The beginning of a twin

[dr gary turner]

Building the skis

First make the sandwich, foam and desired would sides and glue together

I have measurements to Mark Bullard: amount of rocket, desired height at the rear and angle of the ski. He plotted it out on the CAD. and printed the drawing

We then use spray adhesive and attach the drawing to 1/4 in plexiglass. Then bandsaw out the pattern

Then using double sticky tape and attach the pattern to one of the sandwich’s. Make sure the bandsaw blade is 90 deg to the table and then cut out a ski

Stick both skis together with double sticky tape and do final fine sanding

This methodology gets 2 skis as identical as possible

 

[dr gary turner]

More photos

 

[ALLAN YUEN]

What size of props will you run for skis ?

 

[dr gary turner]

Minimum of 2819, especially with the motors going in it.

Hope it comes in around 16#

 

[dr gary turner]

Radio layout completed

Will be going to M Bullard’s shop in the AM to build tanks

About ready to go to paint shop

Groove in skis milled out

Sheet the bottom and they are done

 

[Terry Keeley]

Nice work!

 

[Michael Ehrhart]

looking good I would like to do a twin but I would need to thin the fleet just about out of room

 

[dr gary turner]

Tanks done per Mark Bullard

Skis ready for Jamestown 2 part sealing epoxy which is the best that I have found for sealing

 

[Jim Allen]

Looks like a really careful, thoughtful build Dr. Turner. Does anyone know of someone capable of making a carbon fiber cowling from the plastic piece shown in the photo?

Jim Allen

 

[Shane Bastick]

Ask Brad Nicholas , I reckon Brad could

 

[Jim Allen]

Ask Brad Nicholas , I reckon Brad could

Thanks. I'll check this out.

JA

 

[dr gary turner]

Thanks Jim.

 

[arne kantola]

I have a mold to that cowl and can build a vacumm bagged carbon cowl for a 67 later. To busy right now.
Arne.

 

[dr gary turner]

The boat is in the paint shop
PPG single stage

Initial coat of PPG clear sprayed and scuffed for some paint, NOT MUCH PAINT

 

[brad nichols]

Yes I can build you a carbon cowl Jim. Pm me. This is one I do for REP's 45 boat but it will fit a 67 too. How wide is your tub?

Brad

 

[Jim Allen]

Brad,

I sent you a pm. Did you receive it?

JA

 

[MichaelDornbusch]

Dr. Turner just curious to what size CF tubing you used. I'm building a 45 twin and just trying to figure what an appropriate size would be. Thanks.
Mike

 

[dr gary turner]

Mike,
Boom tube sanded; OD.620 ID.500
Sponson tube .500

Sponson tube OD .700 ID .620

So I have changed the way I do boom tubes and sponson tubes

I have gone to running a hollow tube ALL THE WAY THROUGH THE SPONSON IE JAE STYLE.

I use a lighter Divinycell and thus a lighter sponson. Using the aluminum sponson tube You need to use the 8# Divinycell due to the lateral load being placed on the foam. 4# will crush and the aluminum tube will pull out

Going all the way through the lateral load is on the inside and out side plates

The best place to get CF tubes is
Carbonfibertubeshop.com

If you are going to run the boom tube through an outer tube I would rec that it be a SANDED TUBE. It will be sure then to fit

 

[MichaelDornbusch]

Thank you for the information and pictures! I'm trying to do this right the first time.

Mike

 

[dr gary turner]

Out of DOC’s paint shop

THE QUESTION IS:
Sponsons
Skis
Both sponsons and skis

Veto and WHY