The "Miracle Mod" on hybrid wood hammers Pre-1978

Started by Ben Bove, October 28, 2008, 07:36:21 PM

Previous topic - Next topic

Ben Bove

I wanted to make a sticky covering the early Mark I action because of the high number of requests of how to improve sluggish action.  The fact is that the Rhodes action is extremely simplified compared to an acoustic piano action - the 2 major components are only the hammer, and where the hammer interacts with the key referred to as the key pedestal. 

A grand piano action


The Rhodes action



This topic is about the improvements originally designed by the Rhodes engineers by use of a Pedestal Bump, a small piece of plastic added to each key, to improve the feel and lightness of the action.  The basic concept is the lack of a "jack," or a fixed point where the key propels the hammer.  An aftermarket recreation of this design is available as the "Miracle Mod" action kit from Vintage Vibe or others, and this guide covers installation and an explanation of why it works.  There are other adjustments throughout the Rhodes that should be made for the most ideal action, however the Miracle Mod creates the greatest initial improvement for sluggish action for pre-1978 Rhodes pianos.

Improvements:
1) Faster action by linearizing hammer throw
2) Decreased hammer bounce

The link below provided by Vintage Vibe shows their videos for installation on action beds. 

http://www.vintagevibe.com/t-kitdirections.aspx
"Miracle Mod Video 1-4"

NOTE: Installation for 1976 - mid 1978 pianos is different and will be covered separately below.

HAMMERS
When comparing the hybrid wood-plastic hammers from 1970 - Sept. 1975, against the all plastic hammer from Sept. 1975 onward, the angles on the hammer cam are a very different shape all together from front to back.  The old hybrid hammer is much more rounded in the back, while the plastic hammer from the factory bump era has almost 2 distinct flatter planes and gives a sharper fulcrum point.  This plays into how to place the bump.

Early hybrid wood-plastic hammer


Later all-plastic hammer



EXPLANATION
The early Mark 1 hammer literally rolls over the pedestal: most of the energy is lost when the hammer is forced up because it's rocking horizontally over the ped.  It lacks a "fixed point."



A bump installed on the pedestal creates a "fixed point" throwing where the energy is concentrated at a small point as opposed to spread over the surface area of the pedestal.  If you can imagine, a seesaw exchanges the energy most efficiently from end to end by having only 1 centered fulcrum - if a seesaw was mounted on a ball, it would take much more energy to rock it back and forth.  The consolidation of energy on one fixed point helps to propel the hammer more efficiently without energy loss from unneeded lateral motion.

the hammer is propelled initially by the bump until it reaches maximum point, then bump's position is out of the way while hammer's back brakes on pedestal.  The Rhodes diagram below actually isn't drawn correctly, you'll notice if you push the key as it looks, the key would sink below the case in the front.  The same goes for the pedestal - the hammer should lay flat with the bump, not straddling the bump and the back.  But you'll get the general idea:


HAMMER BOUNCE
Braking occurs when the back of the hammer lays flat on the pedestal, aimed at stopping the kinetic energy of the hammer from bouncing around after it's thrown.  The pedestal bump effectively fills a gap at the rounded surface of the hammer, extending the length by which the hammer comes into stop contact with the key.  This in turn reduces double striking, as the bump helps to catch the hammer from flopping around in the front after it's thrown. 



INSTALLATION
Every piano is different.  The exact placement on pianos can vary from one Rhodes to another, all dependent on where the hammer curve interacts with the key pedestal.  You can try to nail it on the first try, but I always recommend to test at least 3 keys of varying placements so you can feel the differences and see which location feels best to you.  It may or may not be at the very front of the key pedestal.



1)  Test the keys and see how they feel for lightness
2)  See how they feel for hammer bounce after the initial hit - is there any plunking or hard flopping
3)  See how high the hammer sits when you strike and hold a key - a hammer resting too high in the air is not good and can create escapement issues (hammer rests up against tine). 

