Riggers been running great, but the stresses of speed are showing up. This boat turns real hard and stresses alot of parts,Sheared the bolts holding the aluminum servo tray to the tub, The turnfin started to come loose, finally hit a buoy and seperated some seams around the fin.
Well I'm building another set of sponsons, Thought about Balsa cores but like how light my foam core sponsons are. Decided to use balsa around turnfin dowels and foam for the rest. Marc has upgraded the dowel mount to 1/2".
I center drilled the dowels and made a full length brass insert ,threaded on both ends. I will make an aluminum peice for the 3 bolts to go through on the center former. Hopefully the fin mount will be buoyproof.

Nice work Bill, that will be strong for sure!

Almost done ,Ready to seal. The right sponson is 100 grams heavier than the left.
Would there be any benefit to balancing the sponsons?

Normally I would say not to worry about it, but that's about 1/4 lb plus the fin itself... that's like 25-30 of additional weight on one sponson. Hmmm.. I really don't know what I would do here. Add another 1/4lb to the boat by balancing the sponsons? I think, try it as is and see. Most likely will be fine. Worse case you can drill the other and epoxy in some lead if you feel its needed after testing. Keep me posted.

I'll have her back in the water Sunday, hopefuly with some video.

Cool! Looking forward to seeing her run.

Marc, what holes in the turn fin should I start with, Your markings got erased.
Bill

Second hole from the trailing edge goes to rearmost mounting hole in sponson. keep me posted!


www.modelgasboats.com

Sent from my iPhone using Tapatalk.

Ran the new sponson and fin. Still had a little right pull. Some work to do yet.
Ran 72 and 73 mph with 2816 prop. A little hop in the prop. The fin was set up straight and as high as it would go. It works great. The right sponson doesn't pull out of the water as easily with left rudder and the front stays planted even with the hardest turns. Awesome Marc. Ended the day because I found a crack in the speedmaster strut.
The video is with an Iphone, so no close ups.

I think Gary's happy. His Motor wasn't revving (not his wifes fault). He took off the cowl, a modified whiplash cowl and strapped a plastic cup to the carb. Next run was some extra holes on the backside of the cowl and he's smiling.