Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Small pin size issue on Grotrian 189's?

Has anyone heard of Grotrian 189's from the mid-80's having pins that are a little smaller than the standard pins used today? If that is the case, does the entire pin block need to be changed or can the pins just be replaced and the piano restrung?

Measure them and see!

No decent piano should have to have its pin block replaced after 30 years unless it has been damaged or restrung at least once in that time.

The tech did measure them and that is how he said that the original pins are a bit smaller than the pins on current models. He said his socket (sized for current model Grotrians) spun around when placed on the 1985's pins.

Tuning pins are made in different sizes. The standard is #2, and techs will sometimes re-string with oversize pins. If a piano is built with an open faced pin block, they could be #1 pins. That would explain why his tuning lever tip was too loose. Not a big deal. Make sure your tech has a smaller tip.

Thank you, beethoven. I will call him back and make sure that I understood him correctly. He is a very well respected tech in the Chicago area, so I suspect that I am explaining things poorly, rather than he not having the appropriate tools.


Edited to add that I asked the tech to explain it to me again and he said the pins are loose. He said I could get larger pins put in, but that this fix would likely hold for 20 years, not 50. Since I plan on passing this piano down (and actually hoping to play it for more than 20 years, if the powers that be agree) I don't want to have to deal with this again two decades hence.

I know him personally, so no need to defend him to me! To be fair, even if he didn't have a #1 tip, I wouldn't hold it against him. I don't have one, and I bet most techs don't, because 99% of instruments we encounter have #2 or higher pins.




If it were me, in this case, I would treat the pin block with thin CA glue. I have used this technique successfully on a few pianos with prematurely failing blocks, and it is quickly becoming a go-to fix for many other techs. It is much cheaper and less traumatic for the piano.

While I understand your desire to not want to "deal with this again", I think it is overly optimistic to expect a 30 year old piano to perform optimally without a good amount of work, much less a 50 year old piano. Unfortunately, high-performance pianos aren't a product, they're a process, and you're likely going to run into issues with whatever you go with. That said, I've seen the Grotrian on Craigslist... I think their asking price is too high.

Berlitzpiano.
I commented on this problem over on your topic in the Piano Forum.

Grotrians from this era have too little back angle on the tuning pin and this causes problems with the tuning pin actually working its way up out of the hole as you turn the pin during tuning.

The original pin size for Grotrian of that era is 6.75mm.

These can be changed out for 7.15 or 7.25. With the latter size there might be a little hand reaming to accomplish for improved fit and performance while tuning.

Might as well install new wire and bass strings while you are there.