If the bump is too far forward, you'll feel a resistance as the hammer curve "pops" over the bump, where the hammer is actually rubbing laterally against the bump.  Once you get the right placement where there's no dragging feeling or popping, and there's no double-bouncing etc, take your model key and replicate placement on all the rest of the keys.  A word of caution though - sometimes an action rail can be out of adjustment (or never adjusted properly from factory).  So put the very lowest key and very highest key in, and make sure the hammer curve is in the same spot for both.  If your lowest key has a curve that sits on the end of the pedestal, then your highest key has a curve that sits further back, then there's a slant from top to bottom in the action, and the bump will interact differently because it moves out of alignment with the hammers. 

Also as a note, the bump on hybrid wood-plastic hammer models is very touchy, as small differences in placement directly affects the angle interaction on the hammer and key.  Remeber that this early action was never designed for a bump, so to get it right you have to find just the right spot. 



GLUE
For testing the 3 positions on your keys, you may choose to use contact cement so the bumps can be removed after the test. 
Superglue should be used in the end for final installation of the bump and felts.  Reason being, with a contact cement or other higher-volume glue substance, it can fill up the gaps where the felt covers over the bump, and create a sort of slope to the felt.  The felt should be wrapped very tightly over the bump so that it can create the greatest affect.  When the bump is secured with superglue, the felt should then be superglued with a decent amount of pressure applied directly to the area just before the bump.


FELTS ON HAMMERS
September 1975 to Mid-1978 pianos - All plastic hammers, white felt on hammer cams, bare wood pedestals

There are 2 ways to go about a bump modification on these pianos:
1) Leave the felts on the hammers, and install the pedestal bump on the bare key pedestal
2) remove the felts from the hammers, and install the pedestal bump with felts on top of the key pedestals.

Both CAN work, but it's my suggestion to remove the felt from the hammers, and do bump / felt on the keys.  Here's an explanation to why:

From what I can tell, the way the felts were installed at the factory on these models were to line up the felts with the BACK of the hammer cam.  This means any variance in the length of the felts would vary at the hammer curve.  Not good - this is the critical dimension.  So all pianos over these years can be different - some would take the bump on key alone just fine, some with shorter felts would come into what I refer to as a "stop-lock" scenario where the bump collides with the felt in ideal placement - locking the hammer from moving. 



For the key below, placing the bump further back on the key to match the felt, results in the hammer resting very high and slams up against the tine in resting position - the note will thud and not ring. 



CLICK THE VIDEO BELOW FOR DEMONSTRATION:


It takes a lot longer to install the modification incorrectly, remove it and then install it correctly a second time.  For that reason, I really recommend doing bump and felt both on the keys.  It provides for a smooth stroke with the bump UNDER the felt, and prevents any collisions.

CONCLUSION
In my opinion, if you like a lighter and more efficient action it's necessary to have a bump mod.  Through discussions with CBS Fender sources - the bump was originally designed and is present in most of the 1960s Silvertop pianos.  It was removed during the early 70s as deemed either too difficult to manufacture or too difficult to calibrate.  After many technicians in the field began modifying pianos with this method, it was later reintroduced on all pianos mid 1978-1984, including Mark 1,2,3,4 prototype, and Mark 5.  That being said, of almost 20 years of Rhodes production the bump has been factory installed in one way or another for about 12 of those years.

Examples

1967 Silvertop Rhodes pedestal bump metal clip


An original Mark V key pedestal with factory wood bump.


1972 Mark 1 piano with new Pedestal Bump modification


1978 Rhodes piano with felt bump modification (this has been debated as a factory modification, in that before they were able to design the wood bump this might have been done at the factory.  This is seen regularly in identical fashion on early 1978 pianos)


FINAL ADJUSTMENTS
Again as all pianos are different, certain pianos will need minor adjustments after the bump mod is installed.  All the hammers should sit slightly higher than before which is normal.  Depending on how installation goes, you may need to globally raise the harp slightly with a shim at the left, or left and right support blocks.  I recommend all users to experiment raising the harp slightly to see if any double-striking or bark improves - quickest way is to throw a credit card under the harp on the left side.  Should you need to raise the harp, you may also have to adjust the strikeline - the forward and backward location of the harp (search forum). 

