Trying to identify some servo amplifiers

[wpy]

Hello,

Can someone please help me to identify what servo amplifiers were fitted to Series I Interacts? The machine in question has a TNC145 controller and SEM motors.


Best regards,

Bill

[gus]

bosch drives

are yours missing?

[wpy]

Hello Gus,

Thank you for that. I have just read it in the manual - doh (in mitigation I didn't originally have the manual). Do you know what type number they might be or where I could find any data on them? Do you know if they are configured for torque or velocity mode?

To answer your question, no the machine is intact and in reasonable working order. I only just acquired it, but unfortunately am planning to move home soon and most of my workshop machinery is crammed into my garage, rendering the Interact inaccessible.

I want to convert it to Mach3 using some Skyko Pixie boards and would like to order the boards in readiness, but understand that they seem to work best with systems operating in torque mode. Consequently, I'm trying to figure out what the amplifiers are and how they are configured. When I bought the machine I did have a cursory look at the drives but didn't notice any markings.


Best regards,

Bill

[gus]

While I can see why you would want to get rid of the 145 since it only has 1000 blocks, and is a 2 1/2 axis machine, I think I would either leave the thing together from the +- 10v in and the encoder feedback, or get a 100v supply[the bosch are SCR drives so they rectify on the fly] and buy some newer copley or such drives, much stiffer capable of faster accel. What you have there is one of the best wired power enclosures you will ever find. Everyone who rips it out and starts from scratch is a boob.

I still say if you aren't running 3 axis contouring out of a cad cam system, this machine will do almost everything you will ever want.

I run one every day[ for the last 15 years]

[wpy]

Hello Gus,

Thank you very much for your advice.

My cunning plan...

Ditch TNC145
Buy or make step/direction to analogue converters (e.g. Skyko Pixie)
Connect same between new PC and existing Bosch analogue drives
Replace existing (analogue?) encoders

...a plan more cunning than a fox who has just been made Professor of Cunning at Oxford University.

The main flaw is that I am a bit short of data for and experience with the drives.


Kind regards,

Bill

[gus]

What are you planning on doing with the machine?

The servo drives are servo drives, +- 10v and -+ 10v tach inputs. Their accel and stiffness is not up to modern standards, but they do the job. If they die, it will cost more to fix them than a newer drive would cost, but you have no 100 volt supply in that machine.

When choosing a control strategy, remember: cheap, fast, accurate, pick two.

As I type, my 145 driven machine is mowing through aluminum casting over 1 inch think with a 3/4 inch 3 flute carbide end mill like it does every day.

[wpy]

Hello Gus,

Thank you for your interest. The machine is largely for my own amusement, however amongst other things, I want to use it for milling plastic injection moulds for complex 3D shapes. With regard to producing code, yes I have a decent 5 axis CAM package.

After my last post I had a real stroke of luck; I managed to speak to a man who said that he designed the electrical system on the Interact I. He confirmed that the drives were Bosch Z15 (15 amp) units and that they have velocity rather than torque inputs.

Now I am concerned that the Skyko modules will not be a good match for the amplifiers. This leaves me with a bit of a dilemma; from which I am thinking of making my own pulse to analogue adaptors.

With regard to my control strategy, it is biased towards cheap and accurate. Given that the TNC145 is not suited to my purposes, what would you do?


Kind regards,

Bill

[gus]

the cheapest thing would probably be to find a TNC151, which is pin for pin compatible, IOW, it will drop in. It still gives you a memory issue, but if you configured a post well, it might not be a killer. It does also take g code, and can be drip fed apparently.

Everything else you do will require a 100 v power supply and 3 new drives, over a grand probably right there.

[NC Cams]

Suggestion: try to get your machine running BEFORE you start to craft on it.

As the man says, he has his running thru aluminum day in and out pretty much as-is.

The "old" analog +/-10 volt systems are/were the industry standard for true feedback systems for quite some time. Not quite the technology level of step-direction but truly adequate for 2.5 and 3 D system use. Analog drives (both DC and SCR) were used on some real high end machines of their day. Bridgeport used the analog drives with DC power in their VMC's ( the ones with the BMDC/DX32 PC systems). Fanuc used SCR's drives for their turning and milling systems and ran some pretty stout servos with them.

Keep in mind that some of the early machines like yours had lower voltage/high current drives. Today, the amps often are high voltage/low/lower current drives. AMC makes some that drive up to and exceed 25 amps per chanel but these are NOT in the price range of Gecko's or the like.

YOu have a pro/commercial machine, albeit decades old. Before I threw everything but the cabinets and power supplies, I'd see if I could resurrect it. You may find that there is still life remaining in the old buzzard....And there is some tremendous satisfaction in resurrecing old relics from the dead - they also offer some good electronics troubleshooting/learning/engineering lessons which never hurt either.

[wpy]

Hello NC Cams,

Thank you for your suggestion. I'm sure that it would normally be very sage advice. However, I bought the machine in working order from a friend and am aware of its qualities.

I'm not quite sure what you are saying; the only thing that I am proposing to replace is the TNC145 (and possibly the encoders). My understanding is that this controller is unsuited to complex 3D work.

The problem is that I need to find a method of converting the step/direction signals from Mach3 to the analogue velocity signal of the existing drive. Do you have any recommendations or perhaps know of anyone who would?


Many thanks,

Bill

[NC Cams]

I half heartedly tried to do that (Mach to analog with encoder F/B from a full beedback system) and gave up when I couldn't get the folks at Mach to support it - they pretty much are a step/direction system and, unless you're good at science projects and DIY development, you're sort of on your own at adapting analog amps to Mach.

There are probably users who can do it - I didn't find or appreciably look for them as I was looking for a low cost, self service type system to plug and play with for my business - Mach wasn't it.

Try the Mach user group - surely someone has done it already. Watch your interfacing as some of the amps are looking for feedback that may or may not be totally interfaceable to/with Mach's LPT port interface.... They can do AMAZING things but TRUE closed loop feedback is not one - as far as I know/understand.

[Doug Schwochert]

I am converting a Bridgeport Interact series I using the Skyko Pixie boards
I am struggling with tuning issues now. If I do not get them worked out by this weekend. I may abandon the pixies and convert it all over to Gecko servo controllers. converting it to the Geckos was my origional plan but I was convinced by another CNC group that the 132 volt motors would not have enough speed to operate the machine correctly on the Geckos max voltage of 80 Now that I have the machine up and somewhat working. at 50 IPM
I am not using anywheres near 80 volts. this is just a hobby machine so the Geckos would have worked OK. I just hated to convert over to the Geckos when I had 3 boards that were working good. I have since figured out that the pixies work best in torque mode I think the Bosch amps are a velocity drives.Rick at Skyko has been more than helpfull and the pixie boards work fine maybe just not for my application.

Doug S