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Third party software and hardware support forums. => CS-Lab => Topic started by: Johnny Bravo on February 27, 2017, 03:39:00 PM

Title: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on February 27, 2017, 03:39:00 PM
Toying with retrofitting a Romi lathe with a csmio ipa,threading module and handwheel, and using the existing hardware. Totally new to this,but have seen a similar build on here. No doubt I will ask numerous,seemingly stupid questions, but please bare with me
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 04, 2017, 11:34:31 PM
Hi Johnny,

I don't have any experience with lathe retro-fitting but I can help with some general information based on my IP/A mill retrofit:

I'm using windows 7 (32 bit version) and my PC is NOT connected to the internet. Like you I was fearful of the "automatic updates". Mach 3 is running fine on this config. All gcode gets to the mill via a USB thumb drive. Admittedly old school but I like that my mill is safe from all the internet distributed virus and malware crap.

As for running the lathe with a VFD....I run my manual lathe (Southbend 16 x 6) with a VFD because it's 3-phase and I don't have 3-phase in my home shop. Threading is not an issue since the lead screw or cross feed still runs at a fixed fraction of the spindle irregardless of motor RPM. The head on my lathe is belt drive so I'm a big fan of using the VFD to get the spindle speed I want. I find I run on the middle pulley and I almost never use the back-gear. My work is usually 6061 or A36 and I'm not ever trying to mass produce anything...

As for your particular retro-fit... I'd encourage you to go for it if you have a known good lathe (minimal backlash) with an antiquated CNC control. You should verify that your servos, encoders and servo amps are in good working order before proceeding with the IP/A. If you find you need to update your servo amps this this may lead you down a path towards going step/dir rather than analog... Also, encoders should be 500line or better.

Hope this helps!
Mike




Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 05, 2017, 12:36:59 AM
Thanks for your reply Mike.  Still in the process of trying to get it fired up with the old controls to ascertain whether or not the servos and drives are any good. Unfortunately,this machine hails back to the advent of the Elf and Safe Tea movement in the Uk. Had to have all the safety relays etc fitted by Bridgeport before they could sell it in the Uk market. There are very few around,and information is minimal.  It's got an overly complex arrangements of guards and interlocks on it,so that,coupled to a very poor copy of a wiring diagram,is really hampering my efforts at the moment . Chaosengineering,on here,is also doing a csmio ipa retrofit,and, he has said he has a wiring diagram.

Found out yesterday the bridge rectifier in the 24v psu is blown. Have fitted a 500w 24v psu temporarily. Seem to be getting closer to getting it running.  On the subject of running the bed,slideways etc seem to be in excellent condition. That,coupled to the paint on the bed directly underneath the chuck hardly been worn off,,leads me to believe it's seen little use.  A previous owner has obviously spent a fair amount on boards and harnesses. Think this might have been plagued by electrical gremlins from the outset.Having done a fair amount of internet research,i still have to find a single thread where someone hasn't had an electrical problem.

I think it is an ideal candidate for a retrofit,has ballspindles etc already fitted.  Would like to fit a vfd to it, not to run it on single phase,but to be able to control the spindle speed and hopefully get constant cutting speed set up.

How user friendly did you find the whole csmio ipa wiring up and configure when you did your mill, Mike?  I haven't any experience with anything like this. No formal electronics or electrical training,but can find my way around a wiring diagram and can do basic fault finding.

Thanks again
Johnny
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 06, 2017, 12:25:18 AM
I found the csmio-ip/a docs to be quite good. You need a basic understanding of how a closed loop servo control system works. You will need electrical schematics for your machine that show servo, encoder and servo amp wiring. Lastly, you will need a VOM to do basic continuity testing along with perhaps taking voltage measurements. Sounds to me like you have the skills necessary to complete the retrofit....

As for running the lathe with a VFD... I don't see why it shouldn't work. The spindle will have an encoder/tachometer that tells the control how fast it's turning. The control should care less about how the spindle gets to that RPM.

Hopefully Hood will chime in here. I think he's done a lathe retrofit with the CSMIO-IP/A control.

Good luck!
Mike


Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 06, 2017, 01:31:13 AM
Thanks Mike

I have a decent Fluke digital multimeter. Have a wiring diagram and have sussed out pretty much what would need to stay and what's redundant.  Whilst the wiring diagram isn't the greatest, it's a copy of a folded original, at least the fold isn't through the bit I would need to keep
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 06, 2017, 11:43:18 PM
Good luck Johnny, Sounds like a fun project. Let us know how it goes... I can't find the " Chaosengineerings build thread" that you mention?

Mike
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 07, 2017, 12:06:23 AM
Will do. Thanks Mike .

Chaosengineering' s build thread is in "The General Mach Discussion", section,under the heading of ,"Novice to Mach3,may be asking too much??"
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 11, 2017, 01:04:28 AM
Last ditch attempt this weekend to see if I can get this up and running with its original controller. Being based in the Uk, these Bridgeport Romi lathes are few and far between,, and parts availability pretty much zero. I am loathe to spend any money on spares for it from the states, given its reputation for being plagued with electrical gremlins from the start.  So, its decisions time.

