Building a CNC router

[kong]

Truly amazing! i like the "simplicity" of your 4th axis setup too. So was the program a "true" 4 axis movement, or was it only utilizing 3 of the axes? I am interested as it may be a nice winter project, but I can't afford your software.

[HomeCNC]

Hi Kong,

It was a true 4th axis movement. The post from ArtCam translated the Y axis to Degrees of movement. I really do love ArtCam, It may be expensive but it does everything I want.

Oh I just re-read your question. The tool must stay on center of the axis. This is why there are no Y axis movements. The Y axis was translated to angular movements of the 4th axis.

[kong]

Sorry for keeping on Jeff, what I meant was does the y-axis actually move during the cut, or does it stay centered on the workpiece? i know there has been a lot of talk of "unwrapping" a 3d drawing to convert to the a-axis system, so I guess this is what I will have to do without the proper software

[HomeCNC]

The cutter must stay perpendicular to the surface. If my 4th axis was the router, Which would mean I would need to build a pivot on the router mounting. Then the Y axis could move over to the side of the pillar, the Z axis would move down and the router would pivot to keep the tool perpendicular to the surface. In order for the tool to stay perpendicular with my setup, the Y axis must stay on center.

[InventIt]

Very Nice! How long did that cut take? I like the design of your 4th axis. Simple yet effective. What size chuck is that? 3" or 4"?

Nice job.

[HomeCNC]

Thanks InventIT,

The total time is something I don't know. The roughing took about 1 hour. I started the finish cut and went to bed. When I got up it was done!

The spindle that I made for my 4th axis is the same as the 9 x 20 lathe. I was using the 3" chuck this time but I can also fit my 6" bison on it, the 4 jaw or the face plate that I have for my 9 x 20.

[ger21]

I had set the same motor tuning from version 4.0 into 6.11, but it did not like the same settings for some reason. I had to play with tuning when I first went to 4.0 as well. I don't know why Art makes changes in the way a motor runs between versions. I still did not have the tuning correct, when I did the pillar below so I just kept the feed rate down.

Art made a lot of changes in version 6 which supposedly make the pulse train much smoother, perhaps this has to do with your problems. I read the Mach2 group daily, and 6.11c is supposedly very stable. Be sure to let Art know of any problems, he'll probably have them fixed in a day or so.

[Chagrin]

If you're still thinking about chucks you might consider one of these from Grizzly. They run under $40 and you can fairly easily build some large flat-faced jaws for a better grip on the wood.

[HomeCNC]

Well, I got an answer from Art about the slow moving 4th axis. Somewhere on the setup screen there is a place to tell mach 2 the diameter of stock you are working with. I will check this when I get home tonight.

[walter]

This is still the problem I had when I used ArtCam and made my 3D tube with the grapes on it (post 183). I had the problem of lining up the relief when it goes off the edge.

Jeff, Is the seam on the back of the 3d tube visible after machining? And how did you solve the problem with lining up the relief on the edges?

thanks

[HomeCNC]

No edge is visable on the finished carving IF you spend the time to get the graphic lined up. I placed a grid pattern over the graphics to help me get close. I then did some trial and error work to get the relief as close as I could. It worked!

[coych]

I am wanting a home machine. Ive searched and I am not ready to remorgage the place. I am looking for at least a 48x48 . I am not looking for mass production. I have access to mastercam. Any suggetions or references to other companies besides shopbot. Cant afford $7,000 plus.

[JavaDog]

I am wanting a home machine. Ive searched and I am not ready to remorgage the place. I am looking for at least a 48x48 . I am not looking for mass production. I have access to mastercam. Any suggetions or references to other companies besides shopbot. Cant afford $7,000 plus.

You might want to start a whole new thread, that way it would get some attention and we could go over your needs, etc etc.

[walter]

No edge is visable on the finished carving IF you spend the time to get the graphic lined up. I placed a grid pattern over the graphics to help me get close. I then did some trial and error work to get the relief as close as I could. It worked!

Thanks for the reply. I started worrying when I lerned about ArtCam Pro "semi 4 axis" capability. It`a a lot of money and you want good result when working on these fancy turnings.

[wisp]

Another odd thing, or maybe it is normal. The 4th axis moves very slow compared to the other axis. What I mean is.... The jog works fine with the 4th axis, it moves fast. When I set a feed rate in the program to 60 IPM. The X and Z axis would move at that feed rate. When a "A" axis move was issued the feed rate would drop to around 1 IPM then go back to 60 when it was done moving.

Jeff, the reason for the feed change is that 4th axis angular moves are in degrees per minute. So a feedrate of 360 would be one RPM on the 4th axis. That is how Fanuc controls feedrates when using a 4th or 5th axis.

Here is the formula to convert inches per minute to Degrees per minute,

DPM = 360 x IPM / (Diameter x Pi)

cheers.

[HomeCNC]

Thanks for the information. I have been away from using my 4th axis for sometime now, but when I get back into it I will look at your formula and try some tests.

[jkhlaw]

Dear all,
I am think of making an automated cnc saw using spiral saw (rotozip) with 3 -axis machine to saw multiple piece of smaller rectangle wood from a large wood (6'X8') at one go without human intervention.

I am sure can be done in the cutting part but what about the clamping part.

Could anyone share some light with me pertaining automated clamping on automated cnc saw.

Thank in advance.

Jimmy

[joecnc2006]

Dear all,
I am think of making an automated cnc saw using spiral saw (rotozip) with 3 -axis machine to saw multiple piece of smaller rectangle wood from a large wood (6'X8') at one go without human intervention.

I am sure can be done in the cutting part but what about the clamping part.

Could anyone share some light with me pertaining automated clamping on automated cnc saw.

Thank in advance.

Jimmy

Isn't that called a cnc mill? I would not do a vertical if that is what you are thinking, because the pieces will just fall down, then you would need a vac table system to hold the all the parts inplace.

[James Marshall]

Hello. Have you ever decided to make the drawings for your tool holder available ? I would be interested if so. Hows the house coming along? Thank you.

[William A. Lowe]

You didn't say how large a motor you are using to turin the spindle. Wood shapers would usually use a 2 or 3 HP, 3750 RPM motor at apx. 7000 HP. The slowest router I have seen is 16000 RPM x 2 flutes = 32000 cuts per min.

At 20000 cuts per min. you would have to move very slowly to cut wood, but I don't think you would clear the shavings ( sawdust ) from the cut and the machine would "bog down." Without clearing the shvings you will aneal the cutter and it will become dull very quickly.