#garfield Logs

May 07 2022

01:29 AM rue_shop3: nope, no damn heating
01:38 AM rue_shop3: I'll have to go to some kinda resistive arrangement
01:44 AM rue_shop3: teflon coated nichrome/
01:44 AM rue_shop3: ?
01:45 AM rue_shop3: silicone?
02:49 AM Tom_L: .
02:51 AM Tom_L: mica wafers
05:17 AM Tom_L: .
05:18 AM Tom_L: not sure how you're gonna hook up a temp sensor
10:41 AM rue_bed: yes
10:57 AM Tom_L: hi
12:05 PM rue_mohr: morning
12:05 PM rue_mohr: I have an idea
12:05 PM rue_mohr: to make silicone sheets/strips
12:05 PM rue_mohr: wrap the nichrome up in that
12:06 PM rue_mohr: I'm under 300c
01:06 PM Tom_L: the wire will be above that though no?
01:26 PM rue_shop3: its kinda close isn't it?
01:27 PM rue_shop3: the target for the plastic is 185c or so
03:24 PM Tom_L: but it has to heat the pipe first
04:51 PM Tom_L: kapton insul?
04:53 PM Tom_L: Kapton remains stable (in isolation) across a wide range of temperatures, from 4 to 673 K (−269 to +400 °C)
05:50 PM Tom_itx: https://makezine.com/projects/diy-injection-molding/
05:51 PM Tom_itx: the inlet we did looks ok compared to that
05:59 PM Tom_L: so what about a couple decent cartridge heaters like he did?
05:59 PM Tom_L: don't reprap use cartridge heaters?
06:00 PM Tom_L: stick a couple of those on it instead of wrapping the cylinder
06:18 PM rue_shop3: hmm
06:18 PM rue_shop3: I wonder if the heat would be too uneven
06:19 PM Tom_L: use a square or triangle block with 2 or 3 heaters
06:19 PM Tom_L: seems like a simpler solution
06:20 PM Tom_L: those heaters are readily available for not much
06:20 PM Tom_L: as far as the mold, it looks doable to me
06:39 PM rue_shop3: I was pondering a bunch of heaters from glue guns
06:39 PM rue_shop3: maybe I could cast a rectangular block around the pipe
07:04 PM rue_mohr: well, some of the lawn got mowed
07:04 PM rue_mohr: the mowerbot was NOT built for this terrain
07:04 PM rue_mohr: or yard
07:42 PM Tom_L: i think those heaters may be your best bet
08:34 PM rue_shop3: well
08:34 PM rue_shop3: another idea comes to mind
08:34 PM rue_shop3: I have some full on stove elements
08:35 PM rue_shop3: I hear they can be post-shaped
08:36 PM Tom_L: water heater
08:36 PM rue_shop3: actauly stove
08:37 PM Tom_L: just stone or such inside the coil right?
08:44 PM rue_mohr: I think its silicone
08:44 PM rue_mohr: just hard stuff in and ends
08:46 PM Tom_L: oh
09:35 PM rue_shop3: hmm
09:35 PM rue_shop3: wonder where I put all the elements
10:06 PM Tom_L: close to the tip
10:06 PM Tom_L: at least some of them
10:06 PM Tom_L: if you did a box around the pipe, some on top, some on the bottom
10:07 PM Tom_L: not sure about stove elements
10:07 PM Tom_L: You will not be able to bend or straighten out the elements from a stove or oven. The resistive element is encased in some kind of ceramic material. A crack in the ceramic coating will cause the resistive element to oxidize rapidly when hot and "burn open". This will probably cause a hot spot and may lead to a fire.
10:08 PM rue_shop3: experience is that they bend ok, and that if you break them open, the wire is in soft material
10:09 PM Tom_L: aparently new ones are easier to bend
10:09 PM Tom_L: https://www.practicalmachinist.com/vb/general/can-you-bend-oven-elements-217753/
10:11 PM Tom_L: maybe easier to get straight ones and cut them to length tying the wire ends together
10:11 PM Tom_L: put them vertical along the pipe
10:11 PM Tom_L: i dunno
10:11 PM Tom_L: but then where to put the thermocouple
10:14 PM Tom_L: too bad my local guy is gone
10:14 PM Tom_L: he had all sizes of nichrome wire for sale
10:31 PM rue_shop3: they have special ends
10:31 PM rue_shop3: the big wire that comes out is just structural, the actual heating wire is much smaller
10:31 PM rue_shop3: I have a bunch of nichrome wire
10:31 PM rue_shop3: but its useless for this
10:40 PM Tom_L: ok
10:44 PM rue_shop3: I cant just wrap it around the metal pipe :)
10:45 PM Tom_L: not without some sort of insul
10:45 PM Tom_L: i thought about kapton
10:46 PM Tom_L: it's good to about 400c
10:48 PM Tom_L: what about a modified glue gun?
10:49 PM Tom_L: like a real glue gun
10:50 PM Tom_L: https://www.youtube.com/watch?v=oeL4VKlPers
10:50 PM Tom_L: they use kapton on it
10:57 PM Tom_L: i'd say a couple reprap heaters with a thermistor ajacent to them in your cast block
11:03 PM rue_shop3: I can get a bunch of dollar store glue guns, they use a PTC disc
11:03 PM rue_shop3: I should see what temp they go to tho, it might not be enoduhg
11:03 PM rue_shop3: but I want to try a stove element first
11:04 PM Tom_L: ok
11:05 PM Tom_L: the reprap stuff seems easy
11:05 PM Tom_L: and probably cheap since there's so many out there
11:06 PM rue_shop3: if I did a thing around it to mount and spread heat I could see it
11:06 PM Tom_L: your tube is ~1" ID?
11:08 PM rue_shop3: id
11:21 PM rue_mohr: ok I swear this keep changing
11:21 PM rue_mohr: 2559
11:21 PM Tom_L: up
11:22 PM Tom_L: mmm toaster oven elements
11:22 PM Tom_L: about a foot long
11:26 PM Tom_L: 500w quartz bulbs
11:26 PM Tom_L: they get damn hot
11:34 PM rue_mohr: how do I fix it to the pipe tho
11:34 PM rue_mohr: I want to heat the pipe evenly
11:35 PM rue_mohr: which is why I liked the induction thing
11:40 PM Tom_L: a square block at the top and bottom with 4 mounting holes for elements
11:41 PM Tom_L: induction would have been cool if it worked
11:41 PM Tom_L: i'm thinking more like giant reprap now
11:42 PM Tom_L: i could see up to maybe 8 of their heating thingies with a thermistor maybe at the tip and middle of the tube
11:42 PM Tom_L: i dunno how much area those things can heat
11:43 PM Tom_L: maybe 4 instead of 8. i dunno