Taylor Turbo Winder Revisited

[cjd-player]

At Frets.com, Frank Ford shows the modified Black&Decker cordless screwdriver that Taylor uses to string up guitars with the Taylor stringing method.  Taylor modified the screwdriver to make it turn faster, and Frank showed some pictures of the inside modifications.  http://www.frets.com/FRETSPages/Luthier/Tools/SuperDriver/superdriver.html

As a curious tinkerer, I wanted to try the same.  Walmart sells the B&D Alkaline Cordless Screwdriver for $8.88 where I live  ($9.99 at K-Mart), so I figured there was little risk in trying it on the current Black&Decker model.

For those of you who like to tinker in your workshop, it’s a fairly easy modification.

Here is a picture of the top.


And the bottom.


Ready for surgery.


Using a small screwdriver , the retaining clip lifts right out.


The head slides away from the body.



I am an engineer, but I’m not a mechanical engineer, so please forgive any misnomers of the parts of the drive mechanism.
Part of the mechanism stays with the body of the tool and part is retained in the head by an internal clip.


The modification is on the part that stays with the body.  There is a sun gear (that you cannot see yet) that is on the motor shaft.  It rotates at high speed.  The sun gear drives  three gray planetary gears.  On top of the planetary gears is the white, triangular piece that has a sun gear at the center.  The sun gear on this triangular piece drives a second set of planetary gears in the head.



Here I have removed the white triangular piece.  Now you can clearly see the three planetary gears on the body and the sun gear in the center that drives them.  The sun gear actually just sits on the motor shaft, which is ‘D’ shaped to drive the sun gear. (I’m telling you this so you don’t worry if the sun gear falls off.)


The modification consists of replacing the three planetary gears on the body with a solid piece.  By doing that, the sun gear on the triangular white piece rotates at the same high speed as the sun gear on the motor shaft.

I made the solid piece from ¼-inch thick aluminum, finished to 3/16 inch thick, 1-1/8 inches in diameter.  The three holes for the white triangular piece are 5/32-inch diameter.   To make the center, 6-point  star hole for the sun gear, I drilled a 1/8-inch diameter hole, then filed the star teeth by hand with a small triangular file.  It’s not a precise match, but it works.


To reassemble, the new mod piece fits on the body sun gear, and then the white triangular piece sits on top of that.  The three planetary gears are no longer needed or desired.



Slide the head back on and reinsert the retaining clip.

The stock tool turned at about 130 rpm, which I timed by counting revolutions of a masking tape flag placed on the drive end.  The modified tool rotates faster than I can count the revolutions.

A pretty cool tool for $10 and about 2 hours of tinkering.

[AlexRkstr]

This is exactly what I was looking for! Thank you for posting. Where can I buy 1) the solid piece from ¼-inch thick aluminum, 1-1/8 inches in diameter and 2) the drill to make the 1/8in hole and the 3) file to make the incision?

Sorry, I'm a noob when it comes to this. Appreciate the details!

[cjd-player]

You're going to have to make the aluminum piece yourself, or have someone else to make it.  I actually had two 1/8 inch thick pieces of aluminum that I cut from some aluminum angle and super glued together.  You can buy 1/8-inch thick aluminum pieces at Lowes and Home Depot.  After gluing two pieces together, I drilled the center hole and turned the piece on a lathe. 

Any machine shop could make the aluminum piece for you, but I don't know what that would cost.
Maybe your auto mechanic?

A drill, drill bits, and triangular needle files you can get at any good hardware store.

[John429]

You're going to have to make the aluminum piece yourself, or have someone else to make it.  I actually had two 1/8 inch thick pieces of aluminum that I cut from some aluminum angle and super glued together.  You can buy 1/8-inch thick aluminum pieces at Lowes and Home Depot.  After gluing two pieces together, I drilled the center hole and turned the piece on a lathe. 

Any machine shop could make the aluminum piece for you, but I don't know what that would cost.
Maybe your auto mechanic?

A drill, drill bits, and triangular needle files you can get at any good hardware store.

Carl, what an outstanding DIY (Do It Yourself) article with photos and very nicely explained process to make!

Josh - just an idea for consideration. Maybe a future subforum to capture neat "Do It Yourself" tech articles like this one that folks will come up with from time to time? Also, that could be a place to put the thread with a link to the You Tube video showing Taylor's string install process. Just a thought.

[cotten]

...The stock tool turned at about 130 rpm, which I timed by count revolutions of a masking tape flag paced ion the drive end.  The modified tool rotates faster than I can count the revolutions...

Very cool modification! Thanks for sharing that with us.

But as someone who uses either his hand or a manual string winder, I have to ask:  is 130 rpm not fast enough? I'm not being critical, I'm really trying to understand, and would appreciate your help in getting this into my hard noggin! 

cotten

[Gary0319]

...The stock tool turned at about 130 rpm, which I timed by count revolutions of a masking tape flag paced ion the drive end.  The modified tool rotates faster than I can count the revolutions...

Very cool modification! Thanks for sharing that with us.

But as someone who uses either his hand or a manual string winder, I have to ask:  is 130 rpm not fast enough? I'm not being critical, I'm really trying to understand, and would appreciate your help in getting this into my hard noggin! 

cotten

I'm curious about this speed business, too. I use the Ernie Ball powered string winder which turns at 200 RPM and for the life of me I can't imagine needing something faster. Maybe if I owned a guitar store and was faced with changing the strings on 50 or 100 guitars or was a Taylor tech doing string changes at a road show, more speed woud be an advantage; but 200 RPM is fine for keeping my 7 guitars in shape.

