4to5to6

Chris, I’ve sent Columbia an email requesting small quantities in various thicknesses. Jake, what is the most common type and thicknesses used for valves? I have a piccolo, TT, model 14 and G bass. I am going to hopefully put an order together for Columbia Organ leathers. I’ve never purchased from them before. What is the best leather to use for pads? I should also get some pad leather as well. Thanks for all the help. .

My large Gbass Aeola has the plastic reinforcing strips supporting the larger valves. I think David Robertson did the work. I have seen small wire springs run down the center of the valve supporting the tip. I always thought the plastic or wire was there to keep the valve closed and to prevent the large valve from curling up. I never considered a flutter problem while the valve is open. I wonder if this is what is happening??? Interesting. .

Thanks Theo. I’ll check the valve again. Interesting that the valve would make this sound… Maybe the two reeds / two valves are interacting in some way. I am searching for sources of pneumatic leather in small quantities. I will punch out my own valves.

Thanks Greg. I’ll search around. I was resisting making valves but will make up a bunch of punches. It’s time. Maybe a few of us can go in together and get a few hides. I’m still enjoying that model 14 56B baritone G to G treble I got from you a few years back. Ends were replated and wood work French polished. It looks and sounds amazing. I was told I would most likely find a purple unicorn first but you came through. Thanks again.

I was searching as well and could only see CDL in extra heavy duty. Screen capture below. I never got to the check out level or even to the prices but not sure Columbia Leather is an option as I don’t need 6-10 sq ft typical hide size and need to get a number of thicknesses. I am sure this would be very expensive. Is there another source in smaller quantities? Say about 1 or 2 sq ft of 3 or 4 thicknesses? I own everything from a piccolo to a G bass (leather with mylar supported valves) but mostly play my amboyna tenor treble. The immediate need is for a few low notes in a very very nice golden era tenor treble Aeola that I want to soon sell but need it to be perfect first.

What is a good source for pneumatic leather preferably in North America but anywhere is fine? I have a number of spares on hand but I think it’s time I built some different size valve punches and made a good selection to keep on hand of different sizes and thicknesses. This would help with this type of problem and also help to do voicing. Thanks again 😄 .

Ok. Sounds like the jury is back and it’s the valve that is the culprit. I wish I knew better exactly why the valve acts like this and causes this sound when it looks perfectly fine. I will try a different valve. Thanks. .

I’ve always wondered about this. Thanks. The Pythagorean Comma: As a former piano tuner, temperaments are a fascinating topic although the topic can be very controversial. Why oh why couldn't all the intervals just be pure in all keys? Is this Heaven? I highly recommend the book: How Equal Temperament Ruined Harmony: And Why You Should Care by Ross W. Duffin .

Valves look good, flap up and down fine, are not curled… The Instrument hasn’t been played in a while. Maybe things need to just loosen up again.

Please listen to the attached audio files. I’ve come across this a few times over the years and it is still a mystery to me. I get a “blurpy”, raspy sounding low note only on the pull (outside chambered reed). Valves are new maybe 5 years ago and look great still, reed is the perfect fit into the wood…. tongue gaps are fine… What am I missing? Has anyone heard this before? What is the solution? New Recording 1492.m4a New Recording 1490.m4a .

Bass bolt is done! Thanks for all the great advice. Milling attachment for my lathe worked perfectly to cut the slot. I just gently clamped the bolt into a quick change tool holder and had full control in all directions. Photos below. The new bolt is next to a 2-1/8” bass bolt for comparison. I made it a bit longer then the requested 2-1/4” and also increased the length of the threads. It may need to be trimmed but better too long than too short. I’ll send it off next week. If it fits, I’ll make the rest of the set. Threads fit into my Aeolas and a mid 1800s treble as well as a late 1800s Lachenal baritone so 5BA threads on a 0.086 8BA is it. Thanks again for all the awesome advice and help. .

Threads are a success. I ended up redoing the lathe work on the die to line it up better and building a heavier back guide shaft. I used a dial gauge and good bolt to size and center the chasers. First bolt threads were a 100% success! Very clean and even threads. However it took a long time to machine down the brass so I will need another tool similar to the die without threads to size the shaft to 0.086. I think I have some ideas. A three point cutter. The bolt cheese head was a challenge and on nearly the last cut, the bit caught the brass and bent the shaft and the head snapped off. There’s always tomorrow 😄. The good news is that the threads are a success and I was able to try them out on a few concertinas. Ideas to size a 0.086 shaft, 2.25” long with a 0.162” diameter head are welcome. Photos attached. .

