Question on Mesa board best suited for what i need to do.

tommylight wrote:

First 7i84 should be 7i85.

Thanks Tommy. Fixed. You were quite right as always

well if nothing else the 7i97 would reduce space needed. i would just have to figure out what to do about spindle control? so i would probably still need to do something like the 7i85 or 7i85s.

i completely missed the 7i97 ethernet card.

i think the reason analog works better for dual feedback is because you can just let the motor and drive focus on speed and duration for ramping up and down it's strongest points. the instability comes from the mechanical errors on that control loop but those get taken out. and let the linear do what it does best and position things accurately. that's the way it seems to me at this point anyways.

right now i would not need spindle control so a 7i97 would work for now if need to i can add a 7i85 later if i would need more.

the plan is to use a servo motor as a spindle motor, the 750 watt motors actually are rated for 5000 rpm and will do 6000 i was told by DMM running on 240 V the spindle i have now maxes out at 4200 rpm and is only .8 HP the servo would be 1 HP with a boost on speed by 1800 RPM. i doubt the bearings can handle anything beyond 6000 RPM.

so a +/- 10 VDC would probably be the way that would go but that's later.

so now that i have a 7i97 board almost in hand i was looking a little on here and came across someone who used it when it was still pretty new and they had to do things differently because it was so new. Is this still the case or have the issues been sorted out by now?

this was a comment made by PCW last October.

***** The 7I97 is very new so needs LinuxCNC builld from source with some
Mesa patches added currently

The hal file for a 7I97 would be close to a hal file for a 5I2X/7I33 with some minor changes ***

i'm pretty sure the PDF for this board was made from the 7i77 because some of the connections are in the wrong place for this board but right on the 7i77 board. location is right in the title but in the finer details it crosses over to 7i77 locations.

no wonder i keep getting twisted around on this thing.

this might not mess people up that build this sort of thing all the time but i'm not in that group

P.S. still wondering about the last post too

one other thing i came across was the ena pin for the DMM drives was mislabeled at one point in their documentation and it was an active high in the older documentation. is is now labeled right but they switched to an active low enable in the new documentation.

those land mines that keep getting brought up about the internet and information you might find there are an understatement.

it seems if they are active low enable pins those look easier to deal with it appears to me anyways.