ah yes the motor, well i tryed useing a L shaped peice of aluminum, so you would mount the motor on the aluminum then screw the aluminum to a block of wood that is epoxyed to the hull, ive made up the motor mount but the prop shaft is too low in the hull to line up with the motor pin, so im going to go and get a smaller motor and try a different method of mounting it, at this stage its going to be a block of wood that the motor will sit in and two cable ties will hold the motor to the wood
I use the aluminium mount, but I just glue it directly to the hull with urethane, specifically rapid cure Sikaflex TM. I just put a big blob of the stuff on the clean hull, and shove the motor and mount into it. It cures to form a rubberised mounting letting the motor run quietly, because it acts like a damper.
hmm... interesting does that urethane work on everything like wood? i may use this instead of epoxy for my mount now, the main reson why im changing my mount is becasue i think the motors a bit big for the application and i wanted one that is easily removeable, i was thinking with the one i have now it should have been a simple job were you screw the motor to the mount then scew the mount and motor to a block of wood in the hull, so when the motor stuffs up its just 2 screws to change it out for a new one, but becasue the motor is to big, the angle of motor pin to the prop shaft is almost 45 degrees, heres a pic of the motor and mount, im opting for a smaller motor so it can just be a block of wood and cable tie setup, hence even simpler then unscrewing the mount, just cut the cable ties and put two new ties in.
Burnsy, that is a nice motor mount. I use exactly the same style, aluminum L-bar with holes for motor and mounting screws. They're sturdy, easy to work with, and can act as a heat sink if your motor stalls and starts heating up. If I understand correctly, the problem with your current mount is alignment with the propshaft? There are several possible solutions to this issue. 1) Dogbone. Either a true dogbone universal joint, or a flexible tube joint. I use 1/4"OD fuel line, it fits snugly over 1/8" shafts and is very flexible. This is, however, best for correcting minor mis-alignments rather than major ones, so if it's really off, you'd better try option 2 or 3 first. 2) bend the motor mount. The aluminum mount doesn't have to have a perfect 90-degree angle in it, you can bend this to change the angle of the motor. This can help correct many shaft alignment issues. 3) angle the propshaft. Most real ships don't have perfectly horizontal propshafts. Some angle up, others angle down, still others are slightly sideways. If it's not too late, you can angle your propshaft up to get better alignment with your motor. One other tip for aluminum L-bar motor mounts: don't screw the mount down to the hull, run a pair of stainless steel studs up from the bottom of the hull and screw the mount to those studs. This makes for easy maintenance and a very long-lasting mount. Ideally, you can use stainless-steel studs to mount almost every critical component that may need servicing.
yeah i think the only way i think i can fix the problem like you said is use some studs that come up from the hull then use some lock nuts that hold it to the hull, i still have the motor and mount but i went out today and got a smaller motor and made up a new mount out of some wood, i guess i could use the Al mount but instead of studs, use some threaded rod and screw it into the hull, heres a pic of my new mount compared to the al mount, im still deciding which to go for, and also which motor should i go for the big one or the smaller one?
yes, thats the stuff, i forgot the name of it, i will be using that to glue my mount in, to cut vibration as well
ok, just so im clear on the next steps, im aware that you want to get all the electronics in before making the water channel, is this correct?
There's no such thing as a boat that's too small for water channeling. It may not be the deciding factor for your survival every time, but every little bit helps. Water channeling also makes a great place for mounting studs, and for concealing large chunks of lead ballast. Don't worry if you can't include a water channel immediately, but it's a good idea to plan on eventually adding one. At the very least, don't take any steps that make proper water channeling impossible.
yeah i see your point as well, and i have to agree, i was planing out where the battery and other stuff is going to go, and i keep running into the same problem, 'how am i goint to mount it straight to the hull' so i think i will install one so i can just mount things onto the concreate sealer, becasue i really cant be bothered drilling holes in the hull and epoxying studs and making sure its water tight, every time i need to screw something down,
I did say "MAY" not require water channeling. When you float her at the waterline, you may find that any water in the hull will pool nicely in one spot. If it does, put the pump there. Remember, you don't have a lot of weight allowance with her. I used Sikaflex to attach all the mounts into my tiny tug "Defiance" as well as my Rodney and my liberty, it's not failed me yet. I even put the tug into the last man standing event at the Jan 2010 Nationals, and ran around tormenting battleships till the batteries died. It has the advantage of being fairly easy to remove later, if you decide to relocate things.
hmm... well, ok, ill get all the electronics in and do as you said darren, float it and see of the water pools in a spot, if not i can put the water channel in later and if the sikafelx stuff is easy to remove then no harm done i guess, so an update with the build, ive got the motor glued in on its mount, and im waiting for a reply from a rc shop to see if they have any props, once i get the prop i can make the rudder and mount the servo, then its caprailing/deck and skinning and finally paint, more pics once i get the prop, oh and are there any pics on the ausbg website of the jan nationals?
Try http://www.floataboat.com.au/ for the props. They stock some really nice ones. You'll need to download the Fittings catalog, then scroll down it till you see the Raboesch section.
yep, ill try that web site as well, the shop im waiting on is rc model marine, i think ill give them a ring as well, ok, so today i went and got a battery, its a 6v 4.5ah sla battery, basicaly the only battery that jaycar had that fits in th hull, does anyone run these batterys and what sort of run time should i expect to get out of it for my transport? my motor as you see in the pics is the small one, i think its a 3v motor
6v 4.5 Ah is what I run my liberty on, It'll easily cruise around for about two hours, with the pump running.
wow, 2 hours with the pump, thats pritty good, so the little motor is fine to use, wont be an issue if i use a micro viper marine10 ESC? also i had a look at those props on float a boat and they look really good, nice and shiny, especialy the sub props with 7 blades, they look leathal, but... do these props have a grub screw that you tighten up on the prop shaft or are they the sort that have a thread and you need a thread on the drive shaft to screw them on to? on the pdf it has threads that say M3 and M4, not quite sure what this means
M3 and M4 mean 3 and 4 mm threads. They don't use a grubscrew. You just thread the shaft, apply some loctite and screw em on. Some people use a locknut as well.