DAMPERS:
If a piano naturally has tight bridle straps, the bump modification can make your dampers incapable of stopping the tines.  The bump mod slightly lifts the hammers into a higher resting position, which in turn pulls the damper straps a little bit.  If they're very tight, it'll pull them away from the tine in resting position.  The simplest solution is to bend the ends of the damper arm up.  You want to make sure the bend is after the bridle strap point towards the end (if it were before, it would mess with how the bridle strap interacts).  It's best performed with two hands - one holding the damper arm at the bridle strap point, and the other hand bending the end up.  This also prevents a bend in the very back where the damper arm connects to the action rail.  Too high of a bend up will result in hard-strike notes deadening out, as the tine collides with the damper felt.  Not enough of a bend and the damper felts still won't be able to stop the tines.  Also, double check how they all react with the sustain pedal when finished so that damper arms function properly with sustain.

With your faster action, happy 32nd-noting!
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

Rob A

Fantastic post. Well done. This is a significant contribution.

Mark II

I'd like to second Rob's statement.

Well done, thanks a lot.

Mark II
Rhodes Stage 73 Mark II 1980 / modified Peterson Suitcase Preamp

gunnar

This post would have been so helpful when I did the bump mod on my '77 piano...I left the felts on the hammers and after some slight alterations to the harp position, it works a treat and it made a huge improvement on the action.

Great post!
1977 Rhodes Mark 1 73 stage
MicroKorg

james

Indeed. I'm glad I have my piano torn apart right now so I can start rebumping it.
Web Designer/Developer, Webmaster & Co-Creator
The Rhodes Super Site since 1996
1977 Mark I Stage 73 + Vintage Vibe Stereo Vibe

vocalchords88

Your post is extremely well thought out, informative and timely for me since I'm in the process of rebuilding a 1970 Suitcase.
I am about to begin installing the Miracle Mod and I have a few questions.

First, how do you get a clear view of the key and hammer from the side? Even with the keys out, the adjacent  hammers seem to obstruct the view.

Second, if the placement is as critical as you say it is and assuming that the new felt is uncompressed and therefore a bit thicker, how do you find the exact spot for the bump? If you place and mark it with the old felt in place it seems that  the installation of the new felt would cause the hammer to lift a bit in the resting position. Since the new felt is supposed to be installed over the bump, finding the placement with the old felt removed doesn't seem like it would be accurate either.

Am I splitting hairs here?
Thanks.
1970  Fender Rhodes Suitcase Mark I
Yamaha Motif XS8
Yamaha S-90
Kurzweil PC3

Ben Bove

#6
You can either hold the hammers up with your hand, rubberband them together and clip them up, or on some pianos with a little flex in the hammers you can actually push them between the tines and they can get held up there.

I don't know if it's that critical, I was just saying that putting it more forward or more back can affect the hammer's final resting position.  As long as you're in the area of a few mm of measurement it's ok.  The new felts from Vintage Vibe aren't terribly thick, so it shouldn't play that big of a roll in comparison to the old felts.

As far as replicating the placement all the way down on the keys, it is easier to get one key set up then duplicate placement by holding keys side-by-side, rather than eyeballing each one.  Just make sure that your keys are lined up as they sit in your piano (front of keycaps even) as the key pedestals can sometimes be longer or shorter (so you can't say "5mm from front of pedestal")

Best of luck!  Definitely get one key set up and play with placement before doing all keys.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

vocalchords88

One last question.
My keys seem to either have a slight peak just before the slope down or the back of the pedestals are indented from continued use. I was wondering if this is normal and if it will affect the placement of the bump.
Also from further examination the hammers rest on the downward slope of the pedestal, not the flat surface so according to your theory I would need to install the bump on the slope which is contrary to the instructions on Vintage Vibe's video.
1970  Fender Rhodes Suitcase Mark I
Yamaha Motif XS8
Yamaha S-90
Kurzweil PC3

Ben Bove

#8
The pedestal you're referring to around '70-'71 is termed as the Marcel Curve in the Rhodes manual.  There is a slight dip in the pedestal to take the shape of the rounded hammer cam I believe. 