It's basically a low mileage 16,5x40" engine lathe,fitted with ballscrews anda pc based controller from Bridgeport.140v dc servo motors,the one on the x axis showing signs of being rebuilt at some point,( rebuilding company's sticker embedded in a thick coat of paint).  Given it's unreliable status,and showing signs that the previous owner had thrown a fair amount of money at it,coupled to me not being able to test if the servo drivers and servo boards are any good,makes me think he best way forward would be to rip it all out and start again. Financially ,at this point,it would make sense to use a controller that would drive these existing servos,hence my thinking of using a csmio IPA.  If it turns out that the servo or drivers are shot, I need a cost effective solution.  I do like the look of the ac servos,they would make fir a very clean and tidy installation.Here in lies the problem...

Being totally new to this and having never done anything like this,how do I size the ac servos? I want to use servos,not stepper motors. These most likely will be sourced from China.Having read up a bit,there are calculators out there, but not knowing the weight of the saddle ,etc, they seem pretty useless
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 11, 2017, 10:41:06 PM
Hey Johnny,

Mike here again... Have you seen this thread from CNCZone: http://www.cnczone.com/forums/bridgeport-romi-lathes/289634-cnc.html

If I were in your shoes I'd at least try and use the DC Servos that came with the machine. My thinking is that if Bridgport/romi did a good job engineering the machine then the servos should be well matched to the machine. As per the post above, the Gecko drives are reasonably priced. If you go Gecko you'd want to go with the IP-S step/dir.

Mike
 
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 11, 2017, 11:27:35 PM
Hi Mike. No,I hadn't seen that,will look now
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 12, 2017, 07:37:48 AM
Not sold on that Gecko drive idea ,seeing as the SEM servo motors are rated at 140v and the Gecko drive can only handle 80v. Would need to sort out another power supply and then the servos are still running  roughly 40% down on power,so speed and torque would be down too.
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 12, 2017, 03:38:23 PM
Not sold on that Gecko drive idea ,seeing as the SEM servo motors are rated at 140v and the Gecko drive can only handle 80v. Would need to sort out another power supply and then the servos are still running  roughly 40% down on power,so speed and torque would be down too.
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 13, 2017, 12:22:54 AM
Hey Johnny,

Perhaps Gecko are not the best choice... Did not notice they maxed out at 80vdc. I'm using Servo Dynamics amps... They are much more expensive however... Here's the link: http://www.servodynamics.com/product/1525-br-servo-amplifier/
American made so can't compete with the stuff from China on price. Great quality however... You still need to verify servos are good.

Here's the procedure I used to verify my servos and amps were good:

1.) I disconnected the belt from each axis. (not sure if this is possible for you?)
2.) I bypassed all the relays that implement safety and ready status logic so I could enable the amps. Remember once you enable the amps you could have an axis go wild so be careful!
3.) I used a 9vdc battery and a 1k pot to create a 0 to +9vdc input to the servo amp. This allowed me to verify that the servos would turn at an rpm proportional to 0-9vdc.
4.) Lastly, I reattached each belt to verify that the servos would move the table and Z axis. This too needs to be done with great care lest you run an axis past it's limit and damage your machine!

Hope this helps!
Mike



 

Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 13, 2017, 12:47:48 AM
Hi Mike
Thanks for your reply
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: mikecole on March 13, 2017, 10:05:18 PM
Hey Johnny,

Great to hear the gearbox looks pristine. Sounds like you've got a great lathe which will be worth the headache of upgrading the control system. The power supplies in these machine do seem crude but they work. Simple 60hz transformer, rectifier, huge caps... Curious about your servo amps. Do you have a web link for them?

Mike
 
Title: Re: Bridgeport Romi lathe retrofit with csmio ipa
Post by: Johnny Bravo on March 14, 2017, 12:12:51 AM
Hi Mike. Emailed the company about the servo drives.  http://www.trminternational.com/
Not sure if that will work as a link,so you might need to google the name.  Very helpful. Plan on using two of their 20A drivers coupled to a csmio ipa.Long and the short of it is,that 99v is the maximum you can run as the overvoltage protection will shut the drive down at 101v. Being a local manufacturer does help.  Also had a chat to one of the old boys at work. He explained one of the quirks of our power supply grid. Here in the Uk we run 240v ,50hz. Most houses are single phase,the street lights are normally on a different phase,and industrial is three phase. I am pretty rural,down in the South East of England,not far from Rye and Hastings. Two of the phases when measured are over 240v and the third phase is quite along way down. At home it measures out at 248v. At the shop two phases measure out at 248v, with the third being down at 231v.  Because of this,the psu outputs about 104v which isn't any good for my needs.  Everyday a school day!

So,the plan is to get a 2kva toroidal transformer with two windings of 70v. Run the two windings in parallel to double up the amperage,use a 50A bridge rectifier ,a bleed resistor and a smoothing capacitor. This should result in a voltage between 94-98v, dependant on the capacitor used.  Psu will be able to supply 28A which will be more than enough.Not sure about re using the old capacitor,have been told to be wary of big electrolitic capacitors that have stood unused for many years.  Apparently they should be reformed with a lower voltage before reuse? So, I might go down the route of using a bank of new,smaller capacitors connected in parallel for the smoothing part of it.

Well, I haven't gotten very far. Still haven't decided whether or not to convert this lathe,but it is looking more likely as I work my way through some of the issues I already know about. Learning a lot,and I haven't even started