Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1] 2 3 4 5   Go Down

Author Topic: Andy M's scratchbuilt Javelin project  (Read 12511 times)

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Andy M's scratchbuilt Javelin project
« on: February 04, 2022, 05:40:28 pm »

I have several projects on the go just now, all at various stages.
 This one is taking most of my interest  at the moment though. I want to build a Lesro Javelin. I wasnt really looking for a kit, mainly because I imagine they will be quite pricey, and I will be doing well to squeeze a few sheets of ply out of the budget as it is, but also, I like cutting out the bits (mostly)
 I sold my small briggs and stratton generator engined bike to a friend for a (small ish🙁) donation of £50 to my modelling fund. I have had my fun on it, bit dangerous to be honest. It was clocked at nearly 50mph on a forest road, with no suspension. I did well to stay on it.
Anyway, back to the Javelin, for years I liked it so much I wanted to build one to sit in, I had already built my giant Vic Smeed Starlet and sailed in it, but I needed some more speed, basically😁.
 So using some very early photoshop, I used pictures of myself to see what size a Javelin would need to be for me to fit in it. Happy with the mock up images, and already starting to work out how I would do it, I showed my friend, who said 'are you not doing it for 2 people?'  It made sense really, but 2 side by side and using the same proportions was way too long for my budget/building/storage capacity..
 Anyway, I decided to use the side view I had, but that made the hull well over 8ft ply lengths, slightly longer bits were twice the cost, and I was using marine ply.
 I worked out that my version had to be 88 inches long for the bottom and side hull sheets to fit standard sheets. The side view was shortened and my little Viper was born.
 Back to the Javelin, it looked much sleeker than the Viper ended up, I dont have funds to build what I originally wanted to build, a single seater giant Javelin. So a model Javelin it is.
 I have nearly finished my Sea Rover model, it is built almost entirely using 3mm liteply from hobbies, which is unlike liteply I remember, it is slightly heavier but has a very smooth light coloured surface and has strength pretty close to birch ply.
 I am intending to use the same sort of construction, its a bit cheaper than birch ply. I have a few motors that might suit, will get to that department soon. I also have my 3d printed brushless outboard, still in the test stages, but looks promising.
 I went hunting on the internet for some suitable drawings to go from, sometimes even a thumbnail pic of the plan can show enough, but better quality is obviously better, I suppose it is not critical that mine ends up the exact same, but I would like it to be.
 There is a Javelin thread on the forum with some good details but not some of the basic ones that I needed.
 Looking forward to this project, had to do a bit of research to do before I could start finalising my drawings.
Many thanks to Canabus for helping me out with some critical dimensions to check I was headed in the right direction.......and I am, I think😁
Before I commit to using 1/8 liteply, anybody know what thickness of ply skin was on original? I am imagining 1/16?
   The Sea Rover has tighter curves than Javelin, and I skinned it with liteply so I could manage to build Javelin from liteply, but it may be a bit heavier? The Sea Rover isnt that heavy, it is certainly fast enough, and its not even the best planing hull shape. I have the liteply already so will give it a go.
 I am thinking that using modern electrics in the Javelin, instead of the engine/radio gear/fuel it was designed for, will make up for any weight increase from using 3mm light ply.
 Doesnt really matter though, as long as its watertight😁
I have ordered a propshaft, prop, rudder and a water scoop set, thats the generator bike money gone already..... that will be most of the stuff I need though, so I am very happy. (but still a bit sad to see one of my creations being wheeled away)
Cant wait till my bits arrive through the post, I am loving this project already.
Logged

zooma

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,263
  • Never too old to learn !
  • Location: Rossendale and Formby Lancashire
Re: Andy M's scratchbuilt Javelin project
« Reply #1 on: February 04, 2022, 07:36:40 pm »

I think the head is the wrong scale Andy - you need to shrink it a bit  {-)
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #2 on: February 04, 2022, 09:23:48 pm »

Lol.
I still get the urge to do the single seater man carrying version shown, but this one will be a two or 3 man job with suitably sized pilots (eventually)
Is my plan pretty close looking?
Logged

zooma

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,263
  • Never too old to learn !
  • Location: Rossendale and Formby Lancashire
Re: Andy M's scratchbuilt Javelin project
« Reply #3 on: February 04, 2022, 09:47:37 pm »

Lol.
I still get the urge to do the single seater man carrying version shown, but this one will be a two or 3 man job with suitably sized pilots (eventually)
Is my plan pretty close looking?


