CNC Point issue??

[cuebuyer4u]

Ok guys I know this may be a dumb question to some of you but ive never inlaid points before ive always built half splice forearms, but I found a couple pieces of wood id like to make inlay points with.

Im trying to figure out how to set the machine up so it follows the taper of the forearm. I believe I read somewhere that you can adjust this in MACH instead of in Bobcad but im really not sure how to go about it. Ive always just stuck to inlaying buttsleeves, and rings where the issue of having one side a deep pocket and the other shallow really wasn't a issue.

Any help is much appreciated.

 

[cueman]

I use an offset dead center $30 in my tailstock to level the cue a little under the head. I also make a offsetting live center $85 that can put the cue dead level, but for simple point work it is not needed. The dead level part comes into play when wanting to do some four axis engraving and such.

 

[Dave38]

I would think that using an off set live center in the tailstock would work....this would allow you to level the cue and the pocket would be the same depth thru out. If you don't have one, try raising the tailstock off the bed with shims until the cue is level and then secure it
HTH,
Dave

 

[Canadian cue]

It is way easier to set the angle of the forearm so that your x axis is parallel to the taper angle on the cue. I built a sine table to angle my fixture that holds the cue for this purpose. Another way would be to put your fixture (assuming it is based on a flat bar or bed of some sort) and tilt it in a vice. If you want to do a tool path that runs on the angle you would have to use ball nosed end mills and have a rad in the corner of your pockets.

 

[Canadian cue]

I use an offset dead center $30 in my tailstock to level the cue a little under the head. I also make a offsetting live center $85 that can put the cue dead level, but for simple point work it is not needed. The dead level part comes into play when wanting to do some four axis engraving and such.

Chris how are you holding the other end of the cue/part? if you were holding it in a indexer of some sort whether in a chuck or collet you would be bending the part. It would have to be held between centers, in which case it would be hard to index would it not?

 

[cuebuyer4u]

Im using a original cue monster.

I cant chuck up a offset live center, or shim it.

Ive seen the programing done but it was years ago......

 

[Canadian cue]

Im using a original cue monster.

I cant chuck up a offset live center, or shim it.

Ive seen it done but it was years ago......

You cant cut a square bottom pocket on an angle. You can program it so the zaxis moves down as it travels down the cue but the pocket geometry would be wrong. The machine axis has to be the same as the axis that you want to machine, that is the reason for tilting the cue.

 

[cuebuyer4u]

You cant cut a square bottom pocket on an angle. You can program it so the zaxis moves down as it travels down the cue but the pocket geometry would be wrong. The machine axis has to be the same as the axis that you want to machine, that is the reason for tilting the cue.

If I made a offset dead center for the cue monster, I feel like it would bind while indexing on the spur driver....

 

[Canadian cue]

If I made a offset dead center for the cue monster, I feel like it would bind while indexing on the spur driver....

It would, you are just going to have to cut the pocket deep enough t compensate for the difference in height from the front of the pocket to the back.

 

[cuebuyer4u]

thats to deep for my end mills, I wanted to do a 10.5 inch point.

I have a .0123 taper per inch that means pocket would have to be atleast .150 deep so that would leave a .020 thick inlay on one side which would only work if it was skinny if its a wide inlay it would need to be even deeper......

I think i may just say forget it, I think doing V grooves is more comfortable at this point:frown:

 

[scdiveteam]

Ok guys I know this may be a dumb question to some of you but ive never inlaid points before ive always built half splice forearms, but I found a couple pieces of wood id like to make inlay points with.

Im trying to figure out how to set the machine up so it follows the taper of the forearm. I believe I read somewhere that you can adjust this in MACH instead of in Bobcad but im really not sure how to go about it. Ive always just stuck to inlaying buttsleeves, and rings where the issue of having one side a deep pocket and the other shallow really wasn't a issue.

Any help is much appreciated.

Hi,

Take your final Butt diameter and subtract your final joint diameter and divide it by two. This will give you the Z taper offset for your cue between centers.

Don't worry about the spur index device on the other side as it will be a non issue.

