Hi everyone.
Ive been a super long time browser of the forum, and I actually find it embarrassing that I haven't joined until today. Crazy..
Hopefully this is the correct sub forum to post up my machine build andquestions. I couldn't really find the forum that folks chat and discuss fullsize cnc conversions, they look to be mainly model specfic. Anyways, idigress.
Over the past 3 years ive been working on a cnc conversion, and ive been slowly getting into a predicament over choosing a breakout board. Ive spent the last 3 years looking over the options and the past year really researching. Unfortunately ive become more confused over which way to go, obviously each application is different and with a few options ive narrowed it down to, its hard to decide which one wont bite me if i plan to expand my system in the future.
This is going to be a long thread lol..
Before I go into detail with my questions, ill give a brief/detailed history on the machine. The machine i am converting is a Excello 605 CNC. The machine was made in Canada around the mid 80’s and was designed to be a 3 axis cnc from new. Auto lubed box ways, ball screws, a semi auto collet changer; it was hybrid between a standard knee mill and a full tilt cnc machining center. Still weighting atleast 2x a standard bridgeport. This machine was the perfect basis to do an advance hobby/entry pro style cnc for my shop, and when the right deal popped up, i grabbed it in a heartbeat.
The machine itself surprisingly is almost new, its only seen some basic acrylic machining during its lifetime, and spent the past 15 yrs covered up in the corner of a shop.
The machine when i got it, had already partially been converted to use late 90’searly 2000 controls, but still used the original DC servos and resolvers. I spent about 30 min tinkering with the old proprietary system before i had enough and took the path that i wanted to take.
Ill make alist of some of the goodies and conversions ive installed on it:
-New 5hp spindle motor w/ GT2 timing belt drive driven by a Hitachi WJ200-055LF vfd that ive rated to work @240v 1PH household power, and has rs-485 that i plan to use.
-3x Mitsubishi AC servo drives (2x Mr-j3-70A for x,y, and a Mr-j2-40a for the z)
-All new Misumi 5GT series high precision timing belts & pulleys for the axis drives
- Ethernet smoothstepper drive controller system. I currently have the servos running at a1Mhz pulse train
-Dual redundant force guided safety relays, the whole safety system ive designed to be as close as possible to current automation safety requirements without going crazy. I have full safety relays on the servo drives as well. Im trying to make full wiring diagrams for the machine as i design and wire it up, i used to do automation equipment design, so i thought why not.
- I plan to use PoKeysfor the HMI panel push buttons IO along with the BOB IO, that i can easily manually enable extra features within Mach3 (coolant mister, way oiler, x,y,z axisresets, etc)
That is just a shortlist of the few things i have done.
Now to get into business..Here my issue.
Because i have a few extra features or requirements that most hobby cnc machines don’t have or need. My choices for a full featured Breakout Board are kind of narrowed. Currently I have 9 inputs for the xyz limits and homing microswitches. And a bunch of auxiliary relayed inputs and outputs that i want to control using the smooth stepper. Lets say (9+8 inputs, and ~8-10 relayed outputs)
Right now for benchtesting, ive been tinkering about using some cheapy ebay china breakout boards to test the servo control circuts. And surprisingly they actually work decently, the xyz opto isolators actually can handle the 1mhz pulse train i put thru them, and haven’t dropped any steps.
Technically i could use 3 of these cheapy BOB’s and hook them up to the smooth steppers 3 control outputs and all would be kinda ok, there are some slight issues; seeing that i would like to use most of the 2nd and 3rd bob IO as plain relay output controls or plain 5v/24v signal inputs.. Plus it being the heart of the machine, i want something a bit more pro.
There are a few too manychoices out there for ESS BOBs and they literally have me confused.
Add ontop of that, i amhoping to be able to control the VFD using RS485, but i would like a backup plan, maybe 0-10v control if i can get it figured out.
I have my eyes set on afew BOB’s:
- PMDX 126
- CNC4PC C62+ 1x C35S
- 3x CNC4PCC35S
- 1x C32S +1x C35S
Initially i wanted to use the PMDX 126 because of how many satisfied people there are with it, but it has a few features i don’t want, plus it seems to self power the ESS, which in mycase, i integrated a full 5v and 2x 24v power supply system in this machine.
One 24v PS for the large contactor drivecircuit and safety system, and another one for the logic controls so i don’t get any high current/contactor surge feedback.
The CNC4PC stuff seems to be more customizable to what i need (basically it looks like you just buy remote relays and IO RJ45 addon boards), but as silly as this might sound,there seems to be lacking info on some of the features, and their tech support hasn’tbeen the most helpful with detailed questions for “no yet customers” in my case at least.
Are there any new similar options out there that i haven’t come across yet?
I am almost about to bite the bullet on a CNC4PC setup, but i dont know what would be the best config for my system.
See..confused yet. lol