Polar 71 paper cutter blade doesn't move, but the foot moves perfectly - help?

[nelsonind]

I recently purchased a Polar 71ST paper cutter, serial number 4351413. I understood the cutter worked before we moved it in - apparently, I was wrong. I connected the paper cutter to 3 phase electricity (as before) and the clutch now moves clockwise. The motor spins up, the back gauge works perfectly with the MicroCut Jr., the hydraulic clamp moves down, but the cutting blade remains stationary. I cleaned and adjusted the limit switch above the solenoid. If I put the limit switch too high, the clamp doesn't move either. The pawl or bar moves up when the cutter buttons are pushed to enable the transmission to turn. The rings around the clutch have been cleaned and the carbon brushes appear to be in good shape. I opened the front right access door and saw the bar connected to the cutting blade is at the 10 to 11 O'clock position putting the cutting blade at the very top. On the transmission, one of the switches is pushed in and the other switch is still open. I cleaned the contacts on the circuit boards with contact cleaner and very lightly with fine sandpaper. I measured 42 volts DC between the metal rings around the clutch as the cut buttons were pressed at the same time. Could the clutch be rusted together or something? Is there a manual which shows what voltages are supposed to be where ? Suggestions? THANK YOU in advance. Curtis

 

[old guy]

any error messages? polars are usually pretty good at diagnosing themselves. on our 78 there is a latch that would catch the blade in a catastrophic failure. this has to be lifted by a solenoid to a sensor before the blade comes down. we broke a bracket once and the solenoid operated but the latch didnt lift so the blade wouldnt come down. right side of the machine under the cover alongside of the blade.

 

[nelsonind]

Thank you for your suggestion! You are on the right track. No error codes and no computer screen either, except on the micro cut junior. It is pretty old, 1973, if I understand the serial number correctly. The solenoid pulls up the latch and the transmission should be free to pull the blade down. However, that transmission part doesn't move. I understand the clutch is electrical, but I don't know how to check what voltage brings in the clutch and how to check it.

 

[PrintingFools]

One time we had a cutter and everything worked fine. Turned on and sounded great. But we could not get the blade to move or come down. Turned out nothing was actually wrong. One of the employees had set it to "Change Blade" mode on accident. Once that was turned off it ran fine.

 

[printing656]

We had a similar issue once on a Baumcutt. It happened after it was shipped across the country. Turned out a fitting and come loose and wrecked the threads on a pipe inside of the hydraulic tank reservoir. All it took as a new threaded, hydraulic line.

 

[nelsonind]

I like the way you are thinking... Frequently, it is a very simple solution. However, I'm told you need to turn off the machine and use these special threaded tools through the clutch in order to change the blade. I'm unaware of a switch on this cutter to change the blade. Neal from Compound Manufacturing was kind enough to share the parts manual for the Polar 71 / 72. I can easily share it if you need it.

 

[nelsonind]

Jeff from Bindery Tech -http://binderytech.com/ was extremely helpful and I'm grateful to his help.
He has many years of experience and has the parts to repair them.

I finally fixed the cutter and I will share the solution too as it may help others.
Walter from Hicks Brothers Printing Equipment suggested that I release the electric clutch from the transmission and turn it by hand with the power OFF.
I found the tool here:
http://www.compoundmfg.com/index.php...roducts_id=104

I didn't want to spend the $80 plus shipping (2 required) and time so I made my own.
I went to Home Depot and purchased 2 8mm Hex bolts by 110mm length and used 4 washers and some oversize nuts to make up the difference. The OEM tool used for this has a distance of 4.0 inches from the shoulder to the end of the threads. I probably should have purchased 100mm length, but I didn't want to be too short.
As I turned the bolts in, the clutch popped loudly. Apparently, the clutch plates had become rusted or oxidized to the matching surface. I turned the cutter through one cutting revolution by hand, removed the bolts and to my amazement, the cutter worked perfectly. That explains why the 46 volts was measured at the copper rings and the clutch was not disengaging - it was rusted to the matching plate. Now it works great.
Thank you very much for your help!
Awesome!
Thank you!
Curtis Nelson

 

[chock]

Hi i am happy that you fix it the machine
The limiit switches b22a+b with cam plastic in rear gear box, with the time they lose adjustment .
By that reaso you must sure the Knife will be in the most Higher Up position, in order to the Safety bolt Solenoid release in time
and send the +42Vdc to the electromagnetic Clutch(Not hydraulic).
Attached is schematics diagrams for Polar 71/72 , that i did for some emergency.
Blessing
[email protected]
cell+WhatsApp:+505 88611441

 

[chock]

see the complement
Blessing
[email protected]
cell+WhatsApp:+505 88611441