Any old excuse to make another telescope!

[astrolunartick]

Hey Friend. 

Any old excuse to make another telescope!

So I've been planning to rebuild my 20" Dob for sometime. I built the original 20" about 6 years ago when I didn't drive, but 3 years ago I passed my driving test and got a van. The van is now a camper with a rock and roll bed seat. The scope sits in front of the bed seat, when I'm in transit. But when I'm parked up for a night observing and I finish the night to sleep in the van. I have to leave the scope outside, as it wont fit in the van with the rock and roll bed down. which i really don't feel comfortable about.

So the plan was to make a new Dob using the Optics, Focuser and Mirror cell from the original 20" that will fit under the rock and roll bed. Plus I've just fitted a roof rack. So the ladder and truss poles can sit on top now. I started collecting all the materials about 2 months ago and then started the build at the beginning of December. I've had a mad rush to get the scope finished before the Great Conjunction.

Ive taken some  inspiration from Gordon Waite Renegade Telescopes. As this seem to be a design with in my capabilities. 

I managed to get it done in time with some loose ends to tidy up at a later date.

But sadly my area has just gone in to Tier 4 today, so I'm at home . Thankfully the last 2 nights have been clear here. So I've managed to observe the beginning of the Conjunction.

I had a crazy stressful moment yesterday. I had a stinking migraine and was rushing to get the scope done. I stupidly cut 100mm too much off the truss poles and found out last night when I had the scope at home testing it out. So this morning I managed to turn eight hardwood 22mm diameter by 150mm long dowels on my lathe to slip inside the poles and side the 100mm off cut back on to extend the poles again then used more heat shrink  to cover the bodge. What a bodger hey? It doesn't look too bad. I had to hammer the dowels in so they are a tight fit. and i put a small screw through each part so it won't come apart. 

Any way it's together. as i said before I need to spend some more time on the scope to get it finished. 

Some of you might know I have a Youtube channel where I've posted some of my scope build videos. I have filmed this build, I just need to edit the footage down to a watchable length and then I will post it on here.

Thanks for reading

I will update soon

Pete 

 

  

[PeterW]

Nice looking job... if the bodge works who cares! I just taped up an old finder scope to chop a bit off the end... rushed it and the cut is most certainly not straight... however doesn’t affect what I needed it for.

Peter

[astrolunartick]

Heres some of the plans.

[PeterW]

Would it scale to a 13”f3?

Peter

[astrolunartick]

1 minute ago, PeterW said:

Would it scale to a 13”f3?

Peter

I don't see why not. Probably even better than this 20". As when I take it apart the Mirror box is pretty heavy even without the side bearings attached. So with a 13" It would probably be better. I think.

 

[DaveL59]

nice build, I'd just say the heatshrink is to help with handling in the cold nights if anyone asks 🙂

[astrolunartick]

16 hours ago, DaveL59 said:

nice build, I'd just say the heatshrink is to help with handling in the cold nights if anyone asks 🙂

I always use heat shrink on all my truss poles anyway so it was a fairly well hidden mistake. 

[theropod]

While not even in the same hemisphere as the other scopes shown here I’m nonetheless proud of the little refractor I just finished today. It’s not really finished. I still need to paint the pipe fittings inside and out in flat black, and add flocking a couple places, but the views are comparable to those via the C90 Mak, but with a MUCH wider FOV. Very crisp, no CA I can detect and not over sensitive to focus maladjustment. I’m going to have to fit a rail so I can clamp it into my EQM 35 Pro. I eventually may use this as a guide scope.

The 60mm objective is salvaged from a dead pair of Russian (I think) binos. With the prism stack out of the light path that lens really does the work. I have some all metal/glass EP’s I plan on using with this scope to project the sun. I’ll use a full sheet of foam core poster board for a shield and probably a sun funnel type screen.

Edited January 5, 2021 by theropod
Clarity/more info

[theropod]

Here’s the little DIY 60 with dew/light shield attached. Note the V shaped notches/relief cuts in the reduced end of the dew shield* (see below). I may “weld” those closed in situ with my soldering iron, or cover the slots with flocking. After warming over my gas cook stove until pliable I squeezed the scope end down around the objective housing. After clamping down the dovetail, and tightening the cone error screws built into the dovetail, the shield fits like a glove. I notice a marked increase in contrast in daylight observations with the shield, which is painted in the same flat black as the outside. * The sheild is made from thin wall 3” PVC drain pipe, and the swelled end (objective) is closer to 3.5”. This should assure no obstruction and give me a little alignment “play”. My EQM 35, shown, should carry this trinket scope like it wasn’t there. I’d say the scope, dovetail and shield weigh less than 2 pounds. I’m very eager to see how much easier it is to get those 1-2, & 3 star alignments with the greatly wider FOV this scope offers vs my C90 mak. Maybe seeing more than one star at a time will make life easier. Just using the corner of my house to steady me the scope returns an impressive view of M42, but almost any good glass can do that. I’ve less than $25 into the entire scope, sans eyepiece (32 mm that came with C90 and dovetail that came with my mount), focuser is a $17.50 eBay special I’ve tuned up some to lower the slop. Not bad for a pair of binos that had been driven over by a full sized pickup truck. 
 

This little cutie is actually intended to ride on my DIY ALT/AZ mount I built to learn about variable speed drive of stepper motors proportional to joystick input using Arduino. The C90 is just a touch heavy for that rigged up mount, but this kite wannabe should float like a dandelion seed on it.