Older members who were also in SFA and early HPA should remember the late Art Holtzman, Art356A, a frequent contributor to these forums.
One of his late time projects was his chain drive rubber winder, a 1:20 winder for indoor duration flyers.
A chain drive is smoother and more efficient than any other transmission method, especially gears, so it turned out to be quite a piece of equipment.
His initial goal, back in 2011-12 was to make it out of ready to purchase parts for anyone interested and capable of some simple diy work with simple tools. He eventually made some which were very well received by indoor duration flyers, if I remember correctly.
At that time my interest got caught by this and we ended up exchanging many emails, with him sending me sketches and instructions and eventually all the "difficult" parts needed to make one myself.
Priority of other projects, plus no real urgency as I am not a pure indoor duration flyer, meant that this got pushed back and back over the years.
A couple of days ago, a modeller asked in fb about this winder and it somehow reignited my interest in finally building one. Not that I do not have enough projects underway, but with the summer heat already here, it might be something more relaxed to do, since it involves some CAD computer work as well.
So, I am starting this thread for it, to document the process and the progress, as well as the parts needed for the final result, o that others may do it, as Art had wished.
Do not expect a quick result though. Also, do not be surprised if I pause at some point. My lack of commitment to one project at a time is legendary...
George
There is an added complication for me, being left handed while all the sketches are made for a right handed person using the winder...
A second complication, again for me is all the measurments are in inches and am naturally used to work in milimetres.
I will have to decide if I work on a right hand winder and then just mirro the parts, or the opposite.
For now, here are the basic frames, initially concepted as flat plates, Art's sketches.
winder frame.jpg
assy dwg.jpg
And the first step I took back then, drawing the plates up in 3D
winder frames.jpg
Close to 15 years have passed, it will take some time for everything to come back to memory.
Watching with interest. Can you remember the pitch of the chain used and the number of teeth on the sprocket wheels? TIA Steve
Sure I can... And if I couldn't, all I would have to do is measure what I have ;D
chain
https://www.servocity.com/0-1227-pitch-plastic-chain/
sprockets
1 x https://www.servocity.com/8-tooth-press-fit-sprocket-0-1227-pitch/
1 x https://www.servocity.com/10-tooth-press-fit-sprocket-0-1227-pitch/
2 x https://www.servocity.com/40-tooth-press-fit-sprocket-0-1227-pitch/
1st step ratio 10 to 40 = 4
2nd step ration 8 to 40 = 5
total ratio = 4 * 5 = 20
George
some CAD progress...
winder1.jpg
the original concept by Art was for flat 3mm sides.
I am drawing these as such for tha basic layout.
When everything sits in place I will try to create 3d printable body parts as a housing.
The main mechanical side is done, now I have to make the rev counting swith and the rev counter assembly.
Left hand version shown...
Based on what I have re-read so far and the parts I got from Art, it was really a well thought of concept and he put a lot of time and effort into making it as simple to make as possible.
Excelent work!
I hope that close to the end of the "build" of the project you find the way to use the digital counter Mr. Holtzman added to the last versions of the Chain Gang Winder.
TRUMETER digital counter 7000AS – Bi-directional, Add/Subtract version
https://www.trumeter.com/product/7000-7000as/
Keep going!
Julio
Hi Julio,
yes, that is the plan. I am now working on the main body parts but nothing concrete to show yet.
The counter that Art sent me is a 7111.
George
I assume that the rotor shown on the hand sketch is to activate a switch for the counter.
BTW those trumeters (the computer wanted to make it trumpeter - I was tempted to leave it that way) are pricey, at least in Australia. Then again you only ever need one, I suppose.
Hi! I was wondering if there is any information about the counter, as that is what I am most interested in. Are there any plans/schematics for it? I would appreciate any help. :-\
Hi Elijah,
Yes, there is...
I have all the correspondence sketches and parts the late Art sent me back then.
My goal is to complete a set of 3D printable parts to make a winder, together with some bought parts like the chain and related parts.
The only problem is time, too many other projects running parallel and in priority right now.
Give me some time. I can try to upload what I have but that still needs some time.