The 6 bolts around the perimeter are for adjusting the three chasers and the 6 bolts on the face will then clamp the chasers into place. I’ll use an existing 5BA 0.086 bolt as a starting place with all parts in the lathe for correct center alignment. This should be a good starting place then will tweak it to get it perfect. I’ll find out today. .

Finished tool as planned but no time to set it up and make a bolt today. I’ll get back to it by the weekend… All this for a few 2.25” long Wheatstone bolts for a single action G Bass. It’s worth it, he’s a friend. The hardest part was tapping the tiny M2-0.40 threads for the 6 adjustment screws and the 6 clamping cover screws. All I have is forming taps at this size and they easily break if the pilot hole isn’t perfect. An exercise in patience. The back shaft is held loosely in the tail stock’s Jacobs chuck to keep it in alignment. This shaft is hollow for the first 90mm to not interfere with the threading. .

Just completed the design and generated the first CNC tool path. I will machine the holder from both sides then finish it on the lathe. It will take a few hours of fabricating after machining as a lot of very small holes need to be drilled and taped. The end result will be an adjustable 5BA die that was cut into three pieces so the diameter can be reduced down to 0.086 (8BA). 6 bolts will align and adjust the depth of cut using an existing bolt as a guide and the cover plate will clamp everything into place after it has been set up. The two handles will used to turn the die with the bolt blank held in the locked lathe chuck. The center slider shaft will slide into a tail stock drill chuck loosely held or maybe a pipe ??? on the lathe for alignment so threads will cut straight. I'll upload photos of the finished die holder and some sample end bolts when completed. I'm using AutoCAD to generate the vector files and VCarve to generated the tool paths. My CNC machine is a highly modified Bravo Prodigy with an 800 watt water cooled spindle and my lathe is an EMCO Compact 5 also with many do-it-yourself upgrades. Material will be 6061 aluminum 1" thick and 1.75" wide. This is a quick functional layout only drawing so a lot of the details such as the drilled hole in the slider shaft aren't shown. Everything may change after I have thought about it over night but I think this will get the job done. .

I think these were all manufactured to 86 thou but perhaps the tolerance was + or - one thou, my reason is the original receipt Wheatstone had from the company said "8ba shank 5ba thread or something like that. 5 ba is 43 tpi, perhaps the 44 one was just that the lathe was a bit worn or something, it seems a bit weird to change the spec by 1 tpi when actually the 43 or 44 tpi bolt would be most likely interchangeable if the bellows frame nut is only 80 thou thick. Steve Dickinson sells these bolts but I'm not sure what lengths he has. Thanks for confirming the specs Jake. Much, much, much appreciated!!! My original post was to enquire if this special die (0.086” 43TPI, 5BA/8BA) was still available. It sounds like I will have to custom make my own. All the discussion and advice was greatly appreciated. .

I just found these: Uxcell M2.5 X 40mm 304 Stainless Steel Crosshead Phillips Round Head Screws Bolt - 60pcs - $10.91 USD https://www.harfington.com/products/p-1102106 Is 60mm long possible? Almost there 😊 Reference: C. 1900 hex bass - 0.0855, 44tpi, 2.218“ (56.4mm) 1926 Amboyna TT Aeola - 0.0850 5BA thread, 1.240” (31.5mm) 1927 ME TT Aeola - 0.0860 5BA thread, 1.162“ (29.5mm) .

I have yet to find a source for 3-48 bolts and M2.5 x 30, etc. bolts over 1” (25mm) preferably in North America as alternate end bolts. Cheese, fillister or binder head with a slot drive preferred. I am open to Whitworth and BA as well even in a finer thread than 43tpi. Custom made bolts are very expensive so would then have to make my own if not available. It would be awesome to get these off the shelf to save time and money. On this topic… I also have a need for the small 3/8” screws that hold rolled metal end plates on from the inside. I’ll attach a photo. And of course the long thin English thumb strap and pinky rest screws… these also are also impossible to find new. Does anyone know of a source for brand new bolts and screws like these?

