Visit Tony Trischka School of Banjo

 All Forums
 Other Banjo-Related Topics
 Banjo Building, Setup, and Repair
 ARCHIVED TOPIC: Head tension gauge/DIY


Please note this is an archived topic, so it is locked and unable to be replied to. You may, however, start a new topic and refer to this topic with a link.

Page: 1  2  

steve davis - Posted - 08/15/2011:  19:58:23



The amount of head deflection caused by the bridge pressure can be a good indicator of the head tension.



It can be measured with a straight edge and a coin as shown below.A quarter is about .065 thick and just fits under the 10" straightedge,near the bridge, without touching the stick with the head tuned to A..



If the head were tighter,the quarter would bind  between the straightedge and head.This can be a good way to keep you from overtightening the head and tearing it.



This is an old Remo head and I've never torn a head that was to tuned to A or below.



Click to EnlargeClick to Enlarge



This straightedge is 10" long to fit inside the hoop(and slightly off center).



I just taped a piece of sandpaper to a flat surface and sanded the edges of the stick.I backlit the edges with a flashlight while holding them on the flat surface.This told me when to stop sanding.



Edited by - steve davis on 08/15/2011 20:10:42

banjocat - Posted - 08/15/2011:  20:39:14



Steve,



I look forward to reading your posts and you sharing your knowledge. You shoot from the hip, and I like that. I will check this procedure out. You know, you can't own a banjo without "tinkering" and such. Anyway, you have helped me in the past and I sure do appreciate it.



Regards,



Spencer



Edited by - banjocat on 08/15/2011 20:40:20

steve davis - Posted - 08/15/2011:  20:47:23



That's great,Spencer.I've always been frustrated trying to use words to answer the question,"How tight is too tight?" and the straightedge/coin seemed very clear.

I'll tune the head to G and G# and measure those,tomorrow.



Edited by - steve davis on 08/15/2011 20:48:05

dickinnorwich - Posted - 08/16/2011:  06:20:05



Steve:



I'm wondering if a quarter is the best device to use for measurement. With inflation, I know for a fact that my quarters are not worth what they once where and have considerably shrunk in value. Geographical variations in cost of living is also a factor.  Perhaps we should come up with a more stable measuring device.



Just kidding of course. If I actually had a quarter, I would try your technique on the banjo hanging on my office wall. Maybe next week after we get paid.



Question: How does this work for archtops with a reduced effective head size?


KennyB - Posted - 08/16/2011:  06:37:47


I don't want to be discouraging, in fact I'm really looking forward to reading about what the differences would be between A G and G#, but there are a couple more variables that pop up in my head.
The head is deflected downward by the force of the strings on the bridge, which will depend on the break angle over the bridge (tailpiece setup) and the string tension (dependent on string gauge, scale length and tuning - the last two are usually standard).
Also, the note that the head rings at will be dependent on the weight of the head material, and the bridge, independent of its stiffness (deflection under force).
Of course if you keep all those things constant, it should be a good way to control the consistency of setup of an individual banjo, or ones with the same components/characteristics.

steve davis - Posted - 08/16/2011:  07:13:17


I only have weatherkings and am guessing that the 5 Star or Ludwig would deflect less due to its extra couplathou thickness,but this is pure speculation on my part.
As to the archtop results I would expect 5 cents change back from the quarter,Dick,but again,this is speculation.

I will now measure the deflection of the G and G# tensions on a 25 year old weatherking.
At some point,if I ever buy another head,(I have a dozen old ones)I will measure the deflection on a new WK.

steve davis - Posted - 08/16/2011:  07:47:28


G#...2 dimes
G... penny/dime
F#... quarter/dime

Oh and a quarter is only .040+

dickinnorwich - Posted - 08/16/2011:  07:52:10



quote:


Originally posted by steve davis




I only have weatherkings and am guessing that the 5 Star or Ludwig would deflect less due to its extra couplathou thickness,but this is pure speculation on my part.

As to the archtop results I would expect 5 cents change back from the quarter,Dick,but again,this is speculation.



I will now measure the deflection of the G and G# tensions on a 25 year old weatherking.