It looks good to me Andy!   :-))
Logged

zooma

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,263
  • Never too old to learn !
  • Location: Rossendale and Formby Lancashire
Re: Andy M's scratchbuilt Javelin project
« Reply #4 on: February 04, 2022, 10:13:30 pm »

I think Will (and possibly Harry) may have a pdf for the Javelin plans if that would help?



Logged

canabus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,347
  • Boats a hole in the water you pour money into!!!
  • Location: Tasmania,Australia
Re: Andy M's scratchbuilt Javelin project
« Reply #5 on: February 05, 2022, 08:25:54 am »

Hi All


Not me (Harry/Canabus), but if anyone has please share with us !!!


Javelin/Rapier/Stiletto/Arrow I can get them resized no problem.


If you have parts off, trace around, scan and forward on please.


Regards
SIR Harry


Senior- In -Retirement
Logged

madwelshman

  • Learning all the time.
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 428
  • Fairey Marine Fanatic
  • Location: Pembrokeshire, West Wales
Re: Andy M's scratchbuilt Javelin project
« Reply #6 on: February 06, 2022, 08:04:26 pm »

Not me either guys.
I have plans with my Rapier kit and I think there are some in the Javelin kit too, but they are paper plans and although I intend getting them scanned to PDF, it's not high on my to do list with all the other more important (so I'm told) jobs.


Will
Logged
49" Precedent Perkasa
46" Aerokits Sea Queen
42" Veron Fairey Huntsman 28 x2
34" Lesro Sportsman mk1
34" Precedent Fairey Huntsman 31 x3
34" Aerokits Sea Commander x2
29" Aerokits Sea Rover
20" Aerokits Fast Patrol Boat
16" Aerokits Sea Urchin

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #7 on: February 06, 2022, 10:46:36 pm »

I was happy enough with my plan, so I started cutting out some of the parts.
 Due to not having my propshaft or rudder, I have decided to build this Javelin a bit different to usual.
 I have pretty much decided to build 2 versions, but I will see once this one is finished.
Logged

madwelshman

  • Learning all the time.
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 428
  • Fairey Marine Fanatic
  • Location: Pembrokeshire, West Wales
Re: Andy M's scratchbuilt Javelin project
« Reply #8 on: February 06, 2022, 10:51:45 pm »

Nice one Andy. Good to see yet another Lesro boat being made.


Following with interest  O0


Will
Logged
49" Precedent Perkasa
46" Aerokits Sea Queen
42" Veron Fairey Huntsman 28 x2
34" Lesro Sportsman mk1
34" Precedent Fairey Huntsman 31 x3
34" Aerokits Sea Commander x2
29" Aerokits Sea Rover
20" Aerokits Fast Patrol Boat
16" Aerokits Sea Urchin

canabus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,347
  • Boats a hole in the water you pour money into!!!
  • Location: Tasmania,Australia
Re: Andy M's scratchbuilt Javelin project
« Reply #9 on: February 09, 2022, 09:04:28 am »

Hi Andy


That's looking great and a lot less wood that the original ones.


Lovely lines !!!


When you skin the bottom, do the strakes before adding the sides .
Ten times easier !!!
The same with the chine rails before adding the deck .


Canabus
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #10 on: February 18, 2022, 07:33:32 pm »