I've seen a bump on the flat part of pedestal, and also pianos with them on the slope.  Again it's difficult because so many pianos vary so greatly.  I would try vintage vibe's method first on one key, then possibly try it on the slope.  What you want to acheive is a hammer that rests on the bump when not depressed, and then when depressed the bump is out of the way, hammer flat on pedestal, and hammer tip not jammed up against the tine.  I would use contact cement so that the bump and felt are removable when you're experimenting with this one key.

Let me know what you see when the time comes!
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

Chris Carroll

Here is a link to shed some light on the Miracle Mod for Rhodes pianos circa 76-77 with the pedestal felt on the hammers.

http://www.youtube.com/watch?v=9UVcRvnolQQ

Bjammerz  You Rock , awesome presentation man...
Vintage Vibe will do all we can to help anyone out in a fair and honest way. Call us up or email anytime.  "Love is the answer"

peteblues

I'm a little confused about the information given.
I have a 77 Rhodes, with the felt on the hammers, and just got the miracle mod, haven't installed it yet.
Should I just install the bumps on the pedestals and be done? Or should I install the bumps, remove the felts from the hammers, and install felts over my pedestals?

Ben Bove

#11
Modified in the main post above ^
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

peteblues

cool, I'll try that.
And if I don't like it, I can just remove the bumps with Acetone?

Fred

Does acetone thin cyanoacrylate (superglue)? Not sure, but the bumps will be pretty easy to remove if you don't like the feel.
 Or, you can use naptha to remove all traces of felt and adhesive from the hammer cam, and felt the pedistal with the bump in place.
 In my experience, leaving the felt on the cam and installing the mod has great results, alleviating any "slushy" feel. Removing the cam felt (and ALL traces of adhesive!) and felting the pedistal makes for a lighter, quicker action.
  So it's all in what you want out of your action... Just study bjammerz diagrams and watch Quadrapuss's video to be sure you don't interfere with the Rhodes' "stop-lock" position.
Head Designer of the Vintage Vibe Tine Piano
Collector
Electric Piano Technician in New Haven, Ct.
(203) 824-1528

pianotuner steveo

No, I would not use acetone, it might melt the plastic bumps and make a mess- also you shouldnt use acetone too close to keytops,it definitely melts them. I would just scrape them off. I don't like using super glue to mount them,either. Super glue doesnt stick to wood very well.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 270 Butterfly Grand
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
2017 Yamaha P255
2020 Kawai CA99
....and a few guitars...

fjzingo

I guess it's pretty hard to biy the miracle mod kit in europe, and I guess it's quite easy to get hold of key felt material and something to act as the bump.

Has anyone here any tips on what materials to buy and use???

/Fredrik

pianotuner steveo

You can use thin piano bushing felt,but placement of the bump is critical, and the felt method does not work as well as the actual bumps. See the picture(s) regarding bump placement.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 270 Butterfly Grand
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
2017 Yamaha P255
2020 Kawai CA99
....and a few guitars...

fjzingo


Ben Bove

They can be supplemented with perhaps a thin zip-tie... plastic like material.  The harder the better as felts etc will break down/thin over time.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

pianotuner steveo

The bumps sold by Vintage Vibe are plastic. I never thought of the plastic tie tip that bjammerz suggests-great idea,Ben.

Rhodes original  service manual had a mod for making bumps completely out of felt...a  felt bump covered by a piece of felt that covers the whole pedestal top.

The plastic bumps are first glued on, then the felt is glued over them.Some models (such as the new models) have built in wooden bumps, covered in felt.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 270 Butterfly Grand
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
2017 Yamaha P255
2020 Kawai CA99
....and a few guitars...

Ben Bove

I've had a couple people email me about installing the bump, and then the action feel "punchy," like it pops rather than smooth when hitting a key.

