non-working BobCat 225

Date 01-31-2011 20:53

I have a gentleman in my area who has a 1993 BobCat 225, with 613 hours on it, always serviced etc. The story I get is he was welding with it one day, cold in his shop, didn'nt think aircompressor was plugged in, then all of a sudden the air compressor comes on, his arch goes way down and hears a buzzing noise. Now, He says the 16 HP Onan enfine runs fine, but no welding output, generator doen't work. He feels he overloaded it, Has asked around and been told that on older Miller generators when they go out it is almost impossible to get parts and not worth trying to fix. He bought another welder, and wants to sell the Bobcat cheap. Anybody familiar with this type of BobCat problem? Worth trying to fix, Parts? I really value all your advice.

Thanks

Dave in Iowa

By Cactusthewelder (*****)

Date 01-31-2011 23:49

All you need is a Boat with an Anchor Line ! Wah Lah ! Now you have a Boat Anchor

By David Edwards (*)

Date 02-01-2011 00:44

I take it that that's a NO on trying to fix it.

By Cactusthewelder (*****)

Date 02-01-2011 01:05

It could be a simple fix. I was just Razzing you about a Bobcat. It will be a good welder for you as long as you are not trying to become a Rig welder with it. It is ok for Farms, Homeowners Etc...

By David Edwards (*)

Date 02-01-2011 18:13

No pipelining for me, too old to acumulate the years of experience needed just to become proficient in that area, have a plan for a small welding repair shop, mainly agriculture, aluminum flag poles and metal art. Hopefully to supplement SS in a year or so.

By DaveBoyer (*****)

Date 02-01-2011 03:31 Edited 02-01-2011 03:46

Chech this manual:

http://www.millerwelds.com/om/o431g_mil.pdf

Check fuses F1 & F2 on pagees 7-1 & 10-4

Check F1 in particular, 25A 32V. These are suggested spares.

Check brushes & slip rings. check for continuity between slip rings with brushes insulated from slip rings [ put a strip of paper between brushes & slip rings].

If the above are OK, check R1, R2 & SR2.

By David Edwards (*)

Date 02-02-2011 00:22

Will lok at machine this weekend if we can dig out of the snowstorm. Owner also said he put a meter on it and said no voltage is comming of of the armature at all. He figures it's a bad rotor, which is no longer available and almost impossible to find. Your thoughts?

By Cactusthewelder (*****)

Date 02-02-2011 00:46

I would give Kaye a call at Bills Welder Repair 405-232-4799. She can fix ANYTHIING related to Welders !

By DaveBoyer (*****)

Date 02-02-2011 03:43

On a unit like this, voltage is sent to the armature through the fine output control [all the parts I mentioned];

The armature does not make power. The armature becomes magnatised, and the power comes from the stator.

This is pretty much the opposite of how a SA200 works.

By raftergwelding (*****)

Date 02-02-2011 04:16

those machines are to expensive to fix it sounds like a pc boadr to me but im not keen on the machines a pc board for that machine is 800 i say pull the motor off and scrap the rest surely he bought a lincoln this time around

By Regmanager (**)

Date 02-02-2011 14:57

Normally on a Bobcat the problems are a minor fix. Not always, but if the armature and generator are good it's not an expensive problem. BTW, there are no PC boards on Bobcats, only an idler module and this is not related to this current problem. Hope this helps.

By David Edwards (*)

Date 02-03-2011 02:38

The sellers comment to me was that he put a meter on the unit,(said he did not go into the unit) and that there was no power comming from the armature, therefore he feels the rotor is no good and parts are no longer obtainable. I'm going to try and look at the machine this weekend accompanied by a journyman electrition and check the parts mentiioned above. He says the motor works fine, but no welding ability.

Thanks

By NMWELDING (**)

Date 02-03-2011 06:40

Also get on the Miller Welding Discussion Forum and state your problem. There is a fella on there from Canada who works on Lincoln and Miller welders. He`s really good at helping trouble shoot problems. His name on the forum is Cruizer.

By Regmanager (**)

Date 02-03-2011 14:40

You can do a quick OHM check on the rotor to see if it's good. You don't need it running to do this. Power is fed into the rotor to power the generator. It might not have power going in to start the process. Like I said, normally these are not hard to find the problem. Do you have a welder repair shop that someone can give you an estimate? We normally charge $65 for an estimate but that's waved if the customer fixes it. Well worth spending the money and have someone that works on them for a living look at it. JMO.

By Cactusthewelder (*****)

Date 02-03-2011 15:38

Here is the Link to Millers Website. They should be able to answer any Questions

http://www.millerchina.com/