Print

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

[Nordlys]

Would anyone have an unwanted set of plans for a 43" Range Safety Launch (Vic Smeed model) please?
Nordlys....

[JB]

Hi Nordlys

Yes I have a spare set (2 sheets) PM your address and I'll pop them in the post, don't need anything for them I have another set, did have the model a while back, it had a few previous owners and was a bit rough so I sold it on, should be a pic here to spur you on!

   

[Nordlys]

Hello  jb,
PM sent to you earlier - thanks
Did you get round to fitting motor's to this model?
I haven't been able to find any further info on what is a suitable size brushed motor?
Do you think a 600 @8.4v would be sufficient ( if any available  that is)

I have been thinking of running her on a 12v lead acid battery, there is more than enough room.....

N.

[malcolmfrary]

Yes 600s are available (old name is "540".  No, one would to little to move it.  Think 900 at least, forget lead acid.  Yes there is room, but this is a fast boat, not a tug.  For good suggestions regarding powering a planing hull almost 4 feet long, just look for the many other similar threads.

[JB]

Hi Nordlys

RSL plans are in the post, with any luck they should arrive tomorrow.

No I did'nt get around to motors, kept looking at the boat but a lot needed doing to it, was going to build another but my health stopped play!
going to hospital next week doc thinks I might need injections in my back oh heck.

I agree with Malcolm, you're gonna need a bigger motor and ni-mi's or even Lipo's, it's a big boat.

[Nordlys]

When I said about using a 600 size motor with 8.4v I did mean two motors!
However, if this is still too under powered then maybe a 700 BB x 2 at 9.6v would be suitable?
Trying to find a thread relating to this......

Thanks...
N

[JB]

2 x 700 sounds more like it but if I was to build another I'd go for 2 x 900 with Lipo's, ..or a small petrol, now that would be nice

Can't find much except this one

http://www.wicksteedparkmbc.com/raf-thornycroft-range-safety-launch.html

2 x 800 motors, looks like it needs spray rails though!

[Nordlys]

Hi jb,  Yes, 2 powerful motors can generate considerable spray and this is not what I want really as a previous boat
of mine took on board too much water from speed sprays.
However 2 x 700 motors might be just about right  - at considerable cost I might add!
N...

[malcolmfrary]

Size = money
Speed = money
Speed and size, lots of money.

[Nordlys]

I have reached the point where I must decide on which motors to buy to power this launch.
I have a short list of three to choose from but I am struggling to make the final choice.
The three are :-    Mtroniks 600 8.4 v    Graupner 700 BB Turbo at 12v    MFA Torpedo 850 at 12v
The Torpedo is a heavy weight and long at 70mm    Graupner is much lighter and shorter in length.

So my question for advice is What would you choose for a 43inch long RAF Launch?
It is a twin screw,
I eagerly await any recommendations from members.
Thanks all.
Nordlys...

[grasshopper]

Pretty sure you'd be wasting your time with the two 600's....
The 700's are a possibility with the option of upping the voltage for a bit more speed if 12v doesn't give you the performance you'd like. What's your reason for not going brushless?


Your earlier post saying you were going to use a lead acid is where it'll all go pear shaped, plenty of room is one thing, the weight is going to be the real issue as well as the output from the lead acids, a serious look at lipo is the way to go.  The pictures from the wick steed site showing that very nicely finished RSL makes it look heavy in the water, something you need to avoid to get good performance.


On another point, I have a picture of one that ended its life in the Maldives....painted in white rather than the black hull so there is another colour scheme available, reckon there's one in Malta that's been converted to a private launch with a rear cabin too.

[Nordlys]

All the boats I sail are all kitted out with brushed motors and I'm still using 40mhz radio, I guess you could say I'm of the old school!
But I am familiar enough with 2.4ghz just that I haven't converted as yet. Nor have I  considered using brushless motors as the expense of switching
over seems considerable with chargers etc.
I could settle for twin 700BB's quite readily and use Nimh batteries at 9.6v or thereabouts. Can you buy 12v stick batteries as this would probably be
ideal I feel? (for me anyway).
Yes, that Wicksteed RSL did look heavy I agree and I believe it was just 36inch length.
Nordlys...

[Stavros]

600 total waste of time not powerfull enough.... 700 same again....mfa 800 only rev to 5k But if propped rightbcould very well do the job...Mfa 850....far to current hungry by far

Personally I would go brushless with a kva of around 900/vols giving a rpm of 1080 rpm running 2 bladed props of around 55mm...obviously 2 speed cpntroller are required.

If you decide on the Mfa 800 then i would use 60mm 4 bladed ones and Action combined speed controller and mixer.


Dave

[Nordlys]

Can anyone advise me whether I should  run this twin engine launch with 2 Speed controllers ( rather than 1) connected to a P102 Action
distribution board please as shown in their diagram.
Motors are 2 Graupner 700 BB Turbo 12v.
Thanks,
Nordlys.

[raflaunches]

Yes, that Wicksteed RSL did look heavy I agree and I believe it was just 36inch length.
Nordlys...

Yes it is heavy in the water due to the location of the motors being too far forwards instead of being in the engine louvred covers which sit in the rear seating well. The model is 1/12th scale so it is the full 43 inches long but uses the heavy and as mentioned before thirsty MFA 850 motors.


Getting back to your last question, personally in a model of this scale and size I'd prefer to use individual speed controllers as it allows better individual throttle control. However I use a F14 Twinstick Tx but a 6channel 2.4GHz Tx should allow a tank style of throttle control. I prefer to keep things simple when is comes to power circuits.

[Nordlys]

I have pretty much decided on two 40A Esc's now following  on from your advice albeit at some cost!
Thanks.
Was that your launch then pictured at Wicksteed?
N

[raflaunches]

Not mine but I know the owner very well.