At some point,if I ever buy another head,(I have a dozen old ones)I will measure the deflection on a new WK.






Steve:



I had to borrow a quarter from the IT person in our office but after convincing her that I would return it unharmed, I tried your deflection test on my archtop (Orpheum) hanging on the wall. I could just pass the quarter under a ruler at the bridge. This head was tuned to G#. Now I have to go return the quarter.



Edited by - dickinnorwich on 08/16/2011 07:52:52

steve davis - Posted - 08/16/2011:  08:07:39



I would have expected a G# 9 1/2 head to deflect at a direct proportion to area.

like 20%? less.My quarter is a tad loose under the flathead stick.



I should get an archtop set up with a radius fretboard to get some results from these other combos.



Edited by - steve davis on 08/16/2011 08:11:04

uncle.fogey - Posted - 08/16/2011:  08:33:07



Sounds like an excellent idea, Steve - there's a lot of uncertainty out there about head tuning.



This brings up a question I can't answer - This is an abstract question, and I don't use a drum dial or tune all banjo heads to the same note anyway, BUT:



When we tune a head, let's say to a G#, is it the NOTE we're after, or the TENSION / TIGHTNESS OF HEAD it takes to get that note? 



If, as others have said, different thicknesses of heads deflect at different rates, then will all 11" heads of all thicknesses ring the same note if torqued to the same inch/pounds?  Will all heads turned to a certain tension deflect the same amount?


steve davis - Posted - 08/16/2011:  08:57:10



The note is the aural identity of the preferred tension,Ken.It can also serve as a benchmark for excursions into other tensions and bridges...being able to easily return to "home" for comparisons.



I have found a high consistency in the strength of pvc ropes of a given size and believe that there is similar consistency in mylar heads of a certain thickness,.007 for instance.

I imagine they pretty much stay with the same formula for mylar so as to predict its performance and durability for warranty's sake.



My results with a couple of old heads aren't a complete scientific method,but I think will hold up well with new and old .007 mylar heads.

I really need to get a brand new head for a good comparison.Some facts about elasticity over time may be forthcoming.



 



Drum dial or torque wrench numbers compared to deflection would be interesting,too.I don't have those tools.



 



Yes,Ken,I expect heads of the same thickness and diameter to deflect the same amount with string gauge being the variable.



Edited by - steve davis on 08/16/2011 09:04:48

uncle.fogey - Posted - 08/16/2011:  09:12:30



Thanks, Steve.



The benchmark idea makes a lot of sense.



I have always wondered about that, and could go either way with it. I think there are probably a lot out there who are trying to get a certain note for musical reasons, real or imagined, rather than a benchmark. The times I have used a piano to tune a head to a G# or A, I have always deliberately tuned it somewhere in between notes to avoid sympathetic frequencies.  Whatever note I have tuned to, I always wind up changing it up or down later as the banjo settles in.


steve davis - Posted - 08/16/2011:  09:19:26


Its especially handy to maintain a consistent head tension(tone) during the settling in period of a new head and for not having to tune it tight and wait for it to settle down...right at the same tension all the time,no variance.

uncle.fogey - Posted - 08/16/2011:  10:37:58



When I am making a banjo, I always assemble the pot with the head tightened in order to fine-tune the heel angles and dry-fit the neck.  to do this, I tune the head to a G# using a piano.  Then, when I have the whole thing finished, string it and tune it up, I have to adjust the head tension to get the best sound.  I don't pay much attention to the note of the head at this point, but listen to the sound of the banjo and watch the bridge deflection.  The down-pressure of the strings pushing on the bridge alters the head note anyway.


grm405 - Posted - 08/16/2011:  11:03:31


Seems that everyone is ignoring what KebbyB says. He is entirely correct in his assessment.

The deflection of the head is dependent on 2 variables, the tightness of the head (and its tensile modulus) and the downforce on the bridge. If the latter is different from setup to setup then the measurement will be different. The downforce is a function of the string gauge, scale length (generally not a major factor, but since Bishline, RK75 and some other banjos use non-standard scales you must be aware of it) and most importantly, string break angle. If fact, the amount of deflection would be zero with no break angle as there would be no downforce at all.

