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[David Cross]

Hi, Sometime ago I thought I saw some posts on building Vic Smeeds Vivacity. I have had the plans for years, and I also managed to obtain the original engine from a boot sale. The engine runs so all I needed was time, now the cold spell has come I have it. Started off with plywood frames carefully cut to shape and the keel made in several pieces and held together with epoxy glue and dowels. Have set the whole up on a strong back and after making up a propshaft from 1/2" alloy tube, and 3/8" diameter steel shaft, three bronze bearings, turned up and sweated in, then a housing for a thrust bearing ball race. All glued together with epoxy. I ripped some pine plank down to 1/2" X 1/8" to laminate and form the chines and inwhales from. Did not need to steam the wood and laminating makes them stronger. Hope the pics come out alright.


Please post using the forum's system  (not email direct)

regards

ken

[imsinking]

No pics as yet , my friend . . . a 3/8th (9.5mm) shaft ,hmm, have you given any thought to a suitable propeller ?
Bill

[David Cross]

As far as propellers go, a three bladed, 3" diameter metal one. I am making a kitchen rudder as well to be able to obtain Forward-neutral-reverse and steering.  I intend to use the JAP 35cc engine I have, as per the original, I do not really want it to go tearing around the pond, making noise and wake. Just a gentle old lady pottering about, if I use it in Poole harbour there is a 5kt speed limit, and many years ago I got spoken to by the harbour police about speeding with my offshore racer, a 50cc, 6foot long Cigarette hull flat out was a bit too much. I have tried to post pictures but keep getting a message about the files are to big, don't know what to doo about that except maybe I will put them on my facebook page, I'll let you know.

[nivapilot]

Do you have Microsoft Office installed on your computer??

right click the picture you want to upload
choose "open with", microsoft office viewer
go to "edit"
"compress" and choose "document"...OK......you should then be able to upload to forum.

[Rockets]

Hello David,


I will follow your posts with interest as I also have had these plans for a few years. I did obtain the correct engine too but let it go a number of years ago to a friend who had a project ready for it.


I did think it would suit one of Edgar Westbury's fine engine designs too. I hope you don't mind if I ask questions along the way.


Regards,


Rockets.

[David Cross]

Thanks for reading so far, any question and interest in this post is welcome as is constructive criticism
I'm struggling to post pictures at this time but you may find these on my Facebook page (I hope)
I am just starting the engine installation. There are three bolts in the nose of the crankcase. I shall make a alloy plate to pick up on these and mount the engine to the hull. I am using a industrial dog drive coupling with a rubber piece between the two dogs. I have used these before and they are forgiving in alignment, easy to replace the rubber piece and make removal of the shaft or engine easy, also very cheap compared with other bonded rubber couplings. The rudder will be home made, using the kitchen rudder split in two to allow steering, neutral and reverse. Easier than a gearbox to make.
I would love to see a Edgar Westbury engine in these big models, up till now I have used home converted strimmer engines, but two strokes are noisy, very reliable if one mixes the fuel/oil properly and with lots of power if one alters the timing.
I have just binned a lawn mower but kept it's starter motor, so I may try to make it electric start.

[Rockets]

Having done some motorbike racing I agree on the need to get the mixture and timing right on a two stroke. I was thinking about a variable pitch prop as I have a copy of Model Maker from the sixties with a fairly simple design that I would scale up. Those JAP engines run really nice.

[David Cross]

I did think about a variable pitch prop, and I remember seeing how to do it, but I cannot find any pics at the moment. I'm running a 3/8 inch diameter shaft so I probally have the room for dual concentric shafts, at least I think that's what is needed, but any info or pics would be very welcome. Thanks.

[Rockets]

The article is on line somewhere, I'll try to find it and post a link.