Bill Palmer - Posted - 12/04/2009:  22:21:17

---

I got an e-mail from someone who apparently has read my page on head tensioning, and hasn't understood much of it. So I wanted to post an answer to something that is in the archives right here:

http://www.banjohangout.org/forum/p...&FORUM_ID=12

I've been adjusting head tension on banjos for more than 40 years by using the same process professional drummers were using during the 1970's (and for decades before that). It's a process called "tap-tuning." There are a couple of different approaches to tap tuning a banjo. One is to go for a certain pitch and another is to go for the resonant frequency of the banjo. Each approach has its merits and its drawbacks.

If you try to tune the banjo to its resonant frequency while the resonator is off the instrument, you will find that this frequency changes when you put the resonator back on. I'm not going to go into the physics of this; there are others here who can do that to their hearts' content. There is also a potential here for harsh resonances. If you tune your banjo to its resonant frequency, and that resonant frequency coincides with a specific pitch you play in your repertoire, you may find that the banjo goes crazy when you hit that note, and the balance of your band goes out the window. If that does happen, the fix is pretty simple. Lower or raise the tension just a smidge to get away from that pitch. If you have loose pieces of metal or string segments on your banjo (such as between the tailpiece and the bridge) and they resonate at inopportune times, you need to mute them, either by dampening their vibration or by snugging them down. For string segments, a piece of felt woven into these segments will help.

If you tune the head to a specific pitch, such as G# or Bb, you might run into this odd resonance problem, or you might not find the pitch at which your banjo responds the best.

I generally tap-tune the head until I hear the banjo (without the resonator) come to life. Then and only then, I measure this tension with a Neary Drum Torque. I use this measurement to equalize the tension on all the nuts.

I have been asked about the Drum Dial. This is a device that uses a dial indicator to show the deflection of the head at a given point. It is a wonderful device if used on a snare drum or a tympani. There are two reasons for this. The lugs on these types of drums are far enough apart that adjusting the tension on one of them does not affect the tension on the others as much as it does on a banjo. A banjo has brackets that are about 1 1/2" apart. When you tighten one of them, the ones next to it loosen. Also, unless you have a top tension banjo, you have to turn the banjo over to tighten each bracket. The people who make the Drum Dial asked me why I did not recommend their product. I explained how a banjo works, and they agreed that it would not really be suitable, unless, of course, you could make some kind of a jig to hold the banjo horizontal, about a foot off the work surface, so you could get underneath it to adjust the nuts. Even then, it would be a rather tedious process.

In fact, when I tested the Drum Dial on a couple of instruments, I tensioned them using my normal process first. Then I adjusted the tension with the Drum Torque. Then I checked it with the Drum Dial. The results were rather interesting. The Drum Torque produced results that indicated that its tension adjustments were within ± 1% of what the Drum Dial showed. That's very close, and it takes a heck of a lot less time to work with it.

howseth - Posted - 12/04/2009:  23:18:02

---

I check the tension on my 12" open back Ome with a Drum Dial - perhaps, about once every month and half . The banjo sounds quite good at 91 on the Drum Dial - with the head quite close (-1%) to that 91 all around - But, I do notice that all the brackets are not at the same tension to achieve this result. Some are tighter - some are looser. However, the banjo sounds quite 'alive' this way... and I do not find this result hard to achieve with the Drum Dial.

Would you suggest that using a Neary Drum Torque instead - I would get a better result in the sound? What would be the difference?

Howard

Bill Palmer - Posted - 12/05/2009:  10:41:33

---

For one thing, you wouldn't have loose brackets. The fact that some of your brackets are loose and others are tight means that you do not have even tension at the brackets. Try this experiment. Remove all the loose brackets. Then see what your Drum Dial tells you.

By the way, this supports my statement against using the Drum Dial. Would you use anything BUT a torque wrench to tighten the heads on your automobile's engine?

