Rewinder Machine Upgrade Question

[jdbrandt]

traverse

Yes I agree Strantor.

I'm thinking the Hydraulic traverse will need to be upgraded.

I also agree with your thoughts DickDV.
Do you think I should upgrade both the Bridle (Feed nip rollers) and the rewind drive? They would like to use this machine regularly...

Thanks

You could research a CONTREX M-Traverse....

 

[califflash]

Peter,

I was not referring to utilizing the DC drives for control, but PF525's or PF 755's for control. I may have miss understood the discussion but it looked like the OP may be changing to ac drives and motors. I love putting PLC's in older equipment because of the versatility that it adds. But this is a piece of equipment that sounds like it didn't have one before and I question if this process really needs one.

Modern vector ac drives have the capability to run the web control internally. A PID control could handle the bridle tracking and a counter could initiate the end of roll behavior. Please don't miss understand me in that a PLC is my first go to logic device, but I think we can be too reliant on them sometimes.

I merely wanted to point out that what the OP wants to accomplish may be done without the use of a PLC, especially since I have not seen this mentioned yet.

I suggested the 5370 L1 controller not for its speed, but it's value. Integrated motion is not necessarily needed. I would hesitate to suggest a control logic right off the bat without knowing it's needed especially since the OP mentioned this project is budget sensitive.

 

[Critt]

The existing machine has a control system in it, very old circuit board type. We are going to be removing it and replacing this with a PLC. After the feedback I think we be keeping the existing DC motors and replacing the DC drives with something modern. We are also going to be adding some encoders to the system.

 

[califflash]

Please post back with what DC drives you decide on. I was looking for some a while back and never could find any I was completely satisfied with. I was leaning toward KB Electronics though.

 

[Critt]

Hello All, took another look at this machine and after getting quotes back for upgrading the existing DC drives to modern DC Drives (AB Power Flex DC series Priced) think I will get the AB 755 series since they are much cheaper then the DC. Currently working on pricing the AC motors and gear boxes.

The DC Motors look to be in rough shape and by the time we get them overhauled I think we will be better off with new AC Motors

 

[Gerry]

Something to be wary of is the difference in rotor inertia between the existing DC motors and the AC replacements. I'm not sure about general purpose motors, but with servos, like-for-like AC motor rotor inertia is significantly lower than the DC equivalent. The ratio of reflected load inertia to rotor inertia is a critical factor in obtaining tight control. So, simply considering horsepower might get you a big headache when it comes time to commission the system. If motor speed can stay within limit, then a higher gear ratio may be all that's needed.

 

[Critt]

Something to be wary of is the difference in rotor inertia between the existing DC motors and the AC replacements. I'm not sure about general purpose motors, but with servos, like-for-like AC motor rotor inertia is significantly lower than the DC equivalent. The ratio of reflected load inertia to rotor inertia is a critical factor in obtaining tight control. So, simply considering horsepower might get you a big headache when it comes time to commission the system. If motor speed can stay within limit, then a higher gear ratio may be all that's needed.

The existing DC Motor is a SM-Cyclo 5 HP, 180 VDC Arm @ 23.7 Amps can't seem to find much more information then that. How am I going to get the FL Torque or the inertia for this motor? If I use a marathon black max 5HP, 460 VAC I have .52 lb-ft2 inertia with 15 lb-ft of FL Torque....