Well, me being me, I now have three "el cheapo" banjos and loving to tinker and build stuff, I am going to reform one of them. Well, at least play around with some ideas that might convert me to an amateur builder.
So, my "project" has guitar style tuners with 1/4" holes. I want to replace them with planetary ones which will require 3/8" holes.
My question is if I should use a drill bit to bring them up to size or would a reamer be better? If a reamer, what taper ratio?
Mind you, this one and the other spare are very small investments, but just lile to learn these types of things. And, I want to do it the right/best way.
A Forstner bit might work OK. You could plug the hole with a small piece of dowel so the Forstner bit center has something to get started on. Twist bits tend to "dig in" when enlarging holes and can make a terrible mess.
A reamer is probably the least risky.
A violin peg reamer is least risky. If you want to use a forstner bit you will need to plug the existing holes with a dowel
You can use a Forstner bit if you clamp a guide centered over the hole. This setup is quick, easy, and safe. Here it's being used with a 9/32" bit in preparation for reamer violin tuners, but the process is identical for using a Forstner bit without the need to fill the old holes.
The backing wood should be re-located so there is fresh undrilled surface behind the rear surface for each drilled hole.
I've drilled literally hundreds of holes using a standard twist drill bit for larger guitar tuners, but it's imperative that the hole location has a block and rear backing material as shown in the photo above.
Edited by - rudy on 08/23/2019 13:53:44
Follow-up questions on this:
I reamed the holes out to fit the planetary shaft size, but noticed that the length of the shaft on them was shorter by about 1/16" to a couple of mm than the guitar style tuners that I was replacing. I'm wondering if the head thickness is greater on these necks than one that is made for planetary or friction style tuners?
Also, after I did all that, I put new strings on and I'm noticing the tuners are "giving" when I tune to pitch. No, this is not due to "stretching" of the strings, it's the tuners actually turning enough to drop pitch by a step or two. Could this be from the bushing not seating all the way down on the tuner or maybe the angle of the string from the nut to the tuner?
One thing I will say is that I'm getting schooled on how a banjo is put together and I may just have to work on building one in the future. If I do, it will have several upgrades from this one, for sure... I may have to work on building one like that old Johnny Cash song... One Piece at a Time!
Most planetary tuners are 4:1 ratio and will be more susceptible to backspin from string tension. Tightening the button screw and making sure the friction washer between the button and the gear housing will help with backspin, but it can sometimes continue to be a issue, especially when using inexpensive planetary tuners.
I go the other way to "improve" the design of banjos, opting for a good quality guitar-style tuner over planetary tuners in all cases. Planetary tuners have nothing going for them other than a nod to tradition.
I prefer to use a reamer for enlarging the holes, a violin reamer works fine, but just about any tapered reamer will work and can be had for just a few dollars. Taper doesn't matter much, you work from one side, then the other until the tuner shaft will fit.
As long as what you are calling the "bushing" has enough thread to tighten the tuner to the peghead, and the post sticks up enough for a few winds of the strings, all is good. There is no reason this "bushing" needs to be seated. The tuners are designed to accommodate various thickness of the peghead.
I agree that the higher ratio guitar tuners are superior to the 4:1 ratio planetary tuners as far as function goes. A high quality set of six is still about half what a set of decent planetary tuners cost too.
People prefer the look of planetary tuners on a banjo, which is due to the tradition Randy mentions.
The cheap banjos with guitar type tuners usually have cheap guitar type tuners (about $10 a set). Grover Rotomatics are very good tuners, and cost $30-$40 a set (been a while since I ordered any so may be more.
Good planetary banjo tuners such as Gotoh are about $90 a set, the cheap Asian planetary tuners are a lot cheaper, but you get what you pay for.
Really good planetary tuners will of course cost more, and if one is going to spend more I highly recommend the new Rickard 10:1 ratio tuners which are what I intend to use on my higher end banjos from now on. Those are very smooth operating, and due to the better gear design they do not slip.
The problem with a tapered reamer is that if you ream the hole enough to slip the peg in place, you end up with a good fit only on one side of the peghead. If you ream a little on both sides of the peghead, you can cut the error in half. A non-tapered reamer would probably give the best fit. I use a regular drill, chucked in a drill press and it works for me. I've also used Rudy's method of a pre-drilled block of wood used as a drill guide. It works very well. But you still need a drill press to make an accurate guide.
I might disagree with Rudy on the thought that planetary tuners have nothing but tradition going for them. To me, tradition on a traditional instrument like a five string banjo is important--but I like planetary tuners because I dislike the look of guitar tuners on a banjo.
Of course, beauty is in the eye of the beholder.
I also like planetary tuners because it allows me to tune every string without wrist contortions or having to raise my elbow on the lower strings. If I were to go with guitar tuners, I would at least choose classical type tuners on a slotted peghead with the pegs pointing straight back.
It's all a matter of preferences.
Edited by - Dan Drabek on 09/10/2019 14:54:00
I use a reamer on both sides to open the holes just enough for the housing or bushings to enter part way, but then open the holes with a small half round or knifeblade file to finish the job. I only do this job once every couple of years, so production speed isn't an issue. Doing a clean job is.
Terry, most planetary gears have dimples on the face which goes against the wood. They bite into the wood and keep the peg from turning under string tension. Make sure the threaded bushing is tight enough for the dimples to press into the wood.
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