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[chris gillespie]

A guy at the model boat club.

Its quite possible im a dumbass and didnt check for other varients of the "Johnson 600"  however one would assume a johnson 600 rated for 6-12v would be a fairly standard.

the MFA 540 6:1 was recommended by Dave from action electroncis, as he sold it to me lol.

[MikeA]

people have different ideas whats suitable. I personally would have a chose a 555 motor from mmb.

[Welsh Wizard]

Defo go with A 900 motor from ACTion good motor,if to slow then this motor WILL take up to 24V BUT use an ACTion speed controller


Dave

[nick_75au]

The 600 will work as well but it also needs to be geared, 20000 / 6000 = 3.3:1 reduction.

Most motors (especially brushed) need some sort of reduction to be efficient, The Action 900 is large for the power but has the right RPM, a smaller motor with gearing will be more efficient but not enough to be significant unless weight is an issue (not in this case )

http://www.maxxprod.com/mpi/mpi-10a.html

On this page near the very bottom is a relatively cheap 2.9:1 gearbox
Model  ACC365   2.9:1    $21.50 Speed 500, 600
Its close enough to the 3.3:1
Or on this page
http://www.cornwallmodelboats.co.uk/acatalog/gearboxes.html
a couple of 3:1 500-600 gearboxes

There is a Mabuchi RE 800 that has similar specs to the Action 900 as well but I haven't seen them.
Edit, it looks like it might be the MFA torpedo 800

Cheers
Nick

[chris gillespie]

Thanks again Nick

Ill get myself some 3:1 ratio gears as i have 2 johnsons, so i can set it up and i also have a back up

[Welsh Wizard]

Having had experiences of The MFA  geared motors I would not bother

I don't doubt your calculations in the least Nick BUT did you allow windage undercurrents and an emergency situation......Main reason of a 900 motor as simple it has the oomphhhh not only to do the job but has masses of RESERVE to get you out of trouble,.having seen some tugs sailing backwards against a headwind fitted with geared motors.....I for one will not have them near a model.

as for a 900 being large in size it is NO longer than a MFA geared motor.

I would hate for charles to install the wrong motor and then have to re engineer to fit the correct one



It's your choice but i know what i would do


Dave

[nick_75au]

Welsh Wizard, Re-read my post  #18

Ive got a 6:1 MFA sitting in my motor box as well, wonder why its not in a boat? Its better suited to a 80-90 mm prop or a slower model

Nick

[freelance 1]

Hello Chris, a very interesting subject, my questions are what did you use to seal the foam core with, and what did you use for a release agent prior to the fiberglass layup?
Thank you Pat.

[chris gillespie]

Hello Chris, a very interesting subject, my questions are what did you use to seal the foam core with, and what did you use for a release agent prior to the fiberglass layup?
Thank you Pat.

I used polyfilla, which is a compound for filling in plasterboard holes, someone reckoned it was similar to spackling compound, it adhered well to the foam and sanded really easily. Another bonus was it had a good working time, just keep water away even when dry.

when i got smooth i gave the polyfilla a quick spray with some left over paint, which is used for car body work, this worked two fold as it created another seal over the polyfilla to stop it getting damaged and is water proof. I gave it very final fill and sand.

I coated the plug approx 10 times with release wax (pic below) then a sprinkle of baby talc





Chris

[freelance 1]

Hello Chris, many thanks for the information.

Pat.

[oldflyer2]

Very interesting build ... I am looking forward to the rest of it.

Cheers

Tom

[chris gillespie]

So ive basically spent the last few days cutting and glueing the hull ribs, this isnt a particularly glamerous job however very neccessary.
The fibre glass although strong has a certain amount of flex, so the ribs and infills are to act as wall supports to keep a certain amount of rigidity. It is the best that can be done as i need a certain amount of open plan space.

The wife has been harping on about putting some paint on  ive resisted the temptation making sure i have all the structural work finnished first, id say im nearly there. Only deck supports left to do down below, then ill be ready to commence work on the decks.

Ive also been doing some outer hull work only in the form of gentle filling and sanding. the wheel house has also had gentle filling and sanding, so ill maybe prime it tonight, make the wife happy lol.

