Is There Time - The Build of Willy.

[CI]

3D printing the passages and ports would be extremely useful for the more complex engines like the Speedy Twin, or the Dake.
The Dake has complex passages and ports in the piston and in the crankcase.
The downside is you have to rely on someone else to make your "casting/printing", and so not good for the "do-it-yourselfers".

This process is similar to the 3D printed sand molds, where passages and ports can also be 3D printed.
Rather interesting technology for sure.
Seems like this could change the hobby in many ways if it catches on.
All brought on by the advent of 3D modeling.
3D modeling is having a huge effect on the hobby; sort of like the invention of the lathe, but much more impact really than the lathe.
3D modeling is a genesis moment for the hobby.

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[crueby]

A while back I had the bucket/door for a RC excavator model 3D printed in steel, came out looking great and very strong, but the printed powder/melted result was hard to drill though not too bad. Saved a LOT of time piecing it up, all the undercut shapes  and inside corners would have made milling from solid impossible. Quite a neat technology, I'm hoping that the selection of metals for it grows over time. There is still the printed wax/plastic and investment casting approach.

[Jasonb]

Well the paint is drying as I write this so it looks like there is going to be time to complete the engine.

Stay tuned for a Video and some pictures Tomorrow, the build thread can wait a while.

[CI]

 

[petertha]

A while back I had the bucket/door for a RC excavator model 3D printed in steel, came out looking great and very strong, but the printed powder/melted result was hard to drill though not too bad. Saved a LOT of time piecing it up, all the undercut shapes  and inside corners would have made milling from solid impossible. Quite a neat technology

I remember this. Do you recall what the alloy was named? I see some 3DP services make reference to 'stainless', or 316L, 304L specifically. Some are labelled 'nickel steel'. Some are less forthcoming beyond 'steel'. From what little I've read, the printed material is not softer as a function of the manufacturing process, if anything its hard(er). But I'm wondering out loud if the stainless ingredients, chromium or whatever make it more difficult on that basis alone just like bar stock material. I get along fine with 303 but others can be a bugger. This probably belongs in a 3DP thread, but you twigged my memory

[crueby]

A while back I had the bucket/door for a RC excavator model 3D printed in steel, came out looking great and very strong, but the printed powder/melted result was hard to drill though not too bad. Saved a LOT of time piecing it up, all the undercut shapes  and inside corners would have made milling from solid impossible. Quite a neat technology

I remember this. Do you recall what the alloy was named? I see some 3DP services make reference to 'stainless', or 316L, 304L specifically. Some are labelled 'nickel steel'. Some are less forthcoming beyond 'steel'. From what little I've read, the printed material is not softer as a function of the manufacturing process, if anything its hard(er). But I'm wondering out loud if the stainless ingredients, chromium or whatever make it more difficult on that basis alone just like bar stock material. I get along fine with 303 but others can be a bugger. This probably belongs in a 3DP thread, but you twigged my memory

Looked up the order - it was done in 316 stainless steel, from jlcpcb.com

[Jasonb]

Some of the older 3D metal printing mrthodss used a mix of metals that were printed and then a second sintering process was done to bond the elements together and these are what often resulted in hard to machine parts.

The current SLM process just uses a single metal powder and bonds the layers with a lazer. The 316L stainless that I have  had dome are just like machining a bit of the same solid bar. See this thread

https://www.modelenginemaker.com/index.php/topic,12252.msg290225.html#msg290225

[crueby]

Some of the older 3D metal printing mrthodss used a mix of metals that were printed and then a second sintering process was done to bond the elements together and these are what often resulted in hard to machine parts.

The current SLM process just uses a single metal powder and bonds the layers with a lazer. The 316L stainless that I have  had dome are just like machining a bit of the same solid bar. See this thread

https://www.modelenginemaker.com/index.php/topic,12252.msg290225.html#msg290225

Yes - mine was done with the laser SLM. I have not machined much 316 so don't know how the printed compares.

[Jasonb]

It seems there was indeed time and I did not even have to resort to quick drying paint.

Here is the finished engine. There was a little bit of tightness which I have since found so hopefully I can get a slower tick over but I’m more than happy with the speed the Tacho shows and had to stick it to a 20-40-80 block to stop it levitating.

Build thread to follow in the new year and the guess how long it took to make competition is still open for entries.

<a href="https://www.youtube.com/watch?v=OzkpJuu9cZg" target="_blank">http://www.youtube.com/watch?v=OzkpJuu9cZg</a>

[Sanjay F]

There we go, I was waiting for the message to arrive  - looks great as usual and what a mover!! It's been great watching your superb designs and builds come to life over the year and you've certainly clocked up a few

Looking forward to see the next one start ......... very soon 

[PaulR]

Smashing How did you fix the pivot pin in place?

A general question as well... when threading the ends of the piston rod, I always find that at the end of the thread the metal gets 'pushed up' into a slightly larger diameter than the rod, which makes it difficult to get it through the end cover/gland. Is it likely just a result of using coarse metric thread?

[Jasonb]

The pivot pin is 3mm stainless and threads into a tapped hole in the middle of the port face.

You can get some extrusion with stainless steel that does make the diameter over the crests larger than the bar you start with. I just hold a fine file against the thread as it spins in the lathe to knock a bit off the tops of the thread. A finer pitch would not do it as much but I don't tend to use the fine pitches below 3mm.

[astroud]

Re the end of a thread being pushed up, I find it helps to put an under cut there preferably with a radiused tool, this gives a space for the die to run into, the tooth then having no metal to push up. Makes the thread looker neater in my opinion.

[PaulR]

The pivot pin is 3mm stainless and threads into a tapped hole in the middle of the port face.

You can get some extrusion with stainless steel that does make the diameter over the crests larger than the bar you start with. I just hold a fine file against the thread as it spins in the lathe to knock a bit off the tops of the thread. A finer pitch would not do it as much but I don't tend to use the fine pitches below 3mm.

Ah, that's all the same as I do then, I wondered if there was a better way to prevent/remove the slight hump I seem to get in all metals at the end of the thread.

[PaulR]

Re the end of a thread being pushed up, I find it helps to put an under cut there preferably with a radiused tool, this gives a space for the die to run into, the tooth then having no metal to push up. Makes the thread looker neater in my opinion.

That's a good idea - I've only used an undercut where the thread meets a shoulder - I imagine it wouldn't require much depth at all?

Sorry for hijacking the thread Jason!