Yes, once again the subject of dethermalizers ( is that spelled correctly? I could not find it in the dictionary ) is brought up.
It seems that nobody is really happy with what is used. After
researching a lot, I can see why.

1. Too "fiddly"
2. Inconvenient (rubber,elastic or fire )
3. Reliability issues

But, weight is not an issue with HLG. Most DT's I see are pretty
much "narrow minded" with weight. As history has shown, DT's
started as a fuse on the far aft end of an airplane. Weight is
paramount there. But, in the nose of a HLG.........

Well, I would like to submit, for your review, that perhaps,
a heavy,reliable, easy to use, self-powered ( no external rubber or elastic ) and powerful DT mechinism is what  we, as HLG
enthusiasts, need. How about this for a wish list?

Easy to set accurately
Easy to hold
Consistant
Powerful actuation
Easy to mount
Inexpensive

So, in my opinion a spring powered , linear actuating, viscous timed DT may be a worthy pursuit for HLG's.

I lay myself ,prostrate, before the court of HLG opinion!

Bob K

Some pictures would be nice.

more.

I heard there were reliability issues with putty timers. Is there something I should know? Also, how many turns ( more or less) should I be going for?  How many turns does a badge timer use ( more or less ) ?

Bob

The ones I've used & seen only need about 1/4 turn for a minute run, but as Dan says, repeatability is the main thing. You certainly need to calibrate the run time before you fly each day, and also if the temperature changes significantly. The same applies to any viscous damper timer.

The other thing is that the silly putty needs to be changed from time to time, and none of the write-ups seem to mention this. I bought a Sting "Cool Tube" that seized up in a couple of months over winter, and it was Lee Hines who explained that the putty needs changing (also that some colours of silly putty seem to be better than others).

I like the idea of making my own timers, and the cheapness, but from a reliability standpoint, I've gone over to the viscous damper buttons. Out of the dozens I've used over the last few years, I've not had a single failure. The other benefit is that with 1 rpm, you can see the arm move, and it's not a test of faith - the fact that it might stop half way round is another matter!!

Hope this is of some help.

PeterT

$.50 ? Ok, fess up, what's your source and what do they weigh?

We are fortunate in this country to have an excellent supplier of model aircraft equipment called 'Flitehook' which is run by Pauline and John Hook.  Their website is flitehook.net and be careful if you look because another company has used used the same name but with variation of dot suffixes and hyphens, presumably to pick up some free publicity.

They sell a basic button timer, suitable for CLG and HLG and indeed for most other D/T purposes.  The price is 1.50 in English pounds which, at the moment is 2.84 USdollars.

A problem may be that Flitehook don't deal with credit cards.  Their normal way is to sell at model meets or they post the goods with an invoice and the buyer then sends back a cheque.   I don't know where Rocket Bob is situated, because he has witheld his location,  but I do realize that if he is not in the British Isles that postage costs would not make these timers a bargain.   However I would have thought that in most countries, if a few enthusiasts got together, they could do some beneficial overseas buying.

These buttons (viscous timers, rotary dampers!) do need an arm adding to the shaft to make them useful as a timer but that has been well covered on SFA in the past.  PeeTee did it very well, with photographs, not long ago but I can't locate it at the moment.

Like others I find it difficult to understand why anyone would want to persist with tube type timers filled with Silly Putty.  However I must say that I have seen home made rotary damper type timers, filled with Silly Putty, which look quite effective.  Even so, unless you are very supportive of BOM, it seems easier to buy a button ready made.

John B - England

I'm not sure if this will help anyone but, I'm including part of a posting to the ffml (free flight mailing list) from about a year and a half ago-

"I expect that most FFMListers know about the badge and
button timers. I don't know the URL of the makers as I bought my first examples
from a local retailer only recently.

Newer listers may not know that Mike Woodhouse sells a variety of DIY
versions based on modifying damper units from electronic hardware.
He has leaflets of instructions for doing it.

Before I knew about him I read articles about it in Aeromodeller. The
search for suitable dampers in marvellous Melbourne took me to
junked video recorders and CD drives, without success.
The major electronic spares outlets needed a part number.

  However the JVC agency's serviceman recognised the illustration from the
Aeromodeller article as a damper from a CD changer and found the JVC part
No.VK24737-001 Ref. No. RO141. None in stock but there were two in the
Sydney store.
Only two in the country? Well, yes. They don't go wrong very often.
I ordered both.
Sorry folks, you will have to do your own search".

I did a search, in this country (USA) for the part # but, had no luck.
Info on the Mike Woodhouse "cheapo" timers has been posted here by PeeTee and maybe others. They require some modification/completion in order to work.

Ikara makes a 1gm timer. Lee Campbell sells them. It's the only timer he now sells. Price is $12.50ea. I'm not sure what the shipping charges would be on small orders from Lee. I ordered two within a larger order.

Glidetek-http://www.glidetek.com/Timers/Timers.asp

has them. Price is $10ea SHIPPING INCLUDED !

Dave Andreski