Drawbar Cleaning

[Polkahero]

I just started working on my new A-100 (cleaning tube pins/sockets, manuals, etc.), but I'm having a hard time getting the drawbars clean. I initially sprayed DeOxit in the back, then used a toothbrush to scrub the contacts after taking the top cover off. There's still several drawbars that are really noisy and even short out completely when pulled all the way out. HammondWiki mentions about coating contacts with Vaseline, has anyone tried this before with any success? I'm thinking I might have to clean the drawbar buss bars on top. Has anyone on here done that before, and what is the proper procedure? I found a thread here about performing this on a spinet model, but those are set up differently.</P>
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[Brendon Wright]

Re: Drawbar Cleaning



Hiya Polkahero!</p>

When you say short out, do you mean they lose sound when pulled fully out?</p>

As for the Vaseline, yep, surprised the heck out of me too! It actually seems to lubricate them without getting in the way.</p>

Who'd've guessed?</p>

Try giving the contacts a good rub with cotton wool and deoxit too, maybe brasso if that doesn't work.</p>

That's my 42c worth!</p>

Cheers!!</p>

-Brendoon</p>

[Polkahero]

Re: Drawbar Cleaning



Yeah, some actually lose sound when pulled all the wayout. If I wiggle the drawbar back and forth, it comes on.</P>


I've got some simichrome I could use on the contacts, but they look pretty clean already.</P>

[Brendon Wright]

Re: Drawbar Cleaning



It could be a mechanical issue of some sort.</p>

On the sprung bit of the drawbar there are two contact studs one of these is always in contact with one of the bar thingies even when you're changing settings. could it be that when pulled out to 8 this "safety" feature isn't working and there's physically no contact?</p>

There must be some reason why the signal doesn't flow. I'd say rub down the studs as well, and lube everything, it might get rid of the scratchiness.</p>

also check that the wire at the end of the bar isn't making contact with anything, and isn't looking frayed.</p>

They can break off without warning... one hanging by a thread could be pretty scratchy.</p>

[Bobmann]

Re: Drawbar Cleaning



Take a look at my video on YouTube</P>


http://www.youtube.com/user/bobmann107</P>


There is a 4 part video on cleaning the drawbars. The first 2 sections deal with the disassembly of the H series organ, so you may want to skip these.
Thesections 3 &amp; 4 are the actual cleaning of the assembly, which is similar to that which is on your A100.
If I remember correctly, the A100 drawbars need to be unsoldered for removal...but my memory can sometimes be inaccurate. I also don't remember whether these drawbars come out from the front or the back. I can look into this if you cannot figure it out. Please let me know.</P>


Depending on how bad the contacts are, you may need to use something like crocus cloth to clean them. I would be careful not to use anything more abrasive than that. However, all traces of discoloration must be removed. Cleaning the buss bars are equally important; I use a "Pink Pearl" eraser with good success, after a thorough degreasing. Again, using something more abrasive will actually make the drawbars more scratchy sounding.</P>


Vaselene or a pure silicone lube will help keep the bussbars and contacts from re-oxidizing, but I don't think it will clean a dirty contact surface.</P>


Bob</P>

[mashaffer]

Re: Drawbar Cleaning



Thanks for those videos Bob. I have an L-101 that needs some TLC and this will be a very useful reference.</p>

mike</p>

[Polkahero]

Re: Drawbar Cleaning

[quote user="Brendon Wright"]


It could be a mechanical issue of some sort.</P>


On the sprung bit of the drawbar there are two contact studs one of these is always in contact with one of the bar thingies even when you're changing settings. could it be that when pulled out to 8 this "safety" feature isn't working and there's physically no contact?</P>


There must be some reason why the signal doesn't flow. I'd say rub down the studs as well, and lube everything, it might get rid of the scratchiness.</P>


also check that the wire at the end of the bar isn't making contact with anything, and isn't looking frayed.</P>


They can break off without warning... one hanging by a thread could be pretty scratchy.</P>


[/quote]</P>


Thanks for the suggestions. How would I get access to these contact studs? There's a bunch of screws on top of the drawbar assembly. Do most of these have to beremoved to gain access?</P>

[Polkahero]

Re: Drawbar Cleaning

Okay, I figured it out today. I removed the screw that holds the wire to the contact spring and was able to remove thespring to get to the contact studs. Most of these were really discolored. I cleaned these with a pencil eraserand finished with DeOxit. Though they're not perfect, this really made an improvement. At least there aren't anymore dead notes when fully pulled out. Next steps are to replace the start switch, pedal felt, and swell pedal mat.

[Brendon Wright]

Re: Drawbar Cleaning

Well done, old boy!