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Return of the DIY 3 wheel CPC 1100 aluminum tripod dolly

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#1 rigelsys

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Posted 14 July 2020 - 04:29 PM

As promised, Here's a photo of my CPC 1100 tripod dolly constructed from 3" x 1" aluminum channel. Makes for a light weight, sturdy and rigid ride. Definitely saves the back!

 

If you'd like to make one yourself, e-mail me at rigelsys.com and I'll send you the instructions pdf file. Takes about 2 hours.

 

McMaster-Carr can ship the aluminum channel to your doorstep. An 8' length costs about $50 delivered. Part number is 9001K41

 

http://www.mcmaster....hannels/=cbnz38

 

Wheels are 3" polyurethane from Harbor freight ($6 each or so)

 

Bolts are 5/16" diam, 3/4" long stainless steel.

 

Photo shows color after dropping it off to have it anodized orange :-) 

 

Leon

Attached Thumbnails

  • post-18250-14073682699329.jpg
  • post-18250-14073682701249.jpg

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#2 rigelsys

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Posted 14 July 2020 - 04:34 PM

here's the instructions in pdf

Attached Files


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#3 JohnBear

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Posted 14 July 2020 - 05:26 PM

Thank You!  I recently made a dolly out of 2X4s and scrap wood, and I need another one. This certainly looks nicer.



#4 iam1ru12

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Posted 07 November 2020 - 10:09 AM

Many thanks for posting!  I’m considering this DIY option instead of a commercially made unit.  My plan is to keep my CPC 1100 set up in the garage and simply wheel it out onto the driveway (concrete garage floor and concrete driveway).  There is a slight grade going up the driveway so it’s not level but nothing a braked caster couldn’t overcome.

 

What has been your experience with stability, any need to add stability/leveling bolts?  If leveling is required do you think adding bolts is a better option or just use the legs?  Any thoughts on rubber wheels over polyurethane wheels (or am I over thinking this)?

 

Thanks!

-Mike



#5 MarMax

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Posted 07 November 2020 - 06:59 PM

Deleted.


Edited by MarMax, 07 November 2020 - 07:10 PM.


#6 iam1ru12

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Posted 08 November 2020 - 10:37 AM

Just to confirm, the U channel dimensions are as follows:

 

17227A90 3DC6 4000 A83A 30E32B57900B


Also, any pictures showing the fastening of the tripod legs to the dolly?

 

Thanks,

-Mike



#7 iam1ru12

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Posted 22 November 2020 - 05:55 PM

Here’s the progress so far.  I realized (after I cut and assembled everything) that the casters, even when locked, had too much play in them in that the mount would shift a little.  I therefore used some left over U channel to add another 1.25” to add leveling feet.  They will arrive on Tuesday.  Also got a quote for $60 - $80 for powder coating the dolly and a few other things.

 

598D3744 AFFE 4613 9109 4756DB1BE6CF
80678E92 8BDC 40C8 9256 7F5042CC0381

 



#8 iam1ru12

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Posted 27 November 2020 - 04:35 PM

Parts for the leveling legs came in. I had to tweak the design a bit and also got different, more stable wheels.  The leveling feet threaded rods are 1/2” 13 and quite stable when raised up.

 

Now just need to get it powder coated.

 

1CA4F5C6 A719 4F0F B946 FE585C13EB44

Edited by iam1ru12, 27 November 2020 - 04:36 PM.


#9 MarMax

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Posted 14 December 2020 - 02:22 PM

I've been considering this DIY wheelie bar for my new G11G mount and wanted to try something a bit cleaner for the center attachment. I've drawn up a bracket for the center and will give it a try and report back. I've got a local shop that can make one for me.

 

 

gallery_332504_14251_103350.jpg



#10 iam1ru12

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Posted 14 December 2020 - 05:08 PM

I had to make some modifications as well, I didn’t do enough planning.  

 

First I realized I needed to extend the length of the arms (only after I cut the the original U channel) to accommodate the need for leveling feet.  Then the leveling feet pad interfered with the castors’ ability to swivel which required me to move the casters in towards the center which caused the arms to bow up in the center hub when weight was applied and even twist a bit.  The casters where acting like a fulcrum since the tripod legs rested on the other side of the casters.  I used left over U channel to ‘box in’ the center and keep the arms from twisting.  

 

Even with that, I still noticed the center raising by about 1/2” when under the full load the scope (65lbs), tripod (19lbs), wedge (32lbs), counter weights (5lbs)  and maybe another 5 to 10lbs for finders, camera, cables etc. - about 130lbs.  So I Frankenstein’d the build and and steel bars across the top to keep the center hub from raising.  It is now rock solid!

 

-Mike

after the steel braces

40F5E047 1167 4D2F B30A 725620C0AB60

before the steel braces
B8546D94 A648 4373 B80A 562356102983

 


Edited by iam1ru12, 14 December 2020 - 07:44 PM.


