Making your first cut

[matney_models]

I just make my frist cut with the Bot.
I was cutting the air camber for the vac hold down. 1 thing it was only .300" not what I asked for was .375" What did I do wrong?
It make the first cut at .188" the make a second pass at what is said was .375".But when I check it it was only.300"

[rcnewcomb]

What method did you use to zero the Z axis?

Do you have a zero plate? (about 3/4 of the way down on this page: http://www.shopbottools.com/accessories.htm)

[dlcw]

You will want to make sure you've run your parameter setup file. This sets all your default values. You will find them at:

C:\Program Files\ShopBot\ShopBot3\Settings\PRS ShopBots

Than pick the machine that matches yours.

[zeykr]

It could be that a unit value is off. As Don says running the setup should put the proper values in the settings. The UR command will allow you to reset and chose the proper settings.

To test, zero your z just above the table, then do a Move Z 2 and measure to see if it moves up 2". If not, unit values are probably wrong.

If it moves proper amount, you may have pushed it too hard into the material and lost steps or it could have been loose in the collet and bit slipped up. A loose pinion is another slight possibility.

Keep trying - there's a learning curve but you'll get there!

[matney_models]

Just tried a Z move to 2" and it is fine. now what to try.
Even tried a X move to 48" and it too is fine.

[dlcw]

Kevin,

Reload your default unit values. Then try another cut. If this doesn't work, call ShopBot support and they can walk you through what the correct unit values need to be for your drive motors. It might be that for some reason the drive motor ratios aren't working with the unit values you have.

[matney_models]

I tried to the prg you said with no luck. But tryed a new cut and it cut it right & .375"

[matney_models]

how went to cut the holes for the vac hold down. And set it 1.6" on 2 pieces of 3/4" and did not go all the way throw. had to go to 2.25" get get it done.I'm lost

[zeykr]

what type of bit are you using and what is your z move speed set to?

Are you running a .sbp program or manually using a CC command or something?

Give us some details on how you are cutting the holes, i.e. upload the program if not the std shopbot vac plenum program, tell us your feed speeds and rpm, are you running a router or spindle, is this a PRS - a standard or an alpha? How big of a depth of cut are you taking?

Since you told it to move 2 inches and it did so in an air cut, I'm guessing your unit values are ok, but the load of cutting is causing it to lose steps, or bit slipping, or something is loose in z axis.

Particularly if you are using a PRS std, you could be cutting too aggressively (too high a z move speed, too large of depth of cut). A little more info on your machine and how you are cutting will help others diagnose the problem.

[navigator7]

how went to cut the holes for the vac hold down. And set it 1.6" on 2 pieces of 3/4" and did not go all the way throw. had to go to 2.25" get get it done. I'm lost

Is it only the Z that is off?

Another SB'r had this problem.
Count the teeth on your Z pinion gear. Then find out how many teeth the unit is supposed to have.

[matney_models]

I took the dwg I made to make the air camber and added 2/ 2.25" more holes.Then in SB 2.5 pick only the 2 new holes,and save a tool path with a 1.25 cutter to cut 1.6" down. Made a cut and it only went down 1.5" down not 1.6". To get it make the cut all the way down had to say it needed to 2.25" down?

[lemic_ray]

Is it possible the cutter is slipping in the collet?

[burchbot]

Are you plunging a 1.25 inch cutter 1.6 inches deep?. If so that is your problem. My bot won’t take that.
Dan

[navigator7]

To get it make the cut all the way down had to say it needed to 2.25" down?
I understand what your problem is. What I am suggesting is that perhaps the pinion gear on your particular machine is possibly incorrect?
If this is the case???? there is no way you will ever get the right z.
The solution to this theory is to carefully count the teeth on your pinion gear and then call SB and see what the tooth count should be.
If the numbers match, it's something else. If the numbers don't match, you've found the problem.

[bill.young]

Kevin,

A call to ShopBot support is the fastest way to get going...they'll ask the right questions to narrow it down pretty quickly...but here are some thoughts.

*) You said in an earlier posting that when you aren't cutting and tell the Z-axis to move 2" in the air, it really goes 2". That means that the Z-axis unit values are correct for your tool and you have the default pinions...if they were wrong then your no-load moves would be wrong.

If you somehow got an alpha config file, though, the multiplier value could be wrong which effects the distance that the tool moves in jog mode. If your file tells the bit to jog when it lifts (most do), it could lose position and your cut depths will be off.

You can test this by doing the same 2" move test you did before before, but this time give it a JZ,2 move instead of an MZ,2 move and see if it actually goes 2"

*) I'd also be very suspicious of plunging with a 1.25" bit unless it was an end-cutting bit and they are very rare...I've never seen one. If it's not end-cutting and you plunge start down, the edges of the bit are cutting but the center isn't and can cause all kinds of depth issues.

Calling ShopBot support (when you're near the tool and the computer that runs it so that you can check things) is the best way to get running though...that get's my vote.

Bill

[matney_models]

I have the cutter set up to cut a 1/4" at a pass. And the 1st time I counted 7 cuts per hole.

[burchbot]

Kevin
You can’t do what you are trying to do with that diameter of a cutter.
Dan