Square column for mill build

I did a little experiment and used a 1/4 cup granite blast media,about 120 grit and a 1/4 cup black aluminum oxide blast media ,about 60 grit and I mixed that with some resin until I thought it was good enough,then I mixed in the hardener and added a little more of each,resin and hardening and got a good mix.

Was surprised how heavy it was for just that little amount. I beefed up the base and added a column to the concrete and secured it to the concrete and it made a huge difference but I learned exactly what I’ve read that stiffness doesn’t mean no vibrations so the granite epoxy should make it night and day.C0C8793F-0460-4D9C-957C-AA41097FAECD.jpegD2A0E509-4860-42C9-B794-A28FB8D374CD.jpegB43EE27C-80D3-4588-BF3D-0740954F667D.jpeg25E584D7-243D-4D8A-9770-F4FBDF450E88.jpeg
 
I think ima tack a piece of flat bar on the i beam front and back and seal up the corners with caulk and fill those voids with the g epoxy.

I also lowered the mill as far it would go and marked the bottom of the mill carriage, I guess you could call it, and thought about if these mods I’m doing aren’t satisfactory then I will tack some gussets to the column, below the mark I made so I will still have full usable travel.
Other than spending a bunch of money and building a completely new steel frame or buying a new mill all together ,which I really have absolutely no room for that, this thing should be as sturdy and vibration freely as
reasonably possible. I wil most definitely keep the thread updated bc it sucks when you start reading a thread your interested in just to be let down when the thread is never finished.
 
I have an urgent question. So I was thinking about just drilling a 1/2 hole pour the g epoxy through a funnel and fill the base and leave the bolts in. Now after the epoxy has cured how hard do you think it’s going to be to removed the bolts if needed? I will have to remove the bolts holding the column to base so I can fill the Column and I don’t want to pour this stuff and find out the bolts aren’t coming out without an act of god. Thanks
 
Trying to pour granite epoxy thru a small hole is likely to be an extreme exercise in frustration. If at all possible, you want to pour into the open end of the column - upside down if necessary. As for making bolts, etc. removable, a possible approach would be to grease the heck out of 'em before pouring the epoxy. Even better would be if you could put sleeves of some kind over the bolts. Try various sizes of PVC pipe, be sure they're a snug fit across whatever they have to span, and grease the bolts anyway, just in case any epoxy seeps in.

This article may be of help:

CNCCookbook: Epoxy Granite Fill

How to fill your CNC machine's castings with epoxy granite to dampen vibrations
www.cnccookbook.com www.cnccookbook.com
 
You’re right hman it was frustrating. I wasn’t prepared as well as I though. I poured through a hole I drilled in the top of the base and quickly realized the hole was too small and the first batch I didn’t get to use much of,plus I needed to remove the dro glass scale bc it got in the way. I want to say something really fast about my first batch bc I’ve seen the question before and I proved everyone wrong and some confirmed what they thought might be possible...... I used the epoxy I had laying around the house and a couple small kits I could find at hobby lobby and Lowe’s. I combined into a single batch a 4:1 epoxy I bought years ago for carbon fiber lay up and multiple 4 ounce kits of 1:1 and it cured just fine except a little fast. Also these epoxy had 3 different types of hardener speeds and 3 different chemical make-up hardeners so as long as mixed throughly it will set and cure just fine. So if in a pinch I promise it works. Now the second pour went great. I opened the hole a little bigger in the top of the base and poured till no more would go in and I just left the funnel in place. Now on mine I noticed on top of the column where the handwheel screw bracket mounts to the column there is a 3/4 inch hole that That goes straight into the hollow column so I got lucky and didn’t have to remove the column and turn it upside down but I had a problem. I looked through through this hole in the column and it looked like it stopped at the flange that mounts to the base well I was wrong. As I poured the epoxy in through the top of column it was steadily pouring out the funnel I left in the base so I wrapped a rubber glove around the funnel and stuffed paper towels and tied a crescent wrench down onto it to keep the epoxy from flowing out.After that all went well. The epoxy cured and the column is rigid as I think it could possibly be unless I welded some some gussets to the Collins which I won’t have to. Before I could barely take a light cut on aluminum without breaking an end mill and crazy vibrations. Now I went down a length of 3/8 thick aluminum 1/2 deep and cut it like butter. I also can use the side of an end mill where I couldn’t befor. Here’s some pics.4CC88EFB-559B-43C7-8ED5-D84D0A5074F5.jpeg439E109C-C7F0-4172-A00C-8AB078E96DDF.jpegC256083E-0AF6-416A-A7AE-629AE0629FEF.jpeg69D218D3-237F-4693-AA79-C6276AF1ECEF.jpeg37FCEA61-3079-4603-8015-53A0EC9A7140.jpeg7D6EDBDF-44C0-454D-970B-9F731C63071F.jpegF71B70AF-C962-4D28-A949-BDCA326A1AFE.jpeg
 
Yahoo! Good news. I'm happy to hear that you were able to overcome and succeed!
 
Glad the epoxy worked out for you, no guarantee that anyone else mixing different types of epoxy will have the same results. It might not set up at all, or it might smoke and catch fire.

In my experience epoxy is best used as the manufacturer recommends. Anyone who wants to learn about it will do well to read up on what the Gougeon Brothers have to say at epoxyworks.com

Cheers,

John
 
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