This technique would be useful, once you have your setup determined, to maintain the tension. It will be of no use unless you specify the EXACT conditions of your setup. However, since the drumdial essentially measures the head tension mostly independently of the other factors, it would seem more useful.

FWIW I have measured the deflection of the head (using a dial caliper and a straightedge) as about 0.100 at either end of the bridge

Gerry

steve davis - Posted - 08/16/2011:  11:39:50



I just gave you the measured results of 4 different tapped note tensions.

On a "standard" Gibson scale .head thickness and string gauge.

I could measure it with my dial indicator,but that's kind of like measuring a wall stud with a micrometer.



I'll be waiting to hear how close others' comparisons are.I think they'll be very similar in most cases.



 



How about a comparison of drum dial readings compared to deflection and/or torque wrench/deflection numbers.



Edited by - steve davis on 08/16/2011 11:41:53

uncle.fogey - Posted - 08/16/2011:  11:47:27



I would like to see a comparison of drum dial / torque wrench settings vs head notes with different heads - that would be interesting.



PLUS head note strung vs unstrung.


steve davis - Posted - 08/16/2011:  11:52:18



And archtop/flathead differences.Extra light and heavy strings,footprint area,etc.



All this thread is about is how the bridge rides higher or lower at certain tensions (which I identify by tapping the head)and how the tapped note tension can be found by someone that can't hear that tapped head note.



It can be found by adjusting the deflection.That is to say if someone wanted to hear how an A head sounds on their banjo,they can find that A head with a straightedge and a quarter.



Edited by - steve davis on 08/16/2011 12:02:46

uncle.fogey - Posted - 08/16/2011:  13:59:53



Steve,



It was a good thread, it brought on a lot of discussion - made ME think about things I hadn't thought of, so thanks, and I think your deflection gauge, which was the original subject is a cool idea.



It makes me think of another related thing, which I will NOT bring up.



Thanks again!



Ken


steve davis - Posted - 08/16/2011:  16:01:45



I like how it's available to anyone with a quarter and a stick.

You're welcome,Ken.Somehow it reminds me of the reading of bolt stretch rather than torque.



 



And maybe a clearer way to describe,identify and record head tensions.



Edited by - steve davis on 08/16/2011 16:04:13

DantheBanjoMan - Posted - 08/17/2011:  03:32:46



I am quoting Dick from an earlier post on another thread:



"I'm on my second drum dial. From this experience, I don't think all drum dials were created equal. That is, I think there are calibration differences between units that would yield the same tap note. In some cases, those calibration differences can be in the 5% range.

My newest drum dial is locking down at around 87-89 but my first one was in the 93+ range....after I zeroed it out"



If you understand how a drum dial works, it is likely that Steve's method is a more reliable method of comparing head tension from one banjo to the next.  If I have a Gibson RB 100 with a 5 Star head and Steve has the same banjo with the same head, I should be able to set my banjo to the same tension as his using only a stick and coin even though we are many miles apart. On the other hand, if Steve and I had drum dials, I am not sure that would be possible.   It is also a way for me to measure my own head tension for future reference.



All of the comments regarding he limitations are accurate, but any tool has limitations, and a tool has to be judged by what it can do, not what it can't.  I think this is a very handy tool that is going to be put into use in my own shop right away.


Kenneth Logsdon - Posted - 08/17/2011:  11:07:15


What happened to the member that was gonna make and sell bout the same thing several years ago??? If I remember right he was gonna put on a small marked one on a spring that went up and down as you placed it across the head and just read the deflection by the marks..?????

RBuddy - Posted - 08/17/2011:  14:44:11



What I like about Steve's method is that doesn't require it to consider physics and engineering analysis of a moon shot to provide good info. It doesn't require high level math and it only requires a straight stick and pocket change. Factoring in ALL the variables with precision is just too darn hard and not really necessary. It doesn't even have to result in bringing your head to perfect pitch, to be extremely useful. If you can slide 2 quarters under the stick your head could probably be tightened some and if only a dime it's probably too tight. That tells folks a lot both quickly and cheaply. Adjustments from there can be done to find the point where your banjo just sounds good.