I firmly believe that if you have even tension all the way around, ALL of your brackets will have the same tightness. It is that evenness of tension that produces an even response on the head.

BTW, you shouldn't be TUNING your head with the Drum Dial or the Drum Torque. You should be tuning it with your EAR. Read my setup page.

There are some people who use differential tension -- higher tension on the treble side of the head, lower on the bass. They seem to get decent results. But they won't explain the system, and since my banjos sound fine, I'm not going to mess with them.

Here's another thing, though. Some of the people I have been in communication with use their electronic tuners as a reference when tightening their heads. This won't work. The pitch of the head fades away too quickly for most tuners to detect. A tuner requires a sustained note to function properly.

---

Edited by - Bill Palmer on 12/05/2009 10:43:39

grm405 - Posted - 12/05/2009:  11:15:01

---

I have never been able to get a note on a tuner from a head tap. Just not loud or long enough to register in my experience. If you ever record and analyze a note (plucked string) and head tap (I have done plenty) you find they are totally, totally different.

The plucked note has harmonically related peaks corresponding to each order of the vibrating string, from 0 up to probably 10 or 12 before they fade into noise. When plotted conventionally (log frequency scale) they are like a row of equally spaced telephone poles. Not only that, the largest peak of the harmonics is not the nominal fundamental, but, when I measured them, the second order peak. This means the loudest peak for the common G# tuning is not G#, but D#. The fundamental is almost immeasurably low, about 60-70 db below the loudest. This probably has to do with where be pick the string, ie not in the middle, but very near the end.

The head tap has a few unrelated single peaks. When I measured this stuff, most were fixed peaks and did not move as I tightened the head. One which may have was difficult to track as it moved through fixed peaks. I gave up trying to analyze tap-tuning after a few dozen experiments. I have no confidence in tap-tuning to a note, as there are just to may obscuring frequency peaks for a tuner to find one.

I do find it interesting that commonly quoted notes of D# and G# as in Siminoff for the resonator off and on are both harmonics of the same note. I suspect that what is really happening is changing the relative intensity of the harmonics by removing the resonator to make one or the other more prominent. I suspect that when you tune the head, you are really just optimizing the efficiency of the head to produce a particular frequency range, not changing the note.

It was your website which encouraged me to buy a torque wrench 12 years ago. Haven't regretted my decision. The drum dial just seems like a difficult way to achieve a simple task, equalizing the tension on the head.

Gerry

TTreppa - Posted - 12/05/2009:  11:35:47

---

Bill,
What is address to your home page where you talk about head tension? I use an inch pounds torque wrench. I would like to know more about "tap tunig." Thank you.
Terry Treppa

jpiperson2002 - Posted - 12/05/2009:  11:40:16

---

Both the torque wrench and drumdial have limitations. Personally I tighten up my new heads by snugging the bracket nuts with my fingers and then using a bracket wrench to turn each of them the same amount. Once the head tightens up I use a drumdial to check tension as I go around the head to tighten the nuts in sequence.

The main limitation of using the torque wrench alone is that the threads and lubrication on the nuts vary between brackets, so the force required to tighten each nut can variy considerably from bracket to bracket. The drumdial looks at the effective tesion in the head at different points and as pointed out already, some of the individual brackets may be tighter than others. I don't see that as a problem, if I find a loose nut when the head is up to the correct tension I just snug up the nut a bit. Different pots come with different numbers of brackets. It hardly matters if a few brackets are looser than others as long as the average tension acorss the head is correct.

John Piper

Kenneth Logsdon - Posted - 12/05/2009:  12:10:57

---

Unless the threads have been damaged in some way the amount of torque difference on each one is very neglilgible for our use on banjos... Its the most accurate and standard method for all items requiring precision..

howseth - Posted - 12/05/2009:  13:34:39

---

"if I find a loose nut when the head is up to the correct tension I just snug up the nut a bit"

Yeah, that's what I tend to do after getting those 'even-all-around' Drum Dial measurements.

