The Otto D2 by pieter

[Moës_Pieter]

Hi fellow model engineers,

A few months ago, I decided to start a new build project. I already own a few real stationary engines and have always dreamed of owning a pre-1900 engine—so I thought, why not build one myself?

On April 15, I ordered a set of castings from the Engineers Emporium. I was pleasantly surprised by the quality when they arrived—excellent first impressions!

After studying the drawings, I made my first cuts. Fortunately, I came across this forum and got in touch with Pirmin, who’s doing an amazing build of the same engine. His work has been a great reference and inspiration.

Early on, I encountered a few issues, especially with the crank support casting. Aligning it correctly to ensure everything is centered and machinable turned out to be quite a challenge. To avoid further alignment errors, I decided to model the engine in Fusion 360.

So far, I’ve machined the main body and the crank support. To help with precise alignment, I 3D scanned the inlet and exhaust housing castings. I’ll be assembling this scanned data with the 3D CAD models in Fusion, which should allow me to perfectly align everything before making more chips.

The goal is to build this model as close to the original engine as possible, in both function and appearance.

Looking forward to sharing more updates as the build progresses—and always happy to hear advice or ideas from the community!


Engineering regards,
Pieter

[pirmin]

Awesome Start  Pieter !

I must say, i am very Happy that another Member beside Dave Otto and me started  this Build. There is loads of things that can be done better on this Engine, but the Power of our Strong community is endless and i hope, together we can make it a better modell as it already is


I am very convinced that you are on a very good Path with your Laser 3D  Scans and the use of a Erowa pallet to chuck the upper casting for all machining purposes. this is realy Top level Model Engineering .

By the way, i will soon make a update in my Post about the Hot tube, but i am still cobbling some drawings together and want to make a bespoke chimmney box , i hope we can figure all missing links out together as a team!

Cheers Pirmin

[Roger B]

Off to a good start     

Scanning and modelling the castings is an interesting idea 

[Dave Otto]

Hi Pieter

Good to see you posting your D2 project, what you have done so far is looking very nice. Your castings look pretty good, the ones that I received should have been thrown in the scrap bin at the foundry, the base casting is complete rubbish!

Dave

[pirmin]

Miserable castings  Dave, i feel realy a bit sorry that they shipped such a base casting to you. you should reach out to them for a refund casting,i would have asked for a new casting if mine would look that bad

[Casting Iron]

Does look a bit rough.
I am trying to figure out how they molded that.
I see one gate.
.

[Dave Otto]

Does look a bit rough.
I am trying to figure out how they molded that.
I see one gate.
.

One gate that completely ruined those surfaces due to shrink. I see Pieter's casting was gated the same but didn't have the shrink. I just can't imagine why anyone would put a gate on a non-machined cosmetic surface?

Dave

[Jasonb]

That is rough, if I had seen them at the time I would have walked away, not what was on the stand. With the access to CNC that you have I would bin it and cut from solid, maybe two parts to save some material with the cylinder being turned and fitted into the base.

Pat it looks like the whole thing has draft so just pulls out the sand vertically. leaves no part lines so you get a clean cast surface then they go and put the gate there rather than cut it into the other half and have it feed the bottom of the base rather than the side.

[Moës_Pieter]

Hi Dave,

Thanks for sharing those photos — sorry to see the casting quality on your kit is that poor.
Luckily, most of my castings turned out significantly better than what you received.

That said, I did notice one major issue on my side as well: the crank support casting has some serious geometric deviations, as I mentioned in my initial post.

I’d recommend that anyone else building from this kit carefully checks this part before making any irreversible cuts — it could save quite a bit of frustration later on.

I’m currently working my way through some of the smaller parts, and I hope to post an update on my progress later this week.

All the best,
Pieter

[Moës_Pieter]

Hello engineers,

I’ve been working on a few parts, and I’d like to share some photos of the components I’ve recently completed.

The lever arm was machined on a 5-axis machine. I thought it would be a nice challenge to machine it in a single setup, and it turned out to be a great exercise in precision and planning.

Thanks again to everyone for the ongoing support and inspiration – this forum is a fantastic place to learn and share ideas.

Best regards,
Pieter

[Dave Otto]

Beautiful work on fussy little parts Pieter.
The five axis work on the lever arm is especially nice!

Dave

[pirmin]

 

Stunning Job

I cant express my feelings enough when i see such high class model engineering!