Using Steve's tools as a standard, the user of a specific head on an eleven inch rim could pose the question -"I'm using head XXXX, how many coins can you guys slip under your stick?" And from that get some decent info from other folks attempting a similar setup without anyone having to go out to the shop for tools or a scientific calculator. Ideas like this will undoubtedly save a lot of heads and help folks get within a reasonable range quickly.



Great post Steve!



Brian


steve davis - Posted - 08/20/2011:  09:10:52


rerun

Old Hickory - Posted - 08/20/2011:  10:22:24



New coin? Old coin? How much wear? Which image on the reverse?  Do things like that affect the actual thickness of a coin?  Just asking, because I honestly don't know.



I, too, love the simplicity and old world charm of a stick and a coin to measure head deflection with high levels of consistency.



But I always thought coins were make-do tools when you didn't have the real tool handy at the moment. I use a coin all the time instead of a screwdriver when setting lights for my band gigs.  How wide is this gap?  Gee, I don't have my feeler gauges handy.  Here, use a quarter.  How thick is a quarter?  It depends.



Why not set up a head to your specs then measure the gap with feeler gauges and get the exact answer once and for all?  Just as we do for slot width, string height and neck relief.


steve davis - Posted - 08/20/2011:  11:08:13



I have a 1 inch micrometer that I bought from Ace hardware for $15.Very handy tool for measuring shims after they fit just right or string gauges and a million other things.

.



I just miced 6 random quarters and found 4 to be .0445 with 1 each at 425 and 455.

They need to be measured at the very edge for the highest point.



Plenty accurate enough to be used as a universal "feeler gauge" when it comes to a .007 membrane stretched across 11 inches.

It would be very interesting to see how close to a thousandth different heads showed.

I'll measure mine to the nearest thou for the 4 notes and post the numbers,later.



Coins are pretty close on there thicknesses.

There was a few thousandths gap between the quarter and my straightedge on the A head,so if your quarter is a tight fit under the stick,you should start thinking about not tightening any more.



Sometime I may take an old head and tighten it until it bursts,recording the deflection gap at each 1/8 turn of tightening...Crash test.



Edited by - steve davis on 08/20/2011 11:11:04

steve davis - Posted - 08/27/2011:  13:31:56


I just finished setting up my "new" '79 gold Star G85.
It came with its original high crown head which I changed to a Snuffy Smith medium.
I scrubbed the extra frosting off with a green scrubbie until it weighed the same as a standard Remo.
This head is tuned to G#.One head is a well-worn 25 year old WK.
The other is a previously unused Snuffy extra spray medium WK.

They both deflect the same 2 dimes at a G# tension.
The G# head notes match very closely between the 2 heads.

Banjo Saint - Posted - 08/27/2011:  16:29:47



Hey Steve-



 



First, very clever...



 



Second, the torque wrench and drum dial are handy tools, readily available and cheap.  If you enjoy tinkering, they can be useful tools.  If the L brackets and nuts are not clean however, the torque wrench can give you readings that are not comparable between 2 banjos.



Third, while all the theory is interesting and means of measuring is great, in the end of the day those things attached to the sides of your head should be used for making final adjustments.



 


tdennis - Posted - 08/27/2011:  18:09:24



 I agree w/ banjo saint, all the metrics, dials & measuring tricks can't compete w/ the experienced ear for determining the sound of a  well tuned drum (banjo pot).   Banjoist &  drummers are  both facing the perennial question of  proper tone.   I believe dials & measurements are useful to get one to a rough stage, but the final nuances are in the ear.   It's amazing how an hour or two of trial & error can yield  surprising results,  depending on what type of  mylar or skin head one is using.



