Model Boat Mayhem
Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: mrzippy on January 06, 2018, 01:03:00 pm
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Gathering ideas for a new approx 28" tug project powered by a single Schottel drive,
and in an effort to save myself many hours engineering and experimenting anguish,
the large Graupner Schottel Drive with its 65mm prop could fit the bill.
My question is to anyone with experience or thoughts about build quality and reputation of the unit,
are they reliable, would I be buying into something requiring parts upgrades or new gears after little use etc ?
My preference would be to use the specified brushless motor in a hope to obtain reasonable pulling power/grunt,
any thoughts would be appreciated thank you.
regards Paul
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The rotating prop end tends to fall off in the briney.
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The rotating prop end tends to fall off in the briney.
The old Marx/graupner(1775) maybe, but not on the 2335 unit... it's one piece.
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Umi you must have a draw full of these old drives if not shottles it's the old gray voiths. Lol
John
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I have two 2335 for my next tug. They must be limited to 8000rpm I believe and have 3:1 gear reduction. I bought two large brushed motors from components shop that are just a little faster but can limit revs with my transmitter. I'm quite confident about their quality.
(https://photos.smugmug.com/Boat-bits/i-vtk2T9H/0/b3720def/X3/IMG_1241-X3.jpg)
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Hi Paul. Will you be towing with the tug.
John
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The old Marx/graupner(1775) maybe, but not on the 2335 unit... it's one piece.
Hi Umi,
Yes indeed tis the ones. A bit heart breaking when a complete new one has to purchased.
How do the new ones fit to the boat and not become as two pieces.
Cheers
ken
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The old Marx/graupner(1775) maybe, but not on the 2335 unit... it's one piece.
Hi Umi,
Yes indeed tis the ones. A bit heart breaking when a complete new one has to purchased.
How do the new ones fit to the boat and not become as two pieces.
Cheers
ken
The entire bottom end and steering case drop out of the steering gear on both the Graupner #1761, and #2335.
(and I don't have a drawer full) %)
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Hi Ken. This is one of the 2335 unit installed into my flying kestrel. A part of the unit is in the vice to show you that it comes apart,
when the top part of the shottle is stripped the bottom part of the nozzle and shaft drop down, the top part is fitted in the hull then
the bottom half slides back in from the out side, hope this makes sense.
John
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These units are the new units from Bauer Modelle.
John
PS sorry umi 2or 3 lol
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Hi Mr Zippy
AS for a brushless motor times the KV to the voltage to get your revs, eg 600kv x 11.1v(3s)=6660 rpm, 600KV x 14.8v(4s)=8880rpm.
As for power the brushless motors have far more power, eg a L5055B-600kv (1600watts(about 2HP)), but, the main thing is a Lipo Battery to deliver the power.
As for ESC a car one with an electric fan on top is good for low speed as you cannot get the water flow for a water cooled one without a water pump.
Canabus
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Thanks everyone for the interesting replies,
I should have mentioned the Tug I'm researching is a large scale, big model around 30 inches of a Log 'Bronc'
the majority of full size caft are Schottel/Z/Outboard drive - that spin around on a sixpence,
leading me to think schottel drive for manouverability was the way to go.
The short, fat, deep hull with fluid dynamics of a house brick needs big brushless power to motivate the thing
driven in the manner of the full size craft with lots of full power forwards switching instantly
to full power in reverse - I'm thinking will quickly lead to wrecked gears etc.
A good comment has been mentioned about using simple, reliable and powerful old fashioned steerable nozzel,
and I have found a photo of a full size Bronc with conventional prop and nozzel that fits the bill, may go down this route.
While working on the plans, I'm trying to stop myself looking at the wonderful but hideously expensive $500+ Bauer all metal
Schottels for sale on the other side of the planet,
the price of these beauties plus good old uk import tax etc etc ? It would be good sense investing a new lathe !
regards Paul
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Paul is it possible to post a photo of what you are looking at you may be looking at twin screw not single.
John
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Hi John,
Yes of course, they are on Bauer-Modelle 60mm Schottel Drive at $522
http://www.bauer-modelle.com/epages/Bauer_Uwe46269592.sf/en_GB/?ObjectPath=/Shops/Bauer_Uwe46269592/Products/4.9431
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Hi Paul What area are you from?
John
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Hi John,
Leicester Midlands. Paul
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Hi John,
Yes of course, they are on Bauer-Modelle 60mm Schottel Drive at $522
http://www.bauer-modelle.com/epages/Bauer_Uwe46269592.sf/en_GB/?ObjectPath=/Shops/Bauer_Uwe46269592/Products/4.9431
Hi Paul. this is the one I have 75mm It's not been in a boat yet.
John
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Hi John,
Very nice, looks like one of the Bauer units - but with nylon gears ?
perhaps an early version of the current metal geared type ??
Paul
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Could be for sale if interested.
John
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Have you got a pair Poll ?
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Hi Brian. Sorry only got the one. Could be a good pattern for you
Lol.
John
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Cheers John i am just thinking ahead trying to save a bit of work, Stevns Arctic that i am working on at the moment is fitted with schottel drives.
Brian
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Hi John,
Thanks for the offer, I've changed the hull shape and started the build using a Kort,
very interesting to see a metal unit,
was it a Bauer? or someone spending many hours in the workshop??
regards Paul
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Paul are you doing the log pusher like the Bronc? If not could you post a pici of your hull please.
John
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Kort nozzel powered Bronc, see attached drawing if it views ok.