Precedent 34″ Huntsman

[BarzoParticipant @barzo]

What Motor?

[BarzoParticipant @barzo]

Many years ago I built my son a Huntsman and fitted an HP 40 IC Engine. The performance was exhilarating.

 

Unfortunately there are no ponds/lakes that permit IC engines close to where I live.

 

Can any one advise as to the necessary electric setup to replicate the performance of the HP40.

 

Regards Alan

[BarzoParticipant @barzo]

Apologies for a serious typo in my original post. The engine was an OS 40 Glow plug engine.

[RichParticipant @rich]

Alan, have a look over at Model Boat Mayhem, there are at least a couple of electric Huntsman(should that be Huntsmen?)builds over there, that should give you more than enough information to get started.

 

 

Rich 

[Paul TParticipant @pault84577]

Alan

 

Its a shame to ruin such an engine & boat combo by fitting a puny electric motor, are there any canals or rivers nearby where you could sail her as the gods intended…

 

Paul

 

[ashley needhamParticipant @ashleyneedham69188]

Why did I know that post was coming ?? Ashley

[Paul TParticipant @pault84577]

Once a petrol head always a petrol head.

 

It still upsets me that model boaters suffer under strict rules about noise and fuel when anybody can nip to B&Q and buy petrol strimmers and chain saws which make more noise and, in the hands of a novice, spill fuel everywhere.

 

Paul

 

I might be ill but I can still rant.

[BarzoParticipant @barzo]

Hi Guys,

 

Thanks for your comments.

 

I have uploaded 3 pics. of my model, as it appeared in its prime.

 

One of the reasons to rebuild it and perhaps re-engine it, is because on the last occasion it was sailed somebody away from the pond side must have been using a model with the same crystal as my set, (27MHz).

 

So at something like 25mph it hit the concrete pond side.!

 

Quite devastating.

 

Still looking for practical advice.

 

Cheers Alan

 

 

[Ian GardnerParticipant @iangardner62867]

I can only re-iterate Rich’s suggestion. There are a few threads about Huntsmen(?) over on Model Boat Mayhem.

I would also suggest exploring the possibility of  a Graupner 700 motor. Apparently these are happy if you exceed the nominal voltage and again there is stuff about this on Mayhem. Ask the question there as well and you may get some helpful suggestions.

The boat below has an MFA 850 on 14.4 volts but a 700 would be better- I don’t recommend the 850. A friend of mine runs the same boat with a 700 on 9.6v and it is better. Both use about X45 prop. The 700’s come in various voltages.

This is 33” long and weighs 8lb.

[BarzoParticipant @barzo]

Ian,

 

Thanks for your post.

 

It was most helpful.

 

I have had a look in the Mayhem site and have found some items of interest.

 

Cheers Alan

[ashley needhamParticipant @ashleyneedham69188]

Ian, why do you not recommend the 850?? just curious,   generally I feel that the 800/850 motors are not liked, without people exactly saying why.

 

(owner of two MFA boats with 800/850 motors) but no axe to grind.

 

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Ian, why do you not recommend the 850?? just curious,   generally I feel that the 800/850 motors are not liked, without people exactly saying why.

 

(owner of two MFA boats with 800/850 motors) but no axe to grind.

 

Ashley

[Ian GardnerParticipant @iangardner62867]

Hi Ashley,

In my post I mentioned that I was comparing the same boats, two Lesro Sportsmen, one with a 700 on 9.6 v and mine with an 850 on 12v. The 700 seemed better. I increased the voltage in mine to 14.4v which made a marked difference. I did this on the advice of a man more knowledgable than me in these matters.

So my opinion was based on experience, albeit limited, and it is only an opinion.

I felt that the value of a forum like this is to pass on experience, but it is up to each individual to decide whether to take notice or not.

I expect, in the interest of fairness, Alan would be eager to learn of your experience of these motors.

