The DIY dob cart

[Guest]

So as we all know the Orion XX16G is a 200 pound telescope and as good as my first dob cart was.... It was not the way to go.  So i am now making the cart the way it should have been made the first time.  

The frame is square steel tubing that is 1/8 thick and 2 3/4 x 1 3/4.  It is repurposed material from a local factory that is shutting down.  The frame you see cost 4 dollars.  The rear axles are 5/8ths steel rod on 10 inch wheels.  You will notice that there is no steering axle.  That is because thos is designed to be pulled by my lawnmower.  I am not getting any younger and that scope isnt going to get lighter.  The hitch will be completely removable and once the scope is in position i run the levelers down and detach the hitch and slide it under the cart.   Once the metal fab work is done i will get a piece of 3/4 inch pressure treated plywood and screw it to the frame.  I will get back to it next Saturday and finish the metal working.  Not to bad for just a few hours worth of work. 

[Alan White]

Mark 2 looks interesting and love that it’s repurposed material.

Look forward to the next instalment.

 

[Guest]

I am throwing this out right now just so everyone knows this.  It isnt really any bigger then the Mark I model and with the tow bar off it will actually be shorter front to back.  Side to side it will be 8 inches wider.  Weight wise it is definitely lighter then the 2x12 wood model.  I picked up the frame with no effort and put it on the saw horses myself with no issues.  Two of us picked it up once the wheels went on with no effort.  It rolls amazingly well with almost no effort.  

Edited February 12, 2023 by Mike Q

[CraigT82]

4 hours ago, Mike Q said:

It rolls amazingly well with almost no effort.  

That’s surprising considering the front wheel configuration 😉

Nice work though, making me look at welders on machine mart 

[Guest]

7 minutes ago, CraigT82 said:

That’s surprising considering the front wheel configuration 😉

Nice work though, making me look at welders on machine mart 

Hahahaha those arent actually attached to anything and arent even going to be used now.  I wish i could take credit for the welding but thats not me.  I just did the cutting and grinding.  My cousin did the welding.  I should learn how to do it.  Just a 110 volt welder and flux core would be good enough for me. 

Edited February 12, 2023 by Mike Q

[Guest]

So the metal work is all done.  Now to get a some paint, a sheet of plywood, some sheet metal screws.  Getting closer to being done.   Now before anyone asks about the weight i will say this, it is probably half the weight of the wooden model.  I picked it up myself and loaded it in my truck with no effort at all.  This is a definite improvement over the Mark I model. 

Edited February 18, 2023 by Mike Q

[Mr H in Yorkshire]

An impressively substantial cart! As a constructor myself I know that the devil is in the details. With a wooden platform and attached levellers I presume you will be standing on the platform to observe.  Will you stiffen the platform to maintain flatness so that it does not deflect as you move? I ask partly because it appears in the picture that the rear inner cross piece upper is bent downwards slightly which would allow movement? That may be extrapolating too far from a picture so it's a question, not a criticism. A further minor safety point, I would have made the leveller handles removable or somehow flush to avoid the trip hazard in the black of night.

Thinking outside the box, did you ever consider making an even larger cart, large enough to make it a mobile enclosure to keep the wind off you and the scope?

I am about to do something similar in that I have just got an ancient small trailer chassis and plan to attach a more substantial version of my motorised binochair with a much larger binocular (DIY 6" f/5). I was dreaming about putting a cabin of sorts around the chair to keep the icy winds at bay (and end up looking like a WW2 tail-end charlie).

 

[Guest]

No i won't be standing on the cart.   While it looks huge it looks huge it really isnt.  It is 36"x36"  and the scope base is 33"x33".  So it will be a nice fit.  There are actually a couple of spots that might need built up a bit.  That or a good smack with a mini sledge might take care of it.  As to the levelers.  I took these off of the Mark I model as they work perfectly and were never even close to being in the way, so i am pretty sure they will be fine, but removable handles would have been a slick idea now wouldn't it.  As to going even bigger, not a chance.  I needed it to remain somewhat compact.  My scopes live on the carts in my garage, my not very big garage. So bigger is not an option.  As a note of interest we did "stress test" the levelers.  I stood in the middle of the cart (I weigh 212 pounds), my cousing stood on the edges (he goes 280).  It didn't move at all.  So it has now held twice the weight of the scope.  I would think that is good enough.  The last real test is my ability to move it by hand.  The tow bar is 30 inches or so and empty it is very easy to move.  We will see what happens when the 200 pound scope is put on it.  Worst case i may have to buy a handle i can screw onto it or fabricate something. Thanks for the comments, its always nice to have someone come along and give you some food for thought 

[Alan White]

Looking good Mike, Mark ii may be 'The One' or I certainly hope it is for your sake.
I await the paint, wood and first loading.

