Good to hear, Bruce! I'm just putting the finishing touches on a new CNC machine of my own (no Prop though). Glad to hear that it's working so well for you.
Stefan - I'm still putting the finishing touches in it, so no accuracy measurements yet. It is possible to get the backlash to about 0.003". Resolution is 1908 steps per inch in X & Y, and it is currently set to do rapid moves at 900 inches per minute. It won't cut steel, but it'll do soft metals like aluminum or brass. Mostly I'll be cutting wood and plastic - signs, furniture, project parts, etc. This machine has a cutting area of 4' x 5'. My previous one was about 22" square, and made of wood - much slower, and not nearly as sturdy. I don't know exactly what I'm going to do with it yet, but I never seem to have trouble finding things to use it for.
You machine looks really nice. I have a similar machine that I built four or five years ago. I use it all of the time and am having a lot of fun with it. Mine is built in a similar manner and I have found that I can even cut steel with it. You definitely need coolant if you are going to do that though. I made a high density polyethylene catch tray with some of that hold down track that you are using in your table to keep things in place. I'm running a windshield washer pump at something like 6V to keep the bit from developing a red hot blob of steel where it is cutting. It works nicely.
Cons of my setup are that I didn't get the router on perfectly square. I'm off by a degree or so. The reality of it is that this doesn't matter for 99% of what I do but if I machine a large flat area, it has annoying ridges that don't effect anything but are plainly visible. I would also prefer that it was quieter and that it didn't blow so much air down where it was cutting. You are quickly going to find that you are going to have dust everywhere unless you make some sort of dust collector around the bit. I built mine out of something like mcmaster.com's part number 1081A32 with a clear acrylic top and a 2" vacuum hose coming out of it. I also have some LEDs aimed at the bit so that I can see what is going on while cutting and to be able to properly set my Z depth.
I used a Ryobe hand router that I modified to be permanently attached to the CNC machine. I'm pretty much amazed at how tough it is. I'm routinely taking cuts 3/8" deep out of HDPE at about 40" per second with a 1/4" bit. I also am doing a lot of cutting of aluminum and sometimes brass(both of which you don't need coolant for) and this router just won't die. When it does though, I'll probably build my own spindle and motor setup to address the noise, alignment, and dust issues that I have been having.
Have you figured out what your backlash is? I stayed away from rack gear because I was worried about that since I knew that I would want really high precision.
One final comment is that I had been having trouble finding router bits for smaller diameter cuts. Specifically, I wanted 1/16" cuts sometimes and the router bits that I was finding would be 1/16" in diameter but would be 1/4" inch long in their cutting length so they would snap off easily. A couple of weeks ago, I decided to try making some collets to use 3/8" and 1/8" diameter shank end mills. That has worked out great. Now I have all sorts of options to play with!
It has been a while since I updated this thread, but since I have news, I guess now is as good a time as any.
I finally got around to doing some alterations on the machine, such as providing a much straighter path for the wire to travel, and I also made an attachment to ensure less problems and produce a higher quality product.
During the process of making these alterations, I called a HUGE manufacturer/distributor and discussed the patent and my production capabilties of the machine with them. The communication sounded pretty promising and they want to see some samples. Their director of marketing seemed to like the idea, and said he was going to bounce it around with the other big wigs.
Don't know if you've seen this, but this guy is one of the giants in DIY CNC
In particular, check out how he uses ribbon cable and supporting plastic strip to eliminate cable chain.
Pretty nifty idea, but I doubt that ribbon cable is rated for "continuous flex", which might lead to an eventual open or short circuit. I personally like cable chains, and I am glad I have had a chance to work with them and do some designing with them.
Comments
Tell me about your machine. What do you have going?
Bruce
I ran my first cut yesterday, using the machine to cut channels in its own surface for mounting the hold-down tracks.
Looks pretty sweet. Wish I had one
Bruce
wow your cnc machine is quite big!.
What do you plan to cut on it?
on the fotos i can see youu are cutting wood.
Are you planning to cut aluminium or even steel?
Did you measure the precision?
What where the results?
best regards
Stefan
You machine looks really nice. I have a similar machine that I built four or five years ago. I use it all of the time and am having a lot of fun with it. Mine is built in a similar manner and I have found that I can even cut steel with it. You definitely need coolant if you are going to do that though. I made a high density polyethylene catch tray with some of that hold down track that you are using in your table to keep things in place. I'm running a windshield washer pump at something like 6V to keep the bit from developing a red hot blob of steel where it is cutting. It works nicely.
Cons of my setup are that I didn't get the router on perfectly square. I'm off by a degree or so. The reality of it is that this doesn't matter for 99% of what I do but if I machine a large flat area, it has annoying ridges that don't effect anything but are plainly visible. I would also prefer that it was quieter and that it didn't blow so much air down where it was cutting. You are quickly going to find that you are going to have dust everywhere unless you make some sort of dust collector around the bit. I built mine out of something like mcmaster.com's part number 1081A32 with a clear acrylic top and a 2" vacuum hose coming out of it. I also have some LEDs aimed at the bit so that I can see what is going on while cutting and to be able to properly set my Z depth.
I used a Ryobe hand router that I modified to be permanently attached to the CNC machine. I'm pretty much amazed at how tough it is. I'm routinely taking cuts 3/8" deep out of HDPE at about 40" per second with a 1/4" bit. I also am doing a lot of cutting of aluminum and sometimes brass(both of which you don't need coolant for) and this router just won't die. When it does though, I'll probably build my own spindle and motor setup to address the noise, alignment, and dust issues that I have been having.
Have you figured out what your backlash is? I stayed away from rack gear because I was worried about that since I knew that I would want really high precision.
One final comment is that I had been having trouble finding router bits for smaller diameter cuts. Specifically, I wanted 1/16" cuts sometimes and the router bits that I was finding would be 1/16" in diameter but would be 1/4" inch long in their cutting length so they would snap off easily. A couple of weeks ago, I decided to try making some collets to use 3/8" and 1/8" diameter shank end mills. That has worked out great. Now I have all sorts of options to play with!
It has been a while since I updated this thread, but since I have news, I guess now is as good a time as any.
I finally got around to doing some alterations on the machine, such as providing a much straighter path for the wire to travel, and I also made an attachment to ensure less problems and produce a higher quality product.
During the process of making these alterations, I called a HUGE manufacturer/distributor and discussed the patent and my production capabilties of the machine with them. The communication sounded pretty promising and they want to see some samples. Their director of marketing seemed to like the idea, and said he was going to bounce it around with the other big wigs.
Bruce
Don't know if you've seen this, but this guy is one of the giants in DIY CNC
In particular, check out how he uses ribbon cable and supporting plastic strip to eliminate cable chain.
http://reprap.org/wiki/Mendel90
http://hydraraptor.blogspot.com/
https://github.com/nophead/Mendel90
If you are going to patent something, make this won't interfer as prior art.
Me, I'm thinking about kits from this design.
Pretty nifty idea, but I doubt that ribbon cable is rated for "continuous flex", which might lead to an eventual open or short circuit. I personally like cable chains, and I am glad I have had a chance to work with them and do some designing with them.
Bruce