I havent posted anything about this for a while, but I have been busy. Most of the main build is done, still needs a good few things done but I am getting close to fitting my spray rails and rubbing strips.
 I wasnt sure if I liked the vents, so I made them removable using magnets, then decided I actually did like them, dug out the magnets and glued them on. Frames for the mesh screens in the vents are 1/16 square spruce. The mesh was a frying pan splatter guard, £1.79 for a 10 inch circle of fine stainless steel mesh was pretty good, I thought. My son gave me a funny look in the shop when I said it was for my boat. Lol. Half an hour with some pliers released the mesh from the frame, giving me loads of mesh.
 The hatch lid areas under the vents have been cut away so the vents will hopefully work.
 Hatches are held on with magnets, boxed in and capped over to prevent them coming loose, they work well.
I said this version of the Javelin was going to be different....  you may have noticed I have used balsa, not really what you would expect for a boat like this. I intend to treat it with care, so the fact it is a bit more 'ding-able' shouldnt matter too much. Bulkheads are buit up 1/4 inch balsa, 1/2 inch keel pieces. 1/4 x3/8 balsa stringers. Bottom sheeting is 1/4 inch, with 2 laminations of 1/8 instead at the front to cope with curvature. Side sheeting is 1/8, deck is 3/32. Cockpit sides are 1/8, with internal doublers taking them up to 1/4 thick. Fore and aft hatches are topped with 1/8 balsa.
 I have built my battery tray quite long😁 so that I can balance the boat by moving battery forward or backwards. I can also make up a bigger pack if I need to.
There is another difference, I had planned this balsa version to use my experimental 3d printed (but highly modified after printing) brushless outboard, experimental because I have not tested it on open water yet. It has had a bath test with promising results.
 I am going to sheet the transom with 1/16 ply on the outside and a piece of 1/8 ply on the inside. These will give me solid mountings for my outboard.
 The motor in the outboard is the same one I used in my Sea Rover, with same prop but a conventional propshaft, so I imagine power will be similar.
 7.4v on Sea Rover gave brisk performance, 11.1v was rapid.
 My balsa Javelin is a better hull shape and much lighter. There is plenty of space on the transom for a second outboard!
 I have already started 3d printing a second outboard, it will need some of my reinforcing treatment before it gets mechanical bits fitted. I need to order these. I can print up 3 mounts for the transom, that way I can use 1, 2, or even 3 motors. I dont see me doing 3 outboards, but I have 2  motors and speed controls, so I can make another outboard and try the boat with 2.
 To be honest I think it will be fast enough with one.
 I will hopefully manage to test my outboard on open water soon, it is fitted to my depron hydro just now, just a few small finishing off jobs before it is ready.
Logged

madwelshman

  • Learning all the time.
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 428
  • Fairey Marine Fanatic
  • Location: Pembrokeshire, West Wales
Re: Andy M's scratchbuilt Javelin project
« Reply #11 on: February 18, 2022, 08:06:01 pm »

Fair play Andy, you've progressed a fair bit  O0  it looks really good  :-))


Will
Logged
49" Precedent Perkasa
46" Aerokits Sea Queen
42" Veron Fairey Huntsman 28 x2
34" Lesro Sportsman mk1
34" Precedent Fairey Huntsman 31 x3
34" Aerokits Sea Commander x2
29" Aerokits Sea Rover
20" Aerokits Fast Patrol Boat
16" Aerokits Sea Urchin

Stuw

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 314
  • slow motion modeller...
  • Location: Surrey, England
Re: Andy M's scratchbuilt Javelin project
« Reply #12 on: February 18, 2022, 08:14:06 pm »

Looks like a Javelin to me. Great job of eyeballing it!


With better fitting hatch covers! Like the idea of mesh for the vents.


You’re brave with the balsa though!  %%
Logged
2 Lesro Javelins... and that’s it. Not even close to finished!

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #13 on: February 19, 2022, 01:26:49 am »

Cheers. I am happy with how it has turned out considering I didnt have any plans. I know balsa is a bit delicate, but I am going to give it a go, it has turned out pretty light and should be fine if I dont hit anything.
 I think I am still going to do a ply version. How thick are the hull skins on a 'proper' Javelin?
I forgot pictures of the vents.
Logged

mrzippy

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 324
  • Location: Leicester, Midlands
Re: Andy M's scratchbuilt Javelin project
« Reply #14 on: February 19, 2022, 05:39:26 pm »

1/16th ply skins as used throughout Les Rowell Aerokits/Lesro designs.
I'd be tempted to skin the outside of your balsa model with a layer of 1/32nd ply applied with laminating epoxy,
and thoroughly soak the insides with runny mix heated up with a hair dryer - turns it to the consistency of water.
Paul.
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #15 on: February 19, 2022, 06:19:18 pm »

I was tempted to add ply skins, but it defeats the purpose of using balsa for light weight. I will just need to try and be careful...... 😁
Logged

mrzippy

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 324
  • Location: Leicester, Midlands
Re: Andy M's scratchbuilt Javelin project
« Reply #16 on: February 20, 2022, 11:09:59 am »

Duhh should have read ALL the posting before replying - now with it re your weight issues.
Wow that's a huge amount of balsa you've managed to consume during the build -
hope its old stock? bought before recent skyrocketing price hikes ! Lol.

