Author Topic: Im lost restoring mark II 73  (Read 204 times)

Offline Vexeta

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Im lost restoring mark II 73
« on: March 19, 2020, 07:28:09 AM »
Hello, my name is David and Im trying to fix some problems on my 1979 mark II 73 Rhodes.

Ive used it since 1998 to learn classic piano but never fixed the problems it had when my parents bought it. After searching a bit on the forum I didnt find some of the problems Im having.

-First one I guess is a common one. The action is heavier the lower you go on pitch. The treble register is playable.
-Some of the higher notes hit on the damper metal piece and make a loud sound. You can even hear it at low volume.
-Some treble damper fets were out of place because of the hammer hitting the felt. I glued them in place to stop the notes from ringing.

Now that Ive done that 2 or 3 treble keys dont even hit the tines and fail to make a sound and cant figure why.


I'd thank you if you could point me in the right direction, maybe to an old post that I  should read or to some problem in the piano that I didnt notice.



Thanks in advance and forgive my english. Its not my first language and it took a while to write this and learn some terms I didnt use before to make it easier to  communicate (damper, action)



https://imgur.com/a/YZIahlA
https://imgur.com/a/zyYiJSi
« Last Edit: March 19, 2020, 08:01:53 AM by Vexeta »

Offline sean

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Re: Im lost restoring mark II 73
« Reply #1 on: March 19, 2020, 01:41:06 PM »

How can you be lost when you have come to the exact right place: the ep-fourm!

I will bet a nickel that all of your problems are related to escapement and shims on the harp supports.  It sounds to me that your escapement is set too high.

Take a look at the service manual http://www.fenderrhodes.com/org/manual/toc.html

Specifically, chapter 4 - Escapement:  http://www.fenderrhodes.com/org/manual/ch4.html#4-1

There is a technote too: http://www.fenderrhodes.com/service/escapement.html

Your piano probably has wood strips glued to the top of the aluminum harp supports.  There could be black paper shims on top of the wood strips.  You may have to remove the black paper shims or even the wood strip, but first, try to see if you can adjust the escapement sucessfully with the tonebar screws.  Ideally, you want the tonebar to be 3/8' or 9.5mm above the wooden harp surface. 

When you adjust the escapement screw, you also have to re-set the timbre screw, so that the tip of the tine remains in the ideal location near the tip of the pickup.  Read the service manual a few times, and play with a few tines, and you will get the hang of it.

You should also watch Chris Carroll talk about escapement: https://www.youtube.com/watch?v=hSvOh8oMIUw

Sean


Wow!  The Rhodes SuperSite has a new look!  http://www.fenderrhodes.com/service/manual.html
« Last Edit: March 19, 2020, 01:46:23 PM by sean »

Offline Vexeta

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Re: Im lost restoring mark II 73
« Reply #2 on: March 19, 2020, 03:23:28 PM »
Thanks for you answer! This is feeling too dense to fully understand.

Reducing the scapement would make every key easier to play, but then if its too small on the treble I could increase it by tilting those tonebars?

If i have to tilt them to make it easier, wouldn't it be imposible to "aim" it to the ideal location on the pickup? I know that pickups can be moved but only to change volume.



I'll keep reading the service manual and see what I get.



Offline sean

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Re: Im lost restoring mark II 73
« Reply #3 on: March 19, 2020, 06:10:33 PM »

It will be easier to understand once you get fiddling with it a little.

Before you mess with the shims, make a few experiments:

Pick a key where you believe that the hammer is striking the end of the damper.  Lower the tine down (tighten the screws so that the tonebar gets closer to the wooden harp) until the hammer can't swing high enough to whack the damper - it should stay clear of the damper the whole time.  If you get lucky, you will only have to lower the tine and tonebar a little bit (removing shims from the harp supports will do this lowering too).  If that works, then move the tonebar back up to where it was, and remove some harp support shims!

