Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Perkasaman2]

Flying Spark's pics suggest FLJ' s design/plans, like many others at that time, assummed i/c power - 60?. Most modellers would have added ballast weight to help stability/steering and avoid 'skating'. Electric power is now a real option and this is a big light model.

The original' Fairey' Huntsman 28 drawings I've seen show a twin prop layout/engines situated almost mid-length,  carried symmetrically 'high' to clear the deep vee/ enable substantial engine bearers. The rudders/props up on the transom edge - shafts extended to horizontalise thrust as much as possible. The deep Vee stern of this design would certainly enable better flow to the twin props. There's plenty of other relevant threads on the forum re power options/handling etc. - this is a very popular 60's offshore boat kit.  

I'm trying to avoid pedantics/hijacking Derek's thread   - I'd rather try and keep the info/perspectives/observations flowing for  Derek's ''blank canvas'. Stavros has shown what a single MMB 900 can do with the large Perkasa   - I prefer twin prop/tank steering fun with long shafts and motors set as low as possible (original design) but I'd be also tempted to slap a 900 in the vee with long ballrace/high rev shaft and a 50X then pile on the voltage.

[John W E]

 also a small boat kit called the Samurai.
.

And the old FLJ is to blame for that boat as well 

john e

bluebird

[DickyD]

When you think about it FLJ is to blame for quite a lot. 

[FullLeatherJacket]

also a small boat kit called the Samurai.

The 24" Swordsman was originally designed for Precedent but the then-owners of the company, Messrs Ripmax, thought it looked too dated. Samurai is really just a Swordsman with the corners straightened out. The name should be a giveaway!

Perkasaman is right in as much as the boats were orginally designed for IC power. In 1972 we had only just seen the arrival of the Mabuchi 540 motors for model aircraft; these were sold in the guise of the Ripmax Bullet and MFA Hummingbird. It would have been impossible to find even one electric motor with the power to shove a big Huntsman up onto the plane, while battery technology was only just then touching on using Nickel & Cadmium as an alternative to lead and sulphuric acid. The 1/8 scale Huntsman 31 used a HP61F R/C glowplug motor - the same type as 'Ramon' has fitted to his Huntsman 28 model. I left Model Avionics before the 34" model had been tested, but I gather she went like greased weasel pooh with a HP40F R/C.
I haven't designed a model since I made the orginal plank-on-frame 1/40 scale HMCC Sentinel which Model Slipway then took up as a kit, although I have a had a hand in several of Slipway's kits since then.
One day I'll re-do the Huntsman 31 in 1/12 scale for twin Speed 600s.............................one day!
FLJ

[SteamboatPhil]

Xmas day or boxing day then Dave 

[Flying Sparks]

One day I'll re-do the Huntsman 31 in 1/12 scale for twin Speed 600s.............................one day!

Wow, I want one, now  Do you mind if I put twin brushless in mine though 

Samurai is really just a Swordsman with the corners straightened out. The name should be a giveaway!

Doh, it's so obvious but penny didn't drop when I looked at that kit.

Phil.

[Bradley]

One day I'll re-do the Huntsman 31 in 1/12 scale for twin Speed 600s.............................one day!
FLJ

Thanks for all the info, FLJ.  Do you think that twin Speed 600s would get my 1:8 Huntsman up on the plane or would you recommend Speed 700s.  I am trying to keep my costs down to a reasonable level and do not want ridiculously expensive motors .

Derek.

[FullLeatherJacket]

Thanks for all the info, FLJ.  Do you think that twin Speed 600s would get my 1:8 Huntsman up on the plane or would you recommend Speed 700s.  I am trying to keep my costs down to a reasonable level and do not want ridiculously expensive motors .
Derek.

I wouldn't think that Speed 600s would do at all; they're fine for the smaller one maybe. I haven't any experience of fitting twin electric motors in one of these so I'd only be going on instinct. My own choice would be 3:1 geared 785 Darke Horse motors on 20 cells each, but that's a hefty price tag. 700BB Turbos would probably do but perhaps two MMB900 motors on 18v would be the most cost-effective place to start?
I'm open to other suggestions!
FLJ

[Flying Sparks]

What are the advantages of fitting twin motors? I understand it's as the full size was powered but is it more efficient than having one big motor?

