I've read most of the 4th axis posts and haven't seen my problem so I'm hoping somone can help. I'm setting up my forth axis on a camtech router that has been converted to Mach 3 with a CNC4PC, C11G board. Everthing has been working great for a year and a half but now I want to try my forth axis. I'm using Rhino 4 and Rhino Cam 2.0 basic with the 4th axis option. I set up the "A axis" so one revolution equals 360 on the DRO,the problem is when I run the machine at 200 inches a minute feed rate the A axis is rotating at 200 degrees per minute which slows the other axis down as well. Also what is "ROT 360 rollover " and "Ang short Rot on G0"used for? I've checked off "use radius for feedrate" and "A rotations enabled" not sure if that's correct or not. In the rhino cam post there is an editable value under Multiaxis motion, angle value, scale factor, not sure what it's for but I have a request into Mecsoft for the answer. Thanks for your help

Info on configurable items such as "Rot 360 rollover" can be found in Mach3 Installation & Configuration Manual, page 5-37.
Attached is a summary of what is in the manual relating to feedrates.
RICH

In the A diameter DRO on the settings page, you need to enter the diameter of the part, if you have Z zero at the surface of the part. If Z zero is at the center of rotation, enter .001 in the A diameter.

This should give you the proper feedrates. "Use Radius for Feedrates" is only active if the A diameter DRO is not = 0

Thanks for the reply, The machine came with a Mdrive 34 plus stepper for the rotary and it was set at 6320.0894 steps in the previous software. Unfortunately with that motor I can't change or verify the  resolution without a special cable and software. By using a degree wheel i was able to calculate that it is traveling 1 revolution for every 11.9 degrees indicated on the DRO. The number I get to correct the resolution is (360/11.9) X 6320.0894= 1911195.34 and I believe that's too high for 25kHz. any suggestions?

Increase the kernel
Hood

Thanks for the suggestion Hood, How do you make changes to the kernel speed "stick" I've changed it in the driver test program and it says excellent up to 65000. and I've tried to change it in the diagnostics page too and it jumps back to 25000. What am I doing wrong?

Under Config/Ports and Pins.
Be sure to restart Mach after your selection.

Thanks for your help so far, sometimes I think it would be easier to train beavers to look at a photo and then chew out the shape I want.  I have the DRO showing 0- 360 for each  revolution of the A axis but when I run the code it does at least 1 revolution for each line of code I've talked to mecsoft and the say it's not the Rhinocam or post any ideas? Here's a bit of the code and I said each line causes the A to rotate at least a revolution it takes forever before it makes an X move.

G00 G49 G40.1 G17 G80 G50 G90
G20
(4th Axis Parallel Finishing)
M6 T2
M03 S1
G01 X1.0000  Z6.3750 A0.000 F150.
Z6.2500 A0.000
Z6.2499 A-1.145
Z6.2500 A-1.718
Z6.2499 A-4.307
Z6.2500 A-4.781
Z6.2499 A-10.135
Z6.2500 A-12.053
Z6.2499 A-22.961
Z6.2500 A-23.534
Z6.2499 A-29.088
Z6.2500 A-30.233
Z6.2498 A-33.869
Z6.2500 A-34.442
Z6.2499 A-39.223
Z6.2500 A-41.141
Z6.2499 A-54.540
Z6.2500 A-55.685
Z6.2499 A-65.448
Z6.2500 A-66.593
Z6.2499 A-69.576
Z6.2500 A-70.802
Z6.249

Thanks for your help so far, sometimes I think it would be easier to train beavers to look at a photo and then chew out the shape I want. 

Well almost done that already see pic

Can you attach your xml please.
Hood

I thought only Canadians could do that LOL. Thanks for your help it's just got to be one switch or something simple but I can't find it.