Best Shapeways material as a master for whitemetal casting?

[jonhall]

All,

 

As part of my Cargowaggon twin van project I want to print an airbrake cylinder and actuation arms at Shapeways and then use this as a master in whitemetal casting - I have a caster lined up who can take 3d prints as masters, but I now need to understand for small components (this is 4mm so under 20mm longest axis) what material will give the best output quality? Because this is for the master I can live with high cost for highest quality.

 

Second question relates to the price - the STL I've uploaded is a single unit, and the charge will be about $5 for the file and only $0.60 for the actual part - if I simply copy&paste the part 4 times in the same file is that sensible? I see a lot of shapeways users 'sprue' their parts together - is this because there is a per-part charge as well? I'm not great with 3d, and had help turning my 2d file into a 3d one - I was rather hoping not to have to do any further drawing if it could be avoided.

 

 

Thanks

 

Jon

[chris p bacon]

Spoke to you on Sunday Jon, very helpful.

 

I'd speak/email Mike Trice or JCL here and ask about sprueing so you get the maximum number for a print cost, they both have experience of 3D design and also have shops in Shapeways.

[Quarryscapes]

You could use Frosted Exreme Detail, it should turn out OK but I would advise painting it first to make sure the quality is OK. Alternatively find someone with a B9 creator and get them to print it. If you want multiples, sprue it as you want it laid out to be cast (ask your caster). There is no need to sprue, it's just often easier with small parts rather than having lots of fiddly little bits to get lost at the factory etc. Spruing can force the print orientation to be less than optimal. 

[Petri Sallinen]

We have used Shapeways FXD prints as masterparts for making resin castings. FXD works quite well as masters parts but you have to make something for the surface — in my opinion it is not good enough for master using without painting with primer. Two or three coats Surfacer 1200 made by Gunze using the airbrush will make good. Please look at the picture of ready made master parts of Finnish H0 locomotive.

 

 

Here is the ready made model with resin hulls.

 

There are also better ways to make masters for white metal castings or resin castings. 3D prints made by US Proto Lab are excellent — they are ready made for master using but also much more expensive than Shapeways prints. 

 

Here you are able to see the master print made by Proto Lab and the ready made white metal casting. It is very difficult to take the picture of green print but I think you are able to see the excellent details in the white metal part.

 

 

Here is the master part of the same locomotive you are able to see in my second picture. The scale in all parts is H0.

[Joseph_Pestell]

Not a big problem with a part like that, but keep in mind that the master for whitemetal has to be a smidge bigger than the finished model to take account of shrinkage.

 

Seems to me that it would just be a lot easier to have more made by 3D.

[jonhall]

Thanks all, I managed to get fusion 360 to copy the parts and uploaded the file to shapeways successfully, so I'll see in a few days what the outcome is. Martin had drawn and 3d printed most of the bits I need for me, but I wanted a change to this one item and he didn't have time to do so, it was sufficiently simple for me to draw it in 2d and get a friend to convert it to 3d, so it made sense to get the best quality print, and hand finish it if required to get the 4 replicates for the caster. I think a full set of w/metal is whats required, so I've gone with FXD.

 

Jon