Removed broken stuck keyboard axle shaft.

[32251]

Needed to remove the keys. End of the axle shaft is broken off. I have done a few of these and using a different technique…..depending on the way the key and keybed is made. This is a little Hohner 12 bass unit. The key sits completely in a wooden channel. If over the life of the instrument the key channel warps even a very small amount, the key will not function and you will need to remove and sand the key sides to fit again. When the axle is frozen then you have to be invasive. Every 5 keys or so depending on how bound up the shaft is, remove a white key top…easy with some heat….and take a very thin hacksaw blade and cut the axle on both sides of the key. You will only remove a very tiny amount of wood on the key/keybed. There is plenty more wood mating surface to keep the key inline. Then take a long rod the same diameter as the shaft and drive the old axle in towards the vacated key slot and snip with wire cutters many times till you get that section of axel out. Repeat till you are at the last keys. Use a 1/4” Forster bit and drill a nice clean hole in the opposite side of the keyboard frame. Easy to put a nice celluloid plug in later. Then use a little smaller drill to hit the end of the old axle. Then tap the rest of the axle out as I have pictured. Axle shafts can be so frozen in place after decades. The wood is shrinking around the axle all this time. When the shaft goes through every key and all the key bed sides…..it can become locked in place. There are different key/keybed relationships depending on the manufacturer. Take your time. You will be able to get it all out….a piece at a time. Replace with a new shaft.

 

[Dingo40]

Needed to remove the keys. End of the axle shaft is broken off. I have done a few of these and using a different technique…

Thanks for sharing, 32251!
Very interesting!
There was still another method discussed some time ago . That involved essentially shorting a car battery across the ends of the axle rod and the heat generated would loosen the rod.
I wonder if anyone's been game enough to try this technique recently ?
Seems it would save a lot of cutting!

 

[32251]

Thanks for sharing, 32251!
Very interesting!
There was still another method discussed some time ago . That involved essentially shorting a car battery across the end of the axle rod and the heat generated would loosen the rod.
I wonder if anyone's been game enough to try this technique recently ?
Seems it would save a lot of cutting!

If you heat the axle it will expand. It’s in there so tight already, it won’t budge. What keeps the expanded metal rod from cracking the wood? The only times I have had to resort to cutting up the rod is when the rod tip is broken off and nothing to grab. Makes you appreciate the rods that go through metal fittings and are so easy to pull even after decades.

 

[Dingo40]

What keeps the expanded metal rod from cracking the wood?

Good question!
I don't know, but the technique was published in a handbook on how to repair accordions.
Personally, I'm not game enough to try this, but there it is!
I believe this was the book quoted:

Accordion Repairs Made Easy

acordeonesdumboa.es

See the heading:
"SPECIAL METHODS FOR REMOVING TIGHT AXLES
Heating axle pins with electric current."
In the index.
Another reference to it:

http://www.musicforaccordion.com/boutique/inform/reuther/

 

[Dingo40]

Well,
Waddaya know?
Someone has actually made a Facebook video clip of the 12v car battery technique and is claiming success!
See here:
Read the associated video notes on Facebook:
Don't worry if it says "can't open ", just barge ahead: it'll open anyway!

 

[Snoopz]

Wow. Just wow. Car batteries, especially the larger ones, are extremely dangerous, since they can deliver a huge amount of current for quite some time, before possibly exploding and showering the vicinity with battery acid. Luckily the guy in the video used a tiny one.

This axle rod probably only has a couple of milliohms resistance, allowing tens, if not hundreds of amperes to flow. I would actually worry more about lighting the accordion on fire than about the stuck axle.

 

[Dingo40]

And,
Here's our member Kimric Smythe:

removing an accordion axle rod kimric smythe - Google Search

 

[Dingo40]

. I would actually worry more about lighting the accordion on fire than about the stuck axle.

I appreciate your point!
You could easily toast the accordion, never mind the axle!

 

[henry d]

I believe that Mr Reuther is pretty clear on the "for a few seconds while observing closely" aspect. It is also primarily intended to largely address axles stuck as a result of damp hence swollen wood- which an overheated rod would address pretty directly. Given the coefficient of expansion for steel it seems sort of unlikey that the dimensional change in the diameter of the rod would be sufficient to crack the wood; were dimensional change going to factor in it would be more likely to cause slight rod movement as the length changed. That slight movement might well assist in "starting" a frozen in place rod when the rod cooled back down.

That said- discharging lead acid batteries outgas hydrogen which can result in a nasty explosion involving shards of hard rubber battery case in a cloud of battery acid droplets (H2SO4- sulfuric acid). People jump start cars all the time (using jumper cables of really heavy gauge wire. They surely do here in scenic Minnesota during the winter- and based upon the paucity of reports of people being dissolved by pillars of flaming gas and acid I've got to figure it's a rare catastophe. Too thin a cable and the cable would heat vice the rod; almost certainly not a good thing. The big risks are inadvertantly placing the cables crossed -negative to positive, poaitive to negative- which would do a bit of no good to much of the cars electronics- or arcing/sparking at the battery terminals when clamping on final cable to complete the circuit (one makes the final connection to a well grounded metal component well away from the battery to avoid battery gas ignition). If nitwits - and I surely count as one- with hooded parkas, scarf shrouded faces, and thick gloves huddled over the engine compartment of a disabled car- usually in the dark- can handle it I figure it's probably doable- if with caution- on a workbench.

On the other hand I'm not doing it anytime soon myself and:

You could easily toast the accordion, never mind the axle!

Accordion my Aunt Mable- you could easily toast yourself.

Henry

PS Nice OP notion on using a thin saw to sever the axle in situ allowing it to be driven out piecemeal. Same same technique in dealing with stuck hinge rods on saxophones- though the slight longitudinal play created needs to be addressed in that case.