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Hello all,
First time poster here so be gentile.... This is going to be a long post; I have been working on this unit for several months now as time allows.
Last spring, I acquired a Bobcat 225NT from a friend that was not in running condition. The terms of the acquisition were literally get it out of my way. This machine has had a very hard life; it had spent its life in a concrete business. I am only able to read the first three digits on the serial (KKK) and by my homework puts this unit around '99 or '00. This unit has a Kohler engine.
When I first started work on this unit and after a significant amount of carb cleaning I was able to make the motor run well. I verified that the AUX side of the generator was producing "Some" power. I plugged my camper (50a service) into the generator and loaded it for about an hour to see if anything died hard; I measured around 20 amps on each leg. After it survived that test I felt that it was worthy enough to put some money into and started to restore it from the ground up. I tried to weld with the unit and learned that I could not even get a spark. After some forum hunting I checked and verified the F1 fuse and continuity through the brushes and slip rings. The rings were dirty but not scoured, the brushes did not look heat loaded and there was plenty of meat left on them. I learned that the Reactor feed wire (72) was completely corroded off the reactor. I also learned that the reactor was very "fuzzy" with corrosion. I was still a bit skeptical about spending a large amount of money on what I felt was still an unknown condition unit so I located a Stabilizer/ reactor unit on Ebay that was listed to be from a Bobcat 225D. When I looked the parts manuals up they listed the same part number so I purchased it. After it arrived I took the machine apart to install the reactor/ stabilizer only to learn that there was 100# of formed concrete in the bottom of the welder. Because of the work involved and the amount of corrosion noted on the lower pan I elected to purchase a new lower pan unit. Now I know most normal people would have walked away long before this point... but I never was known to back down from a challenge and besides, I have very little cash into this machine at this point.
So... new used Reactor/ Stabilizer install on new pan. Cleaned and painted every part removed and reinstalled, cleaned the fuel tank while it was out. It honestly looks pretty good now... LOL. Once we reassembled everything we fired it up and to our joy I now could produce welding current on all three course settings and while metering the AUX outlets I could see a change on the voltage as I adjust the Rheostat. I attempted a weld, something simple 3/16 flat steel and a 3/32 6011 rod. I could barely produce any heat at all, in any of the three settings in any position on the rheostat. After some looking and a ton of cleaning we learned that the rings/ brushes were soiled and were cleaned to fresh surfaces. The course adjust switch was removed/ disassembled/ cleaned/ reassembled. The polarity switch was also cleaned in the same manner. The F1 fuse showed good continuity but also showed a voltage drop so it was replaced to correct that issue. the Rheostat was cleaned and now provides good smooth change. We did find a significant voltage drop on the oil pressure switch of all things (13v coming in and 9v leaving). It has been corrected as well.
So... My question at this point. We are making it just a little bit better each time we play with it, almost every connection has been cleaned or replaced inside of this thing at this point. I feel that the unit is running "COLD" meaning I do not think it is anywhere near the rated amp output for welding. I am hesitant to spend $110 to have it load tested until I feel better about the output it is creating. Some data for your enjoyment... OCV is 74v, when metering the generator output to the reactor (72) with an amp clamp I do see 70-80 amps while welding. I do have an RPM of 3800 high and 2000 idle. I show 64hz measured at the aux plugs (I know it needs to come down just a touch). My leads are older but only 15 feet in length and clean connections. I am now able to run 3/32 6011 as designed but the machine needs to long arc to run 1/8 6011. Is it possible to have good measurements and still end up with poor generator output? Is it possible that the Reactor could "Choke" the current down as I am seeing? Any and all advice is welcome, I am determined to make this old girl sing again. The hour meter shows a staggering 7700hrs.... the condition of the machine when I picked it up agrees with that number.
Thank you ahead of time,
Jim
First time poster here so be gentile.... This is going to be a long post; I have been working on this unit for several months now as time allows.
Last spring, I acquired a Bobcat 225NT from a friend that was not in running condition. The terms of the acquisition were literally get it out of my way. This machine has had a very hard life; it had spent its life in a concrete business. I am only able to read the first three digits on the serial (KKK) and by my homework puts this unit around '99 or '00. This unit has a Kohler engine.
When I first started work on this unit and after a significant amount of carb cleaning I was able to make the motor run well. I verified that the AUX side of the generator was producing "Some" power. I plugged my camper (50a service) into the generator and loaded it for about an hour to see if anything died hard; I measured around 20 amps on each leg. After it survived that test I felt that it was worthy enough to put some money into and started to restore it from the ground up. I tried to weld with the unit and learned that I could not even get a spark. After some forum hunting I checked and verified the F1 fuse and continuity through the brushes and slip rings. The rings were dirty but not scoured, the brushes did not look heat loaded and there was plenty of meat left on them. I learned that the Reactor feed wire (72) was completely corroded off the reactor. I also learned that the reactor was very "fuzzy" with corrosion. I was still a bit skeptical about spending a large amount of money on what I felt was still an unknown condition unit so I located a Stabilizer/ reactor unit on Ebay that was listed to be from a Bobcat 225D. When I looked the parts manuals up they listed the same part number so I purchased it. After it arrived I took the machine apart to install the reactor/ stabilizer only to learn that there was 100# of formed concrete in the bottom of the welder. Because of the work involved and the amount of corrosion noted on the lower pan I elected to purchase a new lower pan unit. Now I know most normal people would have walked away long before this point... but I never was known to back down from a challenge and besides, I have very little cash into this machine at this point.
So... new used Reactor/ Stabilizer install on new pan. Cleaned and painted every part removed and reinstalled, cleaned the fuel tank while it was out. It honestly looks pretty good now... LOL. Once we reassembled everything we fired it up and to our joy I now could produce welding current on all three course settings and while metering the AUX outlets I could see a change on the voltage as I adjust the Rheostat. I attempted a weld, something simple 3/16 flat steel and a 3/32 6011 rod. I could barely produce any heat at all, in any of the three settings in any position on the rheostat. After some looking and a ton of cleaning we learned that the rings/ brushes were soiled and were cleaned to fresh surfaces. The course adjust switch was removed/ disassembled/ cleaned/ reassembled. The polarity switch was also cleaned in the same manner. The F1 fuse showed good continuity but also showed a voltage drop so it was replaced to correct that issue. the Rheostat was cleaned and now provides good smooth change. We did find a significant voltage drop on the oil pressure switch of all things (13v coming in and 9v leaving). It has been corrected as well.
So... My question at this point. We are making it just a little bit better each time we play with it, almost every connection has been cleaned or replaced inside of this thing at this point. I feel that the unit is running "COLD" meaning I do not think it is anywhere near the rated amp output for welding. I am hesitant to spend $110 to have it load tested until I feel better about the output it is creating. Some data for your enjoyment... OCV is 74v, when metering the generator output to the reactor (72) with an amp clamp I do see 70-80 amps while welding. I do have an RPM of 3800 high and 2000 idle. I show 64hz measured at the aux plugs (I know it needs to come down just a touch). My leads are older but only 15 feet in length and clean connections. I am now able to run 3/32 6011 as designed but the machine needs to long arc to run 1/8 6011. Is it possible to have good measurements and still end up with poor generator output? Is it possible that the Reactor could "Choke" the current down as I am seeing? Any and all advice is welcome, I am determined to make this old girl sing again. The hour meter shows a staggering 7700hrs.... the condition of the machine when I picked it up agrees with that number.
Thank you ahead of time,
Jim
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