rockstardave.. when you say adding shims to the harp.. where do these go exactly?.. on the wooden rests under the harp (where the securing screws go? or is it somewhere else?
Some update on the restoration...
The vintage vibe kits arrived. Lots of fun ensued..
I removed, cleaned and refitted the tonebars with the new screws & grommets. The springs were also cleaned of rust and grit. Given that the tuning springs were moved for the tine cleaning, I need to do a serious tuning session! I've already done a basic retune using an app on my Android phone (gstrings) to get it playable but you can still hear it needs more attention. The tonebars now feel quite secure. Their only movement is what the springs give them. Prior to this, the screws were loose and didn't feel like they were held in that well.
I've installed the new hammer tips, miracle mod bumps/felts and back-checks. I made the silly mistake of installing two thirds of back-checks first before doing the miracle mod. The result that the back-checks needed some re-bending to get them back in contact with the slightly raised hammers as they now sit on the new felts and bump. But no big deal.
For the miracle mod itself, I found I needed to sit the bumps at the very edge of the flat pedestal block. Any further in toward the hammer arm and the hammer would still be still sitting on the bump in the raised position. That seems to be the rule of thumb for positioning these. The post referenced above was very useful to understand what was being achieved here.
Certainly now the bounce effect is significantly reduced for raised keys. When returning to resting position, the back-checks help but do not totally remove the bounce.. but they do remove enough. If you sit the back-check too close, the hammer will stick or sit too high.. so its a compromise to get the best balance possible. I can now play fast sequences between adjacent keys without the whole thing getting caught up. So mission accomplished here.
For the damper felts.. I first removed the old ones and straightened up the dampers to have a consistent alignment in their various sections. One of the problems I have is that the hammers and dampers can impact during play. I trimmed some of them a little to relieve this. However I messed up many of the upper treble dampers in that they became too short, barely clearing the pickup!.
So I had to glue on some thin metal strips to extend them again!. Oh the regret and shame! But in fairness.. I think a previous owner had already trimmed them.. so I was only adding to the issue.
But now most dampers are fine with only some still experiencing the hammer impact. I think I may use some of the old pedestal felts to glue a soft area onto the plastic arm of the hammer where the plastic raises as it connest to the wood. Its right here that the damper and hammer can impact each other. So the tick noise may be lessened with a softer surface.
The fine adjusting of the dampers was slow at best. Your dealing with dampers that do not move at all, versus ones that are not resting on the tine.
For the ones not moving away from the tine, I did some bending near the bridal strap hook to increase tension on the strap. This generally helped bring more movement and occasionally required a little upward bend nearer the felt tip to get it to make contact with the tine. There are still a few needing attention in the mid range. At least 7 at the top need a lot of work to get things right.. but no doubt my clipping and subsequent re-extensions are not helping here. I may even leave some of these undamped as they do not have strong sustains.
I wonder if I should have ordered new bridal straps. But it seems that installing them is very difficult. I reckon if I ever decide to do this, I'll consider getting new dampers aswell and try to get a fresh run at the damping again. Give that such a step would be expensive, I'm going to work to the bitter end with what I've got until I can't stand it any longer!
For escapement, I used a wooden edge that is about the width of a tine block. This helped get things move evenly positioned. Then I worked on the inner screw to get the tines just above centre with the pickup tips. I also moved most of the pickups closer to about 1.5mm from the tine. This has improved the bite a lot. I'm not looking for a dyno-my-rhodes effect, but at the same time, I don't want the sound too soft either. I'm actually quite happy with the results I'm getting.
I'll try and finish the damping work this week-end and also get the tuning sorted. I'll upload another video then to give people an idea of how far I've got.