable observing session or event.

Two bins

My observing records end up in two bins: an observing log in narrative form, which includes notes taken while at the eyepiece that I then extract from the log and group together by object over time in a separate collection of notes files.

My actual observing log, as in the example above and at left, is a session by session narrative. I keep it in a series of Microsoft Word compatible documents, usually one document per year or half year, depending on how much observing I've done, and I'll add images from the internet for many of the objects. 

I note the situation, the people, animal sounds, big gusts of wind, spectacular lightning on the horizon—all those things that bring back the memory like it was yesterday. I'll also make notes at the eyepiece about specific objects. At the beginning of each session, I note the date, day of the week, location, and what equipment I'm observing with.

Periodically I'll extract the notes on specific objects, which I highlight in bold in the log to make them easier to find, and collect them in text files, which I call my observing notes. With this collection of notes, I can look up an object and compare what I'm currently seeing with what I have seen in the past from a variety of locations, in different sky conditions, and with different instruments. I aggregate the notes for each object into a single entry, as in the following example:

Veil Nebula (western portion), NGC 6960

Oct. 13-14, 1993, Chiefland Star Fest, Chiefland, FL

(4.5-inch) Quite bright- tried for dimmer side near the bright star in my scope- only a hint of its brightest part in 100x. Low power would be better if I had it.

Nov. 13-14, 1993, Lake Kissimmee State Park Star Party, FL

(10-inch) Nice view of the fainter section in the 10-inch SCT. Very bright with the nebula filter. Seems like there's a dark lane down the center of the nebulosity (this is the W section). E end visible with the filter.

Sep. 24-25, 2003, Skyline Drive, Shenandoah National Park

(4.5-inch) It's just such a nice transparent night I had to go for the Veil Nebula, and sure enough, it's pretty easy to see around 52 Cygni on both sides, not just the one brighter side, and I can see more than I usually can in those areas. I can see the other segment on the opposite side (NGC 6992) in the finderscope! It shows up nicely in 50x. I gotta say that's about as well as I've seen the Veil show up in this scope. I can trace the whole crescent shape of 6992 for at least 2 fields of view in 50x (almost 2 degrees).

...and so on.

Decades ago I wrote my notes at the eyepiece in pencil or pen. Then I used a handheld tape recorder. Then a digital recorder. Now I dictate in Google Keep using the voice typing feature, copy and paste into my log at a later date, and clean up the dictation errors. Google voice typing has particular difficulty with certain astronomical names, such as when I say "Ophiuchus," and it writes "all for you because," "ophelucas" (huh?), or the usual "off of Lucas." I'm used to correcting such phrases such as "and you see," for "NGC." A recent favorite is "IHOP address" for Saturn's moon Iapetus. 

Find a way to make it easy

Ideally, I would have a charting app at the telescope in which I could click on an object and it would bring up these observing notes for that object. Sky Safari falls short for me in that respect, in that it forces you to organize your notes by observing session, much like my observing log. But I want to see all my notes over the years for a single object in one place. I've tried to use one Sky Safari "session" to put all the observations for a single object in the comments, but the box has no scroll bar, there's no way to add images, and it's very clunky. 

I just wanted a simple app that I can update easily, add images, and most important, import and export through a standard format. 

I think I found just that in the Memento Database app. I started with an astro log template available through the app and modified it to include just two fields: notes and images. While it requires going between the Sky Safari and Memento apps, it's a pretty good second best solution. I use the app Twilight to dim and redden the screen while observing. iPhones do this natively.

I was able to export my notes from Sky Safari on the 1200+ objects I've recorded over the years, then import them to Memento, all via a .csv file. Cool beans. 

I downloaded images of the objects, resized them to keep the database small (the Memento cloud has 100MB free storage), and attached them to each file. Tedious, but fun and it helps me remember some of the objects I haven't observed in a while and should revisit. I like having images at the eyepiece to help determine if what I think I'm seeing is actually there.

Apps will come and go, so one of the keys is to be able to backup your notes and store them in a standard format like text or xml. I figure text is about as standard as you can get, so I stick to that.

