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[BeeJay UK]

I know a Monoperm is a little old hat but I found one recently in the shed. Although it's over 30 years old it works fine, and i fancy a nostalgia kick.


Question is, will a Monoperm on 6v run a 40mm 3 blade prop? It's for a 33 x 13 inch 1-12 scale fishing boat which is of course much more of a tortoise than a hare. Use of the Monoperm isn't set in stone and I wonder if it's a bit small but I have it so want to put it to good use.


If it's not suitable then I am open to other suggestions. I have a 540/1 and a couple of brushless 1500v's going spare but I thick they may be a bit fast for the 'Annie P'. She is an amalgam of several 10m Jersey fishing boats I am building to use up an old GRP hull of indeterminate origin that I had hanging in the garage..

[malcolmfrary]

https://www.modelboatmayhem.co.uk/forum/index.php/topic,11713.25.html  Page 2, top post, is a chart that I asked for and was kindly given a few years ago for the various named Graupner motors.
There are a few monoperms, a lot depends on which flavour yours is.
I suspect it would need gearing, a prop with a larger diameter than the motor can is rarely a good combination.

[BeeJay UK]

Mine's just marked as follows, nothing more specific. However from your chart I would guess at a 2000 as it's 2" long & 6V.


 'Monoperm Super'
          6V= 
       max 3A

[Colin Bishop]

I think a Monoperm would struggle with a hull that size even geared down. I have a 6v Monoperm with a  2:1 pulley drive fitted to my Dean's Medea steam yacht kit driving a 30mm 4 blade prop. Performance is adequate but not overpowered. The hull is very fine lined and 31 inches long with 4.5 inch max beam.
 
I doubt if the Monoperm could push your fishing boat along in anything other than a flat calm. As you suggest, a low drain 545 type would be better.  But make sure you have the right one! I'm sure somebody will be able make a specific suggestion.

Colin

[BeeJay UK]

Thanks Colin. I did think the Monoperm was probably a bit small. When I previously suggested a 540/1 albeit with a 50mm prop I was asked if I was building a speedboat. I was toying with a 540 on a 6-1 gearbox as a possibility, maybe....


I have had to drop to a 40mm prop due to space constraints under the stern and I am using a steerable kort as there isn't really enough space for a prop & rudder without the rudder sticking out beyond the transom. Apart from anything else that would make the steering linkage a bit problematical.

[gingyer]

My dad had used a monoperm before in a Robbe Anje fishing boat
[size=78%]https://www.cornwallmodelboats.co.uk/acatalog/RO-Marin-Dolly-Harbour-Launch-1-20-R1110C.html#SID=2507[/size]
It has about a 30mm prop  anything bigger I would recon it would struggle.

[BeeJay UK]

Mines about 6" longer, 4" wider and twice the weight so I think the Monoperm is out the window.
I'll keep that for 21" tug I reckon. When I get round to that.