3D Printed wax mold

[Rick]

I bought a resin printer to experiment with the castable resins a few months ago. I struggled with any thing other than small jewelry sized pieces. Plus the resins are a bit difficult and expensive. I changed my direction and decided to print a mold for a part for the Shay Loco I am working on. I used a easy to print inexpensive resin and the results are pretty good. This is a the smoke box mount, it is bolted to the smoke box and a link goes from it to a mount on the frame. This mold could have been 3D machined but with the resin printer all three parts of the mold were printed at the same time in 3 hrs. Looks like this is another viable option in the tool box of method to make waxes.

[FKreider]

Excellent work! The surface finish of the SLA resin printers is very good compared to FDM!

[Rick]

Thanks Frank,
Yes surface finish difference between resin and filament is night and day.

[hoppercar]

Interesting...I've been wanting to get into, and experiment with 3d printing patterns.......it looks like it's gonna put traditional wooden patternmakers like me in the poor house. ....how do you deal with the layer lines, that the printer leaves ?......do the lines show up in the casting ?.....I would assume they do ?

[FKreider]

Interesting...I've been wanting to get into, and experiment with 3d printing patterns.......it looks like it's gonna put traditional wooden patternmakers like me in the poor house. ....how do you deal with the layer lines, that the printer leaves ?......do the lines show up in the casting ?.....I would assume they do ?

As I'm sure you know- traditional wooden patterns is a whole other ball of wax vs. the original intent of this thread which is about investment casting with wax "patterns".

I would not attempt to use a SLA or "resin" printer for sand castings, first of all the affordable SLA printers on the market have a pretty small build plate and thus are far better suited to investment cast items such as brass/bronze "jewelry" loco fittings. Secondly I'm guessing the resins would not hold up very well to the sand ramming process. With FDM prints I print them with extremely dense infill in order for them to survive the sand ramming process.

I have used my FDM printer quite a bit for sand patterns and it's quite a bit of work to get rid of the layer lines. I use a combination of bondo spot putty and automotive filler primer in layers to get rid of the lines. Its not a fast process since it takes a day or two between layers for proper drying and then another round of sanding.

[hoppercar]

Interesting...I've been wanting to get into, and experiment with 3d printing patterns.......it looks like it's gonna put traditional wooden patternmakers like me in the poor house. ....how do you deal with the layer lines, that the printer leaves ?......do the lines show up in the casting ?.....I would assume they do ?

As I'm sure you know- traditional wooden patterns is a whole other ball of wax vs. the original intent of this thread which is about investment casting with wax "patterns".

I would not attempt to use a SLA or "resin" printer for sand castings, first of all the affordable SLA printers on the market have a pretty small build plate and thus are far better suited to investment cast items such as brass/bronze "jewelry" loco fittings. Secondly I'm guessing the resins would not hold up very well to the sand ramming process. With FDM prints I print them with extremely dense infill in order for them to survive the sand ramming process.

I have used my FDM printer quite a bit for sand patterns and it's quite a bit of work to get rid of the layer lines. I use a combination of bondo spot putty and automotive filler primer in layers to get rid of the lines. Its not a fast process since it takes a day or two between layers for proper drying and then another round of sanding.

I've seen quite a few 3 d printed patterns come thru the shop for molding and pouring....but I know nothing about if there resin or not ?......I know, I've never been to impressed when I see the finished casting from one....you can usually see the layer lines.......hmmm, interesting

[GlennW]

Its not a fast process since it takes a day or two between layers for proper drying and then another round of sanding.

High build primer with 45 min to 1 hour dry time to sand.

Available in quarts and unbelievably easy to sand.

https://www.axalta.com/content/dam/NA/U ... 15-Eng.pdf

[Rick]

Interesting...I've been wanting to get into, and experiment with 3d printing patterns.......it looks like it's gonna put traditional wooden patternmakers like me in the poor house. ....how do you deal with the layer lines, that the printer leaves ?......do the lines show up in the casting ?.....I would assume they do ?

With the resin SLA/LCD printers there are layer lines , but the layers are only 50micro meters(0.0019 in ) thick.
Also by properly orientating the model when printing the layers basically disappear on the critical surfaces.

I also have used Filament printers for sand patterns and like Frank said there is a bit of work to get them smooth. I have used auto body filler and then sand and sand and sand some more, then do it all again.
For most of my work I am doing lost wax casting.

The resin printed material isn't the strongest, but if designed correctly and with the the wax injection pressure typically less than 10 psi it looks like it's a good fit
For larger parts I still machine my wax molds. The larger resin prints can warp and you also have to deal with shrinking issues of the printed parts. Along with my particular printer can't handle a very big part.