HELP opening & repairing Foot Pedal

admin

does anybody know how to open a Amptrol k870 Lincoln Foot Pedal .?  im not seeing any fastners anywhere on the pedal .........bummed out , it's not lighting the torch or the gas solenoid . A little shop mouse made a nest in it bout a year ago , but i blew all that out and its worked fine until now , just wanna check inside . It will strike an arc in stick mode ... wen i switch it to tig mode the gas will run for its 9 second postflow , but the pedal will not activate anything. Attached Images        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Let me take a look at mine. I'll tell you as soon as I can.Lincoln Idealarc 250 (circa 1962)Lincoln Weldpak 155 w/Mig KitLincoln Squarewave TIG 175
Reply:Okay, I just looked at mine. You are going to have to peel away the anti-skid material on the bottom. I can feel a couple of 'soft spots' under it. One of the oldest tricks in the book. You can buy more of that stuff at HD or Lowes if it doesn't come off cleanly.PapaLincoln Idealarc 250 (circa 1962)Lincoln Weldpak 155 w/Mig KitLincoln Squarewave TIG 175
Reply:hi papa , thx for replying so fast. I peeled that away , and to my suprise no fastners...there were two little holes , i shined a flash-lite and could see the inerts a little , but no fastners still...im wondering about peeling the top now , but i dont feel any soft spots         thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Yeah, I don't think there's anything under the top. I thought that large soft area in the bottom center would reveal a way to perhaps remove the pedal assembly.Will the machine do a scratch start without the pedal plugged in? Just to verify it really is the pedal that's hosed up.Lincoln Idealarc 250 (circa 1962)Lincoln Weldpak 155 w/Mig KitLincoln Squarewave TIG 175
Reply:I'm looking at the schematic. Unplug the cable, and if you have a continuity meter, check between Pin D and E for continuity when you press the pedal off the minimum position. The switch can probably be replaced pretty easy.PapaLincoln Idealarc 250 (circa 1962)Lincoln Weldpak 155 w/Mig KitLincoln Squarewave TIG 175
Reply:Hi, To remove the top of the pedal on my Lincoln K870, The 2 pivot pins that stick out, One on each side are spring loaded. Just push them inwards and the top comes right off, Great little simple attachment idea,All thats in there is a rack arrangement operating a little potentiometer. I honestly do not know why pedals are always sky high prices, The pedal for my Lorch machine is priced at around £450-00.Last edited by gordon stephenson; 09-10-2011 at 06:27 AM.Lincoln SP-170 MigHypertherm powermax 45Lorch T220 AC/DC TigButters FM 215 synergic MigKemppi 180 adaptive mig RULES ARE FOR THE OBEDIENCE OF FOOLS AND THE  GUIDANCE OF WISE MEN.
Reply:Gordon is absolutely right! I just popped the hood on my pedal and took a picture for the OP. The microswitch is what you need to check. Maybe the pin that hits the actuator fell off. The switch is easy to find if you need a new one. Attached ImagesLincoln Idealarc 250 (circa 1962)Lincoln Weldpak 155 w/Mig KitLincoln Squarewave TIG 175
Reply:i got out the multi-meter , disconnected the pedal from the unit and noticed the center bottom pin looked slightly bent , straightend it , put the plug back into the unit and hand tightend all the way down as usual......but , still the same problem.  I had noticed the plug was still 'wiggly' behind the nut , grabbed sum channel locks and was able to get half dozen mor turns befor bottoming the nut. Flipped the machine on tapped the pedal , post flow and arc   happy camper again.....BUT , i notice ther's still sum 'wiggle' in the plug behind the tightening nut ( where my hand is in the picture it still wiggles ) , so the problem may still be underlying. But hopefully this will help others , thanks papaHarley and Gordon Stephenson for your help. Papa , i was worried about opening the pedal ( thot all the parts would fall out )  did it go bak together easily .?  bet theres a place to get the parts cheap because i know this pedals mor than 3 bills Attached Images        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Be careful twisting the shell unless you loosen the clamp and keep the cord still. You can twist the wires off of the plug inside.
Reply:Originally Posted by woi2ldPapa , i was worried about opening the pedal ( thot all the parts would fall out )  did it go bak together easily .?