CNC Work Needed - Anyone?

banjopicker66 · Post by **banjopicker66** » June 22, 2010, 8:26 am

Anyone: I need some CNC work done, and hope somepone here can help out.
I am the Commander of our local camp of the Sons of Confederate Veterans, and we use pop-up tents for re-enactments, displays and fundraising.
Unfortunately, our 4 tents have broken center caps. They are otherwise still very usable. These caps have 4 pivots for the support arms, and enthusiastic folks don't pay enough attention to how to fold and unfold the frame, so the plastic cap gets broken.
Would someone be willing to make them for us? They could be of nylon or some other plastic, or metal; I would defer to your judgment.
Here is a picture for evaluation:
http://fordtruk.com/forums/album_pic.ph ... user_id=48
I will send an almost good one one for a template.
I am willing to pay, but I can also give you a letter for tax deductions.
Thanks!

John M. Sutton
Commander, Col Charles Jones Colcok Camp #2100
Sons of Confederate Veterans
banjopicker1966@hotmail.com

Rusty 63 · Post by **Rusty 63** » June 22, 2010, 9:12 am

Looking at it, i'd suggest a hole-saw'd circle with four pieces of steel angle & weld it up. Compared to plastic it'd be bullet proof, and I bet cheaper than a cnc job...

The Big M · Post by **The Big M** » June 22, 2010, 9:40 am

I tend to agree. A welded assembly would likely be cheaper in this instance, especially since you only need 4 pieces.

You could have it made from 5 pieces of plasma cut plate. Four vertical ribs and one circular base. The vertical ribs could have slots cut into them so that they would lock together like puzzle pieces for alignment, then the whole assembly could be welded up.

What's the approximate diameter of the circular base?

banjopicker66 · Post by **banjopicker66** » June 22, 2010, 9:44 am

Thanks for the ideas guys, this is an area totally out of my expertise. I don't know how to weld, and don't much more than hand tools for equipment.
M, the approximate diameter is about 2.5 inches.
By the way, although the holes are threaded, they don;t need to be - a nut and bolt will suffice.

Max · Post by **Max** » June 22, 2010, 9:48 am

Almost looks like the legs on those typical fold-open lawn chairs. Have you looked for replacement parts? Seems like they would be fairly inexpensive.

banjopicker66 · Post by **banjopicker66** » June 22, 2010, 11:00 am

Got 'em from Harbor freight, no parts available.

fire truck · Post by **fire truck** » June 22, 2010, 12:33 pm

You should be able to make those pretty easy, I would bet that would cost around $50 to get those made on a CNC.

BMJ's 65 · Post by **BMJ's 65** » June 22, 2010, 3:07 pm

I'd be interested in making those for you. I've got access to CNC mills and lathes. I could do those out of billet aluminum for the cost of material and enough extra to cover a case of beer

I'd guess material would be around seven bucks a piece. Pretty simple deal in one of the mills. PM me if you want me to look into it further. I'd be more than happy to help out a fellow Slickster.

jeremyfx4 · Post by **jeremyfx4** » June 22, 2010, 7:21 pm

I just looked at the pic. and kinda went off what you said about the 2.5" OD. But give us some dimensions on the piece. Just take this print into paint and type some numbers in.

Max · Post by **Max** » June 22, 2010, 7:38 pm

That's just cool!

banjopicker66 · Post by **banjopicker66** » June 22, 2010, 8:05 pm

That is WAAAAY kewl!

Here are the dimensions, and a picture of the special caliper I used to measure it with.

http://fordtruk.com/forums/album_pic.ph ... user_id=48

http://fordtruk.com/forums/album_pic.ph ... user_id=48

MadMaxetc · Post by **MadMaxetc** » June 22, 2010, 8:13 pm

CNC will cost more, but there are guys out there with them in the garage that could make them.

Could just be milled (NON Computer Controled)

jeremyfx4,
That is good. Do you use PRO-E or Solid Works? I use CATIA V5. Would you mind a liitle input on your design?

jeremyfx4 · Post by **jeremyfx4** » June 22, 2010, 8:19 pm

Madmaxetc, i use solidworks, i wouldn't mind input. Let me guess what you are going to say. Rads where i have sharp corners?

banjopicker66 · Post by **banjopicker66** » June 22, 2010, 8:21 pm

MadMaxetc wrote:CNC will cost more, but there are guys out there with them in the garage that could make them.

Could just be milled (NON Computer Controlled)

Shows you how much I know about this subject!

MadMaxetc · Post by **MadMaxetc** » June 22, 2010, 8:35 pm

jeremyfx4 wrote:Madmaxetc, i use solidworks, i wouldn't mind input. Let me guess what you are going to say. Rads where i have sharp corners?

DING!!

Also there are no fillets or driven rads. That is realy going to limmit the part.

For Al We use .12" for fillets and .22" for Driven Rad.

Post by **Greg D** » June 22, 2010, 9:54 pm

I would imagine that fillets could be left in as long as the tubing clears it. It would be less prone to cracking that way too.

BMJ's 65 · Post by **BMJ's 65** » June 23, 2010, 6:58 am

Greg, that's what I was thinking. I'd profile the entire thing from the top and leave the corner radii in place for strength. Depending on how long the tubing sets in the slots, a guy could get away with a 1/8" or 3/16" radius. Buzz a corner radius cutter around the top to finish it off and your set.

fire truck · Post by **fire truck** » June 23, 2010, 9:25 am

Wow that's pretty cool guys!

The Big M · Post by **The Big M** » June 23, 2010, 9:57 am

Good job guys! I use SolidWorks and Inventor myself.

And my original comments regarding cost are now rendered moot since BMJ's 65 is willing to do it for the cost of material!

banjopicker66 · Post by **banjopicker66** » June 23, 2010, 10:54 am

Everyone - I sure appreciate the help. Words fail me to express it.
I added 2 pictures to show the correct and incorrect orientation, and hope they will help.

Correct, when the top is up, but you can see this one is nearly gone. The top flange needs somehow to prevent the tube from pushing up.

http://s1031.photobucket.com/albums/y37 ... C03172.jpg

WRONG way!

http://s1031.photobucket.com/albums/y37 ... C03171.jpg

Thanks again so much.