Double Bass Tuning machine replacement woes

[Chansey]

Hi everyone,

I recently paid a visit to a luthier to get new tuning machines fitted on (aged Rubners from Upton music). After bringing it home and doing a careful inspection, I noted that the tuning machine plates were not flush to the scroll and the D string tuner appears to be rather poorly fitted (I have attached some photos).

I called the shop and was told that due to the design of the tuning machines, it is not possible for the plates to be flush against the scroll due to the protuding clasp which secures the tuning key on the underside of the plates (pretty hard to describe what that is here). To remedy this, some surgery will have to be done on the scroll which could result in structural issues.

As I am no expert on this, I am not too sure whether the shop's explanation is acceptable. It is true that the tuning machines are not obviously crooked and the gaps are only visible upon closer examination. Also, the gears work smoothly. Can any kind soul enlighten me on whether I should get this righted out? Thanks!

 

[KUNGfuSHERIFF]

"I called the shop and was told that due to the design of the tuning machines, it is not possible for the plates to be flush against the scroll due to the protuding clasp which secures the tuning key on the underside of the plates (pretty hard to describe what that is here). To remedy this, some surgery will have to be done on the scroll which could result in structural issues."

That sounds...a little dramatic. A good luthier with a Dremel should be able to mill small recesses in the outside of the cheeks to accommodate the protruding gears without much trouble. It's not like you often see basses with shop-fitted Rubners jutting out into space like that.

Call the shop back and voice your dissatisfaction. If they don't want to complete the job to your satisfaction, and they have already accepted payment for the unsatisfactory job, it doesn't sound unreasonable that they pay a willing third party to finish the job adequately.

 

[Jake deVilliers]

Hi everyone,

I recently paid a visit to a luthier to get new tuning machines fitted on (aged Rubners from Upton music). After bringing it home and doing a careful inspection, I noted that the tuning machine plates were not flush to the scroll and the D string tuner appears to be rather poorly fitted (I have attached some photos).View attachment 690648 View attachment 690649 View attachment 690650

I called the shop and was told that due to the design of the tuning machines, it is not possible for the plates to be flush against the scroll due to the protuding clasp which secures the tuning key on the underside of the plates (pretty hard to describe what that is here). To remedy this, some surgery will have to be done on the scroll which could result in structural issues.

As I am no expert on this, I am not too sure whether the shop's explanation is acceptable. It is true that the tuning machines are not obviously crooked and the gaps are only visible upon closer examination. Also, the gears work smoothly. Can any kind soul enlighten me on whether I should get this righted out? Thanks!

You need to find a qualified bass luthier! A few minutes with a moderately sharp gouge will give the gear and clinched fasteners on the back plates all the clearance they need. Sheesh.

 

[james condino]

interesting looking scroll.

If we knew your location, we could reccommend "the guy" to take your bass to. Did this go to a bass specific "luthier" or a guitar shop or fiddle guy who thinks it would be cool to say he worked on a big bass?

In addition to the posts about the backside of the machines sticking out a little bit, it could also be that the side of the post opposite the gear that pokes into the other side of the pegbox needs to be shortened just a tiny bit. They often come long and are cut down to length to fit your pegbox geometry. Since they funtion well, I think either one of these options is within your capability. Five minutes scratchng on a piece of sandpaper for one end or ten seconds with a swiss army knife to make a little divot on the other end.

J
Condino.com
Kaybassrepair.com

 

[KUNGfuSHERIFF]

I installed Rubners on a Shen a few years ago. It was my first experience changing gears on a doublebass.

Trimming the rollers to fit is no big deal if you have a belt sander and a decent eye, but screwing the machines down tight to the pegbox cheeks is a surefire recipe to bind up the gears. They still turn, but...

My point is that even if the rollers are properly fitted, without the plates being properly fitted to the cheeks the only remedy is to loosen the screws holding the gears by 1mm or so. It looks like hell, but it works.

 

[csrund]

...screwing the machines down tight to the pegbox cheeks is a surefire recipe to bind up the gears...

Same experience I had when I upgraded the machines on my Shen. The taper of the peg box as it ascends to the scroll causes the machines to skew out of alignment and bind when they're perfectly flush mounted. Had to ease one of them off just a bit.