Thanks

Phil

[Shipmate60]

One of the biggest advantages of twin shafts is stability.
With 2 props in the water it gives deep stability on each side of the hull.
In a single shaft set up you can reach a point where the power lifts the hull out of the water and starts to lift the "Deep V" which reduces the force on the underside of the hull and can make the hull unstable.

Bob

[Bradley]

Thanks again, FLJ - all very helpful.    Also many thanks to Perkasaman for his helpful PM.  

Phil,
I don't suppose that there are many (any) advantages using twin, as opposed to single, installation.  My thoughts were (1) I wanted the installation to be similar to the full size Huntsman and (2) the twin props do not project quite so far below the lowest point of the hull as a single.  I suppose it all boils down to personal preference really.

Derek.

And having seen Bob's posting just before I posted this one, I would agree with what he says.

[Perkasaman2]

 Another  big advantage of twin props is that they can be 'handed' - LH and RH and thereby avoid 'torque reaction/steering' which a high power single motor/prop layout can cause and should help  'neutralise' handling, especially at high speed. The Graupners (Speed 600/700's perform identically in either L/R direction in my experience.) Is there any advantage/disadvantages to contra spinning the twin props either  'inwards' or 'outwards'? ( My instinct chooses outwards - ?) 

[Flying Sparks]

Thankyou for your input guys, much appreciated. I ask about twin motors as I'm toying with putting two motors in my 34" Huntsman. The present prop shaft has been fitted too far aft and I'm thinking of cutting this off and fitting two tubes in the correct postion, this might be easier moving the current tube and using a single motor. Of course the rudder tube will have to be moved and replaced with twin rudders.

Any thoughts?

Phil.

[FullLeatherJacket]

PM sent.
FLJ

[Perkasaman2]

Hi Flying Sparks, My Higgins had twin Speed 600's with single (larger) central  rudder and steered great at all speeds. A single on the deep vee Huntsman will be a lot easier and very effective. The twin rudders in line of props on flat stern of Perk49 did little to improve its 'crabbing' lousy stering - but  high speed 'drifting' turns were fun. 

[red181]

Derek,
The larger Huntsman hull handles beautifully at speed, dont be worried about single screw. I ran a Graupner 700 BB turbo neodyme, but you have to up the volts to get it moving, I was using 19.2 (2 x 9.6v ) NIMH'S, glad to see you are thinking that way anyway, no memory effect, and give up the amps great, mine where 4600mah.

Direct drive, it was all getting a bit hot , so fitted a 2:1 gearbox. This greatly improved run time from  15 to 30 mins of fast running, and everything was now cold (although water cooled). I was using a Ripmax seasprint esc.
I have subsequently gone brushless, tried to change to 1.5:1 ratio, but got too hot, so reverted back to 2: The chinese cheapo esc's dont like running slow, and a friend really struggled balancing them on a twin screw setup, just could not get them to come in at the same time. I am using a castle creations esc, very expensive, so this has really been a very long build saving up money! . I am testing at present 5 cell 5000mah lipos, still getting the best prop sorted, currently its 52.5mm "x", as seen at the end of the video (you can easily see the changes from 50mm "s" 50mm "x" 50mm racing ally prop, then the 52.5mm "x". Tried a 55mm "x2 but it went no better.

Didnt want to hijack your thread, but there is a lot of info coming over, well here is some visual evidence of this marvelous boat at speed.  

I must however point out, its a Veron hull  ,  my prop is nowhere near where it is in the previos photo, I think that was set up initially for ic running, where weight displacement would be very different, with fuel tank, engine etc, Hope this helps! 6 lipo cells next!!

[Bradley]

Many thanks, Red181, that gives me some more to think about and the video of your boat up and running is brilliant .  Don't worry about 'hijacking the thread', I am only too pleased to read everything that the very helpful Mayhemmers post on here.  Whereabouts in the hull did you mount your motor?  I was thinking of mounting mine under the cockpit floor, where they would have been on the full size boat.