Sometimes I just like to read through my old logs on my computer, and now the notes are portable so I can look them up at the eyepiece and even browse them while I'm waiting at the doctor's office. I did that today, reading my observing notes on the Comet Shoemaker-Levy 9 impacts on Jupiter, which were 30 years ago. I cherish the memories that I've preserved through my observing log and notes. How much would I remember without them?

Make a table for a tabletop telescope

If you or your child are just getting started in visual astronomy, I can recommend a tabletop telescope of 4.5" to 6", such as the Sky-Watcher Heritage 150 Tabletop Dobsonian. This telescope (reviewed here) has good quality optics, is compact and portable, and very comfortable to observe with. But it's missing a table.

Why make one

You would think that a tabletop telescope is designed so that you can use whatever table you may have handy: a picnic table, a foldup table, a stool, or just a small end table. That may have been the intention, or maybe just the marketing, but when you’re looking at objects in powers of 30x, 50x, 100x, or 200x, you need something very stable so the view isn’t all shaky.

Picnic table? Nope. When you sit on it, you’re going to make it shake. It is also unlikely to be in the best spot for observing and you can’t move around the telescope.

Foldup table? Nope. Really shaky unless you get one that’s built like a tank, and that defeats the portability factor that is often the main advantage of the table.

Stool? Maybe, if it’s solid and the right height. You could cut the legs to size, but will it be large enough to fit the telescope? It may also be bulky if you have to transport your telescope to a remote location.

End table? Three legs will be better for leveling on uneven ground, and you have the same problems listed above as a stool.

Well, that’s a bummer. You thought a tabletop scope would be just the thing for portability. Now you’ve got one and no good table to put it on.

Fear not. Some people use a milk crate, build a simple tripod, or buy something at Ikea like this stool.

Or...and you knew this was coming...you could have fun and build your own observing table. It’s not hard (if I can do it!), and you can customize it for your own observing needs. Continue reading to achieve tabletop nirvana.

How to do it

The table I built for my Sky-Watcher Virtuoso GTi 150P, a 6-inch collapsible tabletop telescope, is simply a round piece of 1/2” plywood with holes drilled in it to hold eyepieces and three legs made out of cheap 2x2 lumber that can be unscrewed so the table top lies flat for transport. The legs are cut with about a 10 degree angle so they provide a little more stability than straight legs, although you could make them straight to simplify things even further. Each leg has a 1/4-20 hanger bolt screwed into one end which allows it to be screwed into a t-nut fastened in the tabletop. Easy-peasy, and it takes up very little room in the car if you unscrew the legs.

I started by making a circular cutting jig for my jigsaw since I don’t have a router, the preferable way to cut circles. If you don’t even have a jigsaw, you can buy an edge-glued round piece of wood (I recommend 18”), although some reviewers have said they sometimes come unglued or split.

The base of my scope is about 14" in diameter. I decided on an 18” diameter circle so I would have a couple inches around the outside to drill holes for eyepieces and to put my cell phones and filters down. I used 1/2” plywood to keep the table as light as possible. With the scope feet directly over the table legs, it only needs to be stiff enough to keep the legs in place without bearing the weight of the scope. [9/22/2024 Update: Because the go-to on my scope is unreliable, I added an azimuth circle to the base of the telescope. The circle sticks out about 3/4" all around, so I built a new table, this time using 3/4" plywood and making it 20" in diameter. I like it better, and I recommend you go with those dimensions. It's a little heavier, but not by much. It also makes a great camping side table when you're not observing.]

My mistake in cutting the plywood circle with the jig and jigsaw was I trusted in a YouTube video that showed how easy and neat it was to use a cutting jig. In reality, the saw blade wants to either go inside or outside the circle unless you watch very closely. I had the saw run outside the circle on one part and inside on another, breaking two blades. 

Were I to do it again, I would only cut a couple inches at a time and check to make sure it was still cutting on the circle. Or I would just draw the circle on the wood and cut it freehand with the jigsaw. I’ve done that before and it comes out fine. I just might not do it if I need the precision necessary for an altitude bearing, for example, but for this purpose it’s fine.

