SLowest feed and plunge rates the shopbot software will work with

[drodda]

Does anyone know what the smallest i.e. slowest the bot can got? I am trying to cut Mother Of pearl and the recomended rates of 7.5 IPM and 3 ipm are causing my bot to lose it's palce and it goes crazy and then loses comm port or it loses it's position but never gets to the surface of the material. Does anyone have numbers they have used with a 0.0230" bit from precise bits for cutting through Mother of Pearl 0.06" thick?

SO far I have been just testing the numbers with a v-bit in on corian rather than risking the actual shell bits, however the shopbot seems to have issues with very slow speed rates. I have a PRT Alpha with the upgraded steppers installed on the x and y but the original stepper on the Z axis.

Thanks,
-D

[bob_s]

Dave;
I found this;
http://www.talkshopbot.com/forum/messages/312/15331.html?1165870552
if you look down a few entries there are some feeds and speeds.

Please let me know how it works. I am in the middle of using some epoxy inlay for a friends guitar. He wanted his kids drawings and handwritten names on it in bright colors. Boy did I step in it when i said no probelm. When the drawings get small enough to fit I am cutting with a bit too small to get the inlay material to pour in. I tried Inlace, but it takes forever to harden. I just switched to Systems 3 epoxy and it seems to be better. The bot is cutting some now that cross over the prior pours, I have my fingers crossed, the Inlace shattered when recut.

[drodda]

I have used the inlace a few times and had good results with it but never tried fine lines or anything. I already read that thread that you linked however they are talking feed rates above the mentioned speeds given by precise bits for their tooling. I am using a very thin bit 0.02" and really don't want to break a few to get this right. However I can't even get the bot to move at those slow speeds.

So far the slowest I can get my Bot to work at is 0.2/ips on both the feed and plunge settings. Is there other settings that might effect this like ramp speeds or other parameters for the bot?

The very slow speeds of .125/ips and plunge at .05/ips seems to confuse the bot perhaps it is doing a rounding thing and making the numbers 0?


Thanks for the post though, I appreciate the help.

[shoeshine]

Dave, I get an error when I go below .3ips, but that has worked quite well milling brass with a precicebits .0625 stub mill. I would think you could get away with that in softer material with the smaller bit. Ramp your entry though to avoid shock to the bit.

[shoeshine]

also use very shallow passes, like .01 -.03

[drodda]

I am using Partwizard for cutting and I can't figure out how to ramp the bit in on a cut? ANyone familiar with partwizard and ramping?

Thanks Chris for the tips.

-D

[drodda]

Went ahead and cut the Mother of Pearl with the Precisebit bit at 0.2/ips feed and 0.2/ips plunge adn it cut great. I used a piece of corian screwed to the table and double sided tape to hold the shell in place and cut down through the shell and tape at 0.1" stepdown while using my air blower to clear the dust while cutting.I haev already cut out two inlays and am getting ready to do a third now. Next I will be working on the pockets for the inlays in the wood.

Thought this might help others to record this data on here. ALos so I can find it again when I need it next time.

Thanks,

-D

[drodda]

Here is a picture of my first try at the Mother Of Pearl Inlays in maple.
8008

[beacon14]

Sweet. Thanks for the follow-up.

[lexluthier]

I cut pearl all the time on my bot, even do engraving. Settings are 0.2 ips and pass depth of 0.010. I cut with bits as small as 1/32.
To hold the pearl, I glue it with titebond to balsa wood which I buy at Michael's Art Supply.
They sell strips 0.125 x 4 x 36. I use double sided tape to hold the balsa wood in place.
To separate the pearl from the wood, just immerse it in boiling water for a while and it will easily come apart.
8009

[shoeshine]

Mark,

what is your source for mother of pearl?

[lexluthier]

MassCraft in MA or Rescue Pearl in CA

[shoeshine]

thanks Mark, great links.

[ed_lysne]

I do inlays in shell all the time with my Benchtop Alpha. I run the bits at .5ips and .02 depth. Takes some time but it comes out nice. Here is one I did for a friend in shell. I think it was 19 pieces. Converting his design was the the most time consuming part.

8010