Vista-CNC Tach Issue

[JimsMSM]

I installed a Vista-CNC USB-based Tach on my Tormach-1100. The RPM-DRO in MSM is not showing the correct Spindle RPM, it's running through numbers randomly. I looked at Vista's trouble-shooting and they say with some versions of Mach you have to use the "1024_RPM.set" which changes the RPM-DRO from 39 to 2222. Appreciate any guidance to fix this?

[DaveCVI]

That's a common problem with the Mach RPM DRO. IIRC the action of that DRO is dependent on some other mach settings - and most don't know the details (it's not like there has ever been good MAch technical documetation about things like this). So when they get stumped, people put RPM out to a non-mach DRO (in the case of vista apparently 2222).

There are three ways to solve this:
1) Get vista to understand how to use the Mach dro correctly (then MSM gives the right values from Mach). While this is the technically correct choice, few bother to do it, it takes time and most end users don't care about the details - so I don;t recommend this one.

2) Modify your MSM set file to change the RPM dro # to 2222. This is a simple mod, and the instructions to mod an MSM set file are detailed in the users manual. Of course, this assumes that you know how to edit using mach screen etc.

3) Assuming that you want the standard MSM 4 axis mill screen, I've attached a modified MSM set file for 10x7 and 12x9 resolutions. Copy these into C:\Mach3\MachStdMill\Set Files\Custom then use the Settings page, load screens BUTTON (NOT the similarly named mach menu) to load the one you want.

Dave

[JimsMSM]

Problem Solved: I removed the Tach-Pick-Up from the bracket which is mounted on the frame and it began working fine. Each time I touch the Tach to the frame it reads crazy, so I Isolated it from the frame and it's working fine. I have an identical tach on my other mill and have not had this problem.
Thanks Dave for the research but appears I won't need to change the DRO from 39 to 2222.

[DaveCVI]

OK, no problem - working is working
Dave