Once I had a pseudo-circle cut out, I marked where the three feet of the telescope would go. You can simply place the telescope base in the center and mark where the legs go. To be more precise, you can divide the circle into three sections by drawing a diameter (1), then drawing lines (2 and 3) the length of the radius (9” in this case) from the outer point of the first line (1) to where it intersects the outer edge of the circle on both sides, then drawing the other two lines (4 and 5), as in the diagram.

To make sure I had the scope centered, I partially screwed a wood screw into the top of the circle in the center. Some of these tabletop telescopes have a threaded hole in the center of the base. I just placed that over the screw and marked where the three feet would go.

If you don’t have the center of the circle marked, you can find it by drawing a chord at any point on the circle (line 1) and drawing a second line (line 2) from the midpoint of that line using a carpenter's square or other object that will give you a 90 degree angle. Repeat in a different location (lines 3 and 4) and where lines 2 and 4 cross is the center.

To screw in the table legs you can get angled leg brackets, but I don't like the inserts they use and I wanted a nice flush surface so I could slide the tabletop in between stuff in the car easily. So I put three 1/4-20 t-nuts where the feet would sit. These need to go in from the top of the table so that when you screw in the legs from the bottom, they will be pulled in tighter, rather than pulled out of the wood. Make sure the t-nut barrel is long enough to grab at least a few threads of the hanger bolts in the legs but doesn’t stick out the bottom if it is inset about 1/8” (see below). You want the legs to contact the table when screwed in tightly to give a nice stable grip.

I used a 3/4” Forstner bit in my cordless drill to first inset the holes about 1/8” in the top of the table where the t-nuts would go. I didn’t want to go too deep in 1/2” plywood, but if you use thicker plywood you can go deeper. You just want them inset to give some edge for the telescope feet to catch on so it won’t slide easily.

Then I drilled a hole in the center of each inset with a 9/32” regular drill bit. If you don’t have that size, use a bit that’s just slightly larger than 1/4” because the threaded barrel of the t-nut will be a little larger than 1/4”. Hammer in the t-nuts from the top side until they sit below the surface of the table.

I wanted some eyepiece holders, so I marked off three holes along the outer edge of the table top in each of the three sectors. Test the fit by placing the telescope on the table and your eyepieces where the holes will be. Make sure the telescope clears the eyepieces through its full rotation of 360 degrees. When satisfied it would, I drilled holes with a 1-1/4" hole saw.  I also added a 2" hole to each sector, even though my telescope doesn't have a 2" focuser. I figured I might want to use the table for stuff while using my 10-inch, and I have a couple of 2" eyepieces. It would also lessen the weight further. [8/28/24 update: I may redo the top without the 2" holes. Twice now I've almost dropped an eyepiece through the 2" hole onto the driveway, thinking it was the 1.25" hole. Oops.]

I sanded both sides and the edge of the table top with a random orbital sander and the holes manually with small pieces of sandpaper and a scrap piece of PVC pipe.

As noted above, you can just make the legs straight at whatever height you prefer if you don't want to take the extra steps to angle the legs, although you will sacrifice a little stability. 2x2 lumber is cheap and you can make several sets if you like. I like to use balusters, which are the vertical pieces in a deck railing, because they tend to be straighter than the 8’ lengths of 2x2. Those can be horribly warped and actually cost more per linear foot at my local store.

To make straight legs, drill a hole in the center of one end, as straight as possible, a little deeper than the length of the wood screw part of a 2" 1/4-20 hanger bolt. Use a drill bit a little smaller than 1/4” so the screw will have plenty of wood to bite and hold tight. Screw it in by threading two 1/4-20 nuts and tightening the upper nut with a 7/16” wrench until you get the length sticking out that will work with your t-nuts, roughly 3/8 to 1/2 inch. You can unscrew it if you overdid it by putting the wrench on the lower nut and twisting counterclockwise.

To make angled legs, which will add stability to the whole setup, I found an easy way is to take a typical mitre box and lay the uncut piece of 2x2 diagonally so that one side is up against the top of the box as seen from above and the other against the bottom. Clamp it down. If you cut along the 90 degree slot in the middle you’ll get about a 10 degree angled end. For the first and the last cut, you’ll have to estimate and just clamp the wood down. 

