Hohner Pianet M Bent Reeds

Started by SRKSF, November 09, 2022, 04:00:21 PM

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SRKSF

Hello everyone, long time reader first post.
After years of searching i was lucky enough to find a lovely Pianet M in a decent condition for almost free. Came from a smoke-pet free, temp/humidity controlled house. Almost intact, corrosion & rust free, one of the most well aged keyboards I've ever met. I collect and repair gear, epianos, organs and stuff for 15-20 years now.

After a common full cleaning process (dust off,keys,pads,reeds), late at night, i made a stupid mistake. While re-assembling back the bottom base units (reeds metal ,bottom wooden plate and keys) i put the wooden plate backwards, installed the screws and left like that for about a week in order to repair the amp cabinet later.
So the keys were sitting lifted up and the rear lever hammers/pads lifted down, pushing down the reeds for a whole week.
I only noticed today when finished the amp repair.
Put the wooden bottom plate back in right position and obviously realised some treble notes to be "dead" (pads didn't even touch the reed) as a result of reeds being bent(?).
Is there a way i can fix this?
Could the reeds be recovered back in their previous position by themselves time passing, or what if i slightly bend them back upwards with the help of smthng inserted underneath against pushing up?
I know i can bend the hammer lever ends a bit (common quick fix suggested by VV and many others), already done to one note and did the job indeed, but those notes were playing fine before my mistake, so I'd like to return back to previous original position if possible.
I'm screwed up.

Jenzz

Hi .-)

Since the treble reeds are very stiff, chances are that the hammer levers are bend in that area. The material is relatively soft to allow bending / adjustment.

BTW: I remmoned a re-cap job on the wholw instrument. Esp. the 'golden' Siemens caps are prone to leakage after nearly +45 years. Also keep in mind that the power amp chips are very hard to find.

(...last Pianet M i had in for service had a blown power amp chip + the speaker was fried due to a defective cap)

Jenzz
Rhodes tech in Germany
www.tasteundtechnik.de
www.spontaneousstorytelling.net

VintageVibe 64 ACL + Type 120 (DIY MXR MX-120 clone) Env. Filter, EHX SmallStone, EHX NeoClone

Adams Solist 3.1 Vibraphone

In the Past:
Stage 73 Mk1 (1977)
Stage 88 Mk1 (1975)
Stage 73 Mk2 (1980)
Stage 73 Mk2 (1981 - plastic)
Suitcase 73 Mk1 (1973)
Suitcase 73 Mk1 (1978)

SRKSF

#2
Hallo Jenzz, thanks for reply. Yeap i know, i an audio engineer and repairman too, i'm into electronics, röhren amps and stuff. Mine had a fried ESM532 and a defekt RC4558 ic. Was pretty hard to get the first, found a last one left at an old repair man's cave.
Full recap needed too indeed.

As you come from Germany,  do you know how did mr Werne Bothe produce those T/M pads?
Seems it's a kind of silicone rubber square profile but i guess special attention and experiment is required to find the exact one with appropriate similar sticky properties.

About my bent reeds issue, specially treble ones, do you think it's an un-reversable kind of situation? I tried to slightly bend them back (very carefully) and bending the lever ends a bit in the same time, seems it worked.

Jenzz

Quote from: SRKSF on November 10, 2022, 05:22:55 AMAnother German related subject I'd like to discuss, is about those, almost original, T/M/Duo pads Mr. Werner Bothe was producing, but not anymore. I'd like, for future reference, to be able to produce/get my owns too as i have easy access to labs and small factories with CNCs, Laser cutters/3d printers,plastic molding machines etc. Seems it's a kind of silicone rubber square profile but i guess special attention and experiment is required to find the exact one with appropriate similar sticky properties.
 

Hi :-)

The pads fron Werner Bothe (he is just 30km from me) were made of the original casting compund. But for some reason, he made the pads bigger than the originals (more depth).

This causes them to stick not as good as the originals because of the slight bending of the reed, so they won't touch the reed at the same pressure with their entire surface.

Jenzz
Rhodes tech in Germany
www.tasteundtechnik.de
www.spontaneousstorytelling.net

VintageVibe 64 ACL + Type 120 (DIY MXR MX-120 clone) Env. Filter, EHX SmallStone, EHX NeoClone

Adams Solist 3.1 Vibraphone

In the Past:
Stage 73 Mk1 (1977)
Stage 88 Mk1 (1975)
Stage 73 Mk2 (1980)
Stage 73 Mk2 (1981 - plastic)
Suitcase 73 Mk1 (1973)
Suitcase 73 Mk1 (1978)

SRKSF

#4
I see. Thanks for the reply Jenzz.
I finally managed to solve the issue with bent reeds by slightly bending down the lever ends holding the pads.
About something that came up after this: after bending the levers, because of the pressure applied, three keys now sit a bit lower than the others (probably little rubbers under the keys has moved from their position / bushings or smthng similar). I have to remove them to fix their action?
If that helps, the keys are leveled when two middle underneath screws supporting the wood base aren't tightened, they get low only when i tighten those screws. But when first happens(loose screws-leveled three keys) then pads don't make contact with reeds. In general, do your Pianet T/Ms keys sound when underneath screws are unscrewed or is it how it works to have those screws fully installed so for the instrument to sing?