Motor suggestion for large model

This topic is empty.

Viewing 25 posts - 1 through 25 (of 35 total)

1 2 →

Author

Posts
14 October 2013 at 09:43 #6901
Trevor Holloway
Participant
@trevorholloway99134
Motor required for 2m long Corvette
Advert

14 October 2013 at 09:43 #44386
Trevor Holloway
Participant
@trevorholloway99134
I am about to start on a build of a 1:32 scale (ish) Flower Corvette as this is my first big build I have no idea of what size motor I will need.

The hull will end up approx 2m long and 30cm wide (no idea of weight yet). a reasonable scale speed with a bit in reserve would be nice.

Not started cutting the hull formers yet so want to accomodate the motor mount / coupling / propshaft before it causes too much extra work.

Any suggestions welcome.

Thanks.
14 October 2013 at 10:28 #44387
Dave Milbourn
Participant
@davemilbourn48782
**LINK**

T12 or T24 – number indicates running voltage. Either will turn a large prop (100mm + dia). Bryan also supplies suitable mounts.

Dave M
14 October 2013 at 19:29 #44395
ashley needham
Participant
@ashleyneedham69188
Trevor you sly old dog you. A spiffing 6 plus imperial British feet eh ??? A whopper.

Ashley
15 October 2013 at 09:13 #44403
Trevor Holloway
Participant
@trevorholloway99134
Yup and at the obligatory 1:32 scale for D-Day (to go with the MTB I already have plus a landing craft possibly).

Should keep me quiet during the long winter evenings whilst "Britains got the strictly x-factor on ice ", or whatever it is, is on the TV !
20 October 2013 at 12:10 #44499
Dave Milbourn
Participant
@davemilbourn48782
Trevor

Word from a user is that the T12 would not have the guts to swing a 90mm prop (he's burned out four trying). MMM do a larger 24v motor which would probably be better suited.
Dave M
21 October 2013 at 09:20 #44512
Trevor Holloway
Participant
@trevorholloway99134
Thanks for the feedback – that would have been a bit expensive.

Will keep researching and leave options open for a while.

Thanks
21 October 2013 at 13:42 #44525
ashley needham
Participant
@ashleyneedham69188
Trevot. Exactly how big is this prop, or are you still cogitating.? I have a 2.5;1 geared MFA 540 you could borrow to try out. May be ok on 12v ??

Ashley
21 October 2013 at 14:51 #44529
Trevor Holloway
Participant
@trevorholloway99134
No idea on prop size yet , still haven't cut any wood yet !

Current guess is approx 80mm or 90mm.
21 October 2013 at 21:40 #44537
ashley needham
Participant
@ashleyneedham69188
Geared 850..give it some grunt! I am going to see how the LcT1 fares (30 inches) on two 2mm shaft/40mm props and 385 motors on 9.6v before looking at power for the 5 foot LCT4 ..this will have three shafts. Max was only 10 knots or so on the original so sluggish will be the order of the day. Ashley.
22 October 2013 at 11:39 #44550
Dave Milbourn
Participant
@davemilbourn48782
**LINK**

The 850 unit appears to be a bit too fast on 12v. The 800 would perhaps be a better bet, and a belt drive is much quieter than gears, too.

DM
22 October 2013 at 12:11 #44553
Trevor Holloway
Participant
@trevorholloway99134
Thanks for the suggestions, am bowing to the greater experience on this size of model (largest so far is a 36" rig supply vessel made of balsa) as I do not want to make expensive mistakes or get the "why didn't you use a XYZ123 in it as they are made for this !".
23 October 2013 at 16:24 #44586
Mike Waterhouse 1
Participant
@mikewaterhouse1
Hi Trevor

Have you thought of using a couple of car heater fan motors?

I used 2 Ford Cortina fan motors in a tug driving 55 mm props and they work very well, without too much drain on the batteries.

There was a chap at Blackpool last weekend selling them for £20 each brand new but I didn't get his details, maybe someone else on here could help with them.

If not you could try the car breakers,

Good luck and happy building

Mike
23 October 2013 at 16:28 #44587
Trevor Holloway
Participant
@trevorholloway99134
A very good suggestion.

I have actually got some "new" car radiator cooling fan motors in a come in handy box – after twenty years they may actually have been worth saving (if I can find them) !

Also have a model plane engine starter that could be used too, should have plenty of torque.
23 October 2013 at 18:38 #44588
Dave Milbourn
Participant
@davemilbourn48782
Beware of model aircraft starter motors. I was invited to try a 755 motor, sold as a spare for a starter unit. It certainly had plenty of torque – but it was at 22,500 RPM! The no-load current was over 5A and I dread to think what it would do if fitted into a model corvette with direct drive – probably boil the lake dry before melting the ESC.
The car blower motor is a much more sensible idea.
Dave M
23 October 2013 at 18:53 #44589
John W E
Participant
@johnwe
Hi yaTrevor

I admire a brave man who is going to undertake to build a model of this scale and size. I hope you are blessed with a sturdy back, a deep pocket and an understanding wife not wanting to rain on your parade but have you really given it some serious thought about the disadvantages of the size of this model?

