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Posted: Thu Feb 25, 2010 10:06 am
by webboy
I admit I have not searched elsewhere, but do you still plan on doing a writeup on your heater solution? I am still super curious. ;)

Posted: Thu Feb 25, 2010 12:29 pm
by chrismp
no need to search elsewhere yet ;) i just haven't gotten around doing it. i know it's taking way too long already now, but i hope i can get it done within the next month.

verdict so far is: they're working great, but they're still really ghetto with some self made electrical insulation (that probably can be dangerous).

Posted: Fri Feb 26, 2010 1:09 am
by webboy
Any info on an alternative like yours would be great, so no worries if it takes time. ;)

Posted: Fri Apr 02, 2010 3:48 pm
by chaka
Hey , we are anxious to read more about your heating system. Those isolated carbon sheets on Frenzelit´s web look great.
Please tell us more.

Posted: Sat Apr 03, 2010 10:33 am
by chrismp
i know i'm like silly late with this write-up! sry guys.
i cant access the heating blankets right now for photos since they're locked up at a friends house who's away for the holidays.

still here's a short version:
we got these as free samples. keep in mind that frenzelit usually sells them in huge quantities to the industry, we were just lucky that they had some scraps lying around that fitted our needs...just without the insulation.
i don't know what thei minimum orders are, but i'll talk to them soon.

basically the blankets act as a huge resistor that produces heat. if you just hook it up to some 220v it'll burn through all the power it can get and soon melt down (like really soon! we had to shorten one blanket cause we smoked part of it).
controlling the voltage with transformers would've been way too expensive so we started searching for ways to control the wattage with dimmers. took us some time to find some that could take the power, but finally we found the M028n by Kemo that can take up to 4000watts at 220v.
bought two of these plus some fuses and potis for finer control over the Kemo as well as a thermometer.
hooked everything up and they work like a charm. we got our press from 0°C to 90°C in about 15min.

only "problem" remaining is the insulation. we simply wrapped them in some polyamide vacuum foil thats able to take up to 215° fine when the blankets are not touching anything that conducts electricity.
means you shouldn't touch the aluminum sheets in our press ;) you'll get small electro shocks (nothing too bad but i don't want to find out what happens if our ghetto insulation rips).

Posted: Sat Apr 03, 2010 1:49 pm
by chrismp
found a pic of our assembled press on my hdd :)
the heat blankets aren't in the press in this one though...


i guess he's getting busier sewing bags as i post this ;)

Posted: Wed Apr 14, 2010 2:36 am
by webboy
Thanks, let us know what they say...

Posted: Tue Nov 23, 2010 8:32 am
by chrismp
minimum orders on the heat blankets are 1500m :(
but there's a problem with them anyway. they're really thin and fragile like paper. plus i almost burnt one due to a rip in the insulation.

that's mainly the reason why i'm going to try and build a silicone heat blanket. i should have all the materials for some tests ready by this weekend :)

on another note, i've had some troubles with impressions on my boards. there's always a channel across the width impressed into the top. most of the times it's on the nose and on the last board it's also where the tail rocker starts.
i've had this problem no matter what type of material i use to protect the cassettes from epoxy (first couple of boards i used polyamide film and on this one i used parchment paper).
i place the parchment paper right on the board and above that are the aluminum sheet, heat blanket, mdf sheet and the cattrack.
there's no sign of these dimples on the aluminum.

here's a couple of pics:





the graphic was printed with my epson 2100 on white canvas. we added some white pigments to the epoxy on top of the core, but you can still see part of the core shining through. there's a regular uhmpe topsheet on it.

Posted: Tue Nov 23, 2010 10:56 am
by doughboyshredder
wax your cassette sheets. Anything else will cause ripples

Posted: Tue Nov 23, 2010 11:05 am
by chrismp
doughboyshredder wrote:wax your cassette sheets. Anything else will cause ripples
thanks, i already suspected that it was that.

btw, that graphic wasn't my idea. it was a commission for a friend. ;)

Posted: Tue Nov 23, 2010 11:30 am
by Dr. Delam
Second that. I got rid of the parchment paper and no more wrinkles.

Posted: Fri Feb 11, 2011 11:17 am
by WhitePine
Chris - I was wondering how your boards turned out before you added heat blankets to your press. Did they turn out ok or do they have durability/delamination issues?

I'm considering doing something similar-ish to your design but I probably won't add heat blanket initially. Do you think I'll have issues?

Also, remove the curved piece of wood from your press that covered the pyramid portion?

Posted: Fri Feb 11, 2011 11:42 am
by chrismp
we've used heat blankets since day one, so i have no experiences on that topic. but i think many of the other guys using this kind of press (shopvacs,...) are pressing without heat and they do just fine.

what piece of wood do you mean exactly?

Posted: Fri Feb 11, 2011 12:02 pm
by WhitePine
The one covering the pyramid in the 3rd picture you posted on page 1 of this thread. It looks like it was there to prevent any sharp edges from contacting the fabric. It's not there in all the subsequent photos.

Posted: Fri Feb 11, 2011 12:19 pm
by chrismp
ohh, thats no wood, thats felt fabric ;)
we removed it cause it wasn't really helping and made it kinda hard to slip the cordura on.