 

All the best,

Ian

[RichParticipant @rich]

Posted by Ian Gardner on 11/07/2010 16:42:07:

I can only re-iterate Rich’s suggestion. There are a few threads about Huntsmen(?) over on Model Boat Mayhem.

I would also suggest exploring the possibility of  a Graupner 700 motor. Apparently these are happy if you exceed the nominal voltage and again there is stuff about this on Mayhem. Ask the question there as well and you may get some helpful suggestions.

The boat below has an MFA 850 on 14.4 volts but a 700 would be better- I don’t recommend the 850. A friend of mine runs the same boat with a 700 on 9.6v and it is better. Both use about X45 prop. The 700’s come in various voltages.

This is 33” long and weighs 8lb.

 Is that a Lesro Sportsman I see? My first ever build, a lot of years ago…

[Ian GardnerParticipant @iangardner62867]

Hi Rich,

Yes it is a Lesro Sportsman. I like these old wooden kits althought this was bought as a new kit a couple of years ago from Lesro. I also bought a Rapier from them which I am building (very slowly!) and was told at the time that it was the last one they had, and no more were being made. There are new Sportman kits to be had on ebay but I think the popularity of this kind of thing has waned over the years. I liked the original lines of the boat so left out the flying bridge, which was a later addition.

I have, waiting in the workshop, an old Wavemaster and a Maycraft Mercury which I will restore in the fulness of time. What fun it all is!

You might find it interesting to look at John Walsh’s photos in the album- he is also keen on traditional types of boat, Aerokits and Nor-Star.

 

Best wishes, 

Ian

 

[Dave MilbournParticipant @davemilbourn48782]

Posted by The Fat Controller on 09/07/2010
07:13:54:

Alan

 

Its a shame to ruin
such an engine & boat combo by fitting a puny electric motor, are
there any canals or rivers nearby where you could sail her as the gods
intended…

 

Paul

 

“Gods??” 
Hang on a bit, Paul!

When I designed the thing in 1972 I
only had three A-levels……..maybe I got promoted somewhere along the
way, but without the salary increase?

The prototype 34″ had
an HP40F R/C Marine glowplug engine in it, and it went like greased
weasel pooh on standard fuel and a big Ripmax box silencer (no tuned
pipes then, m’duck).

As for a suitable electric motor, I’d
suggest either investigating brushless types or fitting a Speed 700
Turbo Nutter Loony, although I do have a Darke Horse 785 which would
make this thing sing on about 15 cells. (“Now then, Dave – you know you
don’t have any time for building these days”).

Can’t say
anything about 850 motors without risking legal action, except that 
there are much better big 12v motors around these days.

Dave
M

 

[ashley needhamParticipant @ashleyneedham69188]

My experience of these motors is….I have two boats fitted with them!!!

 

MFA boats= MFA engines. A proven combination easy to fit and running as intended.

 

End of story.

 

I can quite understand the legal point Dave, but am still in the dark as to why these motors are much maligned.

 

Ashley    

 

Disclaimer… not making any points here or extolling the virtues of these or any other engines simply asking . Devils advocate if you will,

[Paul TParticipant @pault84577]

Dave

 

In my experience ‘Gods’ do things for the good (or bad) of all mankind.

But for some reason that I can’t fathom they don’t seem to mind the priests, bishops and holymen taking the huge salaries…..perhaps the gods don’t know about copyright.

 

Paul

 

p.s Your design is still one of the best, strongest and most adaptable that I have ever built.

 

[BarzoParticipant @barzo]

Thanks to every body for your contributions.

 

Reference Paul’s comment to Dave 17/07 – what design is “still one of the best”?

 

On a technical note:

1.   what sort of amperage is drawn with a Graupner 700 motor on 14.5 volts.?

 2.   What sort of running time would you get on the above motor/voltage combination. I am sure that there will be an – “it all depends” type qualification, but some idea will be useful.

 

Thanks again Alan

 

 

P.S. I will weigh my boat and post the result.

