Thank you Stephen for taking the time to look into the file upload sizes. Much appreciated for your time. Cheers Duncan 😊

2nd attempt to upload the video.😌

I hope that this helps; the plans show the rudder servo forward of the frame but I think it is better close to the rudder control arm. I use a NiMH battery laying beside the stuffing box and a counter weight on the opposite side. The original builder put a Y battery harness in so the boat could run off of two batteries for a longer duration. I just use one so as to give the brushed motor a rest .

Ronald,
Thanks! That is a big help!
Dave

Looks nice on the water and runs at a nice scale trot.

Chum444, is your "stuffing box" the size of the large diameter tube under the large filler and the rest of the shaft slips into the shaft tube? If so, the sealing area seems kind of small.

My preference is to have a fairly large sealing area. For example, using the attached drawing, the two ends where the shaft slip fits into are each about 5/8 inch long leaving a long void between the shaft OD and the tube's ID. [EDITED: this area is filled with the sealant lube.] Thus I have no problem with leakage when the entire shaft is below the waterline.

Lew
Florida ⛱️, USA 🇺🇸

Also... as you can see in the photo, the prop shaft is horizontal and sits about 2 inches (50mm) below the waterline. No leaks if you make the stuffing box long enough and use the right sealant lube.
Lew
Florida ⛱️, USA 🇺🇸

Looks great with some fantastic boats, hope the weather holds out as I arrive on the 27th, to late for the show but my mates will be there for sure

What a fantastic event at one of the best harbours in the world !.
Looking forward to seeing the SailGP down in CHCH (Lyttleton) 23-24March😊😀😁
Stay safe JP 😎

Hi good idea, have you been out on the water yet?

I have several 12 -18 volt motors the size of a 550 and run them on 6 -7.2 volts and they will turn over a big prop 45 - 50 mm.

This looks good on a cargo ship where you can almost watch the prop turn over. They do not get hot and have a low current drain. Bonus is they are often cheap! Also I can use slightly cheaper NiMh batteries of about 3300mAhs.

I have a few Pittman motors originally scrounged out of computer tape decks 40 years ago. They are almost silent and work really well.

I always check for hot batteries or motors as I do not want current diverted from the motor to heating up the drive train.

Following a friend I have also found a cheap and effective and silent U/J. It is plastic flexible tubing about 3/8ths inch diameter in less than 2 inch lengths.

You can use it in place of the Huco U/J, keeping the brass inserts on which it is a tight fit. Or if you have a threaded shaft a largish pair of nuts locked together with the tubing forced over them.

They need to be in a straight line and a few fast forward and reverses settles the tubing into position. The drive is silent and efficient and good for up to 20 watts or so.
regards
Roy

I would agree with others, viz. use a smaller prop. When a motor gets hot it normally indicates too high a resistance from the prop, so try a couple of smaller sizes and monitor its performance.
Good luck😉

Ronald, the prop is actually 1-3/4" ... in the photo you hav indexed the left blade to the end of your ruler, not the "0" point on the ruler. My 33" PT109 calls for a single 1" plastic prop to reach scale speed. I think you need a smaller diameter & much less pitch to alleviate your motor heating issue. Heatsinking, & watercooling or a fan will not fix your issue.

She certainly handles well in the water. That would be a nice one to enjoy cruising around with. From the video it looks like the velocity is more of a speed boat rather than a dory.
Nice job!
Barry

It looks very good to the original boat, excelent job! 👍

Just WOW!!

Like your sub!! We have several sub guys in our club, at least one of them uses 2.4. He runs an extension for his antenna up the sail (conning tower) and hides it in either the periscope or antenna. His boats are static divers, but he stays at periscope depth when he submerges. The boats set up to blow ballast and full up planes if he loses contact. Not trying to criticize anything you’re doing, just letting you know 2.4 is doable with restrictions. Most of the ponds here in North Texas are too murky for much below periscope depth anyway.
Anyway, good luck with your sub! Let me know how it turns out.
Cash

I had thought of a float with antenna but in he end use a MHz transmitter was easier. I had sold all mine so I picked up one from eBay. Actually I wound up with two one AM one FM. FM worked better. The dc motor controller was from a car as it had reverse capability plus switchable micas or LiPo. The Ghz band gets water attenuation so it won’t work under water well. Bathtub test showed at least a few feet under was ok. Only thing o don’t like is you seal electronics so it has to be really tested. Battery is on a plastic box like that can open fir access but I put a soda bottle cap structure to access charge connector anyway it’s fun

Getting pretty flash now Phil 👍👍👍 a big improvement on No 1!

JB