Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Replicating (dogbone) resistors what method have you used ?
#16

Richard,
This Alumilite appears to be similar to (maybe supplied by?) the product and process sold by Dow Corning. About fifteen years ago I tried the D-C molding materials and had very good success with them. The give clean smooth surfaces, flow well into details and if you use the correct compatible products as per the instructions, they perform as advertised.

One note :: when I was trying it, the Dow product I was using recommended a vacuum evacuation of air just prior to pouring. It increased the density and strength without compromising the flexibility. I don't see that (unless I missed it) in the Alumilite instructions or spec's.

cheers, good luck and have fun !!

EDIT :: the shelf life on the D-C raw product was very short (a year or so as I recall), so buy the smallest amounts that are economical for your purpose, and be ready to use it.
#17

hello Everyone,
Well it is time to start making some resistors !
My latest Philco 38-10T needs some made one is a 3 watt 10 k power resistor .

Sincerely Richard
#18

Hello Guys,
Well this year is time to final make these resistors because I also have to make some for my Philco 38-10T they are easier then the Zenith !

Sincerely Richard
P.S. I have a week off of work during the week of thanksgiving so in the next few days I will be ordering molding supplies .
#19

Hello Everyone ,
Rockler had a sale on Amazing mold maker and Amazing Casting resin
By Alumilite So I ordered those two items to see how they work .
there is also a knob for my 1950s GE clock radio I want to try casting too.

The Resin says it's good for 185 Degrees

Sincerely Richard
#20

Hello guys,
I have a question has anyone tried using off the shelf Pematex sensor save RTV to make a mold like the one Russ posted to make my dog bone resistors ?

Sincerely Richard


Attached Files Image(s)
   
#21

RTV is flexible. For dog bone replacements you want a rigid material such as epoxy.

Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/
#22

Richard,

The RTV might work for the molds, but it might be too soft, I haven't worked with gasket maker in a few years. The newest idea I have run across is making the shells on a 3D printer. Below is the work of someone else, not myself:

   
   
   
   
   

I believe he made his on a resin printer. I printed some off with plain old PLA filament, but for heat resistance PETG or maybe ABS would probably be best. I have some STL files if you're interested. The third picture is an enlargement I made in TinkerCad.

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
#23

Hello Dale,
I am talking about using the RTV as the mold.
Well John, yes, I have seen that design I think it was one of the ARF forum members he sent me that file.
I really want a 3D printer to use at my home and found one that I really want Prusa MK4S but it's over a grand see I want fully enclosed one we use a Flasforge brand in the classroom at the school I have been using one for over 5 years .
John did you see the domino style capacitors that he made too.
Sincerely Richard
#24

Quote:John did you see the domino style capacitors that he made too.

No, I did not see those Richard. I'll have to try and find it over there.

John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
#25

Hello John,
I can look for the file and email it to you too.

Sincerely Richard
#26

Hello Guys,
I can't wait to try printing some of these I might go ahead and order some from PCB way !

Sincerely Richard




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco 610B oscillator wiring
Some info from Beitmans says late production. David   David — 06:06 PM
Restoring Philco 96
Oh wow! Just found this thread.  Brings me back to early days on this phorum.  I did a 96 back in 2017.  Thread here: ...rfeenstra — 06:05 PM
Philco 610B oscillator wiring
Thanks for the replies. It's not the really the hum that I am after. Just trying to understand why only the shortwave ba...Tubester — 04:01 PM
Restoring Philco 96
70 and 90 are Superhets, but at least the 2x45 model of 90 uses the Plate detector (and so does 70). Also the Atwaters,...morzh — 03:28 PM
Restoring Philco 96
Morzh, Prayers for your mom. I am sure that there was enough pain living through the Holocaust as a child. I pray dail...MrFixr55 — 02:19 PM
Philco 610B oscillator wiring
Hi Dan, Divide and conquer. First off trry to differentiate between 60Hz and 120 Hz hum. 120 Hz hum has a higher pit...MrFixr55 — 01:49 PM
Restoring Philco 96
Yes, other than takin a toll on your back, they are undeed way more repair friendly than many other Philcos. To me, som...morzh — 01:04 PM
Philco 610B oscillator wiring
If the wires look like they were this way from the factory (very neat and very dull soldering joints), I'd leave them be...morzh — 12:58 PM
My Philco 37-116 Restore
I managed to open up the Expander Unit and replace the grid cap wires. Tested the connections found they looked good and...dconant — 12:19 PM
610B Oscillator Questions
I've included a picture of the 'actual' schematic I created. I double checked several times and it appears to be accur...Tubester — 09:26 AM

[-]
Who's Online
There are currently 2836 online users. [Complete List]
» 4 Member(s) | 2832 Guest(s)
AvatarAvatarAvatarAvatar

>