Finally got a console - Hammond BC & HR40

[ArnoldLayne]

The VERY day I found this on Craigslist the Organ Forum went down. For some reason I cannot login or get a reply from the webmaster as to why. I can sit on this no longer so I am going to post here. Okay?

There is a problem with the chorus generator I believe I have attributed to the run motor:

1.) the generator spins freely

2.) It starts with the start motor and I can hear it working but it slowly spins to a stop upon turning it to run.

3.) turning the run switch on without starting the generators and the generator spins freely. It is not supposed to and my M3 does not performing the same test.

 

I want to pull the run motor from my 1949 M and replace it in the BC. If anyone has done this before and can give me a heads up on how best to do this I would appreciate it greatly.

 

 

 

http://img254.imagevenue.com/loc458/th_82893_HammondBCHR401_122_458lo.jpghttp://img31.imagevenue.com/loc173/th_82896_HammondBCHR402_122_173lo.jpghttp://img239.imagevenue.com/loc116/th_82901_HammondBCHR403_122_116lo.jpg

http://img207.imagevenue.com/loc30/th_82924_101_5198new_122_30lo.jpghttp://img157.imagevenue.com/loc505/th_82954_101_5202new_122_505lo.jpg

 

[NewImprov]

Can't answer your question, but what a beauty! Good score!

[B3Nut]

Do both generators spin freely? Is the chorus generator still in the organ? Also, do the preamp tubes light when you turn the organ on?

 

Gorgeous BC, BTW.

 

TP

[ArnoldLayne]

Thank you very much. It appears to be exactly what the seller claimed - from a funeral home in Hart, Mi. The bass is unreal and the highs are strong and crisp. The key response is like no Hammond I have ever played - almost bouncy. The inside is clean as a whistle...$550 out the door with pedals, bench (not original) and the HR40 is just as nice.

 

Both generators spin freely. The organ plays perfectly except for the chorus generator does not stay running after the run switch is on. You can hear the chorus sound if you play quickly after starting but the sound winds down in pitch as the chorus generator slowly spins to a stop. The main generator stays running no problem.

 

I was told the chorus (or main for that matter) generators should NOT spin by hand if you turn on the run switch without starting the organ. The chorus generator DOES spin by hand with the run switch on.

 

I did this same test on my working M3 and the generator does NOT spin by hand with the run switch on (skipping the start process).

 

I believe all run motors are the same which is why I want to pull the one from my old beat up M (not the M3...I still like her).

 

I was hoping someone could give me some "do this...don't do that" advice before I started the process.

[mate stubb]

You should never ever fire up the run motor without the generator spinning. It is very low torque and will rapidly burn out.

 

It could be that your run motor on the chorus generator is bad. Or a wire is broken and it is not getting any juice.

[Meisenhower]

+1. to what Mate_stubb said.

 

That is exactly the problem I had with my BC when I brought it home. It turned out to be a bad connection going to the run motor on the chorus generator.

 

Given everything you have described, it is most likely one of only two things.

 

1. The run motor itself is burned out.

2. The run motor isn't getting power.

 

Start there. You can put a meter on the motor and see if there's anything happening. There's a procedure for this test and it is on the net, if you search. I have a hard copy "somewhere", but it may be in storage. If I can lay my hands on it, or I find the procedure, I'll post it.

[darc68]

Great score man. Good Luck w/ it.

[ArnoldLayne]

Interesting about the run switch as I got that test from the Benton Electronics web page. I only had it on for a second. They also had a resistance check that did not work out for me either. It said the run motor in the BC was bad but also said the run motor in my M3 was bad and it works fine.

Maybe this is the same page you are thinking of Meisenhower?

http://www.bentonelectronics.com/runmotor.html

 

 

[MoodyBluesKeys]

The problem with their description of how to read the resistance of the run motor is that the preamp power transformer also connects to the terminals, making any reading with an ohmmeter be the parallel of the motor windings AND preamp power transformer primary.

 

Only accurate way I found to read the motor coils is to disconnect one end of them from everything. In over 25 years of servicing (Hammonds and others), I don't ever remember having to replace a run motor - but it can go bad, like all mechanical/electrical parts.

 

An additional possibility - especially if ONE of the two coils is open - is that the generator has more friction than it should (sticking bearing most likely) and is loading the motor too much. The start motor generates more torque than the run motor, so it sould still start OK.

 

[Meisenhower]

Arnold, that is not the same page I remember, however the procedures are pretty similar but not exact and Moodyblueskeys is right about testing the motor coils.

 

I'll look and see if I can find my stuff, as my hammond tech validated it as the "correct" way to test a run motor.

 

 

 

 

[mate stubb]

Allow me to tell my burned out run motor story.

 

My B-3 in the basement is on a switched power line. It has rubber isolation washers on the generator mounts and runs completely silent. There is no power light as on some of the late models.

 

As you have already guessed, I switched off the power one night with the organ still running. Next day, turned on the power, and didn't realize the organ was switched on.

 

The run motor of course could not turn the generator from a stop by itself, but it tried until it died.

 

Moral: don't put your organ on a switched power line!

[ArnoldLayne]

Also, be careful not to break the wicks when removing the run motor from your M.

 

Oops...too late. I broke 2 of three. One was for the vibrato scanner but I will not be needing that one. The other was the one at the back of the motor for the axle that sticks out slightly.

 

Can I replace with regular thread? I can't really see how it connects to the axle.

 

Also I tested the M run motor after I disconnected it and got about 90 ohms like the Benton website stated as okay.