Pattern making

Is anyone here using 3D printing to make casting patterns? If so was it successful or not worth the effort, best stay with conventional methods.

Would 3D printing patterns be better than using a "desktop CNC router/engraver"? I am guessing that either could produce a pattern but both techniques would require some degree of hand finishing.

I can see advantages to both, having said that I have no recent experience of either. When I was last involved in either of these processes 3D printing was called Stereolithography and CNC used punched tape.

I think the best solution would be a machine that could do both, does such a thing exist?

As for price I am surprised how little these machines cost, it begs the question are they any good? I would rather pay more rather than less for a reliable machine.

As for size, a 250mm cube of capacity would be good. Although most of the machines from the bottom end of the market seem somewhat restricted in the Z axis. I'm sure its possible to work around that.

Sorry for all the questions, i'm looking forward to your comments guys.

John

I seem to only get the need for a casting once or twice a year so stick to traditional methods. For a one off if it gets to a reasonable size I make polystyrene patterns. I think at 70 years old I would spend far to long learning how to model in 3D and program the machine but I realise the 3D printing is the future.

John, I can only comment on your post rather than answer your questions but I am similarly curious. I have a small cnc milling/router/engraver that takes .250" dia bits max and has a working area of x200 y175 and z90. After having had it for a couple of years I am still trying to get my head round around the complexity of actually producing on a regular basis. For me though, self teaching CAD/CAM post processors and gcode etc etc beats the hell out of navel contemplation and crossword puzzles.>>

Just to make things a little more interesting I have just purchased one of ALDI's Balco 3D printers, so another toy to get my head around once I assemble it later this morn.>>

Like you, I have wondered about producing patterns using such kit but in reality I am unlikely to need to do so with half a dozen just started/half finished models in the "to do" cupboard awaiting my precious time - I'm 72. Like Chris I would probably go the manually cobbled polystyrene route for the occasional "lost wax" pattern>>

I do occasionally complete a model or item of tooling which is nice but my great pleasure lies in the journey. The destination is secondary - but it is good to “arrive” now and again. >>

Rik>>

I suppose printed has the advantage over routed that you can burn out the PLA if needed which allows more complex castings without having to resort to cores and looses pieces. You can also print shapes that would be hard to cut on a 3-axis CNC such as with overhangs etc.

Mr pete 222 on you tube has done quite a bit on 3D printing for casting very informed guy check him out.

H

likewise Myfordboy has been doing a lot of printing recently and using the patterns for his casting work.

If you read the older threads on this forum on 3D printing you will find half of them were talking about patternmaking complete with examples. Just do a bit of searching.

I have had some lost wax castings done by Shapeways as a trial for a 5" gauge loco. They are small parts typically around a 12mm long but complex and a pain to make conventionally. They only cost around £12 each plus postage so it was well worth the punt. The quality is reasonable and at normal viewing distances look completely acceptable.

The first photo shows a typical CAD model, The second shows the mesh for the stl file (note This was a coarse mesh and on subsequent parts I have increased the cells numbers. the rest of the photos shows the finished parts and a couple of other castings. hope this may be of interest.

Thank you for the replies. As Rik S says puzzling out a new process beats watching the idiot box etc every time. I'm OK with the modelling software, learnt to use that years ago but can still get frustrated by it!

The patterns I want to make are for a motorcycle related project ( to begin with) and there will be the need to use the patterns several times so polystyrene is not the way forward.

I've viewed the suggested videos on YouTube, useful information.

DS14, thats some good work there, many years ago I had the patterns for a motorcycle engine cast in steel from a 3D printed patterns. Worked well but the pattern needed a lot of "cleaning up", I believe surface finish has moved on since then.

At the moment I am leaning towards CNC routing.

For the work I want it to do, think of a motorcycle cylinder. Probably milled/routed from polyurethane foam as a kit of parts then glued together.

John

First attempt (the base is 3/8" square) - home brewed aluminium bronze, not ideal:

Second attempt, 2 out of 4 success rate - needed a greater 'head' of molten metal.

3rd attempt, central runner is 1/8", note large base just to provide that 'head':