Edited by - tdennis on 08/27/2011 18:17:25

slou92 - Posted - 08/27/2011:  18:20:57


Steve, I'm sitting here watching the hurricane knock over my trees and reading the hangout. What height bridge and tailpiece height are you using? I think the amount of deflection would be influenced by these. For example, a 5/8 bridge with a tailpiece up 5/16 would defect less at an A than a head with an 11/16 bridge and 1/4 tailpiece. For comparison purposes, what are your measurements?

steve davis - Posted - 08/27/2011:  19:29:50



A range of variables needs to be set up for a clear picture,but right now

Gold Star 3/4 bridge/Cox tailpiece/Snuffy head(scrubbed down)...2 dimes or .050 @ the bridge foot



2 conversion .656 bridge/Cox TP/old used weatherking from the 80s...2 dimes,also.Both heads G#.



11-22 strings on both...I see its usefulness as a consistency gauge.Once finding the desired tone,measure the deflection.If you have a time where the good tone weakens,measuring that deflection will instantly tell you if the head tension has changed and in which direction.



Edited by - steve davis on 08/27/2011 19:32:41

steve davis - Posted - 09/18/2011:  08:35:40



quote:


Originally posted by steve davis




I would have expected a G# 9 1/2 head to deflect at a direct proportion to area.

like 20%? less.My quarter is a tad loose under the flathead stick.



I should get an archtop set up with a radius fretboard to get some results from these other combos.






 I was too quick with this "logic" as I'm working with a 10" st. edge so that's only about 5% diff...not much and similar readings (coin combos)should be seen with archies.



Again:



A head is 1 quarter



G# is 2 dimes



G is penny and dime



F# is quarter and dime



Edited by - steve davis on 09/18/2011 08:38:50

steve davis - Posted - 09/19/2011:  13:07:48


Most plastic rulers should be quite straight...just cut off at the 10 or the 2.

KI4PRK - Posted - 09/19/2011:  21:52:39



Okay, I just skimmed this topic because I was wondering the question "how tight is too tight".



The highest measurement I see here is an A, but I keep my banjo head (a Remo) tuned to just barely flat of a C#. Yes, I've been told several times that I'm living dangerously, but I happen to love the sound. I can't use this measurement system here because my bridge makes virtually no indentation.



A friend of mine "guesstimated" that a Remo would go to about a C# (which is what I've been using as my limit), and a 5-star would go just sharp of that, maybe to a D. Has anyone actually tested this?



73, Brennen



Edited by - KI4PRK on 09/19/2011 21:54:02

steve davis - Posted - 09/21/2011:  12:33:44


I don't use those notes.
A fairly loose banjo head is found at F#.The G head is still quite hollow sounding and better all around tones are found at G# to A.
The head has been tuned as high as B by some,but I like A the best.

Another thing I like about going no higher than A is that there is no chance of breaking the head.

Tony Trischka has a nice sounding Tenbrooks with a tight A head.

Old Hickory - Posted - 09/21/2011:  13:02:04



quote:


Originally posted by KI4PRK

I keep my banjo head (a Remo) tuned to just barely flat of a C#. Yes, I've been told several times that I'm living dangerously, but I happen to love the sound.





I think I killed an AMB head (a Remo with extra frosting) earlier this year by tightening it either to a B or even just shy of a D.  I was having the hardest time hearing a note. Not something that has given me problems before.  Have to admit I really liked the snap.



But I loosened it back to something that was definitely G# to A. Next day, it was sounding a G, so I tightened it up again. Next day it was back to G again.  I know new heads can stretch and need retightening before they settle in, but I don't think they should stretch that much that quickly.  I took the head off, examined the hoop as closely as I could, but found no tears.  So I don't know what's up.



I reinstalled an 8-years-old First Quality/Ludwig and tightened it to G#-A.  Going to try a U.S. Remo that I have here.



And cut myself a 10-inch straightedge to measure the deflection.


steve davis - Posted - 09/22/2011:  11:12:24



I wouldn't recommend tuning a Remo head to C or C#.



It's too bad to lose those glorious lows at that kind of tension,not to mention the possibility of popping the thing.



Edited by - steve davis on 09/22/2011 11:14:35

Quickstep192 - Posted - 09/22/2011:  12:09:09



Just for fun, I googled the dimensions of a new quarter and found that the thickness is 1.75 millimeters or 0.069". Naturally this gets smaller over time.



Steve, I love these simple, straight forward solutions.



