Chain Gang winder

[g_kandylakis]

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

[g_kandylakis]

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.

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And the first step I took back then, drawing the plates up in 3D

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Close to 15 years have passed, it will take some time for everything to come back to memory.

[steve-de24]

Watching with interest. Can you remember the pitch of the chain used and the number of teeth on the sprocket wheels? TIA Steve

[g_kandylakis]

Sure I can... And if I couldn't, all I would have to do is measure what I have 

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

[g_kandylakis]

some CAD progress...

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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.

[Julio]

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

[g_kandylakis]

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

[Jmk89]

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.