The bump has to be placed far enough back that it doesn't allow the hammer to drag across it.  If you install the bump too close to the end of the pedestal, the hammer when it rises will drag forward and prevent smooth movement.  This is particularly more noticeable on the all-plastic hammer models because the hammer curve is sharper, like the first pictures at the top.  This would create the "popping" feeling.

I've added this paragraph to the stickey:

INSTALLATION:
I recommend installing one bump on one key first, and wait for glue to dry.  Adjust the placement on this key until it feels right, or even install 3 bumps on 3 adjacent keys in slightly different places to feel the difference.  Once you get the right placement where there's no dragging feeling or popping, and there's no double-bouncing etc, take your model key and replicate placement on all the rest of the keys.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

musomarc

Quote from: Quadrapuss on February 27, 2009, 07:50:18 PM
Here is a link to shed some light on the Miracle Mod for Rhodes pianos circa 76-77 with the pedestal felt on the hammers.

http://www.youtube.com/watch?v=9UVcRvnolQQ

Bjammerz  You Rock , awesome presentation man...
Hi,
:)
Hi,
Just checking before installing Miracle mod on a 1975 Stage Mk1.Regarding Bjammer's advice:-
Am I correct in stating that "the resting position of the hammers after installing MM will be in a HIGHER position than without the MM bump added to the key pedestal" and that the hammers will now have less ditance to travel before hitting the tine.
Great discussion , very helpful stuff.
Regards

Fred

  Yes. At rest, the hammer will sit higher. With the key depressed, the hammer should sit exactly where it did before (stop-lock position). The leading edge of the bump should be just contacting the hammer cam. 

  Correct, this does limit travel, but the hammer now has a lot less friction on the up-stroke. You will be able to play with a lighter touch than before, and will have just as much bark (if not more) when you lay into it.
Head Designer of the Vintage Vibe Tine Piano
Collector
Electric Piano Technician in New Haven, Ct.
(203) 824-1528

Ben Bove

I just did a big re-write to the main posting on the Miracle Mod for the interested parties, much more complete with photos and comparison for the felted hammer models.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

Chris Carroll

Hey Ben,
Fantastic rewrite- We are working on our service manual for the Vintage Vibe Piano- I would love to send it to you for editing !

Great Job-

Peace and Happiness to you

Chris
Vintage Vibe will do all we can to help anyone out in a fair and honest way. Call us up or email anytime.  "Love is the answer"

greenjeans8888

Great post....thanks for sharing.

I am trying to install the miracle mod on my hybrid hammer Stage 88.

The question I have is how to know where to position the bumps before putting the felt on the pedestal.  It seems that the felt adds a little thickness and thus functionally places the bump a bit further back on the pedestal.  As I have currently set it up (on just the bottom octave so on a less important range), the hammer just rests on the felted bump when I have the key lightly depressed, but if I push the key down hard it lifts up just enough to get off the bump.  Do I want the bump further back?  It's not like this mod is easily reversible so I want to get it right on the first try.

Thanks for everyone's input.

David Aubke

Quote from: greenjeans8888 on November 17, 2012, 12:46:21 AMIt seems that the felt adds a little thickness and thus functionally places the bump a bit further back on the pedestal.

I've wondered about this myself but disregarded the issue when it came time to position the bumps. My understanding is that the only contact should be between the bump and the hammer cam until after the tine has been struck at which point the hammer should contact the entire face of the pedestal with the bump supporting the curve of the cam. Truth is, I haven't closely observed the action since installing bumps. I assume it's working properly because the difference in feel is profound.

It's possible that my technique is flawed such that I tend to install the bumps a bit forward of where I intended thereby dealing with this issue automatically.
Dave Aubke
Shadetree Keys

Ben Bove

The best advice for this is to try 3 keys in 3 different bump positions - using either a contact cement or other removable glue.  Even if you have the pedestal felts with the self-stick backing, if you remove them they should be able to be re-glued.