[oldflyer2]

A happy wife makes a happy boat builder

Cheers

[chris gillespie]

That is so true, she affords me a great amount of undesturbed time (3 kids). However shes wanted finnished paint and dare i say fittings since fibreglass hehe

[chris gillespie]

Ok heres pictrues of the rib and infill work for strength.









I primed the hull, then added one top coat of white paint, i stilll have to sand it, the wheelhouse was given a prime and one coat as well.

[MikeK]

Looking great Chris, do you intend putting in any transverse bulkheads just to make absolutely sure there is no twisting of the hull or is she nice and stiff now ? just wondered as there seems to be a fair bit of unbraced hull between the side knees

cheers

Mike

[chris gillespie]

Looking great Chris, do you intend putting in any transverse bulkheads just to make absolutely sure there is no twisting of the hull or is she nice and stiff now ? just wondered as there seems to be a fair bit of unbraced hull between the side knees

cheers

Mike

She is nice and stiff at the moment, iam planning a forward bulkhead, and possibly one at the stern where the engine will be mounted, maybe another at the back of exhaust stack.
Ive basically set myself up with open plan at the moment to see what i can fit in, as i have a bit of hardware etc. The deck where the wheelhouse is will be permanantly fixed to the exhaust stack,
She is really rigid at teh moment so itll be fine till i work it all out 

[MikeK]

That's good news then, my thoughts were on when she is just sitting there with all the parts setting off hard, sometimes a twist can slowly take up in the hull. OK zip put in place across cake hole back to watching and enjoying ! 

Mike

[chris gillespie]

So ive spent the last few days, remaking my mould, as i had made good adjustments to the hull and felt it worthwhile to re do for future. At this stage im thinking ahead of maybe making an Early Dawn and North American also. This would involve reducing the length which can be done by adding a temporary stern plate to my mould, as the Early Dawn and North American are the same hull just havent been lengthened.

Ive worked out and penciled all the hull markings and openings, ive primed the lower hull ready for first coat of red anti foul.

no photos at the moment as interent is at a trickle at the moment

[Norseman]

no photos at the moment as interent is at a trickle at the moment

I'm interested Chris 

Dave

[chris gillespie]

ok internet is working better today, here is some photos of the mould and hull prime work. The mould was a great success nice and tight, strong and secure.
Sadly because of the heat reaction it took some of the top layer of paint with it, and bubbled large areas. So i know it wasnt lack of release agent, just the heat reaction with the resin and hardner.

[Norseman]

no photos at the moment as interent is at a trickle at the moment

  that is so funny Chris. My last reply read your spelling mistake 'interent' as interest and not internet.
I thought you felt no one was interested - I'm wetting myself here mate 

Dave

[Netleyned]

I thought exactly the same 
I thought 'Oh No not another build thread that's going to peter out'

I also think that the Northwestern is the best looking crabber.
Being stretched twice makes a lot of difference comparing her
with Early Dawn and North American.  Mind you, not so many
pots to construct if building one of those 

Keep the piccies coming Chris

Ned

[chris gillespie]

that is so funny Chris. My last reply read your spelling mistake 'interent' as interest and not internet.
I thought you felt no one was interested - I'm wetting myself here mate 

Dave

Oh i see...

There has been plenty of views, not much debate and conversation about it, i would have thought it would be popular and spark conversations etc.
Maybe itll happen when it looks recognisable.

Regardless ill keep updating even if one person likes it or is inspired then itll be worth it

I thought exactly the same 
I thought 'Oh No not another build thread that's going to peter out'

I also think that the Northwestern is the best looking crabber.
Being stretched twice makes a lot of difference comparing her
with Early Dawn and North American.  Mind you, not so many
pots to construct if building one of those 

Keep the piccies coming Chris

Ned

No itll not peter out, if spent an awful  lot of money for materials, never mind man hours. Besides its kicked a kind of obsessive compulsion and passion in me

thanks for the interest guys

[Norseman]

I thought 'Oh No not another build thread that's going to peter out'

Hi guys - re quote - just posted a thread of that name.

Dave