Edited by - Quickstep192 on 09/22/2011 12:18:00

steve davis - Posted - 09/22/2011:  13:44:58


I just mic'd a dozen quarters old and brand new and they're all within .002 of .045
I don't think that .069 is right.
Very consistent thickness with coins so that they work in vending machines.

KI4PRK - Posted - 09/22/2011:  16:03:05



Well, tone being the subject to as much personal preference as it it, I happen to love the tone I get (yes, I am also a fan of Ralph Stanley's classic tone).


 


73, Brennen


quote:


Originally posted by steve davis




I wouldn't recommend tuning a Remo head to C or C#.



It's too bad to lose those glorious lows at that kind of tension,not to mention the possibility of popping the thing.






 


steve davis - Posted - 09/22/2011:  16:11:03


Just right for Stanley tone.

steve davis - Posted - 09/23/2011:  08:57:36


Do you use a 5 Star or a Remo head,Brennen?
You can get a higher tension out of a 5 Star.

n1wr - Posted - 09/23/2011:  09:55:42



Just curious after reading through this post - do banjo heads age?  I have a 25 year old five star on my flat head Stewart Mac.  Sounds fine to me, but I'm wondering if changing it for a new one would make any difference?



Wayne in Maryland


steve davis - Posted - 09/23/2011:  10:25:37


When I first compared 2 of my banjos,one had a 25-30 year old WK and the other head much newer.
They both deflected the same at the same head notes which I tested at F#,G G# and A.

The only enemy of plastic/mylar is prolonged exposure to the sun.The sun's rays make the plastic brittle and weak.

Randy5string - Posted - 09/23/2011:  10:51:53


This straight edge is a good idea. I just measured a bunch of quarters from my register with a digital caliper and they all come out around .066 to .069"

steve davis - Posted - 09/23/2011:  11:00:43


If you measure the quarters' thickness with a 0-1 micrometer you will find .045(+or- .002)

Randy5string - Posted - 09/23/2011:  11:15:06


I checked the digital caliper by measuring a .068 steel guitar string and some feeler gauges and it is accurate, so it must be a difference in measuring the middle and edge of the quarter. With the caliper I can only measure the edge.

steve davis - Posted - 09/23/2011:  11:43:19



Wow,I've been using a new mic and just tried my old one.

2 different numbers and I know my old one is right.

It is indeed .069 and I think I'll return 1 new mic.



Anyway,the number of coins in my formula are correct,but the .045 I've previously written should read .069(+ or - .002)



Thank you,Randy.



Edited by - steve davis on 09/23/2011 11:44:06

steve davis - Posted - 09/24/2011:  04:59:56



quote:


Originally posted by tdennis




 I agree w/ banjo saint, all the metrics, dials & measuring tricks can't compete w/ the experienced ear for determining the sound of a  well tuned drum (banjo pot).   Banjoist &  drummers are  both facing the perennial question of  proper tone.   I believe dials & measurements are useful to get one to a rough stage, but the final nuances are in the ear.   It's amazing how an hour or two of trial & error can yield  surprising results,  depending on what type of  mylar or skin head one is using.






 It's also amazing that one can either hear(tap tuning) or see (deflection measure) the tension of the head in a few of seconds with either tapping with a finger or measuring with a coin and stick.



That's about as cheap,quick,simple and accurate as you can get.



When your banjo's sounding great,discern the note or deflection for ultra quick reference later.



I have better things to do than spend hours hunting for the right head tension/favorite tone.



Edited by - steve davis on 09/24/2011 05:00:47

steve davis - Posted - 09/25/2011:  05:48:28


Coin thicknesses remic'd with old faithful.
Quarter .069
2 Dimes .092
Penny and Dime .100
Quarter and Dime .112

Page: 1  2  



Want to hide these Google ads? Join the Players Union!




You are not logged in.
Log In


Not a member? Create an Account (FREE!)



1731 BANJO LOVERS ONLINE

HOME | FORUMS | MEMBERS | MEDIA ARCHIVE | TABS & LESSONS | CLASSIFIEDS | REVIEWS | LINKS | CALENDAR | STORE | TERMS OF USE