probably the rookiest of rookie questions:

[Hoytbasses]

Greetings:

I've had the desktop about 10 days and today cut my first project!

it was a little sign, 8"x20"x .75" : vcarve lettering, a vcarved JPG of a striped bass, and a profile cut .

no cataclysmic failures, and my fingers are all attached. The writing cut perfectly, the striped bass came out great, but the profile cut was set to .70" deep. The problem is it only cut about .375" deep.

here are the specs: Zzero was set at the top of the material (at 0,0), when I changed to the 1/2 bit i zero'ed the Z to the top of the material (as I did with the V carve bit for the writing and fish vectors): climbing cut, 1/2" x .250 tabs.

my initial thought was that I didn't secure the bit quite tight enough and the bit migrated into the collet. doubtful because I've been using porter cable routers for decades.


http://i97.photobucket.com/albums/l238/hoytbasses/thewrightplace.png

I still chalk it up as a win! but want to know what I did wrong:

next question: If I reference the BOTTOM of the material as the Z reference, do I Zero the Z on the spoil board or the top of the material?

I'm already loving this forum for the wealth of information and friendly helpers available !

thanks:

Karl Hoyt

[dana_swift]

Karl.. the only way to be sure the bit didn't slip is to check it before the cut and see how far below the router it is, then again afterwards.

I had used a PC router for years before I got my SB and was surprised that the bits slipped with the SB. The reason appears to be the CNC motion system can push into the material harder and faster than a person would, so the bit experiences heavier cut forces.

First thing to do is measure the bit and be sure its not slipping. If its not, then we can talk about other possible causes.

Good luck, and welcome!

D

[Hoytbasses]

thanks for getting back to me.


I watched the router in it's first pass and the bit was 1/2" off the material.

was my procedure correct? it's the same thing I did for the V bit......

so I'm confused.......


take care

Karl Hoyt

[curtiss]

Is the font you are cutting a single or a double line ?

A profile cut on a single line font should go to the depth you select.

You may be "v-carving" between two lines which might be affecting your depth.

[Hoytbasses]

the font and fish came out great: (v bits)

it was the profile cut that was shallow......

thanks for the feedback

kfh

[gc3]

preview of toolpaths should have shown you same as actual cuts

[adrianm]

If that's the actual preview of the job then you've got something wrong at that stage rather than at the machine end as that profile cut shouldn't be green (the toolpath colour).

It should be all the way through with the background visible through it. If possible could you attach the actual CRV file so we can check the settings?

If you're referencing the bottom of the material as your Z reference then you should be zeroing to the spoilboard.

[Hoytbasses]

If that's the actual preview of the job then you've got something wrong at that stage rather than at the machine end as that profile cut shouldn't be green (the toolpath colour).

It should be all the way through with the background visible through it. If possible could you attach the actual CRV file so we can check the settings?

If you're referencing the bottom of the material as your Z reference then you should be zeroing to the spoilboard.

thanks for all of your patience . I've attached a screen shot of the project. I couldn't attach the CRV file and the SBP file was too big to attach......

I didn't want to wreck the spoil board, so i set the project to undercut (.73 I think) and zero'ed it to the top of the material so when i pressed 'go' the cutter was probably a half inch off the material on the first pass, so I don't think the cutter had migrated in the router.

I think I'll go wreck some more sacrificial wood and figure it out. but first, I have to fish a broken drywall screw out of the spoil board. another lesson learned.

Thanks very much

Karl Hoyt

[paul_z]

Karl,

If you use screws to hold down your material, I'd recommend using Kreg screws. They are very strong, use a square drive and can be reused many, many times.

Paul Z

[Joe Porter]

Karl, go back and look at your tool data for that bit. I think the depth of cut has to be greater than your material as a starting point. then you set the actual depth of cut in the toolpathing section of the software and edit the depth of cut per pass....joe

[adrianm]

From the screen shot it's not possible to tell where you've set the z origin.

If your material is 0.73" thick and you're setting the z zero in SB3 to the same as you're set the z origin in PartWorks then it should be cutting fine.

The cut depth and the number of passes looks like you've got a 0.25" pass depth on the tool which is fine.

I'm a bit confused as to why you think the bit should have been half an inch off the material because you underspecified it. If the material is 1.25" thick (for example) and you've set a 0.73" cut and you've zeroed the z on top of the material (with the origin set to match) then the bit should still have started on top of the material not half an inch above it.

You can zip the CRV file and attach it that way or just rename it to an allowed extension (such as pdf).