New idea for insulating a hot end rapidly

[AR_LA]

Typically with that sort of product it's the adhesive that has the lower temp rating. It can release gas or fail altogether at high temps.

I just ordered some of the fiberglass tubing as well as the silicone coated fiberglass tubing. To try out. I have been using just high temp silicone rubber cut to wrap the hot end, secured with fiberglass tape.

Keep in mind even high temp Kapton tape has a max temp rating of 500F, and again it's the rating of the adhesive, but people use it all the time. A little insulation between the tape and the hot end goes a long way.

[firesped]

and in case you were wondering what kapton tape looks like when you burn it.

This was removed from the hotend that had a thermal runaway. It was insulated with kapton layer, ceramic fiber layer and another kapton layer outside that. I have no clue how hot it actually got.

[zemlin]

Hadn't considered the potential benefits of insulation - and it's a simple enough task.
My Makergear printer uses a glass-lined stretchy silicone sleeve.
I decided I'd try these:

https://www.mcmaster.com/#7569k12/=1aa7grf

https://www.mcmaster.com/#2573k18/=1aa7gju
If the second one ends up being a better solution, I'll have about 9' of insulating tubing to get rid of for cheap. Stay tuned.

[Michael.P@Raise3D]

@zemlin,

That is one way to go about it! I have gotten annoyed with my printer at home, the hotend is not insulated at all and when testing the BVOH I am having to clean off the extruder blocks quite a bit. I might have to take you up on the offer if it works out for you.

[Noren]

I checked the rating of the hose you linked to. And it’s only rated for 390°F (200°C). Do you think that is enough? If it is I have a similar product in a local shop with the same rating I would like to try out.

[zemlin]

I checked the rating of the hose you linked to. And it’s only rated for 390°F (200°C). Do you think that is enough? If it is I have a similar product in a local shop with the same rating I would like to try out.

The heavier hose is good to 500F. I will compare the thinner tube to what I've had on the Makergear printer when it arrives. It sounds like the same stuff though - and it's surviving a 250C and hotter hot end on that machine. If I'm wrong, I might have a mess on my hands.

[Noren]

Ok. The tube i have locally is rates 200°C but has a melting point of 600°C. Guess a try and observation is the way to go.

[Michael.P@Raise3D]

Keep a close eye on it, we dont want anything happening to you!

[AR_LA]

And beware of the fumes from whatever adhesive is used.

[AR_LA]

Just wanted to build off of John's original post. The 3/4" tubing looked like it had some extra space, so I tried out 5/8", and it's nice and snug. Here's 5/8" ID silicone covered fiberglass like Jetguy mentioned earlier. Purchased from McMaster-Carr

I'm not sure how it's going to hold up to temps over 260C. I read some papers about the affects of high heat on silicone, and it looks to affect modulus, elasticity, etc... but nothing to really let me know what to expect with prolonged, and cyclical exposure to 300Cish. For the last year or so I've just been using silicone over my hot ends and it showed no signs of damage, but the hottest print I did was just a 12hr poly-plus at like 260. I think it'll be fine, but I'm no expert here.

[zemlin]

Is that
https://www.mcmaster.com/#8772k56
or
https://www.mcmaster.com/#6172t14
Wish those had turned up when I did my searching - would have added them to the order.

[AR_LA]

6172T14, but the other should work just as well. I also got 88155K63 but that just wants to unravel when you look at it.

[firesped]

the ceratex cermic fiber cloth tape I am using is rated for 1,800 °F. for Continuous Use, 2300 °F Maximum. the ceratex was fine, it was the kapton tape that burned.

[DrewPetitclerc]

You should check out my post here.
viewtopic.php?f=4&t=4634#p21471
Could be helpful.

[JohnSays]

Depends on what you print with. Most of my printing is done between 240C and 260C. The heat block is going to be very near those temperatures.

[zemlin]

This sleeve has been working out well on my machine.
https://www.mcmaster.com/#2573k18/=1aa7gju
I also picked up a punch for cutting out circular holes and worked out the cutouts for the sleeves. It's thin enough that it will wrap both hot ends on an N2 dual. The notch I cut in the top leaves a good amount of room for airflow past the heat break.

If you want me to cut a sleeve for you, $5 each plus postage. I'm pretty certain I can just mail these in a standard envelope with no surcharge so call US shipping $1.

If you'd rather cut your own, I'll throw 3.5" in an envelope for $2 (includes postage) - that's enough for two sleeves.
PM me with your email address so we can work out the details if you're interested.

[Julia Truchsess]

The key parameter is insulation, or "k" factor. The insulators I sell for Zortrax printers have a k factor of 0.48. And installation couldn't be much easier - a couple of silicone o-rings.

[Casale8]

This sleeve has been working out well on my machine.
https://www.mcmaster.com/#2573k18/=1aa7gju

I've been reading through these posts, and am curious the 390°f top temp is only ~199°c, isn't there a concern that this is low considering most printing is often done over 200°c?

I'm looking at the https://www.mcmaster.com/#6172t14/=1as41bc and see this is better for the 300°c the N series printers can print up to...

Thoughts?

[zemlin]

I've been reading through these posts, and am curious the 390°f top temp is only ~199°c, isn't there a concern that this is low considering most printing is often done over 200°c?
Thoughts?

My thoughts ... there's going to be a temperature differential across any insulator.The glass liner sees the highest temps right against the heater block. The silicone outer skin will see the lowest temps in ambient (or enclosure temp) air. According to my IR thermometer the skin temp on this is about half the extruder temp. I might have been more nervous about the temps, except that my Makergear printer is insulated with what looks like an identical sleeve, and it's been fine at extruder temps as high as 300C.

The heavier insulation shows a wall thickness of 5/32". Multiply that 2x if you want to insulate a dual. Do you have an 8mm or 5/16" gap between the heater blocks?

[Casale8]

Noted. I'll try both sizes and see how it goes.