Has anyone tried ThermoMorph?

[Last Ox]

ThermoMorph (or Instamorph) polycaprolactone (PCL) beads is a commercial product. You melt them in hot water (to a bubblegum consistency) and mold them by whatever means. 3D printing plastic is fine, but hard to get any real strength out of. The great thing about PCL is, once it cools, it appoaches Delrin in strength and is very tough. It will (permanently) deform under load, but I haven't seen it fracture - it absorbs a lot of energy as it fails. I got some to play with and now use it for all sorts of small parts and jigs, and to make custom-fit shims/spacers to 'bed' parts together. I chill parts with ice water - until they are cold clear through they can slump or deform. You can handle the hot plastic with wet metal (or, after it cools a tad, with wet fingers) but it sticks like fury to many plastics (including nitrile gloves).

Try it, you'll like it!

(I see it is now available as a printing filament - a little pricey and tricky to use - it melts at 60C vice 160C - would make bullet-proof fins if you could get it to print)

 

[BEC]

Interesting. Some years ago, I made a prop for a play my daughter was stage managing out of Instamorph, but it was basically a lump with room inside for couple of AA cells, an LED and a microswitch. It was supposed to be a stone that glowed on command, and it was set up so that the actress could press the switch to make it light up while holding it in the palm of her hand.

Because the shape was basically the shape of a flattened potato, I didn't really experience or play with its durability properties. I still have some of the material. I will have to experiment some.

 

[shockie]

Interesting. Some years ago, I made a prop for a play my daughter was stage managing out of Instamorph, but it was basically a lump with room inside for couple of AA cells, an LED and a microswitch. It was supposed to be a stone that glowed on command, and it was set up so that the actress could press the switch to make it light up while holding it in the palm of her hand.

Because the shape was basically the shape of a flattened potato, I didn't really experience or play with its durability properties. I still have some of the material. I will have to experiment some.

I used some last year to create some custom igniter plugs. I used MJG BP igniters and at first, I boiled the pellets and then just squeezed the plastic up around the igniter that was already in place. Notice how well it conforms to the nozzle shape. The igniter pyrogen butts right up against the blackpowder core top for guaranteed ignition. Later I just used a hair dryer to melt them. I later switched to 3d printed ones.

 

[bad_idea]

I used some last year to create some custom igniter plugs. I used MJG BP igniters and at first, I boiled the pellets and then just squeezed the plastic up around the igniter that was already in place. Notice how well it conforms to the nozzle shape. The igniter pyrogen butts right up against the blackpowder core top for guaranteed ignition. Later I just used a hair dryer to melt them. I later switched to 3d printed ones.

Interesting. I use poster putty with the MJGs, but sometimes the weight of all the wires for a big cluster tends to pull one or more of them out of the motor, so I spend more time fiddling at the pad than I'd like. Would you be willing to share your 3d files? (No worries if not.)

 

[shockie]

Interesting. I use poster putty with the MJGs, but sometimes the weight of all the wires for a big cluster tends to pull one or more of them out of the motor, so I spend more time fiddling at the pad than I'd like. Would you be willing to share your 3d files? (No worries if not.)

They are just a single layer of filament with a hole in them big enough to pass thru the igniter then I add a drop of rubber CA top and bottom to hold the igniter wire in place.
I slide the igniter disk up through the bottom of the disk until it comes to rest against the engine nozzle area while the igniter touches the propellant.
I use a small tape strip to hold it in place. You could 3d print a 2,3,4,etc multi-igniter disk as one piece and then tape the entire assembly on with a cluster.

I didn't like putting them in water to melt them, so I started using a hairdryer i had laying around. Because you have to de-wet them on a paper towel.It dawns on me now that I could have used a simple water bath and silicon cups with the plastic pellets inside.

I'm attaching a few pics.

 

[jqavins]

1. How sandable is it once hardened?
2. I wonder how effective it would be as filler to smooth the layer lines in a rough 3D print.

 

[fyrwrxz]

Decades ago there was a product called "Friendly Plastic" that came in sheets or pellets. I'm wondering if it isn't this just rebranded to sound higher tech.

 

[Sandy H.]

Decades ago there was a product called "Friendly Plastic" that came in sheets or pellets. I'm wondering if it isn't this just rebranded to sound higher tech.

My dad told me about it and gave me some. It was before the 3DP became a thing and seemed like an awesome solution for every problem. Regretfully, I never actually found a use for it that couldn't be done a better or easier way. Does seem like a great product, but my brain isn't smart enough to find the right application!

 

[Art Upton]

I have a bag of the pellets somewhere , but never used them yet

 

[Last Ox]

I've never tried to sand it, but expect it would be a challenge. You'd probably need to mold it (against polished metal or glass) to final finish. It is moderately strong, very tough and (unfortunately for many potential sites) will begin to soften at 135-140F. Sanding would likely either smear it (rather than shearing off fine dust) and if you were aggressive, think Dremel, it would be easy to heat it to the softening point. Like lots of things, it does better in its niche than outside it. A niche you have to work out yourself, but not something you'd make a motor mount with.

I've used it to make tool handles - the specific shape it not critical. I've molded small parts with it, but it has been handiest when bedding two oddly shaped parts, where you cannot just throw a washer or standard spacer between them.

I need to ask the son we outsource our 3d printing to about it. The filament (which I did not know was a thing until I posted this) is intended for biomedical use and is expensive, but I've seen enough 3D prints fail mechanically, I be interested in seeing how it works.

 

[jqavins]

It sounds like, not the classic "solution looking for a problem", but like a solution looking for more than just a couple of small niche problems.