There are three indoor specialty tools I would like to somehow make available.
A very accurate and easy to use balsa stripper should be online soon after it is published in Aeromodeller. Free for all.
The chain gang winder too, no article this time, just a presentation, drawings and parts, again free to use.
The last item is the most ambitious one, a "modern" rubber stripper based on the Harlan and the Polish Chiapala one.
The plan for this is to be reverse engineered and manufactured out of aluminium by a friend who makes his own 4 stroke multicylinder ic motors. He has the machining knowledge and experience and the equipment to do the job.
This will be made for sale, not by or for me. More will follow on that when the prototype is complete. Proper rubber strippers can no longer be found so it would be good to have them available...
George
All three tools are very useful . Please count me in for all three of them .
Dear George,
Thank you for all of your hard work. I'm sure many members of the FF community appreciate you.
George
You might not have to reverse engineer. I've seen Ray Harlan recently. He might be happy to advise you, maybe even send drawings. However, don't quote me. https://www.indoorspecialties.com/contents/en-us/contactus.html (https://www.indoorspecialties.com/contents/en-us/contactus.html) BTW, I am jealous of Ray. He has the most amazing machine tools in his basement. He is also very skilled. At one time, he was making devices that used #000 (.86 mm ) screws. If you drop one of those, it's not worth the trouble to try to find it!
---------
It seems that the price on that counter varies widely, though I don't know which of the vendors are in Australia. I think the lowest I saw was $13 US or so.
At one time, I made a counter from a cheap calculator, a magnet, and a reed switch. I don't think it was my idea. The switch was wired to the = key, which can be tricky. My winder has an unusual ratio. I think it is 8.3:1 or so. I'd key in 8.3 + . Every turn of the handle would add 8.3 to the display. After years, the counter failed. I should try to fix it or make another. I wonder if there are any affordable reed switches or sensors and counters or calculators fast enough to handle, say, 2,000 rpm or more, to count turns directly.
BTW, solar powered calculators are convenient for this. Maybe even more convenient with a so-called supercapacitor. They can be very inexpensive and I'd guess could run the counter for hours or days in dim light.
Hi George - I'm one of those 'older' modellers who remember when this was first discussed and I've always wanted one. So I am watching with great interest. Though I do think Trevithick may have built the first one... tho maybe without the chain element!
Hi Lincoln,
Thanks, I will try contacting Ray. I wanted to anyway to ask if he might have any objections.
Hi Tim,
That is quite an interesting apparatus there. But with gears and not with sprockets and chains.
Art was quite adamant though that gears are not as efficient and as friction free as a chain drive.
I do have to put my projects in some order and priority, too many open simultaneously. Rather typical of me...
George
Quote from: g_kandylakis on Aug 30, 2026, 02:46 PMHi Lincoln,
Art was quite adamant though that gears are not as efficient and as friction free as a chain drive.
Hi George,
Straight cut spur gears (against helically cut spur gears) are exceptionally efficient, equal to or even marginally better than a chain drive, and at the scale of your winder there wouldn't really be much in it.
In either case a big factor in the friction of the system overall is the pivots or shaft bearings.
I have a question though. Why would the efficiency be
that important? It just means a
marginally more elbow grease on the part of the operator against the torque of the motor - or have missed something?
ATB
Andrew
Hi Andrew,
It was not efficiency per se but minimal friction that would allow the person winding to get a full feeling of the rubber resistance/torque.
Art's intented use was for F1D models where a very smooth and easy running winder would be of advantage.
Not for larger thicker rubber...
Fair enough, just wondered, but it still stands that gears would be equally efficient....
I have pondered making a very low cost winder using a round (toothless) rubber belt as the gearing. The problem of course is lack of "synchronicity" (wasn't that an album by the police? ;D ) however with a counter on the output it wouldn't matter. Belt drives are very inefficient though...
Watching with interest.
Andrew
I think I may have mixed up my comments on this thread with ones in a thread on rubber strippers. I don't think Ray ever made a fancy winder.
Does anyone have more plans on the winder layout? I was hoping to be able to share a cad model soon.. :D