Howard.

grm405 - Posted - 12/05/2009:  17:19:41

---

"the threads and lubrication on the nuts vary between brackets, so the force required to tighten each nut can variy considerably from bracket to bracket"

Do you have any experience to back this up?? I have, and I find it largely a red herring. The threads on brackets are quite small and have very, very little friction compared to the torque applied. These are not 1/2" bolts, but 8-26 threads for the most part. It is only with damaged threads where this is true, and I have found one damaged hook in the 300 or so I have tightened. It was obvious by both sight and visually before I applied the wrench.

Lets not forget that all a torque wrench is doing is putting an objective number to the "feel" we all used to use to tighten the nuts evenly. Any error we encounter is the same whether it is the wrench doing it or your fingers. Except the torque wrench is more accurate than most peoples fingers and easier to explain to a newbie.

Gerry

Hotrodtruck - Posted - 12/05/2009:  18:25:51

---

Bill, I'm still waiting to hear the story about the $20.00 Mexican gold piece and the Gibson tone ring(s).

Mike Casey - Posted - 12/05/2009:  19:35:08

---

When I tension a head I snug it up free hand then with the Drum Torque to pull the head to an even tension as measured by the Drum Dial. The torque wrench on a banjo brackets is not the most accurate measurement. As has been pointed out bracket nuts and head elasticity are not lug nuts on a car wheel. The DT will give you a good read, but the D D tells you exactly how much and where... good information. If you want the very best out of your banjo you should have even tension all around the head and the head tightened to the point that it sizzles when its picked. I find it is easier to use good measurement tools to get to that sweet spot, especially with a finiky banjo.

FiveStringPop - Posted - 12/05/2009:  20:34:27

---

quote:

---

Bill,
What is address to your home page where you talk about head tension? I use an inch pounds torque wrench. I would like to know more about "tap tunig." Thank you.
Terry Treppa

---

Bill has an interesting web site and has packed a lot of information into it.

Here is the home page...
http://www.banjowizard.com/banjset.htm

Here is the page on head tension...
http://www.banjowizard.com/hedtens.htm

jpiperson2002 - Posted - 12/06/2009:  06:11:58

---

quote:

---

Originally posted by grm405

"the threads and lubrication on the nuts vary between brackets, so the force required to tighten each nut can variy considerably from bracket to bracket"

Do you have any experience to back this up?? ....

---

That's a fair question Gerry. I only have a modest amount of experience with banjo nuts, I own 4 banjos but have only done 9 head replacements on them so far. I was trained as a mechanical engineer so the general topic of point loads and force distribution is familiar but my limited experience with different types of banjo nuts doesn't make me an expert like someone who's changed a lot of heads on many types of banjos.

I should have pointed out in my initial post that the variance in torque required to snug the nuts on own my banjos is likely related to the fact that they're entry level products (Goodtime, GT CC OT, GT BG250, Enoch Tradesman). The Tradesman in particular seems to have better quality bracket threads than the others and they tighten smoothly around the head with the BG250 next in line. The CC OT and Goodtime have noticeable variation in the force required to tighten them up. I assume that better quality banjos than I own myself would have less torque variation than inexpensive banjos or old banjos with variable thread quality or corrosion.

Some of my brackets are so thin that their hooked ends flatten out a bit when tightened to the desired head tension. I wouldn't trust a torque reading on those but it probably wouldn't be a problem seen with more rigid brackets. Another consideration is that we can't know whether most of the people reading these posts have ever tightened or changed a head before. It's quite possible that they won't lubricate the nut threads evenly before tightening or mount the tension band evenly when replacing a head. Errors like that might skew the torques reading for individual brackets but they wouldn't effect the accuracy of the tension readings indicated by a drumdial.

