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Old May 14, 2011, 01:27 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
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Discussion
KPG25 Vs KPG27

Ive searched the interwebs to try and work out if theres any actual difference in strength between these two. All I can find is that the 27 has a 6mm output shaft, 25 has a 5mm.

Reason I ask is that the 27 is rocking horse shizzle too find, and am wondering if the 25 is as strong.

Has anyone actually busted a 5mm KPG25 shaft???


Along similar lines, but does anyone know if its possible to swap the gearing on the KPG25. Say I had a 5.2, and I wanted to drop 4.2 gearing into it. Is the outer ring gear the same? I had both a 5.2 and 4.2 in bits yesterday, but forgot to check, and now both are loctited up


And, while Im at it, Anyone have a source for KPG27's?
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Old May 14, 2011, 02:27 AM
I B Chargin'
Charger's Avatar
Arizona
Joined Aug 2003
1,525 Posts
You may be able to find the gear boxes, but, as I understand it for the KPG25, there is an adapter flange you will need, if you are planning to use the box on a Mega motor........and that flange is unobtainium for my efforts..........hopefully someone has a solution for you.
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Old May 14, 2011, 02:43 AM
Sure it'll work
Flyextreme's Avatar
United States, CA, Torrance
Joined Nov 2005
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You have a PM jacko'

Bill
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Old May 14, 2011, 04:34 AM
Grow old disgracefully!
dickw's Avatar
Luton, UK
Joined May 2006
1,122 Posts
The KP27 is bigger and stronger than the KP25 and will take a lot more power.
Information on the gears is here
http://www.kontronik.com/index.php?o...mid=63&lang=en
And for adaptor flanges for the KP25 look here
http://www.kontronik.com/index.php?o...mid=64&lang=en
Price list is here
http://www.kontronik.com/images/stor..._List_2011.pdf

Have you tried contacting Kontronik direct?
An email in English usually gets me a sensible answer.

Dick
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Old May 14, 2011, 08:37 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
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Cheers!

I just emailed kontronic
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Old May 14, 2011, 11:47 AM
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la528it's Avatar
United States, WA, Redmond
Joined Dec 2007
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The kpg27 is no longer being produced according to kontronik Germany. I do believe it is still being offered on Kira motors, but that's it
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Old May 14, 2011, 07:54 PM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
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Bugger.

What sort of power limit would you think is reasonable for both the 25 and the 27? In a hotliner setup, with a tamed start up curve
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Old May 15, 2011, 12:56 AM
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Hastings, Hawkes Bay, New Zealand (Aotearoa)
Joined Feb 2000
1,449 Posts
Jacko, don't forget we can order what ever you want from Kontronik. The KPG27 is listed in there latest price list from memory but adaptor flanges are probably an issue .

Heather (Watts Up Hobbies)
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Old May 15, 2011, 01:15 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
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Cheers Heather,

I assumed the flanges are interchangeable between a KPG25 and 27?
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Old May 15, 2011, 04:17 AM
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I was under the impression Kontronik only supplies 3.17mm pinions for the KPG27 boxes, or am I mistaken?

Regards,
Gerben
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Old May 16, 2011, 01:00 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
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Gerben, from what ive seen with extensive googling is 3.17 is the only pinion available for both KPG25 and 27's. The 6.7(?) KPG 27 uses a pinion machined into the shaft, so no pinions are available for that ratio.

Doesnt sound like one can buy KPG27's anymore
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Old May 16, 2011, 01:34 AM
Sure it'll work
Flyextreme's Avatar
United States, CA, Torrance
Joined Nov 2005
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Quote:
Originally Posted by jackosmeister View Post

Doesnt sound like one can buy KPG27's anymore
It does sound like you can get parts for the KPG27 if you already have one, or can find a used one that needs rebuilt.

Bill
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Old May 16, 2011, 02:27 AM
f5b-uk
Mike Seale's Avatar
United Kingdom, Dorset
Joined May 2002
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A quick question to you engineering types about the KPG pinions...is it possible to increase the diameter of the 3.17 pinion to fit a 5mm shaft and/or reduce the shaft diameter down to 3.17 in order to fit the pinion? I have access to someone who can do the work if it's possible or advisable.

Mike
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Old May 16, 2011, 03:04 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
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I just gave up and bought a new kontronic drive 502 set, purely to get the KPG27. Crazy world ! Anyone happen to want a Drive 502 with a KPG25 gearbox for dirt cheap?

Mike -

There wont be anything left of the pinion if it was opened up to 5mm, but I know Mega turns down the shaft of the longer can ACn 16's from 5mm inbetween the bearings, to 4mm or 3.2mm at output end of the shaft, so in theory at least its probably the way to go.
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Old May 16, 2011, 06:01 AM
f5b-uk
Mike Seale's Avatar
United Kingdom, Dorset
Joined May 2002
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That makes sense. I was thinking of just tapering the shaft beyond the bearing, but from what you say I should turn it down before the front bearing and raplace the bearing with a smaller one.

Mike
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