Looking forward to your outboard experiments -
I'm also designing an outboard project (1/6th scale) based on an exellent article in a recent Model Boats mag,
using horizontal motor and vertical toothed belt drive - is this your route?

Way back in the 80's local club members raced the original Streaker's, aka Javelin's, against exotic glass fibre flatties,
powered by quick HP40 rear induction glows they were competitive, especially in rough conditions.
We added 3 small spray rails along each hull bottom skin parallel with the keel,
plus one along the chine blended in with car body filler to create lift, made a difference to the performance.
Paul.

Logged

canabus

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,347
  • Boats a hole in the water you pour money into!!!
  • Location: Tasmania,Australia
Re: Andy M's scratchbuilt Javelin project
« Reply #17 on: February 20, 2022, 11:28:01 am »

HI Andy
 Just found a PDF plan of the boat by Circlip on another forum site which looks very good.


Canabus
Logged

madwelshman

  • Learning all the time.
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 428
  • Fairey Marine Fanatic
  • Location: Pembrokeshire, West Wales
Re: Andy M's scratchbuilt Javelin project
« Reply #18 on: February 20, 2022, 02:40:05 pm »

Well done and thank you Harry, that's a nice clean, clear plan.


Will
Logged
49" Precedent Perkasa
46" Aerokits Sea Queen
42" Veron Fairey Huntsman 28 x2
34" Lesro Sportsman mk1
34" Precedent Fairey Huntsman 31 x3
34" Aerokits Sea Commander x2
29" Aerokits Sea Rover
20" Aerokits Fast Patrol Boat
16" Aerokits Sea Urchin

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #19 on: February 20, 2022, 07:34:01 pm »

Well done finding the plan, it will be good to check mine against it and see how far out I have ended up.
Its all new balsa...... Ply version may have been cheaper!
 The outboard I am using has vertical motor and bevel gears. It worked fine in bath test, still to be tested in open water.
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #20 on: February 20, 2022, 07:45:21 pm »

The 3d print includes printed bevel gears, I never planned on using these and bought brass ones instead. I am going to build another one using bigger steel gears. I have most of the parts printed, ready for re-inforcement proceedures.
I am pleased with the outboard, only costs a pound or so in filament. An abs version would probably be tougher and maybe not need reinforcing but my printer isn't set up for abs.
I am willing to keep experimenting with the pla prints, hopefully resulting in a reliable unit.
It all depends on results of the open water  testing.....
Logged

mrzippy

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 324
  • Location: Leicester, Midlands
Re: Andy M's scratchbuilt Javelin project
« Reply #21 on: February 21, 2022, 04:40:42 pm »

Wow instant outboard !  things are coming on in giant leaps these days -
I cannot imagine plastic gears standing up to the grunt of a brushless for too long,
are bearings used? or is it just shafts running in the plastic casing??
Paul.
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #22 on: February 21, 2022, 08:00:50 pm »

Hi Paul, it has plastic printed bevel gears but I went for nice brass ones instead. My motor is a wee beast, propels my Sea Rover up to very un-scale speeds.
  It has 3 bearings, 2 on propshaft and 1 above the motor side bevel gear.
Instant... not quite, theres a good few hours printing but mostly the hours I put in reinforcing what I thought could be weak areas, might just be my printer but the fin on the bottom casing snapped off really easily, it is hollow for some reason, I carved a hard balsa filler and epoxied it in.
 So I wasnt really trusting it to hold together by itself so I added my reinforcing to it.
 Theres a few mods I have done, I might start a new thread dedicated to this motor, I plan on building another one, I have been printing out the parts for last few days, so I can show what I do to mine to reinforce it.
It does look pretty good with some paint on it
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #23 on: February 21, 2022, 08:05:04 pm »

Forgot to put photos on. 😁
Logged

Andy M

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,504
Re: Andy M's scratchbuilt Javelin project
« Reply #24 on: February 21, 2022, 09:30:40 pm »

Is this the outboard you were talking about? Lol. I imagine its similar apart from 50s look.
Logged
Pages: [1] 2 3 4 5   Go Up
 

Page created in 0.087 seconds with 21 queries.