Gary

[cjd-player]

But as someone who uses either his hand or a manual string winder, I have to ask:  is 130 rpm not fast enough? I'm not being critical, I'm really trying to understand, and would appreciate your help in getting this into my hard noggin! 

cotten

First, I'm a consummate tinkerer, and this looked like a fun project on a cheap tool to pass some time in cabin fever season.  Is cold outside here.   Actually, I have never tried using the Taylor stringing method, but there are a large number of favorable reviews.  I have always used the "loop under and lock" method shown on the old Taylor Tech Sheet, and like you, I have always used a hand winder.   

In reading forum responses to the Taylor stringing method and the Ernie Ball String Winder, and after watching the Taylor stringing vid on You Tube I got the impression that one of the issues with the Taylor method is having the winder spin fast enough so that the tuning post quickly grabs the end of the string when it is inserted into the post hole.   In reality, that may not be critical, but I don't know.

When my on-line-ordered power winder attachment arrives, I will try the Taylor method with my new tool for the first time.

[Gary0319]

I use the Taylor method with the Ernie Ball winder and never have any problem with the post grabbing the string. I leave about 1/8" of the string exposed past the post hole for the wound strings and about 3/4 of an inch on the unwound strings (trim after the string is partialy wound)...........zip, all done, and no blood.

Gary

[not darth]

Very cool mod!
Did you notice, did the torque decrease since you increased the speed?
I would think it should, given the conservation of energy.
This would be good, in my mind, I don't like the idea of high-speed/high-torque anywhere near my Taylor!   

Also, if the stock tool rotated at ~130 rpm, and the planetary gears were 20 tooth, I think that means that now the toolhead spins at ~2600 rpm (130x20).  I'm sure I'll be corrected if this is incorrect.

-K
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EDIT: Hmmm, thinking more about the gear ratio, when stock, the 20 tooth planetary's engaged the 6 tooth sun, for a ratio of 3.33:1 so by removing that geardown we're not increasing the speed by 20x, but by 3.33x so the new speed is actually more like 433rpm (130 x 3.33).  Is that right?

[Cindy]

This is excellent info, Carl! Thanks for the tutorial. I doubt I'll make any changes to my B&D cordless screwdriver as I don't mind the slow winding speed, but my biggest problem is that the high E string pops out of the hole before it gets anchored. So I can see the benefit of having increased speed!

[cjd-player]

...
Did you notice, did the torque decrease since you increased the speed?
...
 so the new speed is actually more like 433rpm (130 x 3.33).  Is that right?

 
I have no way to measure the torque, and I did not before the mod, so I don't know.

Sounds like you know gearing calculations.  About 400 rpm for the new speed is probably about right, comparing it to my hand drill.   It's much faster, but not crazy fast.

... my biggest problem is that the high E string pops out of the hole before it gets anchored. So I can see the benefit of having increased speed!

The need for speed seems to be the question.  And we have two opposite answers right here in this thread. 

[Walt Q.]

Outstanding idea and explanation. I'm gonna give this a shot.

[taylor96]

  EXCELLENT article and pics of the modification to the driver... I just bought one this morning  (14.99 at Walmart here in Canada)  and JFYI  29.99 at a Zellers store ))   Great unit.. I don't think I would modify it at this time as it appears to be fast enough for me, but I will keep your article in case I do decide to in the future , thank you

Also I agree with the comment made John429.. This suggestion to me makes a whole lot of sense... so 2 votes now... 

""Josh - just an idea for consideration. Maybe a future subforum to capture neat "Do It Yourself" tech articles like this one that folks will come up with from time to time? Also, that could be a place to put the thread with a link to the You Tube video showing Taylor's string install process. Just a thought. by john429 """

[not darth]

...
Did you notice, did the torque decrease since you increased the speed?
...
 so the new speed is actually more like 433rpm (130 x 3.33).  Is that right?

 
I have no way to measure the torque, and I did not before the mod, so I don't know.

Sounds like you know gearing calculations.  About 400 rpm for the new speed is probably about right, comparing it to my hand drill.   It's much faster, but not crazy fast.

... my biggest problem is that the high E string pops out of the hole before it gets anchored. So I can see the benefit of having increased speed!

The need for speed seems to be the question.  And we have two opposite answers right here in this thread. 

Very cool.  I guess the only way I'd measure torque would be to chuck a phillips bit into the toolhead and grab it with gloved fingers to see if I could stall the motor.  And then trying it again after the mod.  (I'm sure real engineers have fancy tools laying around and they could give us the numbers, but I'm just a tinkerer and my fingers-torque-wrench is all I've got, lol.)

I do remember enough high-school physics to know that in a lever system if you increase the movement you decrease the force, and vice versa. 
*Since gears are just rotating levers the same should hold true.*
 
That's actually advantageous as you really don't want high torque on those precision tuning machines found on a multi-thousand dollar guitar. 

-K

[cjd-player]

Very cool mod!
Did you notice, did the torque decrease since you increased the speed?
...   

I received my Dunlop Turbo Winder yesterday and gave the modded screwdriver a try with it.  So to answer your question, yes, the torque has been reduced.

Much to my delight, as the string begins to tighten, the screwdriver actually slows down. 
I can actually tune to pitch with the driver because when the string is that tight, the driver slows down a lot.
Certainly not accurate enough to actually stop at the desired pitch, but I can get close.

Now, if this could be combined with an electronic tuner to control the motor ... hmmmmmmm