#11 MarMax

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Posted 15 December 2020 - 02:00 AM

I've decided to go with a structural channel instead of the architectural channel. This requires using 4" channel to have 3" clear on the inside. Hopefully with the stainless center plate and the structural channel things wont flex. There is a metals place nearby so I picked up a 6 foot remnant for $30.

 

I'll also need to use 6" wheels since I navigate over grass and a decomposed granite driveway. I still need to figure out leveling but may just level with the tripod and block the wheels. I'll be using two fixed wheels and one swivel caster wheel with a brake.


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#12 iam1ru12

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Posted 15 December 2020 - 02:38 AM

I've decided to go with a structural channel instead of the architectural channel. This requires using 4" channel to have 3" clear on the inside. Hopefully with the stainless center plate and the structural channel things wont flex. There is a metals place nearby so I picked up a 6 foot remnant for $30.

 

I'll also need to use 6" wheels since I navigate over grass and a decomposed granite driveway. I still need to figure out leveling but may just level with the tripod and block the wheels. I'll be using two fixed wheels and one swivel caster wheel with a brake.

Keep us posted on your progress.



#13 MarMax

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Posted 15 December 2020 - 12:29 PM

Here is a rough layout of what I'm planning. The 4" channel messed me up a bit but I made some adjustments and it should work. The fixed wheels will only attach with two bolts. And since the channel touches in the middle I could take it to a shop to heliarc those connections, which would add some rigidity.

 

Also need to consider leveling and a pull handle so things may be adjusted for that.

 

gallery_332504_14251_18926.jpg



#14 MarMax

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Posted 17 December 2020 - 06:30 PM

I picked up the laser cut center bracket today and it's got me thinking that I should just have another made and sandwich the channel with two brackets. This might be overkill but since I'm using 4" structural channel it should work nicely. With im1ru12 (Mike's) need to beef up the center this should do the same.

 

gallery_332504_14251_96505.jpg


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#15 iam1ru12

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Posted 17 December 2020 - 07:24 PM

MarMax,

That looks really good!  May I ask how much it cost that have that made up?  I may consider commissioning something similar as I don't quite like the Frankenstein look of the braces I put on.  I definitely recommend beefing up the center, especially if you'll be going over something other than flat concrete which may cause the center of mass to shift.

 

-Mike



#16 MarMax

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Posted 17 December 2020 - 07:36 PM

MarMax,

That looks really good!  May I ask how much it cost that have that made up? 

The shop is a friend of a friend so I kinda got a deal on it at $25. I did send the shop a DXF file so setup time was minimal for the cutting machine. But I'd expect a single piece like this to be at least $50. Now if you made a bunch the per piece cost could be in the $5-10 range.

 

The bracket as laid out is perfect for the 3" architectural channel. If you were to use 4" channel I'd modify it slightly and add some length. The inside hole is getting close to the edge of the channel as I've had them cut. I'd like to have at least a 1/2" from edge of hole to edge of channel but can live with the 7/32" with the two bracket sandwich.



#17 MarMax

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Posted 30 December 2020 - 09:45 PM

OK, a little more progress on this. I've laid it out again with the tripod and the legs will not clear the wheel mounting bolts so the wheels need to sit outside the tripod legs. The yellow is the outline of the tripod legs and blue is the wheel mounting pads. A bit wider than I had liked but it was never going to fit through a regular door regardless.

 

gallery_332504_14251_39428.jpg

 

The thing I have not addressed yet is how to keep the tripod from moving around slightly on the wheelie bar. Maybe the weight of the fully loaded rig will greatly overcome any potential movement? It can only move a very minor amount but it could be enough to affect alignment and tracking.



#18 MarMax

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Posted 03 January 2021 - 01:24 AM

I decided to get off my rear end today and put the wheelie bar together. It came out nice and the 1/8" 304 stainless plate brackets are quite solid. All the bolts, washers and nuts are 5/16" stainless. Since I bought a remnant piece of 4" aluminum channel it needed some cleanup so it got a wire brushing before cutting into 24" pieces. With a careful layout, trimming, and 17 holes later it was assembled. Took me about 5 hours from start to finish.

 

And I've changed gears along the way and will use it with the Losmandy G11G mount instead of the C11. I'll keep the C11 on the wood (4x4) wheelie bar for now since it rolls better across grass.

 

Here is the closeup of the wheelie bar.

 

gallery_332504_15525_124593.jpg

 

Here is the whole rig with the 130mm.

 

gallery_332504_15525_138939.jpg

 

And here is a closeup of the stainless plate bracket.

 

gallery_332504_15525_198761.jpg

 

I'll figure out a handle and leveling later. I've got some ideas but really needed a finished product to finalize anything. I'm going to experiment with some wood blocks first and do the leveling with the tripod. Seems like this should work.


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