Wheel center cap needed.

I need this center cap as they are not available anywhere. It is for a 2004 Joe Gibbs Silverado. I thought about trying, but after researching I realized I didn't have the experience needed. It is 7 inches diameter and about 5/8 thick. The face has details that I think would be The difficult part.

 

Welcome Northlee.
The cover was originally sand cast so the design on the front probably wouldnt be a big problem assuming you provided an existing cover. Shrinkage would likely be a huge hurdle though. Prolly around 1.5% which would be enough to throw off your hole spacing a reduce your overall diameters.

Pete

 

Sort of just thinking out loud here:
So, one-off? If you are planning to use the one you have as a pattern, just Bondo the holes shut, Maybe build up the lugs in back. You will probably want to machine the cast face. as it will not look perfect as cast. getting someone like Kelly to CNC a general disc pattern not necesssarily in foam and then adding an epoxy or Repro cast of the logo to "glue" into the center might be the way to go. That way shrinkage could be accounted for except in the logo.

Another way to go might be to simply turn an aluminum disc with a center hole into which a turned logo-dome could be dropped and welded. Directly copy the logo as a pattern for the center portion---a 1.5% size change wont matter. The welder will have to do a good job leaving enough weld filler to machine cleanly and a little extra thickness to make this easier could be planned. But that should be possible. The holes likely don't have to located in individual collumns in back. I'll bet they could be located in a solid raised circular boss on the back.

Like I said, just musing.

Denis

 

Scan it into a *.STL or *.OBJ file, 3D print with the appropriate size increase, cast in Petrobond then vapor blast/hone and polish as needed.
All the above dependent on if you have a 3D scanner. There are 3d scanner apps for phone that might work in place of a laser scanner.
3D printing can also be used to make a drill jig using off the shelf drill guide bushings.

 

This all kind of depends on if the customer wants one or is going to need tooling to resell a few and how much post cast processing can be tolerated.

SW can lay that logo on the surface pretty easily. The foundation sketch is probably in the <20 minute range with part in hand. That still leaves going from CAD to solid. Not everyone has good CAD/CAM but 3D printers are pretty easy to find/use.
My scanner software makes nice watertight meshes and even some 3D printer software has the capability to repair poor scans. Everything is just so easy and accurate once you have a good electronic file to work with.
I do find going from a*.STL to a parametric *.sldprt a real chore. Is there inexpensive software that does a better job of this than the SW import option?

But the real fun is in the casting. The rest is just ........ work.
Looking forward to melting some aluminum again. Lousy time of year to try to get anything done.

 

That never seemed to work for me. Bought myself a nice brand new TIG back in the Halliburton days. It was 6 weeks before I had time to unbox it.
Having the toys and no time to use them is even more depressing..........Got to the point I thought a 12 hour day was slackers.

 

Northernlee I have quoted several different customers on hubcaps for next year projects and I quoted them $250 a hubcap and another $250 for a chroming. I could fit making it in my schedule so if you are interested let me know.

Good luck,
Patrick

 

I should have claified why I need this. I have a 2004 Joe Gibbs Silverado, local tire company did not tighten the retaining screw and it went into the woods in Wisconsin. I am planning on selling the truck this spring and I really want to sell a complete truck. I have 3 caps, one is shown.

I was not sure this could even be reproduced. I only need one, but if one figured out how to reproduce, there have been several looking for them, which could be income for you.
My thoughts are I would ship this one which has been cleaned up, any guess estimates? Polishing etc I can do if that helps. As to how much it's worth to me, maybe $200, never been in this position to have a clue for your time and costs.

 

How many people would you say are looking for these, because it would be more cost effective for me to reproduce it if I was making more than one. As for estimates I will have to calculate one for you.
Patrick

 

I can't say how many are looking right now, I can go to a forum and see if I get a response.

 

Can your pin router be set up to enlarge/reduce like a basic pantograph duplicator?
Seems like such a device would be handy for someone that routinely duplicates existing parts.

 

Just a comment on using the original as a pattern and compensating for the 1.5% or so shrinkage that is likely to happen. I have used a material called Celastic to enlarge and repair parts so they could be used as patterns. Post 5 in this thread is a fairly extreme example of building up an area with Celastic.

Casting Windmill Parts from Original Cast Parts. Celastic for Adding Draft

I have used this material several times since. It is quite durable and relatively easy to use.
It is about like working pine wood in terms of how it cuts and sands. No grain though and no tendency to split.

Once the original had served its purpose as a pattern, the celastic could be removed with acetone. I would think that only a rim wrap and perhaps building up the lugs would be needed.

Denis

 

From top of center dome, it's 3/4 inch thick.

There is a tongue lip for a slot in wheel and only one bolt to hold center cap on. The other 6 holes are just for looks with same type of bolt head.
As to secondary machining, I don't think so, original is one piece.

I am willing to do any work needed after casting to make it work.

So far there has been no response on the Gibbs forum, traffic there has drastically slowed.
I figure I could get 5 made, then I'd see if ebay post catches attention.