Now, occasionally there were Rhodes pianos that come out of the factory with the unlucky situation where you can't get this fixed without clipping off a mm or two off the damper spring arms, but that should be a last resort.  You could also try bending the damper arm so that it has a greater (to effectively shorten it), but this risks ruining your damper setting.  (You might have to re-adjust the dampers if you drastically change the escapement anyway.)

I don't like to bend the damper springs much at all... as soon as I start messing with it, I have trouble getting it back to where I started.
Yes, I agree that there is an overwhealming fiddly balance there, but you won't solve it until you start fiddling with it.

If there are a few shims on the harp supports, it is easy to unscrew the harp, pull out the shims, and try the difference.  Before you unscrew the harp, make marks on the harp and the harp supports so that you can find the exact position that you started from.  You might want to change the strike line, but you might not.


Sean

Offline Vexeta

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Re: Im lost restoring mark II 73
« Reply #4 on: March 21, 2020, 01:05:19 PM »
Ive been playing the whole day, its been years since the last time.

Theres a single thick shim over the aluminum harp supports

https://imgur.com/J62oU4D


My concern about lowering the whole harp is that maybe it will fix the scapement on the bass but it would make it too small on the treble side. I'll upload a video to show how hard is to play on the bass notes, Treble are kind of fine, but then I see some people doing glissando and there NO way Im doing that even on treble and thats the part I think its playable.




Offline sean

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Re: Im lost restoring mark II 73
« Reply #5 on: March 22, 2020, 02:27:00 PM »

David,

You can remove the wood strip on the bass side and leave it on the treble side if that would fix your escapement problem. 

Try to measure what the exact escapement is on the bass keys.  That means you have to measure from the top of the hammer tip to the bootom of the tine surface when the key is depressed.  This is a really difficult thing to measure, because every part of the piano is in the way.  I use the tail end of my dial calipers to measure from the tip of the hammer to the top of the tine, and then subtract the thickness of the tine.  But it is a fiddly inexact-but-close-enough method:  it is hard to keep from pressing the tine down with the calipers, and hard to know when you are barely touching the hammer tip.  But three-digit accuracy is not required.

Another method is to cut an index card to create a feeler gauge; but instead of using the thickness of the card, use the width of the strip to measure.  Cut a half-inch wide strip of paper, and then either fold it or use a piece of tape as a handle.  Put the half-inch wide strip to extend below the tine, and push down the key.  If the hammer touches the paper, then you can cut the paper thinner and thinner until the hammer barely doesn't touch anymore.  Then measure the width of the paper, and that is your escapment measurement.

Both methods are fine when the tonebar is twisted, but the flat tonebars are inconveniently in the way.  So just measure the escapement at the bass end of the piano, and try to eyeball a guess at the treble end.

If the escapement at the bass end is close to 3/4", then you would almost certainly want to remove that wooden spacer from the top of the harp support.  It will be glued to the aluminum, so sometimes they are a bear to remove.  Some folks have said that it came off easily.  I don't know if anyone has tried using a clothes iron to heat the strip and soften the glue. 

If the escapement is less than 1/2" of an inch, you might remove the wooden strip, and then add cardboard (poster board, or a cut-up file folder) spacers on top of the aluminum harp support to get the escapement into your preferred range, and then fine tune with the screws at the end of the tonebars.

On the treble end, the escapement is remarkably close to zero by eye.  You have said that the treble notes are playable, so you may be able to leave the wood strip alone, or you could remove it, and build that side up with layers of paper as well.

Sean

« Last Edit: March 22, 2020, 02:29:01 PM by sean »

Offline sean

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Re: Im lost restoring mark II 73
« Reply #6 on: March 22, 2020, 02:37:44 PM »

Hey David,

Your piano seems to have a white spacer UNDER your wooden strip on the harp support.  I haven't noticed that before.
Maybe your wooden strip will come off easily.

Sean