I've Got 3 M3s

[Blind Lemon]

Good afternoon all. First post here in a long time.

Yea I have 3 M3s, a 1958, 59, 60. They were all given to me. I guess I'm the default destination for these things because of my experience with tube amps. They all have been setting a while as I don't know how to play. The 58 works really well, the 59 has an intermittent run motor problem. I really don't think its the tone-wheel related as they will free wheel for about 17 seconds after start motor is disengaged. Thanks to this board I learned about the naphtha trick.

Anyway, back to the 59. The start motor does its job getting the assembly up to speed and sometimes the run motor will take over and will run it for a long as left on and other times the run motor won't come up to speed and just turns slow. Any thoughts from the experts out there would be appreciated.

The 60 has had the least attention and isn't currently working. Concentrating on the other two for now.

Whats my intent as far as what will happen to them, I can't bring myself to hack them up for parts. I really want to get them going and pass them on to some of my musician friends. Keep one for myself and for my baby granddaughters. Hell, I may even take some lessons.

TIA for any words of wisdom.

BL

[Roger Memphis]

Hi BL -
Where are you located... might be useful if there are technical helpers, Hammond Hobbyists
or willing buyers nearby, or you decide to sell any of those M-3s.
Good Luck on the repairs !
Roger Memphis"

[Sweet Pete]

If you bypass the start motor resistor(the big one on the genny AC panel) it will most likely get up to speed.Alligator clip a lead across that puppy and give her a try!
Caveat; if the return spring on the start switch is broken always turn it off manually.....

[Blind Lemon]

RM - I'm in Tulsa, we're practically neighbors.

SP - This one? Didn't help. Whats madding is that after messing with it this morning and it sounding great when the wife got home I went to show her it was like "once a day is enough for you Buddy"

BTW: the Start motor is disengaging.

[Sweet Pete]

Have been oiled and the resistor bypass didn't work? Bad run switch? Get out the continuity meter and test that run switch.
I see an aux AC plug below the genny shelf.Extra AC loads can cause these run switches to fail. Two Leslies will kill one.

[Blind Lemon]

Could be. I had the same thought, maybe carbon buildup on the contacts. I bought a new switch for the 60, I’ll solder it in and see if that works.

BL

[Blind Lemon]

Replaced the switch and it didn't help> so I started looking at voltages to the run motor. So I check the start voltage and it looks good, on the power bus, then I checked the run voltage and it looks good at power bus before going into the motor. went through the start cycle and I'll be damned if it doesn't stay running, not as fast as the 58. 58 is the best one of the bunch. Voltage looked good.

So its intermittent and is not running at fun speed.

I have never pulled a motor off one of these and not sure if there is anything that can be done with it.

Not sure what my next step is and I will say again it takes this one, 59, as long to coast down as the 58. About 17 sec.

Any thoughts?

BL

- - - Updated - - -

Turned it off and it won't come back up again.

BL

[Blind Lemon]

Been doing some research the last couple of hours, you know how that goes mostly wondering aimlessly on the internet until I found this:

http://bentonelectronics.com/hammond...ous-run-motor/

Cool site. I read through and the motor is free, so I check continuity as he said and I'm only getting 2.7 ohms. Looking at the cloth wiring going to the motor its oil soaked. I'm wondering if thats the problem and how hard it is to remove the scanner from the motor?.

BL

[tom hoffstatter]

time to break out the hair dryer. your scanner is all gummed up, apply some heat and it'll stay running'

[geoelectro]

Been doing some research the last couple of hours, you know how that goes mostly wondering aimlessly on the internet until I found this:

http://bentonelectronics.com/hammond...ous-run-motor/

Cool site. I read through and the motor is free, so I check continuity as he said and I'm only getting 2.7 ohms. Looking at the cloth wiring going to the motor its oil soaked. I'm wondering if thats the problem and how hard it is to remove the scanner from the motor?.

BL

When checking continuity you must disconnect one side of the motor because it's wired in parallel with the power transformer. That low reading is actually the transformer winding.

Geo

[Blind Lemon]

Tom, will try it. I’ve got a brother at the other end of the lake, Ketchum. I may pull it apart if it ohms out good.

GE, thanks. Kind of figured but it was getting late. On my way to give it a try now.

BL

[Blind Lemon]

The windings in the motor is good, 90ohms and I think I have a good schematic now.

Here is what strange about the 2 different organs. The good one, 58, starts up and runs and sounds good. coast down time for the TW motor assembly is right at 18 sec. according to what I have read it should maybe be up over 20, so I started feeding it naphtha. I really don't want to pull the motor and scanner out unless necessary.

The one thats not working quite right has a coast down of about 23 sec and does not seem to come up to the rpm as the 58. wish I had a strobe tach so I could measure the rpm. It will not always maintain enough rpm to sound right or luggs down to much and I turnit off to keep from burning the motor up.

The 60 is getting fed naphtha right now waiting its turn.

BL

[Roger Memphis]

It will not always maintain enough rpm to sound right or luggs down to much and I turnit off to keep from burning the motor up.

Hi BL -
FWIW, The run motor does not "object" to a locked rotor situation. It's a synchronous, impedance-protected device like an electric clock motor. Hammonds have sat around for months with the amps and run motors on, but the TWG not turning, because of intermittent power failures, or because someone didn't know how the start sequence works, etc., etc.
Cheers !
Roger Memphis

[tom hoffstatter]

I still think your scanner is gummed up not the genny. Scanners often get over oiled. Heat that Scanner up and it'll stay running

[Blind Lemon]

Pulled the motor and scanner. Scanner was not gummed up, looks like someone in the past had it apart. The scanner spun very easy.

On to the motor.

BL