Oh and just checking, Small Garage in American = Big space in UK terms? 

[Guest]

21 hours ago, Alan White said:

Looking good Mike, Mark ii may be 'The One' or I certainly hope it is for your sake.
I await the paint, wood and first loading.

Oh and just checking, Small Garage in American = Big space in UK terms? 

My garage is technically considered a 2 car garage.  I remember there being 2 cars in it at one time, but that was back in the 70s and the cars that were in there were smallish.  It is probably 20' deep by 35'wide.  No way my 22 foot truck will fit in there. So the mowers, snow blower, wood shop and bullet casting area is out there.  Now my cousins shop, where the cart was built, now it is nice.  While i didnt measure it, it has to be 40x60 at least, has a car lift in it and a full machine shop.  So yeah it is probably huge by UK standards.  As a point of interest my garage is actually a old barracks that my grandfather bought and moved out here after WW II.   

When i paint it today, I will have to pull everything out of the garage cut the wood then rearrange to do the paint work.  Then when done i will put everything back.  What i need to do is just bite the bullet and add on a 25 deep by 35 long garage addition and call it good. 

Edited February 20, 2023 by Mike Q

[Mr H in Yorkshire]

2 hours ago, Mike Q said:

No i won't be standing on the cart.

Hi Mike, always pleased to get into a discussion, people who make their own stuff are getting scarce. I actually put more time into making than looking I'm somewhat ashamed to say. Regarding manually moving it, because of the rearward location of the wheels you are constrained to leverage a considerable weight. You ought to do a test with a dummy scope weight, before you check in to the physio! Maybe you could consider a jockey wheel built onto the tow bar, that should be relatively easy and in one of your pics you had a couple of spares. As I said, I will be making something not too far removed from this myself - just collected the trailer, I have all the optics and my binochair project has proved (to me at least) that I have a successful working concept. I mentioned  to my daughter about my trailer mounted binoscope, she cruelly suggested just building it on to a mobility scooter - in anticipation. Maybe I'll do a feasibility study! All the best with your construction.

[Guest]

If the tow bar isnt long enough to provide the leverage i need, i have what we call a spud bar i can shove in there and extend its length.  Fortunately i am a very experienced in backing wagons and trailers and getting them right about where i want them.  The benefits of being a farm boy do come in handy.  If i do everything just right it will require very little effort to actually move into it's final location.  I will keep you posted.  It is finally starting to warm up outside now and in an hour or so i will be able to get out there and start messing with this. 

Edited February 19, 2023 by Mike Q

[Guest]

So here it is.  99% done.  I need to buy a handle for the tow bar and then it will be done.  The handle just makes it easier to move manually.  So what did I do.  Well the frame was covered in black paint.  The wood is 3/4 pressure treated plywood.  It has had a treatment of water seal all the way, top and bottom.  The wood is fastened in place with number 8 self piercing sheet metal screws and a one inch washer.  That is not coming off anytime soon.  You will notice how nicely the tow bar stows out of the way when not in use.  In storage mode Mark II is 20 inches shorter then Mark I, so i have saved some space in the garage.  Yes that is a Stellarvue 80mm finder ...and its views are stunning.... Now back to the cart.  So it was designed to be moved around by my lawn mower.  Yep it works just fine for that.  Now the big question.....moving it manually, how well does it work.  It works just as it was designed to do and moves fairly easily.  Adding a handle will make lifting it easier.  Yes it is a 200 plus pound scope and i wont say its light but it can be done with just a little effort.  The other major difference between Mark I and Mark II..... weight.  Mark II is half the weight of Mark I and it is way stronger.  Someone earlier mentioned flex in the plywood or something along those lines.  Well as the wife and i tore it down, moved it and reassembled it there was no flex at all, this thing is solid as a rock .  This is the cart I should have made the first time.  So whats the cost you ask.  Well the frame was repurposed and cost me 4 dollars.  The plywood, all the hardware, paint, including two absolutely worthless drill bits that were completely junk was 100 bucks.  The levelers came off of Mark I.  The tires were 12 bucks each and the rod for the axle was 15.  The last expense was a roll of . 030" welding wire that i bought for cousin who did all the welding. It was 50 dollars.  So all in we are right under 200 bucks.  Not to bad.  I think this will last a long long long time and i dont think there is a need for a Mark III.  As always i am open to comments and critical analysis.  

Edited February 19, 2023 by Mike Q

[cajen2]

Great bit of work, Mike. 👍

[saac]

Job well done Mike - good to see Mk I and MK II side by side for comparison of size. 