A source for new bolts would be appreciated. Preferable a North American source but anywhere is fine. C. 1900 bass - 0.0855, 44tpi, 2.218“ 1926 Amboyna TT - 0.0850 5BA, 1.240” 1927 ME TT - 0.0860 5BA, 1.162“ Thanks.

Good advice… the search for the perfect instrument can be endless… I can say this… it is more impressive to be a great player on a mediocre instrument than a poor player on an amazing instrument. Also, concertinas are funny in how they sound and play better and better the more that they are played. .

I found Geoff’s post: Interesting stuff.

Thanks Alex. The Swiss Thurly standard explanation helps me with the Louis Lachenal reference. It was off the cuff but maybe that’s where I got the connection from as I understand he was a Swiss Engineer and screw maker. The time line is off as Stephen pointed out but practices are often put into place years before they become official standards. Is it not true that a feature of the BA thread is the rounded crest and root versus the sharper peaks and valleys of SAE and metric threads? .

Thanks Stephen. I greatly appreciate your help. And thanks for the push as usual and please forgive my impatience. I’ll search for Geoff’s thread (pun intended) on concertina bolts. He’s a highly respected craftsman and instrument builder who has set me straight countless times. I wait to be humbled again. I have a container full of spare bolts and bolt plates but often don’t have the one that fits. Actually, most of the time. There was certainly no standard, especially in the early instruments. I will check again but was quite convinced for this one that I was after the 5BA thread / 8BA shaft combo. As stated in the OP, I was just enquiring to see if this threading die was commonly available somewhere in the world. I will dig deeper… I just checked and have the metric & America SAE type & British Whitworth & BA pitch gauges as well as a simple tpi gauge and will use my very nice Mitutoyo digital calliper to get the shaft sizes. I still absolutely love your former 31xxx Amboyna TT. Wow! What a joy to play. Possibly the best concertina ever made although I am sure these can be fighting words. All I know is that there is music I can only play on this instrument although also love my mint condition 1856 treble who’s serial is sandwiched between a Blagrove and Regondi purchase. I’m sure that I’m not alone in this but have reversed engineered countless concertinas trying to come up with the perfect reed scale myself and this Amboyna TT still tops the list in both design and craftmanship. The spread sheet curves don’t lie and back me up. I’m actually currently measuring the reeds on my 1922 G to G, 56 button model 14 as I am thinking of selling it and the reeds are near perfect as well. Only half way done so haven’t seen the curves yet. Steve Dickinson did an absolute perfect job of setting up air flows, voicing the reeds, sizing valves etc. etc. on the Amboyna TT. Let’s please put this on hold for a few days until I get some time to do some reading and take some measurements. I already split apart my 5BA die… It broke while trying to squeeze it down to size but I hope to turn lemons in lemonade so broke it again and started designing an adjustsble holder which I will soon CNC out. I just checked a piece of the 5BA die with a bolt out of the large single action Wheststone bass, circa 1900 and the 5BA 43 tpi is a match. Okay, okay… my wife is mad but I just dug out my tools and took the end bolts out to measured them: C. 1900 SA bass - 0.0855, 44tpi closest 1926 Amboyna TT - 0.0850 5BA closest 1927 ME TT - 0.0860 5BA closest Although 44tpi, the bass bolt easily threads into both the 1926 and 1927 Aeolas by hand. Overall bolt lengths are 2.218, 1.240, 1.162 inches respectively. Interesting enough, my SAE thread gauge jumps from 42 to 44 tpi. I’m trusting that my 5BA gauge and broken die are 43 tpi. Maybe Jake can jump in here and come to my rescue. 😉 I’ve already had emails from both Steve and Jake but not sure what is proprietary info. The true test will happen when I make the bolts with the die and also single point on the lathe. Okay… I must go and put the end bolts back in and beg forgiveness from my wife.

Sounds like the only way to get this die is to custom make it. Thanks everyone for your feedback.

Stephen… I stand corrected. Indeed BA threads were standardized after Louis Lachenal’s days although BA threads have a strong metric influence long before the metric standardization so I presumed the Swiss influence. Then again, that’s only 23 years difference so the threads could have been around before the standardization. Bolts! Threads! Standardization. It’s like discussing A440 versus A453 Philharmonic pitch. I’m more interested in how to get this job done then the history.