And a Happy Christmas to everyone, hope Santa brought you everything you wanted

Derek..

[bugs]

And a Happy Christmas to everyone, hope Santa brought you everything you wanted

Yep - plans for a scatch built Fairey Huntsman 28, a scroll saw, and £ donations toward the build fund! Now I just need to get the 5 week old to stop crying and the 5 year old to be an extra pair of helpful hands!

[red181]

Ha Ha, no chance there Bugs, and it gets no easier my 20 yr old is moaning I am on the pc on Xmas day!

Derek, here is a pic of the motor mount and prop position, I am going to do a full build tghread now its finished

[Bradley]

Bugs, I am glad to say that we are well past that stage now ,  my xx year old daughter is here with us helping to taste the champers .

Thanks for the photos Red and looking foward to your build thread.

Derek.

[model boat martin]

Hi

I built one last year with Brushless motors and it works really well.  I chose 2 Graupner 750 in-line motors and got them from Gliders in Newark powered by two 14.8 volt lipos and 2 100 amp ESC's.

I thought the build was a real hassle getting the GRP hull and ply internals to fit and fitting the hatch to the deck was not easy either.  It made me think that building it from scratch would have been more rewarding.

Good luck with the rest of the build.  The model works really well in very choppy water and mine flies through the air just like the big ones did on a good swell.

Must go got some sprouts to peel.

Cheers

Martin

[Bradley]

Hi Martin,

Thanks for the input.  As you have probably read, I was interested in brushless motors (and still am) but had problems with programming them.   Did yours run forward and reverse or foward only?   I know that there are ESC's on the market that do both, but at prices that are prohibitive to my level of the hobby.   My ESC's and programming card were from China/Hong Kong and were cheap enough to give up on, if necessary, but, at the same time, rather disappointing.

Derek.

[Bradley]

Further to what Martin said about this boat.  I would agree with him about the fit of the framework to the hull (as previously mentioned by Martin Admin).  I have just started to fix mine in place and I think I will have to be very careful not to end up with a hull/deck edge that is not completely out of shape.  I think that the answer would be to build from scratch from decent drawings but, unfortunately, you could never achieve satisfaction using the 'Precedent' kits without a lot of work to correct the inbuilt problems.
I wish that Anglia Model Centre would read this listing and get their act together to put out a decent kit (or pass it on to someone who was prepared to do that) as it is a smart looking boat suffering from lack of interest and development.   I don't suppose they will as they appear to be able to sell kits without a lot of input from themselves and a complaint from one individual would get nowhere - a great shame as, I think, this boat deserves better.

Derek.

[HS93 (RIP)]

this is a picture of two Turborix speed controllers just layed in my mini fire Tender they where a pain to set up BUT when I was at Deans marine end of year show there was a chap there with the same controllers in a BIG lifeboat with Thumper motors in he had it crawling along and then when needed he could put a spurt on but because it was a small pond (Puddle) he had it back and forward no problem docking etc he said it took him a bit of time to sort them out but he was very happy, Martin Mayhem may know if he is a member and he  may be able to help, I took mine out as it was just overpowered it was turning with the deck in the water etc and every run was nearly its last. but the parts where bought 3 years ago nearly if you look at the blog on fire boat website but we know a bit more now and it has been re motored (prob still to much)
I have some vids of Paul's red181 boat when it had the 700 bb in and it went well and you got 20+ min flat out most of the time, if it was mixed running it would prob be 40 min and they where old cells Nimhs at the time.the distand to the back need to be considerd carfully as we altered Paul's to suite electric running where you can move the weight about to suite, i think Paul was going to measure the distance we settled at, Ramon had a lot of handling problems with his but his prop was much furthere back.

Peter

[model boat martin]

Hi Derek

The ESC's are Danlions 100AMP which have reverse as well.  I got them from Astec.  They are programmable but work perfectly well on the standard factory settings.  I built the internals and deck to fit the GRP hull so it is a bit wider than scale.  There is a hollow in the moulding, port side towards the bow which I did not see until it was painted.  If it's not too late have a look for it.

I have to admit I do not know how to attach photos on this forum?

Cheers

Martin