 

[Dave MilbournParticipant @davemilbourn48782]

Alan

It ain’t that easy, mate! There are six different types of Speed 700 for a start. Each will draw different currents and consequently the running time will depend on which one you fit; the weight of the model; the capacity of the battery pack, and the diameter/pitch/material of the prop……o, yes – and also how long you run it at full chat.

Rich’s mate sounds like he has a good basis for experiment, but whatever you do don’t be tempted to fit a lead-acid battery for longer running times. You will surely kill the performance of the model and be very disappointed. Fairey boats were designed to do one thing, and that was go very fast in a straight line. They did it very well, so don’t compromise on performance with a model of one…….I may get reports back if you do…..

 

Paul

I’m all embarrassed now…..but thank you.

Dave M

[Paul TParticipant @pault84577]

Dave

 

Why be embarrassed….praise where praise is due

 

Paul

[BarzoParticipant @barzo]

Hi guys,

 

I have decided to go with a 900 motor with 2 x 9.6v NiMh (3700 mAh) batteries, an Action P98 ESC and BEC.

 

Several members of my local MBC use the GiantCod T4U Rx/Tx combo., any comments?

 

My biggest problem at the moment is to align the motor with the existing prop. shaft, I have no inclination to hack the existing shaft out of the hull.

 

If any one is interested I have managed to find a charger that will charge my two battery packs  simultaneously. It took two hrs to fully charge my new batteries.

 

Regards Alan

 

 PS the hull with motor, batteries and radio equipment weighs just over 3 lbs.

 

 

 

 

[BarzoParticipant @barzo]

Having fitted the motor in the boat and aligned the propshaft, I have measured the current drawn, with no load, viz,the prop running in air.

The batteries are fully charged and indicate 20 volts (no load), the current drawn was just under 2 amps.

Does this sound reasonable?

First bath tests shows the hull settling onto its marks nicely, with a simple on/off switch I applied the full voltage to the motor – mm looks promising – water every where.

I have ordered a GiantCod T4 and hope to be able to complete the radio installation soon.

Looking at the GiantCod web site there appears to be a small problem with initial power settings when first switched on – has any one had any experience with this ‘feature’?

Cheers Alan

[BarzoParticipant @barzo]

Hi Folks,

 

Some more progress, The GiantCod Tx/Rx set is more accurately described as a RadioLink T4EU.

 

With respect to my query regarding the power settings, I was now experiencing a failure of the ESC to respond to the Tx commands, it would only run at full speed in reverse. A quick call was made to Dave at Action RC Electronics to see if he had any experience of these symptoms. He had not, but generously offered me the opportunity to return the ESC for checking.   I felt at this stage I should research my problem further before taking up his offer.

 

After trawling various boating web sites with no success I thought of trying the GiantCod web site, forum section.

 

Eureka, one of the postings “Setting the failsafe on RadioLink 2.4ghz.. To cut the longer story short – a posting by ‘Phil_G March 24, 2010, described the condition and the background. Having implemented his recommendations, low tech. version – set the Tx ‘on’ (not the Rx.) and move the throttle stick to ‘full reverse’ then move the stick to ‘ full forward’  and finally to the ‘stop’ position. The Rx can now be switched ‘on’. The net effect was that the ESC now responded correctly to the Tx commands.

 

Note – the Tx was set in ‘mode 2’ and the ESC on Rx channel 3.

 

I am now one closer step to the boating lake.

 

Thanks to all Alan.

 

[Mark Beard 1Participant @markbeard1]

Alan,

 

Done some quick calculations and if you’re drawing 2A at 20V I reckon your alignment is spot on.  By my numbers, the motor should draw 1.1A  no load (that is, no coupling connected), and your coupling and prop shaft are loading the motor with a torque of only 15mNm.  Bearing in mind the motor bearings take 20mNm and that you’ll get 700mNm at peak power, that’s a very sweet installation – particularly since it’s a retro-fit!

 

Mark

Edited By Billysugger on 10/10/2010 11:37:27

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