I've been curious about how to make a mechanical DT and will revive and old thread to share what I have found.

I was browsing YouTube and found an interesting video on this: https://www.youtube.com/watch?v=6Pv1CLggmVk&ab_channel=SDGG2

When I got looking further I found that the mechanical timer is light and relatively cheap (~$9.00). It appears (based on the video) that it can be modified with a simple shaft inserted in the gear...

The following are links to suppliers I have found:
https://www.acecontrols.com/us/products/motion-control/rotary-dampers/frt-c2-and...
https://www.grainger.com/search?searchQuery=FRT+C2+301+G1&s_kwcid=AL!2966!10!794...

I'm going to get some of these and experiment with them, and maybe others will find these useful, too.

Cheers!
Scott Z

Here's a link to some DT's and how to make them on the RCGroups site: Click Here

Here's another link to our Articles section that has articles on Silly Putty Dethermalizers and "how to" build them.
Click Here
Tom

I think that the way of the future is electronic dethermalizers. There are already some on the market. The problem is not weight, but price.
see: http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=20894.0
ian

Breathing life into this 5yo thread.
I am completely new to ff and would love to see/read more details about dt. Especially the silly putty idea.

Thank you Ziess.  I hope to have time this weekend to chase those links and a couple others. 
Thanks.

Was digging thu old threads and found this link from Papa. 

http://www.vintagemodelairplane.com/pages/Downloads/CRB_Tasters/SillyPutty01.htm...

A Silly Putty timer consists of Silly Putty inside a tube, with either a perforated tube or (tiny) paddle on a wire embedded in the Putty (there are more details to it than that; I can post a construction photo sequence if needed); the inner wire or tube is rotated by a string wrapped around, which is driven by a spring (like the rotary damper video you linked) or elastic.  The damping effect of the Silly Putty on the perfed tube or paddle causes the tension to rotate the core very slowly -- my last one does about two minutes for 135º of rotation, driven by a single office type rubber band stretched about double length.

The rest of the setup is the same you'd have with the rotary damper -- some way to let the tension on the drive line hold a flying surface in place, then release it promptly when the tension loop slips off the drive arm, producing the same effect you'd get with a fuse burning through a thin rubber band.

The advantage of Silly Putty over commercial dampers is price -- I spent about $10 on tubing and an egg of putty, added some super glue and bamboo skewers I had around, and have everything I need to make a dozen or more timers; that's less than 1/3 the price of the commercial dampers, and my timers can be customized -- make the tube longer, you get more damping, and the timer runs slower on a given tension.  I could easily make a Silly Putty timer that would run five minutes or more for a 270º rotation, still with a tensioner strong enough to lock a pretty robust DT mechanism...

Yep, it's a commercially made equivalent of a Silly Putty timer.