Cut three legs so the ends are all at parallel 10 degree angles, i.e., the piece looks like a parallelogram from the side. I cut my legs 10-5/8” long, which, with the 1/2” plywood top and the 10 degree angle, gives me a table top height of about 11 inches, just right for my adjustable observing chair at the height I like to sit.

Now put each leg in a vise if you have one, so that the angled face is horizontal. Then just drill your hole in the center vertically. Screw in the hanger bolts as described above using two 1/4-20 nuts and a 7/16” wrench. When you screw the leg into the table, the other end will trace a small circle, but it will work. 

I adjusted the depth of each screw so that the leg would screw in tight to a particular t-nut where it points outward, and just marked each pair with painter’s tape on the table and leg so I could easily match the leg to the hole. Later I’ll use a Sharpie once I’m sure everything fits well. You can always readjust the screw depths as things wear.

If you use outdoor plywood, you don’t really need to paint it because you're not going to leave it out in the rain, but I got a spray can of spar varnish and gave the table a few coats. A cheaper option would be paint. I recommend white so it's easy to see at night and you can see where to put your eyepieces. If you use treated wood for the legs, they don't need to be painted but you can paint them. If a few drops of water soak in, they are dry enough to be painted, otherwise wait a week or two for the chemical treatment to dry completely before painting. Use a tack cloth after sanding everything to remove any sawdust and grit.

Lastly, I put a piece of white duct tape on the table top at each point where the legs go to assist setting the scope on the table so the feet are directly over the t-nuts.

That’s it. If you mess up, all the parts are cheap and you can redo any or all of it. You can also make legs of different lengths if needed.

My Sky-Watcher Virtuoso GTi 150P tabletop telescope (same as the recommended scope at the beginning of this article but with an electronic mount) on the table I built for it. It looks happy, doesn't it?

[9/22/2024 Update]: Here's the new table I built to accomodate the addition of an azimuth circle to replace the go-to. I made all the eyepiece holes 1.25" and painted it white. 20" diameter using 3/4" plywood. The scope is even happier now!

Materials:

Piece of Plywood 1/2" to 3/4" thick big enough to cut a suitable sized circle (18" is usually good) or precut wood circle

One or two 2x2" stair balusters

Three 1/4-20 t-nuts, short enough not to stick out from the plywood, depending on the thickness

Three 2" x 1/4-20 hanger bolts

Two 1/4-20 hex nuts

Paint or varnish

Tools:

Mitre box and hand saw

Power drill with 9/32" (for t-nut holes),  1/8" or 3/16" bit (for hanger bolt holes), 3/4" Forstner bit, 1-1/4" hole saw

Jigsaw (unless you are buying a precut wood circle)

7/16" wrench

Sandpaper, sander (or sanding block), and dust mask (I like this one for sanding, painting, and gluing)

Tack cloth

Two bar clamps or C clamps large enough to clamp a 2x2 in your mitre box and to the workbench surface (which could be a piece of plywood laid over two saw horses if necessary).

Bench vise

Hammer (a big, short bolt helps to hammer the t-nuts below level so you don't damage the table surface)

Carpenter's Square or L-Square 

Pencil or X-acto knife (makes more precise measuring marks for cutting)

A simple dolly for moving a Dobsonian telescope from the garage or shed

Reader Pete suggested I write up something about my dob dolly pictured in the post on making the heavy 10-inch Dobsonian telescope more easily transportable. A dolly or hand truck is useful if you are using a heavy telescope at home or next to where it is stored, versus disassembling it and moving it by hand or transporting it to a dark sky site.

My home is around Bortle 8 (badly light polluted), but I still like to get the 10-inch dob out sometimes because it shows more in a light polluted sky than either my 4.5 inch or my new 6-inch reflector. So rather than heft the base and tube out onto the driveway every time I want to observe, I built a crude but effective flat dolly for it, as detailed below.

Option 1: buy a hand truck

If you don’t want to build a little dolly, you can simply buy a hand truck such as this one at Harbor Freight for somewhere between $50 and $100 and make a few minor modification to carry your Dobsonian. Usually this involves adding a plywood piece to make the toeplate larger (the flat part that the object sits on), adding padding for the scope tube about halfway up the frame, and a strap to hold the scope tube to the hand truck. 

