trinity-users@lists.pearsoncomputing.net

Message: previous - next
Month: March 2018

Re: [trinity-users] my silly project continues

From: "Dr. Nikolaus Klepp" <office@...>
Date: Tue, 20 Mar 2018 13:19:14 +0100
Hi Gene!

Am Montag, 19. März 2018 schrieb Gene Heskett:
> [...]
> The install is armbian jessie lite. Downloadable from the armbian site
> LinuxCNC is the uspace version of 2.8-pre. Weird config, no PID's used 
> Works fine.
> 
> PM me, and I can send you what should be working configs IF you've 
> installed and wired up a pair of MPJA's 100 ppr a/b encoders to function 
> as hand wheels. This encoder is also available elsewhere, s/b under $25 
> a copy. Interface is a mesa 7i90HD, with 3 7i42TA's to protect the 3.3 
> volt 7i90HD from the noises. Spindle control is a 240 volt single ph 
> input 1.5 hp vfd, running an old (probably about 40 yo) 3 ph, 1 horse I 
> took off a scrapped air compressor.
> But no use further cluttering this list, so PM me.

Thank you for your hint. Sorry, no mesas in my shop, but at least I have some encoders waiting :-)

Ages ago I had a single RPi2 (the newer ones) running with linuxcnc + TDE and GPIO for signals, just like the parallelport. Latency was not so great (~ 20000ns), but at least the steppers turned. Last week I wanted to resurrect the project, just finding the RPi beeing unable to boot. Well, following your hints I came to the conclusion that almost anything is better than a RPi for CNC (oh my, never thought I would write that). 

Now I've placed a T60 mainboard into a 15.4" T61p with libreboot (stock bios gives horrible latency) + linuxcnc + TDE + NativeCAM, looks neat and has nice latency (<2000ns).

Nik



-- 
Please do not email me anything that you are not comfortable also sharing with the NSA, CIA ...