Siemens rotary in 1/48?

Brad · 19 January 2006, 07:07 AM

Gents,

I'm trying to figure out where to get the Siemens rotary used in the SS DI, or how to modify an existing engine of some sort. Any suggestions?

I'm converting the old cheap Testors (I THINK that is who made it) kit. Not a great kit, but for about $5 it works ok.

Thanks!

Brad

ChrisSavaglio · 20 January 2006, 07:34 AM

I don't know if it's the correct motor, but Copper State models has a Siemens rotory.

http://www.amug.org/~copperst/details_48.html

Chris

MicroSculpt · 20 January 2006, 10:18 AM

Brad:

I believe Rosemont Hobbies at one point carried a 1/48 resin Siemens Haskle rotary by Atlee that was quite nice. I'm not sure it is still available though.

Cheers!

Tom

Rowan Broadbent · 20 January 2006, 01:54 PM

[QUOTE=Brad]Gents,

"I'm trying to figure out where to get the Siemens rotary used in the SS DI, or how to modify an existing engine of some sort. Any suggestions?"

The engine was the ShI, a nine cylinder counter rotating rotary (crankcase in one direction at 8-900 rpm and the prop in the other at the same speed). The Atlee and CSM ones are for the eleven cylinder Sh III - a very different animal.

From pictures I have seen the ShI had a very similar appearance to the Gnome Monosupape engines - single front pushrod - so I would think the very nice Vector one or Aeroclub's white metal Mono would be quite convincing. Crankcase detail would be obscured by the front mounting spider, so any nine cylinder with single front pushrods should fit the bill.

Brad · 20 January 2006, 02:39 PM

[QUOTE=Rowan Broadbent]

Quote:

Originally Posted by Brad

Gents,

"I'm trying to figure out where to get the Siemens rotary used in the SS DI, or how to modify an existing engine of some sort. Any suggestions?"

The engine was the ShI, a nine cylinder counter rotating rotary (crankcase in one direction at 8-900 rpm and the prop in the other at the same speed). The Atlee and CSM ones are for the eleven cylinder Sh III - a very different animal.

From pictures I have seen the ShI had a very similar appearance to the Gnome Monosupape engines - single front pushrod - so I would think the very nice Vector one or Aeroclub's white metal Mono would be quite convincing. Crankcase detail would be obscured by the front mounting spider, so any nine cylinder with single front pushrods should fit the bill.

That's a very good tip, thank you sir!

StephenLawson · 20 January 2006, 06:02 PM

Greetings Rowan;

There were two types of "counter rotaries"

On the SSW D.I The complex production of the chosen power plant, the Siemens-Halske Sh. I (100hp) became the major factor in production delays. With this ‘Counter Rotary’ the Propeller and Crankshaft turned in one direction while the Cylinders turn in the opposite direction.

On later SSW D.III The Propeller and the Cylinders turned at 900 rpms in one direction, while and the Crankshaft turned 900 rpms in the other direction.

Brad · 23 January 2006, 09:00 AM

Quote:

Originally Posted by StephenLawson

Greetings Rowan;

There were two types of "counter rotaries"

On the SSW D.I The complex production of the chosen power plant, the Siemens-Halske Sh. I (100hp) became the major factor in production delays. With this ‘Counter Rotary’ the Propeller and Crankshaft turned in one direction while the Cylinders turn in the opposite direction.

On later SSW D.III The Propeller and the Cylinders turned at 900 rpms in one direction, while and the Crankshaft turned 900 rpms in the other direction.

Stephen,

So any suggestions how to make this look somewhat "correct?" I have no idea what the difference in appearance should be.

StephenLawson · 23 January 2006, 03:27 PM

I used the Nieuport kit engine. With the modification of cowling, the kit rotary engine (PP A 15) is now too big and needs to be modified. I prefer to remove the cylinders from the crankcase and shorten the cylinders at their base ends. This keeps the head details intact. Now replace them back on the crankcase drilling corresponding holes in both pieces and adding brass stay pins. This reinforces the whole assembly. The air induction pipes for the cylinders needs to be removed from the crankcase face plate (PP B 16) and then placed behind the cylinders leading down to the back of the crankcase. Finally, add small sections of brass wire to represent the push rods leading from the front of the cylinder heads to the front of the crankcase near the propeller shaft.