Luckily this isn't an either/or situation. I've taken your advice and ordered a Neary drum torque wrench while writing this post, only $34 including shipping from Amazon. The next time I swap out a head I'll use the torque wrench to pretighten all of the nuts the same amount and then bring up tension across the head using the drum dial as a reference. I think we'd agree that each tool tests for a different physical characteristic and that they compliment rather than exclude each other. A person who doesn't have any experience tightening heads can't go wrong using both devices especially if they're only tightening or changing a head every few months.

John Piper

---

Edited by - jpiperson2002 on 12/06/2009 10:06:57

Bastertone - Posted - 12/06/2009:  13:44:42

---

I did the same thing, amazon arriving in two weeks or less. New opportunity for tinkering.

jpiperson2002 - Posted - 12/19/2009:  05:23:34

---

My new Neary drum torque wrench arrived the other day and I was curious to try it in combination with a Drumdial. So I backed off all of the nuts on my Goodtime and GT BG250 heads until they were loose enough to reposition the heads, wiped the bracket threads with an oily cloth to be sure they were all lubricated, and tightened the nuts by hand until there was some resistance. Then went around the head with the torque wrench gradually tightening the nuts and testing the head tension with the drum dial.

The Neary definitely makes the whole process easier and faster than using the regular tuning wrenches. I wasn't sure how much torque would be required so I was very conservative at first only going up a couple of points on the torque dial for each pass around the head.

I was surprised that some of the nuts would require considerably more turning than others to bring them up to the same torque as the others, requiring anywhere from 1/8 turn to 3/4 turn. A couple of nuts even needed to be backed off slightly on each go round to keep them all at the desired torque. This just shows that the tension is distributed unevenly across the head as it is tightened at specific points and that each bracket in the sequence reacts slightly differently to the sum of pressure points on the head.

So I got the nuts all tightened up to the same torque and to a sound I liked, which for the Goodtime turned out to be about 11 on the torque wrench dial for 89 on the Drumdial, and for the GT BG250 turned out to be about 13 on the torque wrench for 90 on the Drumdial. When I went around the heads with the Drumdial the last time after the nuts had been torqued evenly the Drumdial tension reading varied 2 - 3 points at different spots on the head. So I let the heads sit over night to settle and then hand tightened some of the nuts to even out the Drumdial readings around the head.

I'm waiting for a skin head to arrive for my 12" Tradesman and will have another chance to test the tools in combination when it gets here. Some points to consider;

My banjos require 3 different size tuning wrenches and it was difficult to keep the small wrenches from slipping off the bracket on the end of the Neary. I ended up taping them in place but there needs to be a better way (this is discussed in other posts about the Neary). Midway through the process I ordered this wrench which fits the 3 standard size banjo nuts: MYBANJO three head tuning wrench http://elderly.com/accessories/items/BTW.htm I plan to use a rubber band to hold the single 3-way wrench on the end of the torque wrench.

The smallest nuts were on the Goodtime and those showed the largest variation in torque vs the number of turns required. The Goodtime brackets are relatively thin and a few of the bracket hooks bent back and popped off the head when they were being tightened. Before I had the torque wrench I'd just left those brackets less tight than the others as they started to bend and used the Drumdial to verify an even tension across the head. Because I was testing the torque wrench this time around I just rebent the end hooks on those brackets back into position and carefully eased them up to the same torque as the others. Some of the nuts still needed to be selectively tightened at the end to get the Drumdial reading even all around the head.

The BG250 has heavier brackets than the Goodtime and none of them bent or popped off the head while tightening. I still needed to selectively tighten some of them to get a consistent Drumdial reading at the end but the variation was less than with the Goodtime.

My analysis of this is that the Neary torque wrench and the Drumdial tension meter are complimentary tools. The torque wrench makes it much easier and faster to tighten the head evenly compared to using a regular tuning wrench. It can bring a head up to a fairly even level of tension on its own assuming that the bracket threads are lubricated and the head is on straight and so forth. The Drumdial shows the actual tension at any point on the head and that's mainly what I'm looking for. The head tension can be very uniform even when there is a large variation in the torque reading on individual brackets.