Jim 

[bosun21]

Nice job Mike. Pleased to see it nearing completion.

[Guest]

14 minutes ago, saac said:

Job well done Mike - good to see Mk I and MK II side by side for comparison of size. 

Jim 

All the weakness of the original have been removed and not allowed to be in Mark II.  What i ended up with may just be perfect for me. 

[Guest]

7 hours ago, Mr H in Yorkshire said:

Hi Mike, always pleased to get into a discussion, people who make their own stuff are getting scarce. I actually put more time into making than looking I'm somewhat ashamed to say. Regarding manually moving it, because of the rearward location of the wheels you are constrained to leverage a considerable weight. You ought to do a test with a dummy scope weight, before you check in to the physio! Maybe you could consider a jockey wheel built onto the tow bar, that should be relatively easy and in one of your pics you had a couple of spares. As I said, I will be making something not too far removed from this myself - just collected the trailer, I have all the optics and my binochair project has proved (to me at least) that I have a successful working concept. I mentioned  to my daughter about my trailer mounted binoscope, she cruelly suggested just building it on to a mobility scooter - in anticipation. Maybe I'll do a feasibility study! All the best with your construction.

There is a guy here somewhere that did a cart on a mobility scooter.  Its a awesome idea.  I did look for one for sale but didn't find what i was looking for.   As to a jockey wheel.... well it could happen.  It would be pretty easy to do from here.  I could make a second tow bar that is a bit shorter.  Find or make a three way bushing and drill a hole.  Ok.... Thats oversimplified but the basic idea.  For now i am not over concerned about it. 

Edited February 19, 2023 by Mike Q

[Mr H in Yorkshire]

Mike that cart looks the bees knees, certainly a great improvement on the Mk 1, just bigger wheels alone would have been a significant upgrade, but the new design is cracking.  The detachable tow bar will certainly make it easy if a jockey wheel proves worthwhile, even something like a bolt-on caravan accessory one would do. 

 

[Guest]

2 hours ago, Mr H in Yorkshire said:

Mike that cart looks the bees knees, certainly a great improvement on the Mk 1, just bigger wheels alone would have been a significant upgrade, but the new design is cracking.  The detachable tow bar will certainly make it easy if a jockey wheel proves worthwhile, even something like a bolt-on caravan accessory one would do. 

 

Thanks, i appreciate the comments.  A jockey wheel was rumbling around in my head last night.  I would make it a dual wheel system to give it a nice wide but compact stance.  For now I will use it as is.  I did tow the scope around yesterday afternoon.  Just a pass around the drive and once through the yard.  I am happy to report that the scope did not move at all.  However i will add some small wood blocks in front of the scope feet to as a positive barrier to keep it from moving 

Edited February 20, 2023 by Mike Q

[Guest]

11 hours ago, saac said:

Job well done Mike - good to see Mk I and MK II side by side for comparison of size. 

Jim 

I knew Mark II would be shorter then Mark I, but even i didnt think it would be 20 inches shorter, i am not complaining at all about that. 

[Guest]

11 hours ago, bosun21 said:

Nice job Mike. Pleased to see it nearing completion.

Thanks, just a couple minor tweeks to do and it will be wrapped up. 

[Guest]

On 19/02/2023 at 17:24, saac said:

Job well done Mike - good to see Mk I and MK II side by side for comparison of size. 

Jim 

It seemed like a good idea to show both 

[Swoop1]

On 19/02/2023 at 07:36, Mr H in Yorkshire said:

Thinking outside the box, did you ever consider making an even larger cart, large enough to make it a mobile enclosure to keep the wind off you and the scope?

I am about to do something similar in that I have just got an ancient small trailer chassis and plan to attach a more substantial version of my motorised binochair with a much larger binocular (DIY 6" f/5). I was dreaming about putting a cabin of sorts around the chair to keep the icy winds at bay (and end up looking like a WW2 tail-end charlie).

 

A micro Astrocaravan? Can't wait to see the build thread for that baby!

[Mr H in Yorkshire]

4 hours ago, Swoop1 said:

A micro Astrocaravan? Can't wait to see the build thread for that baby!

I picked up the trailer remains yesterday, ridiculously over-engineered for its size - the framing is all 1 1/2" angle, 1/4" thick! Anyway I've already cut off all the surplus, shortened the chassis by about 2' and now I can lift it onto a workbench for some bits to weld. I'll post a couple of pics if you're interested. It will probably look like the petrified dead gunner in 'Alien' most of the time but with a lightweight cabin for winter use. Winter experience with my recently completed motorised binochair has been a painful lesson.