I have built several models of a similar size myself – one sitting on the bench right now – nearing completion – its been pointed out to me 'how am I going to lift it' and you may end up with the same problem.

Along with your propulsion problems, have you given it thought as to how you are going to ballast this model down to the water line. To give you an idea, I built the modern day HMS Leeds Castle at 1:48 scale which turns out roughly about 66 inches long and to bring this down to the water line I have to use 2 invalid carriage batteries (12 volt gel cell type) and they barely bring it down to the water line. There are already built in about 3 lb weight of lead ballast at the bow and stern on top of this weight and it takes 2 to lift the model into the lake prior to installing the batteries that is just one problem.

The next one is the cost of the building materials; depending on how you are going to source your materials, you will find if you have to buy all your planking from a model shop; you will spend 3 times the amount.

I know this all sounds doom and gloom – but give it some good hard thought – as long as you have transport for the model as well from your home to the lake.

Sorry for my negativity but I have to rely on friends now if I want to use the Leeds Castle and Mr Milbourne can confirm all of this; as not so long ago we all attended a model show at Whickstead and I have to have the model transported down by a friend and his people carrier and he stayed with the model overnight at Mr Milbourne's residence and that was like putting a lamb amongst a pack of wolves if you are wondering why, all the electronics in the Leeds Castle are from Electronize and Mr Milbourne had just taken over ACTion Electronics. Hey I am surprised the model came back in one piece – happy days eh Dave?

But Terry, do give it some serious thought – as a lot of work will go into your model.

aye

john
23 October 2013 at 19:37 #44591
Dave Milbourn
Participant
@davemilbourn48782
That was a long while ago, Bloobs – or it certainly seems like it. Riggers survived his stay but his head was in a very delicate state the following day – as was mine.
As for large models I can only agree with you. Anything that won't fit easily across the back seat is too big for me. Get the beggars any distance from the bank and they all look much the same anyway.
That said – go for it Trevor, and get it out of your system at least!

Dave M
24 October 2013 at 08:36 #44597
ashley needham
Participant
@ashleyneedham69188
Trevor has stated that he is going to build it in two bits, so accomodation should not be an issue. The size is warranted by our proposed D-day event and the neccessary scale.

The ballast is an issue of course. I have not built anything quite so large (yet) and I am not sure exactly what i would do. I might favour water ballast by simply building in waterproof sections between frames and having a portable pump to fill/empty them. Bodies at the pond side for lifting this in and out the water will not be an issue.

The big 5 foot landing craft I will build for next year will be a "no-draught" design and so will not need any ballast at all (other than for trimming probably).

Ashley
26 October 2013 at 09:48 #44626
Francis Macnaughton
Participant
@francismacnaughton39461
A boat that size is not for the faint hearted but can be done – see my 1/32nd type 42 destroyer in the thread on motor and prop survey **LINK**

On ballast I used plastic milk containers filled with gravel – cheap and easy to handle

Good luck!
28 October 2013 at 09:35 #44645
Trevor Holloway
Participant
@trevorholloway99134
Thanks for the input so far (I'm sure there will be more questions later).

Firstly I measured our new cars boot at well over 1m wide, with a hull that can be split in the middle gave 2m overall length.

A search of WW2 craft at 1:32 to match the landing craft and my Vosper MTB (GG free plan – thanks) meant that a Flower "fitted the boot".

Hull will be 1/2" ply formers and 1/8" ply planking – so not exotic (one 8' x 4' sheet of each should do) materials, superstructure and armament will be scratch build stand off scale from bits lying around. With approx 300 Flowers built in various shipyards and all modified during their lives it should give me almost free reign as to how to fit it out.

With two 1m hull sections and removable superstructure handling should be OK, ballast currently envisged as mixture of lead flashing (already have some spare from builing work) and water filled bottles, pumped in / out when hull is bolted together on the pond.

Yes, I have an understanding wife and as I keep telling her "Its cheaper than golf" and she knows where I am !

As a D-day ship it falls down as I can not find any that were there.

It will probably be the biggest model I will build.
30 October 2013 at 06:06 #44675
Paul75
Participant
@paul75
Hello Everyone.

What about a lovely 1:32 HMS Rodney to provide heavy fire support, as she did on D-Day? At 22 feet long and drawing 1 foot we’d have to ballast her by sitting inside drinking from crates of beer! Not sure if good seamanship would last for long though…

Paul
30 October 2013 at 08:02 #44676
ashley needham
Participant
@ashleyneedham69188
Paul. Now you are talking….

Ashley
30 October 2013 at 13:35 #44684
Trevor Holloway
Participant
@trevorholloway99134
Original idea was for a large boat booming covering fire over the little landers – however common sense crept in !
30 October 2013 at 14:12 #44685
ashley needham
Participant
@ashleyneedham69188
Trevor….but just how big could we build, as a one off…stand off scale… Ashley
30 October 2013 at 14:27 #44686
Trevor Holloway
Participant
@trevorholloway99134
How long is a piece of elastic ?

How far off would you stand ?

An old canoe painted grey, with some grey box superstructure and turrets may work.

Free flooding with waterproof section for power and control, canoe condition immeterial as long as its free.

However, I do not have a roof rack for transportation.
Author

Posts