In fact, this is what I am recommending for my brother who has a 6-inch Orion SkyQuest XT6. The scope is not very heavy, 31.5 lbs. total, but to get to a decent park in the city to observe he has to tote it about six blocks (he doesn't drive). Ugh. So a hand truck makes sense for him. Here’s a Cloudy Nights post that might give you some ideas.

Another advantage of a hand truck is that it's very useful around the house (toting bags of yard waste around, moving furniture, etc.).

Option 2: build a flat rolling dolly

Here’s how I built a very simple but also very crude rolling dolly for my 10-inch Dobsonian. Caveat- there are no handles, so I just push and pull on the scope base to move it. Also, mine has front and rear wheels that are different sizes because my driveway is on a three percent slope. This makes it level without any further adjustment so I can use my azimuth circle/digital angle gauge setup to find objects. Using a hand truck in this case would involve too much fuss and potential trouble. If your driveway or path is level or if you don’t need the scope to be level, you can use the same size wheels. If your driveway or path is not paved, or if you have to negotiate steps or anything taller than an inch or so, you are probably better off with a hand truck with 6” or larger wheels.

I had some scrap pieces of 5/8” roof sheathing plywood leftover from a roofing job. (Always see what your workers are throwing away and ask them to save it if you might find it useful.) The base of my 10-inch is a 22” diameter circle, so the dimensions are optimized for that.

I cut a 22” x 26” rectangle from the plywood. The extra 2 inches in front and back provide room to fasten the wheels on without getting in the way of the feet on the scope base or having the bolts sticking out and scraping the base.

I needed the front of the dolly to be 1” higher than the back to compensate for my sloped driveway. I bought a pair of 3” rubber rigid casters and a pair of 2” rubber swivel casters at Harbor Freight. These are 3-5/8” and 2-5/8” high, respectively, which gave me the just about the right adjustment for my sloped driveway. I thought about getting casters with brake levers on them, but these aren't strong enough to hold anything on a slope, just keep it from rolling on a level floor. The casters bolt through the plywood with four bolts each. You’ll need a drill and a pair of wrenches. Make sure you buy bolts that fit the caster holes.

I was able to put the nuts on the bottom of the fixed casters, but the swivel casters were smaller and the threaded bolt ends sticking up would have prevented them from swiveling, so I had to have them sticking up on the upper side of the plywood. It’s not optimal, but that’s what I had to do.

With an azimuth circle on the dob base, I wanted to make it easy to align with the cardinal directions, so I put a mark on the dob ground board that would align with a mark on the dolly to position the base so it would be roughly aligned in azimuth and I would just need to fine tune it each session.

I put the scope base where I would be placing it on the plywood and painted a white circle all the way around on the dolly’s surface to help me align it when plunking it down. 

To keep the base from sliding around, because I would be pushing and pulling it, I glued pieces of wood just outside each dob foot. Normally dobs have three feet, but I found adding three more feet from wood made it more stable on uneven ground, so I have six little pieces of wood glued to the dolly. Just make sure they are shorter than the dob feet so they don’t touch the ground board.

That’s pretty much it. I didn’t even waste paint on it, since it will be spending most of the time in my garage, and paint is often one of the more costly parts of any woodworking project.

So how well does it work?

My only real complaint is that it’s a little hard to maneuver with the two swivel wheels, so I just have to go slowly when pulling/pushing it in and out of the garage. To keep the scope from rolling down into the street, I use a rubber wheel chock from Harbor Freight and a rubber sanding block under each front wheel. If you use something different, make sure it's not going to just slide down the slope. I always stand on the downhill side of the scope when rolling it to and from the driveway.

If you have to roll the scope over a threshold, for example I have a 1” bump from my driveway into the garage, use a piece of baseboard molding a bit longer than the width of the dolly. It has a tapered profile that works nicely as a little ramp. Tip: Save some pieces of any molding you replace. I’ve found multiple uses for this.

