3D printing warp help

[Dave V]

The Yelton Models PRR MO Tower from Cresson is a nice little kit. The staircase that came with it, though, had some minor warpage with the cross braces cricled below:



My first instinct as an old-school modeler is to trim away the braces completely and replace them with styrene.

But before I do that, I thought that I might ask you guys if there's a quick and easy that I haven't thought of. Wary of using a heat gun lest I ruin it all.

[Chris333]

Hot water works, followed with cold water. Doubt it will stay straight even if you get it straight.

But if that was me I'd just clip it and replace.

[Dave V]

Hot water works, followed with cold water. Doubt it will stay straight even if you get it straight.

But if that was me I'd just clip it and replace.

Yeah, that's what I thought. Physically speaking it's hard to imagine a way to shorten and straighten it such that it'd remain that way.

Easy peasy. But I'll hold off and see if anyone else has ideas.

[Lemosteam]

That warp looks to be caused by shrinkage in the heavier cross section legs, as they shrunk, they pushed the thinner cross section into noodles. If it were me, I would lightly use a thin cutoff wheel to gap the warped strap. After, I would use a UV resin glue in multiple applications as filler and harden each application quickly to build up the cross section that was cut away. Then file or sand the filler to shape.

[AlwaysSolutions]

You can try to throw it in a food dehydrator for a couple hours but I dunno if that would work after it has gone through its final cure.

Mike

[Dave V]

That warp looks to be caused by shrinkage in the heavier cross section legs, as they shrunk, they pushed the thinner cross section into noodles. If it were me, I would lightly use a thin cutoff wheel to gap the warped strap. After, I would use a UV resin glue in multiple applications as filler and harden each application quickly to build up the cross section that was cut away. Then file or sand the filler to shape.

Creative for sure. I don't have UV resin glue on hand or a UV light to cure it, so that actually sounds like an order of magnitude more trouble than a snip n' replace. I suppose if I had all the material on hand that'd be a much more attractive option.

[robert3985]

For fine warped parts, i'm using boiling water.

(1) Place the warped part in a pan deep enough to submerse what sections are warped on your part

(2) Boil enough water to cover your part (or more)

(3) Pour the boiling hot water on to your part, covering it.

(4) Let the part sit in the hot water for enough time so that it's heated completely through. Thinner parts require less time, thicker parts more.  The parts I've done are very small, so I haven't ever had to heat them longer than a minute...usually around 30 seconds.

(5) Remove the part from the water and immediately place on a flat surface and press down, straightening it if possible.  If not, use your fingers to straighten the part and hold it positioned until it cools

(6) The warped part should straighten up and stay there.  If it doesn't work completely on the first attempt, do it again until it stays straight to your satisfaction.

So far, all of my straightened parts using this method have stayed straight.

Cheerio!
Bob Gilmore

[Dave V]

OK, now you're talkin.' I'll give that a shot, Bob!

[Sumner]

I use a hobby heat gun....

https://www.amazon.com/dp/B07RLT77L2?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_15


Heat it move it into position and hold or fix it there and let it cool.  Sometimes will do it a second time but usually it holds the new shape.

Sumner

[Dave V]

I use a hobby heat gun....

https://www.amazon.com/dp/B07RLT77L2?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_15


Heat it move it into position and hold or fix it there and let it cool.  Sometimes will do it a second time but usually it holds the new shape.

Sumner

I have one of those, but I feel like that's bringing a bazooka to a knife fight... I don't want to melt everything around it.

[Scottl]

Resin won't melt, in fact quite heat resistant.  A soldering iron won't melt it.

The water solution might work, but make sure it dries thoroughly before painting.  Many resins absorb water and appear dry.

[Chris333]

I feel like the staircase might look like Will Smith eating spaghetti when you are done.

[JeffB]

Resin won't melt, in fact quite heat resistant.  A soldering iron won't melt it.

The water solution might work, but make sure it dries thoroughly before painting.  Many resins absorb water and appear dry.

Exactly... 

Jeff

[Lemosteam]

Being that the legs are straight, and only the straps are warped tells me that heat will only make things worse.  The straps need to SHRINK.

@Dave V , Resin glue with UV light can be purchased at ACE Hardware and other various local hardware stores and is not very expensive at all.

https://www.homedepot.com/p/0-18-oz-SuperWeld-Light-Activated-Glue-33301SRP-6/308683595

[Dave V]

eing that the legs are straigh, and only the straps are warped tells me that heat will only make things worse.  The straps need to SHRINK.

@Dave V , Resin glue with UV light can be purchased at ACE Hardware and other various local hardware stores and is not very expensive at all.

https://www.homedepot.com/p/0-18-oz-SuperWeld-Light-Activated-Glue-33301SRP-6/308683595

Not really my point. That just seems like an order of magnitude more effort than this trivial problem seems to demand.