If I were limited to a single device I'd use the Drumdial because it tests for even head tension and that's what matters to me. I'd recommend the use of both devices for less experienced people who don't tighten or replace their banjo heads very often and who can afford the ~$100 it would cost to get both devices. The folks who have owned and worked on many types of banjos over the years may not need any fancy gadgets like this to get the job done but in my case they are very useful tools which help to make up for a lack of expertise and experience.

John Piper

---

Edited by - jpiperson2002 on 12/19/2009 07:18:10

jpiperson2002 - Posted - 01/03/2010:  10:27:55

---

In case you're interested here are some pictures of a Neary torque wrench used with a 3-headed Mybanjo tuning wrench from Elderly. I've seen a similar 3 headed wrench listed in the classifieds recently.

The Neary comes with two removable end brackets. The end bracket shown below can be used with a standard tuning wrench though it's considerably wider than my tuning wrenches and slips around unless it's held in place with rubber bands or tape. The Neary also comes with a socket bracket that accepts a special ~$20 conversion fitting (sold separately at http://www.janetdavismusic.com/drmtrq.html) which allows it to accepts standard 1/4in socket wrench fittings. See other posts about the Neary for alternate ways to attach 1/4in sockets directly to the torque wrench without buying the conversion fitting.



I need all 3 sizes of wrench for my banjos so I like the combination of the Neary with the 3 headed "Mybanjo" tuning wrench. The 3 headed wrench has a wide rubbery grip which almost fills the gap in the holding bracket on the Neary. A rubber band is sufficient to hold the wrench securely in place;



Here's a close-up of the dial. The end bracket with the wrench is connected to a spring loaded rod inside the torque wrench, so when you tighten the nut the whole inner face of the Neary spins around until the arrow points to the desired tension;



John Piper

steve davis - Posted - 01/03/2010:  10:44:23

---

As far as equal tension,I think some of the problem lies in using a criss-cross pattern
to tighten the head as you would with a wheel or cylinder head.

A stretched membrane is a different animal than one flat plate tightened against another flat plate.

When you go from one nut to the next in order,you can easily feel the matching tension
of the previous nut.

When I tap tune my banjo head I get the exact same note whether the resonator is on or off.
I just hear the tension of the head.

Glenn Tate - Posted - 01/03/2010:  14:41:06

---

I also tap tune by banjo heads, but I use the Neary Torque wrench to do the tightening. When head "comes in" I am already torqued the same all the way around. Also, whether right or wrong, I put a small amount of light sowing machine oil on a rag, and wipe the tension hook threads across it. It seems to alleviate the squeeking of some of the nuts when tightening them.

El Chino - Posted - 01/03/2010:  20:35:59

---

I'm new here, but I may have something to add to this topic.
I've had a few banjos over the years and have built many racing bicycle and motorcycle wheels (hey, Geoff Stelling is a biker).

Banjo heads and spoked wheels have something in common; for best performance, they should have equal tension all around.
On this, everyone would agree.
For banjos, that means the head is stretched uniformly across its plane; for wheels, the rim is round and in a flat plane.

I have omitted some points for brevity, but:

On both banjos and wheels, there are proponents of tuning by sound (tap tuning heads or pinging the spokes) or by tension (torque wrenches). I think its a combination of both.

I believe it is very possible to have a perfectly tuned head, with uniform "Drum Dial" tension all around, but with some of the bracket nuts at differing torques from others.
Why?; for one thing, the tension hoop may be a bit out of plane so that some brackets need to pull down harder than the others.
For another, the metal in the hoop may not be uniform in stiffness (isn't there a brazed joint in the hoop?)
The tension method relies on perfectly uniform thread engagement, chrome thickness etc. (ie. friction). In a perfect world, it would work fine by itself.