Make a shim plate that has holes in it that are indexed to the dowel pins and through bolts of your Cue Monster's tailstock footprint.

I use a Cue Monster and this plate has worked well for me!

I hope this helps you.

Rick

Here are two pics of my shim which is .200.




This will level your cue for you. My butt geometry is compound and my .200 tail stock shim plate gets me very close and when I do a 10" floating point the pocket floor is only off about .005. I make pockets floors between .120 and .180 depending the width.

Here are two cues with longer floating points and with the Z offset shim plate they fit in real tight and go in plumb with the same compensation numbers that would work on the table.





It also makes the longer butt inlays behave also when fitting

 

[whammo57]

I put a .200 thick piece of masonite under my tail stock on my cuemonster......... makes it flat............

Kim

 

[cuebuyer4u]

I think I need a pic of it in action to understand what your talking about.....

Im not near my cue monster to look at it. Are you disassembling the tailstock?

In my head I see the tailstock a solid piece of aluminum fitted on 2 rails with a dead center..

 

[scdiveteam]

I think I need a pic of it in action to understand what your talking about.....

Im not near my cue monster to look at it. Are you disassembling the tailstock?

In my head I see the tailstock a solid piece of aluminum fitted on 2 rails with a dead center..

Ok,


There should be two Allen bolts on the top of the head stock which is a milled billet block.

Loosen those bolts and lift the tail stock off the dowel pins.

The plate installs under the block but you need to index the holes on the plate.

Good luck,

Rick

 

[whammo57]

After you install the shim under the tailstock..... push the tailstock center all the way out and slide the tailstock up to the headstock .... lock it down and make sure the headstock and tailstock line up with each other before tightening the tailstock bolts.............


Kim

 

[whammo57]

Ok,


There should be two Allen bolts on the top of the head stock which is a milled billet block.

Loosen those bolts and lift the tail stock off the dowel pins.

The plate installs under the block but you need to index the holes on the plate.

Good luck,

Rick

There are no dowel pins under my tailstock...................

Kim

 

[cueman]

Chris how are you holding the other end of the cue/part? if you were holding it in a indexer of some sort whether in a chuck or collet you would be bending the part. It would have to be held between centers, in which case it would be hard to index would it not?

You only grab a little of the other end of the cue and it does not cause the bending you might expect.

 

[cueman]

It would, you are just going to have to cut the pocket deep enough t compensate for the difference in height from the front of the pocket to the back.

I think you might want to try it before you say it will not work. I have inlaid over 90% of all inlay work I have done with both manual and CNC machines with the offset center and it does not cause the indexing to mess up. My offset center offsets about 1/8". That takes care of enough of the offset to keep the ends of box points and regular points from cutting out.

 

[scdiveteam]

There are no dowel pins under my tailstock...................

Kim

Yeah I forgot. I had dowel pins added by my friend Ray who was a tool and die guy.

My set up squares up and indexes on the pins and the two bolts just torque down.

Sorry if I confused anyone. I did this in 07.

Rick

 

[Canadian cue]

I think you might want to try it before you say it will not work. I have inlaid over 90% of all inlay work I have done with both manual and CNC machines with the offset center and it does not cause the indexing to mess up. My offset center offsets about 1/8". That takes care of enough of the offset to keep the ends of box points and regular points from cutting out.

Chris,
I have not used a cue monster but I have used a lathe and mill for indexing. In fact I have an indexing set up for the lathe for building recut points. That particular setup works between centers. It has the ability to offset the tail stock. It is designed such that the work piece can pivot on the center and still remain indexed. In the idea you guys propose you are cheating really. If you hold one end rigid and try forcing the other end off center something has to give. So either your piece is bending or it is slipping in the jaws of your chuck. In this case if I remember how the the cue monster works you are relying on a pin that is parallel to your center to drive your piece. In which case it will be driving itself in and out of the piece as you rotate or index. Can it work...sure, but is it a very reliable way of indexing? I guess in this case if it works and it gets you through the job great.
Here is a pic of my setup for in between points indexing. I have given this a fair amount of thought. This set up also allows me to remove the piece from the machine multiple times to do other operations and not lose my indexing.