Hi all,
I have been watching some youtubes of Millar Agnew and his AMPS company. I also knew Mr. Agnew as he lived and worked near to where I lived. His outboards were powered not by weak K&B engines, but hot Rossi and OPS engines and they were gear driven, SO, why not gears for 152, so we can have some nice realistic legs? I really fancy a Sorriano look alike! Flat 6, twin cam per bank, supercharged. Yes please!!!

Cheers,
Martin

Hello Stoo
Have you seen this Page : www.152vo.de/index.php/modelle/modellaussenborder.html
you'll have big problems a lake to find for Nitro Engines in germany

The gears are said to be unreliable due to the high RPMs. But as of my (limited) knowledge of mechanical engineering, the relevant factor is torque, not rotational speed. I'm definitely going to give it a try but am still looking for a pair of suitable gearwheels.

Only the combustion engine is no real option here in germany. As Snake said, regulations are very strict and they are banned almost everywhere.

Guys,
I was only using Millar Agnew's Nitro engines as a comparison for revs. Obviously we must have BL motors for 152vo. I had no idea, though, that you have the same problem with IC in Germany as we do in England. It is so crazy, when you think of how many IC engines are flying around in aircraft!
And in large scale road vehicles.

Torque is the big problem with gear choice. My friend worked for a company who did gears for Hewland racing gearboxes and he said it was harder to make gears for touring cars than F1 because of the difference in torque required.

I can get 10mm diameter steel bevel gears here, but nothing smaller.

Martin

Those are the smallest gears I found so far (unless you go for plastic ):
www.ebay.de/itm/191538546119
They are just over 10mm in outer diameter.

A quick estimation of the torque, assuming the motor puts out 100W at 30.000 RPM:

M = P / (2 * PI * n) = 100 / (2 * 3,14 * (30.000 / 60)) = 0.032 [Nm]

They look like the ones I can get in England from S.H. Muffett, very fine old suppliers.
Your calculations are way over my head! But thanks anyway.

Martin

VollNormal schrieb:
A more accurate power estimate is 400 to 500 Watt at 25000 RPM. At least according to my telemetry data of several setups we use in 152VO. (35 to 45 Amps at 11,1 volt, peak power while accelerating around 50-55 amps) Doing the math with 500 Watt at 25000 RPM means 0,191 Nm torque.

Personally I don't believe in geared outboards with the ammount of power and RPM that we drive them. Jan Ilmer has constructed a geared 152VO motor and quickly converted that to flexshaft after only a few testruns. He used hardned Traxas gears used in diffs. The torque is one issue, lubrication is an other ..

I have worried about lubrication on a geared outboard, but I'm sure some serious steel bevels would do a nice job. For me, everything has to be "does it look good?" And the lower unit of a flexi drive OB looks terrible.
If I can't get a geared leg with 10mm diameter gears to look good, that will not be built either, but it's worth trying for the sake of aesthetics.

Martin

Well i think we get a solution for the VX class

look at the new TFL geardriven Outboarder just realeasing now

Axel


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Mod.: Bildquelle ergänzt. Fremde Fotos bitte immer(!) mit Bildquelle versehen, um Copyrights zu wahren und externe Rechtsstreitigkeiten zu vermeiden. Danke!

Ich finde im Web keine Infos zu dem Antrieb. Bist du sicher, dass das ein Kegelrad-Antrieb ist? Bzw. hast du irgendwo ein paar technische Daten gefunden?

Der "Große" sieht nämlich dem kleinen chinesischen Flexwellen-AB sehr ähnlich, allerdings mit senkrecht stehendem 36mm Inrunner (statt schräg stehendem 28er).


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