Then when you have the best feeling position, you can replicate the best position of the bump all the way down the key bed.  One thing to be mindful of though - check to see where your hammer rests on your lowest keys, and on your highest keys.  If for example the hammer appears to be closer to the end of the pedestal on one side vs. another, your keybed / action rail might be slightly mis-aligned which means the ideal placement of the bump might change from top to bottom.  It's not a significant change but you'll want to see if there's any variance before just slapping all the bumps on the keys right away.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

Max Brink

Quote from: bjammerz on June 08, 2009, 11:59:28 AM
They can be supplemented with perhaps a thin zip-tie... plastic like material.  The harder the better as felts etc will break down/thin over time.

This made my day! A few months ago I was waiting on an order of my usual bump material and a customer wanted to get his pano back before a weekend gig. After digging around the shop for a while I found some zip ties that were just the right size to come through for the fast turnaround on the job.

...Sure helped me out of a 'bind!'

MB
Max Brink
The Chicago Electric Piano Co.

ph: (312)476-9528
e: max@chicagoelectricpiano.com

w: http://www.chicagoelectricpiano.com/
fb: http://facebook.com/electricpianoco/
tw&ig: @electricpianoco

Chris Carroll

Plastic Tie wrap has been around for a long time, much better than using felt- Steve Hayes R.I.P use to sell them as his bump kit. If you get the right ones they are effective ,especially if you do not have a Miracle Mod handy .  I have used them in the past. Still you have to cut them by hand and your left with a piano with cut pieces of tie clips, it's time consuming and they never cut evenly. The Miracle mod plastic bump was made from a custom mold and they come all uniformly the same size with an accurate height. They are also a rounded surface that the cam rolls over easily into a brake position.  We had them made red so they blend with the red pedestal felt for a professional looking and performing job our customers deserve. One day down the road when the next tech looks in there he'll say to himself one of two things, nice professional looking work or, look at this dubious job- I would want my name on that piano to stand for excellence cosmetically as well as mechanically.
Vintage Vibe will do all we can to help anyone out in a fair and honest way. Call us up or email anytime.  "Love is the answer"

eisenhower

Quote from: bjammerz on September 22, 2009, 11:37:31 AM
take your model key and replicate placement on all the rest of the keys.

Should a straight edge be used to line up the rest of the keys and place the bumps?

Ben Bove

You can do that - just make sure that the keys are all aligned at the very front of the keycaps as if they were in the piano - they're not perfectly uniform so sometimes key pedestals are longer, wider, etc. and as mentioned, if the action rail isn't perfectly level front-to-back in the piano, the point can shift from the bass register to the treble.  So you have to check the lowest note in the piano, see where the hammer rests on the pedestal, and check if that's relatively the same spot as the high register.

It's not a perfect science, to really get the most even action you will probably have to redo a few of them because the manufacturing tolerances weren't the most exact.  You'll feel those trouble notes after you install the mod over the piano.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

eisenhower

how much escapement difference is too much? the hammer is resting on the tine, and to fix it, a very large shim is required on the right side..

Ben Bove

This means that the bumps are probably too far back on the pedestal. 

Experiment with a few keys with the bumps a little closer towards the front.  The bump should really be out of the way with the key depressed - the hammer should rest almost entirely on the pedestal by itself, almost not in contact with the bump.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

David Ell

One thing I don't see ever mentioned is checking the back flange of the piano before doing any mod at all. Many times it is not up tight against the key bed. You have to ask yourself if this was done after assembly to ease double strike (common on late 70s rhodes) or was it never flush to begin with? You can do all the mods you want, but not getting this right, well....
Also, there is nothing wrong with doing the old version of the key pedestal mod like they did in early '78. It's all about getting the bump the right size per the piano. Done right it does not increase double strike. It was good enough for the late 70's/early '80s pianos and feels great if done correctly.

Gonzo

I did install the Miracle Mod - including the re-felt on a '77. It feels so shitty! The action is lighter - but more toysynth-like lighter. I get a very small area of velocity where the dynamic range lays. When touched very lightly i don't get a note compared to the non MM-Keys and the MM keys are rebouncing much after hitting the tine (dont know if this is meant by "double strike").