Just be aware that you’ll be adding about 4” or so to the height of the eyepiece when observing. Even my adjustable observing chair needs a booster cushion at its highest adjustment for some positions when the scope is on the dolly. I don’t notice any instability or shaking in the views from being on the dolly.

If you have a telescope on a heavy tripod and mount and want to build a dolly, here's an article from BBC Sky at Night that might give you some ideas.

Bonus Tip: If you have a store like Harbor Freight or Northern Tool near you, or can order from one, you can save a lot of money on many items, including tools that you’ll only use occasionally. Better to have the right cheap tool than the wrong high quality tool. I don’t have any affiliation with them, I just like to save money if I can.

Making a heavy dob base more manageable: divide and conquer!

The problem

I’ve had my 10-inch solid tube Dobsonian telescope, a Hardin "Deep Space Hunter" made by Guan Sheng Optical (GSO), for 20 years now and it has served me well. In fact, it’s doing better than my own body at this point. I’ve found it harder to load it in and out of the car to get to my darker sky sites. I needed to make it easier.

The solution

I can’t do much about the tube, which weighs about 32 lbs., but a post on Cloudy Nights got the neurons firing in my brain. It showed what one amateur astronomer did with the base of his 12-inch, and I decided to try it on my 10-inch.

The base is made of particle board and weighs about 38 lbs. It's heavy and awkward to get into the car. What if I could split it into two pieces that could be easily reassembled? That’s the idea, and it works! I separated the two round ground boards as one section, actually the round bottom of the rocker box and the ground board, from the rocker box as the other section. These are shown in the pink boxes below. These two sections were originally put together with six long wood screws coming up from underneath the rocker box bottom and into the bottom edges of the rocker box (indicated by the blue arrow below). The pink boxes denote the sections that would be separated:

 

To reassemble the two sections, I bolted two aluminum angles to the inside of each side of the rocker box and fastened them to the round rocker box bottom with four knobs inserted into holes drilled in the horizontal leg of each angle and screwed into t-nuts inserted in the underside of the rocker box bottom.

Inside the rocker box, showing the first angle
fully assembled. The knobs will be used to disassemble
 and reassemble the base.

The outside of the rocker box, showing the
bolts holding the angle. These will stay put.

The whole project took one afternoon, and was only complicated by the fact that I had replaced the original “lazy Susan” azimuth bearing (as shown in the diagram above) with Teflon pads riding on Ebony Star Formica (alas, no longer available). The pads would be in the way of the holes for the knobs, so I had to relocate them closer to the center. Telescope makers will tell you the pads should be located directly over the feet, but I found that in this scope it caused too much friction, so I had located the pads about a third of the way in from the edges, and the azimuth bearing was a lot smoother. Moving them further in would be pushing it, but it actually moves even more smoothly now.

The base is now easy to disassemble and reassemble.

Fully assembled. (The scope sits on a plywood
 dolly I made to make it easy to roll out on the
 driveway when I set up my Redneck Observatory.)

The rocker box now fits around
the tube in the car, saving much-
needed space.

How to do it

If you try this at home, think carefully about where you will put all the holes and measure everything precisely. I had to dodge the holes in the rocker sides from the original wood screws, make sure the knobs didn’t intersect with the circular path of the Teflon pads, avoid a pipe that I installed that holds a swivel table, and leave room to turn the knobs. It was a tight fit, but it works.

The tools and materials I used:

Materials (links to the ones I used):

Two aluminum angles, 1/4” thick, 2” legs (that turned out to be 1-3/4” in reality), and 12” lengths (that were actually 11-5/8”, although they were 1/4" thick, as advertised).

Four male knobs with 1” 1/4-20 threads. (3/4” might have been better- fewer turns needed as long as they reached the threads of the t-nuts.)

Four t-nuts (1/4-20 x 7/16 length); epoxy 

Eight 1-1/2" 1/4-20 bolts, eight 1/4-20 nylon lock nuts, 24 1/4” ID - 3/4” OD flat washers

Tools:

Cordless drill with 1/16”, 1/4”, and 5/16” drill bits, and one 3/4” Forstner bit

Hammer and short thick rusty bolt for hammering in the t-nuts below flush

Two 6” quick-release clamps

Metal file and sandpaper to round the sharp edges of the aluminum angles.

