Retrieved: January 13, 2011
Last Post: June 2003
Good news guys, I finally got a start on my 1911 frame. I'll be doing this project just like the AR-15 receiver that I finished a few weeks ago.... starting out with a billet of aluminum and machining the whole thing out until I get a working frame.
Picture of what I hope to finally get my project to look like.
After 1/2" hog end mill
After 3/8 carbide end mill
Picture after all the holes were drilled.
This is a picture after the 13/32 corner rounding end mill ran. This is the set that is saving me a lot of time. This way I don't have to "3-D" the curves on the part.
I only ran 1 of these frames tonight, because I ran into a small problem. The radius around the trigger guard (that the corner rounding end mill left) isn't what I am looking for. The CR end mill done a good job on the rest of the part though. So I'm going to have to go back and program some "3-D" work so I can get the radius that I'm looking for. I also started to cut the under cut for the trigger, but I stopped it, because I knew that I was going to have to rerun the part again. It'll probably be this weekend before I get to do anything else on this frame, but I'll post some more pics when I get something new to show you guys.
What are the odds that someone could do this work on a mini-mill converted over to CNC? I'm debating on whether it would be worth it to buy a mini-mill, add some stepper/servo motors, motor drivers, etc., and try to do what Justin is doing. What do you guys think? Is it possible?
I'd say your chances were quite good, but not 100%. This guy Mini Mill CNC and a few others have shown that it is possible to get great results with a CNC Mini mill. However, as with all things on the Mini mill, you may have a problem with the capacity of the Y and Z axis. For example, from top to bottom, the 1911 would exceed the 4 inches of travel you have on the Y axis. For this hobby, I think it makes more sense to convert one of the larger $1000 mill drills to CNC. With the mini, you may need to break an operation up into several steps so that the work can be repositioned more often.
Obviously you would also not have the cool automatic tool changes
I'm not clear on how you're going to be able to cut the trigger bow channel with that undercut tool... can you explain?
Also, how are you doing the magazine well?
Well, if I understand your question correctly, you are talking about the slot where the trigger slides in (what I'm using the woodruff cutter for)...
With this woodruff cutter, I'm cutting most of the material out (as you can see from the picture) but I'm not able to get all the material out of there. So after I get the frame completly, I'm going to take a file and file out the material that remains. I know this probably isn't the best way of doing this, but I'm pretty sure it will work. There's not going to be that much material left to file out, so I'm hoping this won't take very long to do. I will keep posting pics of my progress, so hopefully you can see how I'm going to finish the frame.
It seems to me that you're talking about using the Woodruff cutter to open the vertical slot where the trigger itself protrudes into the trigger guard.
I'm wondering how you're planning on machining the interior of the frame, specifically, the magazine well and the horizontal slot where the trigger bow or stirrup rides.
Both of these features have square corners, which would seem to present a challenge.
Oh ok, I know what you talking about now
I'm going to do a couple more operations, then I'm going to drill the mag well out and then use a end mill to get all the material out of the mag well that I can. I will probably drill half of it on one side and then flip it over to do the other half... since the over all length of the mag well is around 4.5" and I hate drilling over a couple of inches deep. Then after the mag well is clear, I'm going to stand the part up so I can put the holes in the top of the frame... and during this operation I'm going to use ground back end mill and plunge down into the mag well and under cut the rest of the trigger bow. From what I'm thinking right now, there will only be a thin wall left to file out so the trigger will fit in. I believe, this is how the aluminum frame that I bought was made... except it looks like they used a broach instead of filing the rest of the material out.
I have really thought about how I'm going to make every cut, so hopefully if every goes as planned I'll be able to finish this project. I know this project won't be as cut and dry as the AR-15 receiver I made, since there will a little more filing to do....but hell, that's why they call it a project... I'm not going into full production.... haha
The part that I'm most scared about is using the 3" saw blade to cut the back of the frame out :thinking:. People are probably going to think I'm crazy by the way I'm going to do this... since I'm going to stack 3 0.057 thick saw blades on top of each other and slowly and I mean "SLOWLY" cut radius from the back of the frame. My brother said that we have stacked saw blades up like that before, but I myself have never seen it done. I'm probably going to leave that as one of the last things to do.
I was able to mill both ends of the stock that the frame was on.... so I could get the stock square. I needed to do this because I stood the frame up on the on it's end, so I could mill the (i think it's called "dust cover"... the "U" shape on the front of the frame where the slide sets over) If I didn't mill both ends, the stock might set at an angle, because it would be setting on a surface that just had a saw cut. After I got both ends milled, I stood it up to machine the "dust cover". I used a 3.5" long endmill and made very small passes (0.041" deep each time). I started out using this 3.5" long endmill, but as I started to make the first cut.... it started chattering really really bad. I was only able to cut in about half way on the first pass. Then I stop the machine because I was affraid that the endmill would break because of all the viberation. I think this might have worked better if I was using a carbide endmill, but the only one that I could find was a High Speed Steel endmill. So I pretty much trashed the idea of machining the "dust cover" this way :(
so I started thinking, and I believe what I'm going to do is... when I stand the frame up to put the holes in the top of the frame, I'm going to use a ball nose endmill and 3-D the "U" shape. This is going to leave a small radius at the bottom of the dust cover (near the center of the frame), but I hope I'm able to stand this frame up again and machine out this small radius... otherwise I may have to use a dremel to remove it. I think this will work better, because there will be no way for the ball nose endmill to viberate.
Nobody said this project was going to be easy... haha. The reason this project is going so slow, is because I'm trying plan the best way to machine the frame. I'm making 10 frames, and I damn sure don't want to make a mistake to where I have to start all over... haha
So what I'm going to do next is, remove the material on the back of the frame, so I have the basic frame profile finished (kinda like a 0% casting).
If anybody can see a better way to start my next step... I'm all ears