I don't know what i did wrong. When installing it more towards the hammer it affects the stop lock position slightly.
Installing it more towards the keys is impossible since the bump is already at the end of the pedestal.

The strange thing is, that even before the keys where slightly above the "theoretical" stop lock position (which would be when they where lying flat).



David Aubke

Gonzo, are you able to take any pictures?

"The strange thing is, that even before the keys where slightly above the "theoretical" stop lock position (which would be when they where lying flat). " - I can't figure out what this sentence means.
Dave Aubke
Shadetree Keys

Gonzo

Yeah sorry, dont know how to describe.

I mean - when you press a key very slowly the hammer will rest on the pedestal just as flat as it is supposed to.
But when pressed faster/harder I have the feeling that the hammer will rest (stop lock) higher than that - not using the full flat area of it.

Similar to when you press the key without the harp very hard: the hammer will tilt at the end of it. 
Maybe this is normal - but because of that it is kind of hard to place the bump, since it won't support the hammer when it is just placed on the geometrical correct place behind the curve. Maybe this is the rebouncing?

I will take some pictures soon. I have a feeling that the keys on the upper register are much better, so maybe it isn't the mod itself.
But Maybe I just like the wobbly sluggish rhodes feeling since I'm not into the fast playing stuff (I don't know any better at the moment ;)


goldphinga

#38
I've just finished two 1975 Golden Tine pianos and I've done the Miracle Mod to both. It was interesting how different a placement the bump needed to be on each piano. One had the bump quite a way in from the front of the pedestal for it to feel fast and light whilst the other required the bump to be right on the front edge of the pedestal.

Now whats interesting is many folks say be careful not to have the bump too far forward but sometimes the bump needs to be right at the front of the pedestal.

I think one of the 3 or 4 trial bump positions should always include a bump right on the front edge of the flat pedestal, especially as in the MKV and my 1980 Mk2 the bump is right on the front edge from the factory.

Anyone care to add anything to this? Seems to me ideal placement is not necessarily as in the diagrams on this thread but can also be right on the front edge as on the 1978 pic with the white felt above.

Anyway, be creative and dont be afraid to try radically different bump positions. Though the very front edge may seem like a none too ideal place, it might just be the best place for the piano youre working on and in fact it seems like the standard factory placement unless im mistaken...


Ben Bove

Completely in agreement.  In fact, I recently did a piano with the bump in the front.  However, I think most people default to that position - and it's many times not ideal.  And they end up with popping hammers.

I did a bump mod on a 1971 with the marcel curve, and the bump was exactly on the crest of the highest point of the pedestal - not in the curve.  What I noticed, is that the curve isn't severe enough of a dimension to mess up the process.  The hammer butt lined up perfectly with the back of the key pedestal when the key is depressed, and the bump was directly after the curve ended.

One last point, I saw a bump mod where a heavy amount of contact cement was used.  What happened was that the cement filled up a gap from where the felt met the bump, and sort of created a gradual slope up to the bump - not a hard separation.  So what was happening, was the effectiveness of the bump was taken away - it went back to a non-linear projectile.

At this point I'm advising to use superglue to adhere the pedestal felts, with emphasis on creating a tight fit of the felt around the bump, so that it juts out distinctly. 
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

David Aubke

Quote from: bjammerz on December 05, 2014, 06:34:00 PMAt this point I'm advising to use superglue to adhere the pedestal felts, with emphasis on creating a tight fit of the felt around the bump, so that it juts out distinctly.

I made a clamping caul from the block of a broken tine.
Dave Aubke
Shadetree Keys

Ben Bove

Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet


voltergeist

Quote from: bjammerz on December 05, 2014, 06:34:00 PM
At this point I'm advising to use superglue to adhere the pedestal felts, with emphasis on creating a tight fit of the felt around the bump, so that it juts out distinctly.

Oy, superglue for pedestal felts?  I don't know about that.  Sounds like a nightmare the next time they need to be replaced, besides superglue being generally awful to work with.  Much respect, bjammerz, but superglue on pedestal felts doesn't strike me as a good idea.  If there's a problem with contact cement, I'd say it's in how it's applied, not in the suitability of the adhesive.

