XQQME – Vic Smeed 3.5cc Multi Racer Build

[Michael Campbell 2Participant @michaelcampbell2]

I am normally a model flyer but a friend of my wife's friend is a keen model boater who has raced internationally for many years and tempted me to the "dark side" of model boating. I remember having a copy of Model Boats magazine June 1975 which had the plan for a wooden multi-racer boat designed by Vic Smeed. As I have my own CNC router machine, I thought it would be ideal to redraw in CAD and cut the parts on the machine (see YouTube link here&nbsp

[Michael Campbell 2Participant @michaelcampbell2]

Build log

[Michael Campbell 2Participant @michaelcampbell2]

..and here are some pictures of the build in progress

[Ray Wood 3Participant @raywood3]

Hi Micheal,

There are quite a few of us on here that are flyers as well as boaters, the advantage with boating is there is less chance of going home with a bin liner full of bits

Are you going for ic power for your boat as that's what Vic designed it for ? or brushless is just as good ! but no smoke & noise, but there are a lot less places you can use an ic boat these days.

If going electric there is no need for such heavy construction, say 1/32" ply sides & bottom & glass cloth ?

Keep us posted, love the SLEC fuselage jig, I never had one but they look good.

Regards Ray

[Tim RoweParticipant @timrowe83142]

Michael and Ray

I swear by my SLEC jig. I bought extra clamps, screws and captive nuts at time of purchase to give many more options. It is stuck to a piece of multi-ply with a cork facing on the other side, so also a building board.

Can't think of an aircraft of boat I have built that has not been on it at some time.

My latest project is finishing odd earlier "latest projects"

Tim R

[Michael Campbell 2Participant @michaelcampbell2]

Posted by Ray Wood 2 on 21/12/2020 11:01:54:

Hi Micheal,

There are quite a few of us on here that are flyers as well as boaters, the advantage with boating is there is less chance of going home with a bin liner full of bits

Are you going for ic power for your boat as that's what Vic designed it for ? or brushless is just as good ! but no smoke & noise, but there are a lot less places you can use an ic boat these days.

If going electric there is no need for such heavy construction, say 1/32" ply sides & bottom & glass cloth ?

Keep us posted, love the SLEC fuselage jig, I never had one but they look good.

Regards Ray

Hi Ray

I'm building as per the article i.e. 1/16 ply sides and top. I will epoxy glass the interior joints with glass tape and a coat of 50% diluted epoxy to waterproof and fuel proof. I will be powering it with an Irvine 20 marine – so it limits where I can run it but hey oily and smelly! I'm fortunate that I'm not too far from a water where I can run ic. The SLEC jig made this so much easier to build the hull without twisting. Hope to make more progress over christmas. Once it is built, I may build another for electric power. That's the advantage of CAD and CNC!. I guess a boat like this would need around 300w of power? and I could build it lighter as well. Hmm that's a good suggestion Ray.

[Michael Campbell 2Participant @michaelcampbell2]

Posted by Tim Rowe on 21/12/2020 12:08:20:

Michael and Ray

I swear by my SLEC jig. I bought extra clamps, screws and captive nuts at time of purchase to give many more options. It is stuck to a piece of multi-ply with a cork facing on the other side, so also a building board.

Can't think of an aircraft of boat I have built that has not been on it at some time.

My latest project is finishing odd earlier "latest projects"

Tim R

Hi Tim – definitely agree with your comment. I've had this board for years but only constructed 1 fuselage with it. But it is always useful to have something like this around. Bloke's buy tools, wives buy handbags!

[Tim RoweParticipant @timrowe83142]

Hello Michael

Diluting the epoxy 50% rings alarm bells as at that level it might not cure properly and will be neither waterproof or fuel proof. Typically epoxies can tolerate up to 10% dilution but you may have some product information with the materials you are using. If yours says 50% then go for it but otherwise be careful.

If you are diluting with alcohol make sure it is as pure as possible. A lot of alcohol products contain water which mixes well and I have had trouble with 90% pure alcohol even with very low dilution.

Tim R

[Ray Wood 3Participant @raywood3]

Hi All,

Yes Tim's spot on with that advice.

My current mixing ratio is :- 25% Gin + 75% Tonic

Happy modelling is having a mini bar in the workshop !!

Regards Ray

[Michael Campbell 2Participant @michaelcampbell2]

Thanks guys for the advice regarding the epoxy dilution – saw on Scott Myers channel "M5 Performance Hdyroplanes" https://www.youtube.com/watch?v=3XDOhJPo-KY&list=PLN1BConcF3a2Ipiq0VOKo4lX-YX3W3b1i&index=9 at the 5minute mark. On watching it again, probably not 50% dilution

I'll do a test first to find the ideal dilution for the epoxy I'm using.

Cheers and happy christmas to you all!

[Michael Campbell 2Participant @michaelcampbell2]

A bit slow at the moment in progressing the build (too busy working from home at the moment!) so I've add the bow blocks ready for carving:

[Chris FellowsParticipant @chrisfellows72943]

That's funny, Ray has managed to do more model building whilst working from home!

Chris

[Michael Campbell 2Participant @michaelcampbell2]

…made a bit more progress with the bow block now shaped, but should have done this AFTER adding the side and bottom skins – then it would have blended in all nicely! Now to add the bottom and side skins. I have to check the CAD drawings first to make sure they are the correct size before cutting. Can't beat the old adage "measure twice cut once…" CAD is only as good as your drawing!

Edited By Michael Campbell 2 on 11/03/2021 23:06:37

[Michael Campbell 2Participant @michaelcampbell2]

..my friend Greg also reminded me to mention the modifications to the original design he advised me to do

1) Shallower propshaft angle

2) Re-positioned water pickup

3) Soft mount for engine

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