Lots of questions from a beginner -- please advise

[Justin N]

I am new to FE boating and would really appreciate some advice. My only experience is with a Dumas Chris Craft Utility boat that came out quite nicely. It was a simple straight shaft through a brass stuffing tube with supplied prop and a mild motor. This thing is a lead block with the ply-hull and mahogany planking and is fully fiber-glassed. See pics of its first run on the water (didn’t have the windshield & flag on yet but couldn’t wait to get it on the water!). Not fast, but fun and was fun to build.

Now I’m looking for some speed, but didn’t want to give up the building aspect and am just building for my own entertainment, not racing.

I have almost completed a 24” Dumas Deep-V wood kit – all that is left is final coats of paint and clear and associated sanding of course. Hull weighs 1lb 6.4oz and I don’t expect it will gain much more with paint/clear.

Is that heavy?

I have a surface drive unit with a flex cable that I am planning to use that is brand new (can’t remember the maker, FE ‘bag’ type boats – I think they went under).

My questions are related to how best to power this boat. I will not be racing it competitively but do want to get the most speed possible out of it.

Please offer suggestions on:

Geared vs. Direct drive and what are the benefits of each?

Type of motor – probably want to stick w/brushed 05 car type. Suggestions? #turns?

Number of cells required? – I’d like to stick w/ 6 if possible since I have plenty around from my days w/ cars & trucks.

Size of prop?

What all do I need to attach the shaft to the motor? I’ve read some things about flex-hex and bearings but I don’t think I really understand – could anyone point me to a diagram? And how long should the flex cable be (i.e. where to place the motor in the hull).

How to mount motor?

Anything else that may help me?

THANK YOU ALL!

[Justin N]

Thanks for any responses I may get!

[eddieh]

hey justin, not sure about the weight sounds a bit heavy, long list of questions but i'll try to help

1. power/motor starting out it's hard to beat the graupner 700bb 8.4 or a fine desiign 775 neo, basically the same type of motor difference between these and the car motors is the size and the size of the shaft (5mm), for starters I recommend giving andrewg a look at www.fastelectrics.com he has the 8.4 for 33 bucks free shipping the neo is on sale from fine design for about 40-45
2. batteries these run very well on 12 cells, you have 6 cell packs, you need to either make an adapter to run them in series 14.4 v or wire them up with sermos connectors,
3.geared versus direct, Fine design offers a very nice turbo trans for this motor, but then there's cost, this motor will handle direct drive no problem and you will be happy with the speed, but maybe not the run time, it won't be short but not like with a tranny, but the speed will be up, I run mine direct drive (electrovee)
4. how to attach the flex cable to the motor, hobby-lobby sells a basic connector, fine design has a clamping collet for the 5mm shaft.
5. is the bag shot boats a 1/8 "shaft? .098 cable??? this might cause problems with durability and definately problems mounting bigger props (we'll get to those) if possible ($) go for a 3/16ths set up, if not you may be able to make due with a prop adapter and this hardware I am really not that familiar with it except it was set up for a very light weight plastic hull boat 21 inches or so and an o5 if you have a lot of car stuff, you may consider the of in a tranny 1.5 to 1 1.7 to 1 something like that and use your car motors, but it won't be as fast and or durable as the 700,
going with the 700 i recommend the 640-642 octura props
for the 05 I am not sure maybe a x632 y 535 possibly a 440, not much experience, I run a 632 with my graupner 600 on a single step hydro(mono) and on 8 cells it's pretty fast, some of the other guys will jump in here and save me soon,,,LOL
where to place the motor
hmmm general consensus is 28-30% of the hull length from the stern,,, so roughly 6.5-7.5 inches up
6. how to mount the motor, well you could buy a mount, or take some aluminum angle and make one, drill the holes etc, then bend it till it is as in line with the cable as possible.

the cable should go inside a teflon tube which will then go into a brass tube, the brass tube will exit the boat at the very bottom ov the vee, so that it will be in line with the keel, the brass tube will then be bent in such a way as to be as straight as possible and still have good alignment with the output shaft of the motor,

water cooling, if you decide on an 05, search the site for the threads regarding water cooling, this goes for the 700 too,, now for the speed control
Andy Kunz has probably the best boat speed controls on the market, he should use the slogan you can pay me now or pay me later, they are water proof and water cooled and there are models that can handle any brushed motors you will come across,
I personally have an astro 212, 207 and a 208, but i bought these before I ran across andy's when the blow that's whatI'm getting, check the swop shop, a lot of great stuff there at discount, because these guys are crazy, LOL they are always looking at the latest and greatest and anything that will give them an edge in a race, and also most of them are out to help the sport, so they aren't going top nickle and dime you , great stuff , at a very fair price, ok that's all for now, good luck and welcome ,,,cheers eddie

[eddieh]

Oh Mannearly forgot, I really really dig your utility justin, especially the motion shot, what's the motor/prop set up on that?? I build a lot of fast scale boats, and I just have a soft spot for chris crafts, have a look at doug robichauds runaabout really really nice here's the link
http://www.rumrunnerracing.com/feforums/attachment.php?s=&postid=9483, cheers eddie