drifting chassis

[wendowg]

i am having trouble with a chassis. the sweep drifts past the guards and zero. i've tried it on all of our machines, and it does it on all of them. i've tried so many different boards in it, and just recently got a new omegatek mk-70ec board into it. i've changed relays in it and checked out the wiring, all seems to be fine.

at the moment i've got it on the machine that it drifts least on. and i have adjusted the camfingers to incorporate the drifting. so i have it at the stage where it's neally stopping at the right places but on the first cycle it hits the bottom of the head pin, i have adjusted the respot so that the pin is sitting the highest it can in the table, and it still hits it. if i try and adjust the position of the first guard anymore it stops cycling.

please help

[dewbowler]

Re: drifting chassis

Just 2 minutes ago, same thing but with SS, changed to MP and everythings good! SS's are great, but some times the speed of state of the art is too fast for the machines it is hooked to?
Not electronical genius, but I believe you can adjust the timing persa of the sweep in the chassis itself, I am unclear on how it's done though? Somebody out here knows though!

[wb8yjf]

Re: drifting chassis

When a sweep drifts, it is most likely the normally closed contacts on the sweep contactor. If you have original Allen Bradley (open frame contacts), replace them with a newer style like the contactors that have the "button" at the top of the unit (you can run manually by pushing the button). The aftermarket "open" contacts suck! They just are not good! If you need more info, let me know [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img] I acn send pix if you need to see what kind I am talking about. That is more than likely the problem....also check the C1 pins for burnt, broken, or bad connections (also check the crimp job on the pins!)

G'day!
Jon [img]/content/btubb/images/%%GRAEMLIN_URL%%/usflag.jpg[/img]

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[img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[MCSS]

Re: drifting chassis

As stated already it's most likely the lower contacts. I am removing all my allen bradley relays with the siemens-allis relays. p/n 610-704-141.

I have not had one of those relays go bad yet.

Mike

[felix]

Re: drifting chassis

[img]/content/btubb/images/%%GRAEMLIN_URL%%/cool.gif[/img]

[Rep]

Re: drifting chassis

We're using the Siemens replacements as well, they work quite well for us. Last time I had the problem you describe it was pins in the C1 plug. You couldn't really see the burn marks until popped out of the plug. Using the C1 chart (thanks again "G" [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img] )I replaced ALL the pins for the sweep and it stops on a dime now. Good luck!

[Clutch Plate]

Re: drifting chassis

Originally posted by wendowg:
i am having trouble with a chassis. the sweep drifts past the guards and zero. i've tried it on all of our machines, and it does it on all of them. i've tried so many different boards in it, and just recently got a new omegatek mk-70ec board into it. i've changed relays in it and checked out the wiring, all seems to be fine.

at the moment i've got it on the machine that it drifts least on. and i have adjusted the camfingers to incorporate the drifting. so i have it at the stage where it's neally stopping at the right places but on the first cycle it hits the bottom of the head pin, i have adjusted the respot so that the pin is sitting the highest it can in the table, and it still hits it. if i try and adjust the position of the first guard anymore it stops cycling.

please help

<font size="2" face="Verdana, Helvetica, sans-serif">wb8yjf is correct, chances are it is the lower sweep contacts or a burned contactor wire. The open style are all i have with very little problems. I have the money to buy the enclosed contactors, but the open style dont give me any reason to justify the expence.

[Rep]

Re: drifting chassis

Yes, the lower contacts are the braking contacts. And also check the C1 pins. I was pulling my hair out when it was the C1 pins, changed contacts, capacitors, brushes, and finally checked the pins by getting them out of the plug and they were burned way in where I couldn't see it. Those are (for me anyway) the most common causes if the problem is narrowed down to the chassis. Keep us posted [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

[Louie_IV]

Re: drifting chassis

Well, he said he changed the relays, so I doubt it's the bottom contacts. The first place I would look is the C1 pins (as Rep said) and also compare the sweep contactor wiring to a chassis that works correctly and make sure all of the wires go to the right place. I had an 82-70 chassis that would coast the sweep on every lane, after some research I found 2 wires that were switched around. I put them where they go and the coasting problem went away.

Louie

[Rep]

Re: drifting chassis

My apoligies, I fogrot he said he changed relays. Odds are it's something simple like switched wires or bad C1 pins. Either or sounds like a good bet to me

[wb8yjf]

Re: drifting chassis

I assumed when he said he changed the relays, he meant the 3 plug in's, not the contactors. Problem is in the braking circuit, thats fer sure! [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img]
Jon [img]/content/btubb/images/%%GRAEMLIN_URL%%/usflag.jpg[/img]

[JimDorsin]

Re: drifting chassis

If you are thinking about replacing the relays, I would seriously consider the SS conversion, from Bowltronics....They are awsome and cost about the same.

[wendowg]

Re: drifting chassis

hey, thanks guys for your feedback. it was the contactor. i swapped the sweep and table contactors round to see what would happen, and the problem shifted to the table... luckily we had a spare contactor hanging round, so i chucked that in. everything is sweet now. (P.S i'm a female)

[Louie_IV]

Re: drifting chassis

Oh, sorry. SHE said SHE changed the relays. Sorry for assuming. [img]/content/btubb/images/%%GRAEMLIN_URL%%/wink.gif[/img] [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img] Anyway, I'm glad you got the problem fixed. When you said you changed the relays I assumed (There I go assuming again ) that you meant the contactors.

Louie

[Dutch]

Re: drifting chassis

As for the A/B replacement contacts being junk... A while back, I told Chad about it. He told the "powers that be" what I told him &amp; they fixed the problem. Last fall, at the Western Trade Show, Chad gave me some of the new contacts to try. I put them in &amp; haven't had a problem. If you're still not convinced, try ordering them from JCP. I've been using theirs for about 5 years without a single failure.