Vacuum forming coil housings.

[bernte_one]

strenghten the sensible parts with epoxy and glasfibre
1 liter can 10euro in hardware store in the corner with yacht or boat articles and paints

[mikebg]

Don, I would like to produce housings for a model differential sensing head. My loop configuration is DOD as shown below.
My question is how to form robust ears for clevis tube? With your former they will be hollow and will have thin walls.

[bernte_one]

@ lunamay

use polystyrol instead of abs
here abs cost double than polystyrol thats the reason for my experiment

the plastic bottom of a paint bucket is not so good if you meld this plastic it gets holes and it shrinks

[bklein]

Go to a (big) company that does packaging solutions for larger companies. They typically use this material to create vacuformed accessory/product packaging pieces for volume shipment boxes and containers. They have huge vacuform ovens that use this plastic in huge roll form. When the material gets near the end of the roll at the end of a product run they often just scrap the remainder. They use the thick clear and black. Maybe the black isn't quite thick enough - not sure. I am friends with head of one of this type company and hope to someday get some material from him to try making coilforms with. Or you could pay them to make you hundreds/thousands of them if you pay for the aluminum tool.... They are willing to make things like RC car bodies that become pretty profitable in retail.

Barry

[lunamay]

in my country this abs sheet is very expensive..i don't know why..i'm looking for an alternative..maybe buttom of a big bucket for paint (plastic) like 10L or bigger would be good:P

best regards
martin

[bernte_one]

hello
you had to put the holes there where you want it gets close to coil
for example the border line of your form
it is not necessary to get it hermetic, the plastic is half liquid when you put it over your form and press on at the vacuum cleaner
more important is the right temperature and one big hole for the vacuum cleaner and not too much little holes the holes they are not needed are closed with tape
to get more vacuum effect at the right points

ps polystyrol works but not thicker than 1,5mm next try i use 1mm it is very stable after hot forming 1mm should be enough and it is cheaper too

[lunamay]

hi
i was wonder.. how did you resolve problem with hermetic between frame with plastic and vaccum box .did you use any seal or something like that?..also what should be the number of holes in vaccum box and how big shuld they be..is it important?

best regards
martin

[dfbowers]

hello don,

have you experience with polystyrol or is it better to use abs plastics?
I can buy polystyrol in large plates here in town (very cheap and easy to cut), but abs only per webshop (costs more).
Should i make a try with polystyrol or do you think it is crap.

http://www.modulor.de/shop/oxid.php/.../AAA/anid/AAAC

No, I have no experience besides ABS and styrene. I would be tempted to use it as I have seen some websites suggesting that it can be theromformed. Maybe see if you can find suggested working temperatures?

[bernte_one]

hello don,

have you experience with polystyrol or is it better to use abs plastics?
I can buy polystyrol in large plates here in town (very cheap and easy to cut), but abs only per webshop (costs more).
Should i make a try with polystyrol or do you think it is crap.

http://www.modulor.de/shop/oxid.php/.../AAA/anid/AAAC

[simonbaker]

I finally found a source of "real" strain reliefs:



http://www.amazon.com/Heyco-PIGTAIL-...5455753&sr=8-1

Good to know, thanks!

-SB

[dfbowers]

I think I get it. To confirm:

Am I correct that you sacrifice one connector of the USB cable, cutting close to the pins so the cable strain relief is still part of the cable, then just position the strain relief part to poke through the coil shell, and solder the coil wires to whatever is left when you cut the connector?

I am interested in your streamlined coil shell for some time later, it looks nice and light.

For now, I'm going to try a non-standard approach (as usual), and use your coil shell to make a mold. I will then just try to pour a coil housing in the mold, poking the cable through a hole in the mold. So my coil housing will be pure resin, no shell. I plan to paint it white.

SB


(If you're not failing, you're not trying hard enough...)

I finally found a source of "real" strain reliefs:



http://www.amazon.com/Heyco-PIGTAIL-LIQUID-CONNECTOR-package/dp/B001BQ02VE/ref=sr_1_1?ie=UTF8&s=industrial&qid=1295455753&sr= 8-1

[simonbaker]

Could you put a little dremel with a cutting tool in a jig, put the forms on your coil winder turntable, and rotate it around? (probably take me weeks to set up... not to mention plastic dust... never mind!)

Laser is the way to go! I think Goldfinger had one that would do nicely...

-SB

[dfbowers]

Nice work Don. Could you use a hot wire to cut them?

I can give it a try, but I'm wondering if it would just melt the plastic and weld back together after the wire passes. I've done model airplane foam wing cores before and the wire just vaporizes the foam as the wire passes.

[hobbes_lives]

Nice work Don. Could you use a hot wire to cut them?

[simonbaker]

I was on a roll today..
I can crank one out about every 10 minutes.. but I have to find a faster way to cut them..

Hoowee -- i'm salivating...!

-SB