Hello!

Hello, I’m Chris and I’m new and hope this is the right spot for introductions, If not please move I have an idea of what I would like to do with an Open Build C-Beam CNC machine. After a few days of reading though, I’m just knowledgeable enough to be dangerous.

I want to make small ABS / Delrin parts to supplement my income. I’m starting all work by:

1. Drawing in Sketchup and slicing it into CNC workable dimensions.

2. I would then use the C-Beam to create small part masters from aluminum.

3. Mold masters in a 12” latex/silicon mold. Vulcanize.

4. Then spin the mold in my Contenti spincaster machine.

Molds could then be poured with molten lead, abs, delrin, or polyester resin depending on the need. Think of it as a sort of poor man’s injection molding machine.

The reason I’m not going for a 3D printer is quality, and speed. A friend has the filament type printer. The quality is “meh”, and its speed could best be described as “glacial”. The mold I spin is a 12” by 3”, so my parts are limited to roughly 2.5 inches in thickness or less. But as long as they are small(ish) otherwise, I can throw several at once in the ‘caster. I can throw 12-18 lead fishing jig heads at once in mine in about 15 minutes, including prep time. A GINORMOUS time savings compared to the hours required for the printer. And it’s reasonably accurate as well for the parts I’m looking to make.

Technical questions:

1. I know there will be a learning curve. I expect it. But I am looking at something like combining ymilords “The Hog”, and 1 of the “big mouth” builds as my first build. The first serious project I have to accomplish is new vulcanization rings. These rings are made from 12” aluminum pipe (1/2 thickness), 3 ¼” tall. With 1/2” thick matching plates top and bottom with rabbeted edges to match the ring. These Vulcanization rings have an interior of 12”x 3”, and are what’s needed to hold the layers of rubber together while the mold vulcanizes in my oven. My originals got lost/nicked, and local shops quote me $600+ for steel builds, and more for aluminum. For the price of 2 I can buy one of your machines, with upgrades. And machine my own rings/plates once I’ve climbed part of the learning curve. I know the bundled C-Beam machine has a z of 1.25 inches, so my initial build is going to need some changes.

2. What is the smallest burr realistically usable for detail work in aluminum? I need some detail work that’s 1 x 1 mm channel cut in flat plate. Is it realistic to design parts in 1 mm detail in Sketchup and expect the burr to cut it? What software is recommended? I’ve been reading over at CNC Cookbook for weeks now… whew. I have a lot ahead of me. J

So much to read and learn… I’m kind of hoping Open Builds has a sale for Christmas. I’ve been a very good boy this year. If you have any illumination to throw on my first build, I’d appreciate it, and thanks for reading.

 

Thanks for the reply!

I probably didn’t explain it well; I’m not much of a technical writer. I apologize, and I’ll try harder.

I have a used spincaster. It uses an electric motor to spin vulcanized rubber molds that can be filled with lead, white metal, or plastics. The spin uses centrifugal force to distribute materials throughout the mold. I’ve attached a YouTube video list, showing the use of one. That’s not me in the video, though I think that guy is really talented.



In order to have a mold I can spin, I need to vulcanize layers of raw silicon/latex soft rubber into harder homogeneous mold halves. In order to vulcanize the molds, they need to be placed in what’s called a ring frame. There is a good view of a homemade one in the third video, about 1:39 in. I was looking locally to having one made, but everywhere I went was brutally expensive. Here is a link to the item itself:

Mold Rubber Ring Frames | Contenti

$472 + S&H (the cheapest so far) for a 12” tube, 3” thick, with a pair of rabbeted (sorry for the carpentry term) plates.

Then I found the Open Build site and thought I might be able to craft one myself. The plate cutter (c-beam) bundle might work. I read it’s X axis at 13.5”. Ymilord’s “The hog” makes me reason I can increase the Y axis enough so the total work area is 13+” x 13+”. The Z axis travel of 6” may be enough for me to shoe horn in my 3.25” width pipe to be machined smooth. If so, a big hurdle is cleared because 1’ lengths of 12”, ½ thick aluminum pipe can be had for <$100.

From there, the sky is the limit really. Any small part that can be machined from aluminum on a c-beam, and can fit inside of a 3” mold (figure 2.5”) is cast-able in Delrin or ABS . For a small would-be business person like me, that’s a huge range of opportunity...



Thanks again!