The bottom line is that the head is stretched uniformly across the diaphragm for banjos. For this, I'd say the Drum Dial is the final arbiter when the right note is gotten.
Bottom line for wheels is that the rim is round and in a flat plane (my spoke torque wrenches just get me in the ballpark), the truing stand has the final say.

steve davis - Posted - 01/03/2010:  20:51:54

---

There's no reason to have nuts that are looser than others.
They all feel like the same torque to my fingers and share the load equally.
The hoop is even all the way around and the crush on the tonering/rim is even.

Drivel - Posted - 01/03/2010:  22:04:20

---

I use my computer. I already have one, and the program was free. Head tap on a Cascade, screen shot on my home page.

I'm new so I've only replaced a couple of heads. I used a depth gage ( Cheep ) to keep the hoop level, about 1/100" all around. ( this is probably to slow a process for those in production ) I used the socket from a screw driver type socket driver without the driver. When all the brackets were finger tight the head was G3 196Hz. all over the head on both Banjos. I then put the handle on and tweaked the frequency to what I wanted by going around 1/4, or 1/8 turn. For Free.

Bill - The tinkerer

A mic like this would be good enough. http://cgi.ebay.com/Hands-Free-Clip...em3ca8e2589c

---

Edited by - Drivel on 01/03/2010 22:27:25

goldtopia - Posted - 01/04/2010:  00:10:43

---

As these microphones are so cheap I have ordered one on eBay. I hope it works as well (or better) than tap tuning.

Bill.O

www.bluegrassminstrels.co.uk

Drivel - Posted - 01/04/2010:  00:39:00

---

I use a mic. that had a little plastic housing to stick it on the computer somewhere, but I lost the plastic part. Now all I have is the guts to it. looks like a transistor on the end of a wire. Anything will work. You don't really have to damp the strings, Audio Tuner homes into the loudest sound. It's neat to play with. You can find the frequency/ note to 'ANYTHING'.

Bill

Scout70 - Posted - 01/04/2010:  03:30:52

---

This is an interesting article about a very technical approach to dialing in a banjo. I can see how this could be an obsession for some trying to find the "perfect" set up. Funny how JD or Earl never went down this path.

steve davis - Posted - 01/04/2010:  05:27:38

---

I don't use the head note to find my perfect set-up.
I use my perfect set-up to find the head note.

Hotrodtruck - Posted - 01/04/2010:  08:09:40

---

I used a Neary Drum Torque for several years with O.K. results. I would still have to tweak the lug nuts to get a consistent tap tone all the way around the head. The lug nuts do not have to be at equal torque, but none should be "loose" - meaning all should be at least a little more than finger tight. Others have pointed out the potential problem of relying strictly on torque readings, and those of us who have used torque wrenches professionally know the pitfalls to be wary of. The torque wrench is a useful tool and can get in the ball park, but the objective is head tension- not even torque. That is why I use the Drun Dial now. I know what tension I want, from previously finding what I like; I can read it directly (torque reading on the lug nut is an indirect method); and it provides the best consistency.

However, if you can set your banjo up the way you like it, by whatever means, that is all that matters

goldtopia - Posted - 01/04/2010:  08:23:17

---

Of course the perfect set up is for each individual. to decide. I have found there is an area of tightness that gives the best sound. For a Fitch Palomino it is somewhere between G and G#. Above or below gives a different kind of resonance, a dullness like the weather on a skin vellum. It is probably different with each banjo, only the owner can decide that. There have so many comments about this, one of the most intriguing is the sound of a dinging string, usually the fifth string which could be attributed to the harmonic of the head tuning. I had this problem a while ago and overcome it, by another BHO tip of putting a small piece of paper under the string on the bridge. If this is the remedy to enable the head tuning to be kept then it may be worth considering. These drum dial things do work, there's no doubt about that because they enable the head tension to be measured for all round evenness. But they cannot be relied upon for the tap note because different makes of drum dial have different readings also different makes and types of head.

Bill.O

www.bluegrassminstrels.co.uk