Working With 3D Models

[Lawton Maner]

I'm beginning to work with my first 3D printed model of an East Broad Top RR hopper.  It came from the vendor with the top rim slightly squeezed in.  How do I straighten the sides? 

When the 2025 On30 Annual arrived I learned of a company in Tennessee that sells models of ALL of the EBT's hoppers in 4 scales.  The EBT had a few 1 off hoppers which would have never been produced as models otherwise, making them a boon for EBT modelers.  The finished models will be "layout grade" models not the jaw dropping work highlighted on this forum. 

[Peter_T1958]

I was confronted with the same problem while building my Büssing tractor (Another Artillery Tractor #19). My producer gave me the advice to righten such problems in heating up the resin parts in hot water for some seconds. I used VERY hot water and it worked quite well. But you better try out on some spare parts...

[Lawrence@NZFinescale]

Resins vary a bit. So don't take advice as gospel.

I find hot water (freshly boiled in the kettle) moderately successful. If I need something flat (like a floor) I try to take it too far as it will tend to relax back a bit ie aim for a reverse curve.  I've used formers as well (for the inside of cars).  A friend prefers a hot air gun. In my experience hot water doesn't quite do it in some cases.

The problem is control.  Heat will certainly solve your problem, but may lead to others. For a floor I might tape to a steel rule, pour over boiling water and then flex the rule gently to set a reverse curve.  Once things cool down a bit and the part relaxes, hopefully things will stay flat. 

I prefer to avoid the problem (by proper curing), but that's not available if you are buying in.  Putting the onus back on the supplier is not unreasonable though. Models that are properly cured and straight tend to stay that way.  Models that are heat straightened are prone to subsequent movement in my experience.  Straightening is useful if you are subsequently going to incorporate a part into a glued/braced structure. I find large, flat, unbraced areas are more problematic.

[Lawton Maner]

Thanks.  I'll probably cut a former out of balsa to insert into the open top of the hopper.

[Bernhard]

When the 2025 On30 Annual arrived I learned of a company in Tennessee that sells models of ALL of the EBT's hoppers in 4 scales.  The EBT had a few 1 off hoppers which would have never been produced as models otherwise, making them a boon for EBT modelers.  The finished models will be "layout grade" models not the jaw dropping work highlighted on this forum. 

Does this supplier also offer hoppers in 1 scale (1:32)? I have been looking for some for my Hulett ore unloader for a long time.

Bernhard

[Lawton Maner]

Unfortunately no.  You are out of luck there.  On3/30 is as large as it gets.  EBT, Tweetsy, and Colorado prototypes.

[Lawrence@NZFinescale]

Unfortunately no.  You are out of luck there.  On3/30 is as large as it gets.  EBT, Tweetsy, and Colorado prototypes.

As someone who does such things, I'm always open to looking at doing an existing project in a different scale.  There's always practical and economic considerations, but I'll consider it.  So worth getting in touch with the vendor if they have what you want - you never know.

[Bernhard]

Unfortunately no.  You are out of luck there.  On3/30 is as large as it gets.  EBT, Tweetsy, and Colorado prototypes.

As someone who does such things, I'm always open to looking at doing an existing project in a different scale.  There's always practical and economic considerations, but I'll consider it.  So worth getting in touch with the vendor if they have what you want - you never know.

Good idea, Lawrence. I will get in touch with the supplier.

Bernhard