Hand vacuum to keep the aluminum shavings from getting everywhere

Process (for my particular dob, but most should be similar):

Caution! Aluminum angle edges may be extremely sharp. File and sand them before working with them.

Measure and plan where you are going to position the angles and drill all the holes. Do it a few times and set the angles, bolts, and nuts in position to see if there will be any issues before you start drilling. Mark the drill points clearly in pencil on the angles.

Disassemble and then reassemble the rocker box and round rocker box bottom, leaving the round ground board off. You will need to drill in the botton of the round rocker box bottom piece.

Cut the angles if needed (with a metal hacksaw), file any sharp edges that will be exposed, and clamp to the rocker box sides. In my case, there is a front stiffener board that precluded clamping on that end, so I found a piece of wood that fit tightly inside between the two angles that kept the front ends pressed against the sides. Improvise as needed.

I found it easier to do one side first, then the other.

Using a small drill bit, 1/16” or so, drill pilot holes for the two knobs from above, through the angle and the round rocker box bottom. (I did each hole one at a time.) You need to keep these holes small because the Forstner bit you will use to inset the t-nuts on the underside of the rocker box bottom needs to be able to center and it can’t do so with a larger hole drilled through.

Turn the assembly on its side and use the 3/4” Forstner bit to inset the two holes about 1/8”. This ensures that the t-nuts won’t stick out and scrape the ground board surface. I found later that the t-nuts don't hold well in the particle board, only an issue when the base is disassembled, so I epoxied them in.

T-nut epoxied and hammered into place on the
underside of the rocker box bottom. Note the
1/8" recess cut using a 3/4" Forstner bit.

Turn the assembly upright again and drill out the two holes with a 1/4” bit, all the way through.

Turn the assembly on its side again and widen the centers of the t-nut insets with a 5/16” bit.

Hammer a t-nut partially in, then fit the knob from the other side and make sure they meet up properly and there is no binding. I had to use the Forstner bit to widen the sides for several of the holes due to, ahem, user error, but got them all working. Once they line up, coat them with epoxy, being careful not to get any into the threaded tube, and hammer the t-nuts all the way in so they are below the level of the bearing surface.

Turn the assembly upright again and once both knob holes are drilled, screw in the knobs tightly.

With the sides still clamped/braced to the angles, drill small (1/6”) pilot holes horizontally through the angles and the sides from inside (aluminum first) to outside. Widen the holes with a 1/4” bit and insert the bolts from the outside with flat washers and put the nylon lock nuts with flat washers on the inside (aluminum surface).

Before assembling the base to the ground board, a little trick for Teflon bearings is to rub a bar of soap on the bearing surface that contacts the Teflon to give it a little more smoothness.

Once you are done, remove the original wood screws holding the rocker box to the ground boards, assemble the base with the knobs, and test the fully assembled telescope for function.

Now when you have to transport the telescope, you only have four knobs to separate and reassemble the two parts of the base, which is no longer a heavy, ungainly bulk. In fact, you should be able to cradle the rocker box around the bottom of the tube to save space in your vehicle, as in the image above.

What if you want a 10-inch solid tube dob, but don't want to mess with this mod?

All dobs are not created equal. If you are in the market for a lighter weight basic Dobsonian, consider the Orion Sky Quest series. Now that they are apparently made by Jinghua Optical Corporation (JOC), they are even lighter than the Synta-made scopes, and are the lightest mass-produced solid tube basic dobs I have come across. For example, the XT 10 has a 24.2 lb. tube, a 21.5 lb base, for a total of 46 lbs. In contrast, an Apertura AD10, made by Guan Sheng Optical (GSO), has a 34.8 lb. tube, a 31.4 lb. base, for a total of 66.2 lbs., a difference of 20.2 lbs. for the same size aperture! [7-12-24 update: Orion's parent company has closed up, so Orion may not be around much longer. If you're interested, make your decision quickly. 7-19-24 update: Looks like Orion is belly up. Maybe another company will supply the XT10s under a different name??]