Proper application of contact cement should not result in a buildup that would affect the transition to the bump.  I use the back of my Exacto knife to seat the felt at the base of the bump and define the bump in the felt (both sides of the bump). 
Restored or Overhauled: '65 A-model Sparkletop, '78 Suitcase 73, early-'75 Satellite 88, '81 MkII Stage 73, two '77 Mk1 Stage 73's, '74 Mk1 Stage 73
In Progress: 1 '78 Suitcase (2nd one), '70 KMC - Customized w/ Peterson 4x12, '77 Wurli 270

sean



Really Ben?

Don't you mean that the superglue would be used for the bump strip only, not the felt?

David Aubke

Quote from: Student Rhodes on December 10, 2014, 03:47:50 PMIs this caul for holding the felt around the bump?  What's getting clamped?

The caul is for holding the felt down over the bump while the glue sets up. I have a picture of it in action but unfortunately, it was taken from an angle that made the image very confusing.

I use hot hide glue which sets up in less than a minute.
Dave Aubke
Shadetree Keys

goldphinga

I've had no issues using contact cement on the felt and pedestals but everyone has their own preferred method-

For getting the felt to fit round the bump I use the edge of a flat head screwdriver to gently press the felt into the bump on both edges first before glueing the rest of the pedestal felt down.

Ben Bove

#47
I completely agree about contact cement, and continue to use it myself.  I have tested superglue which was a good result as well on felts ... it's definitely not the cement at question, but how it's applied.  With this DIY thread I'm looking at it from a point of view where there will be the least amount of user error possible - factoring in people that aren't techs or experts, and would be doing this one time on their Rhodes piano.

I just had to look at it again when someone said "I followed your thread on the miracle mod" and when I saw the contact cement buildup and a poor install that basically invalidated the improvement, it showed me that you have to plan for people not knowing how to do things and something didn't translate here, and I had to undo and redo the process.  I guess there could be an image or something demonstrating the tight fit required of the felt around the bump, otherwise it can be a problem if the volume of the contact cement isn't controlled.

On a future worn felt replacement, dipping the key pedestal in straight acetone should make for easy removal.  If you know what you're doing and install with contact cement as a few people noted with clamps, screwdriver pushing down, the caul thing is interesting - then that is a great solution.
Retro Rentals
Vintage Music Gear

http://www.retrorentals.net
(818) 806-9606
info@retrorentals.net

FB: https://www.facebook.com/retrorentals.net/
IG: @RetroRentalsNet

ppeterso2

I think I want to try this mod because I can't stand the action on my weird 1975 73 Suitcase w/ hybrid wood hammers compared to the 1977 I had (but I prefer the sound...lol).  It hurts my hands to play it for a while.  I'm no Rhodes expert (but I've had 3 lol), but this 1975 seems like an in-between model???  It's like a cross btw a 1974 "Fender Rhodes" and a 1976 plastic hammer model--I've never seen one like this.

Anyway, sorry for the newbie question, but to install this mod, do I have to take the piano out of the case like I see in most of the videos? 

And does anyone know what I'm talking about with this seemingly short-run 1975 model?  Any gotcha's with the 1975?

Thanks!

Student Rhodes

I'm not sure which features on your piano you think may deem this an "in-between" model.  The Mk I had hybrid hammers until around mid-September of '75 (as seen on the date code) after which the factory installed an action as found on your '77 -- plastic hammers, aluminum harp supports, felt on the back of the hammer cam etc.  Generally, the later model with felt on the back of the hammers were found to be more prone to being sluggish than the pre Sept/75 models.  Either way, I'm sure if you do the miracle mod, your action will be dramatically improved.  I think to access the key pedestals you need remove the action rail (with hammers and dampers) which I believe requires pulling the bed, and removing the harp supports etc. 

As far as the differences in tone: I believe by '77, Rhodes had switch tines supplier, from Torrington to either Singer or Schaller.  Everyone seems to have a preference.