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




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Speaker Replacement
The spider is glued on the cone and so is the voice coil. I think you can use a cotton swab dipped in acetone and carefu...RodB — 02:42 PM
Restoring Philco 37-604C
Yes I saw that. If I knew, I'd probably try to arrange for getting it myself. But I have just got one. Which does not m...morzh — 01:44 PM
Philco 38-2 Automatic Tuning
When you push the lever, you are supposed to rotate the disk to the desired station. Then the magnetic tuning will acqu...morzh — 01:42 PM
Philco 38-2 Automatic Tuning
I figure out the muting from another picture that helped. Now I need to know how the automatic tuning works. When I push...dconant — 12:11 PM
Philco 91 Speaker Replacement
How would I go about removing the spider from the cone?dconant — 12:04 PM
Philco 38-2 Automatic Tuning
Hello, I am having trouble getting my automatic tuning to stay unmuted. If I play with the tuning handle I can get it to...dconant — 10:51 AM
Does anyone make photofinish replacements?
Here’s the link to the DIY photofinish section of our site: klondike98 — 09:46 AM
Delco car radio Peko vibrator converstion issues
Hi Richard, Thx for posting the schematic.  As I remember as a kid, these were great performers for the time, likely...MrFixr55 — 08:56 AM
Delco car radio Peko vibrator converstion issues
hello mr Fixr, The Electro  Powersupply that I am powering the radio with has a huge choke plus a 10,000ufd electrolyti...radiorich — 10:58 PM
Delco car radio Peko vibrator converstion issues
How about putting a choke in the power supply? The big cap was likely an attempt to stabilize the DC. Kids who cre...MrFixr55 — 09:19 PM

[-]
Who's Online
There are currently 3981 online users. [Complete List]
» 1 Member(s) | 3980 Guest(s)
Avatar

>