Propeller RPM on OHIO sub - .

[robse]

Hi fellow subbers.

I'm building an Ohio 1/96, and have gotten to the point where I need to pick and engine. Does anyone have an idea of the RPM that the propeller needs? A friend mentioned a "Speed 550" engine with a 3 -> 1 gearing, but I can not find anything on it on the net.

Yours Sincerely, Robert, Denmark / Europe

[anonymous]

Hello Robert,

Below is a link

Hello Robert,

Below is a link charting the Graupner 'Speed' series motors. When you mentioned 'speed' then I knew your friend was referring to Graupner motor products.

http://homepage.ntlworld.com/edward.....ner.htm

A Speed 550 is not on the chart, but your friend might have been referring to a Graupner Speed 500? I would recommend a 500 size motor with 'BB' (ball bearings), or a motor in the 600 class size as the very largest considered in this application. You should not need the 'race' versions in this 500 class. Use a 3 to 1 gear or belt reduction. This is a common gear reduction arrangement for 1/96 scale R/C subs. You are lucky you live in Europe, as the full range of Graupner motors should be available to you. In the United States for instance, the Graupner 900 BB Torque is not available. Hobby shops in Europe are much more complete and larger in their selections to the customer. Wish we had such complete hobby shops in this country. The Graupner 900 BB Torque is a remarkably efficient high torque motor for it's price. German modelers often use this Speed 900 BB Torque on their larger single screw models employing a direct drive. Don't use a 900 in your Ohio model though!

I have not personally built a 1/96 Ohio sub so I hope others whom have can share their propulsion arrangements used on their Ohio SSBN (and future SSGN) models.

Best wishes,

Steve Reichmuth

[robse]

Hello Steve.

Thank you for your

Hello Steve.

Thank you for your answer. I think my friend does refer to 500 too, and by looking at the great link you supply, I'm quite sure that it's a typing error.
This lookes great, as the prop. RPM is somewhere around 5 -> 6½ thausant. (Some-what higher than I had imagined...)

...and yes, you're right. The model shops are quite well supplied here, and a few internet based stores has developed as well. It's strange that a small country like mine, with only 5.500.000 people (About as many as on Manhatten!) have got SO much more model-things...one should think that the marked was at least a trillion times bigger in the US.
Hmm... maybe one should open a web-shop for such things..

Thanks for your reply, and great help.

Yours Sincerely, Robert Holsting
Denmark / Europe
www.robse.dk