[Coco] [coco] Coco CNC

[George Ramsower]

From: "Gene Heskett"

> On Saturday 09 February 2008, George Ramsower wrote:
>>I did my first fully automated CNC machining this morning. I finished
>>cutting the groove for the X axis lead screw into the X axis table. It
>>worked but with a problem with (I think) the Dremmel. Twice, the end mill
>>began dropping down into the part..slowly.
>
> I've had several occasions where a bit would ever so slowly walk out of 
> the
> dremel's collet.  They could stand to have a better tightening mechanism.
>
>>However, I don't think it is
>>moving inside the chuck. I think perhaps the dremmel is moving in the 
>>clamps
>>I made, since they are simply pressed onto the dremmel. It might be also 
>>the
>>output shaft on the dremmel that is moving. I'll have to look into this. 
>>It
>>didn't hurt anything as I'm only making room for the lead screw and 
>>nothing
>>is supposed to come in contact with this groove. It only makes room for 
>>the
>>screw.
>> But this issue will need to be dealt with before actually trying to make
>>parts.

 I was thinking of taking the chuck off of it and putting a collet on to see 
if that may help. But as I thought on it, I realized that it would not then 
be able to reach the slot I'm working on. The chuck does extend the length 
of the dremmel.  Other than that, this machine worked as well as I expected. 
The only weak point is the dremmel, as I knew this when I began this 
project. This is why I said in an earlier post that the dremmel may become 
only the drive motor for a new mill head. The work I did with it on the lead 
screw slot turned out pretty good.
 The side to side milling had issues, because the Z axis was extended far 
beyond safe limits because it was actally milling below the slide surface, 
which in turn began 1/4 inch below the designed work surface. So flexing in 
the whole affair is considerable. I'll have to go really slow and make small 
cuts to make the pocket for the lead nut.
 When the Z axis began to fall, I discovered that the machine can cut a lot 
deeper and with more tool pressure than I thought it could do. It actually 
made a pretty decent looking cut. Hmmmm.
 The B09 program is working quite well. However, I do need to get the thing 
to use an external file to tell it what to do. This would reduce the amount 
of disk space used quite a bit. I expect once the thing is totally working 
as intended, the program itself may push the limits of the available memory 
for the window. Passing params to smaller processes  are an option, but 
right now, I'm avoiding it. Even keypresses halt the process and this short 
halt can be seen in the part while the machine is cutting.
 I need to create a new boot disk to take advantage of the no-halt 
controller I have in this coco. I've just been lazy on that.
 I have a 6309 and have been thinking of installing it and converting to 
Nitros9 on this machine. It's a darned site easier than doing it on the 
other coco.

 George