Going for the tripple
12-11-2004 | 05:00 PM
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From: bournemouth, UNITED KINGDOM
Going for the tripple
Hi to all, have decided to build own racer from scratch, have allready got 3.3' grp hull and topsides but i want to do a tripple eletric install wit surface piercing drives.
firstly has anyone done a tripple before and if so what if any probs with it ??
secondly does anyone know if i can get surface drives, not just normal doglegs ??
and lastly whats the best speed controler for 3 engines - do they exist.
Thanks to anyone who replies, any links welcomed.
Russ.
firstly has anyone done a tripple before and if so what if any probs with it ??
secondly does anyone know if i can get surface drives, not just normal doglegs ??
and lastly whats the best speed controler for 3 engines - do they exist.
Thanks to anyone who replies, any links welcomed.
Russ.
12-12-2004 | 07:34 AM
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From: Sneek, NETHERLANDS
RE: Going for the tripple
Hi Russ,
Do you have any pics of the hull to share, that makes it easier to give advice.
Good luck on your tripple project, keep us informed.
Regards, Jan.
Do you have any pics of the hull to share, that makes it easier to give advice.
ORIGINAL: Boson the t-maxxer
firstly has anyone done a tripple before and if so what if any probs with it ??
As I'm only into FE, I have not tried tripples, as tripples would be too heavy to be a serious race boat.
You'll need to place the propshafts as close together as possible to avoid the outside ones drawing air in turns.
Also the V-angle of the hull may give you some headache as how to position the shafts, should the center one be set deeper, or at the same level?
Lightweight is the keyword, as with three motors, propshafts, two or more rudders, three batterypacks, etc., your tripple will be heavier than with only two or one motor. On top of that, small props are less efficient than bigger ones.
Take into account that the three (small) motors will be less powerfull than two or a single bigger one, you'll understand that I have my doubts that your boat will run at much more than scale speed, which is dissappointingly slow, I can tell you.
Graupner had a tripple in it's programm a while ago (the Fiat Uno) and it was amazingly slow with 25 Kmh, later versions all had a single or dual motor set-up, driving a single outdrive...
secondly does anyone know if i can get surface drives, not just normal doglegs ??
I build my own drivelines, so I can't help you there.
and lastly whats the best speed controler for 3 engines - do they exist.
Yes they exist, I guess you'll end up with three 600 motors, no gears, pulling about 20-25Amps each on a 37,5K prop and a 7cell pack, so If you get a ESC that can handle 100A, you'll be fine.
(Personally I'd go for two 700 motors in direct drive, on 12-16 cells each and have a blast...)
Tip: the Wotan ESC from CTI handles 30V/100A without cooling and is smaller than a stamp and costs about 42 Euros ex shipping.
[email protected]
You can mail Helmut Marshall at CTI for info, he ships to the UK.
Thanks to anyone who replies, any links welcomed.
Russ.
firstly has anyone done a tripple before and if so what if any probs with it ??
As I'm only into FE, I have not tried tripples, as tripples would be too heavy to be a serious race boat.
You'll need to place the propshafts as close together as possible to avoid the outside ones drawing air in turns.
Also the V-angle of the hull may give you some headache as how to position the shafts, should the center one be set deeper, or at the same level?
Lightweight is the keyword, as with three motors, propshafts, two or more rudders, three batterypacks, etc., your tripple will be heavier than with only two or one motor. On top of that, small props are less efficient than bigger ones.
Take into account that the three (small) motors will be less powerfull than two or a single bigger one, you'll understand that I have my doubts that your boat will run at much more than scale speed, which is dissappointingly slow, I can tell you.
Graupner had a tripple in it's programm a while ago (the Fiat Uno) and it was amazingly slow with 25 Kmh, later versions all had a single or dual motor set-up, driving a single outdrive...
secondly does anyone know if i can get surface drives, not just normal doglegs ??
I build my own drivelines, so I can't help you there.
and lastly whats the best speed controler for 3 engines - do they exist.
Yes they exist, I guess you'll end up with three 600 motors, no gears, pulling about 20-25Amps each on a 37,5K prop and a 7cell pack, so If you get a ESC that can handle 100A, you'll be fine.
(Personally I'd go for two 700 motors in direct drive, on 12-16 cells each and have a blast...)
Tip: the Wotan ESC from CTI handles 30V/100A without cooling and is smaller than a stamp and costs about 42 Euros ex shipping.
[email protected]
You can mail Helmut Marshall at CTI for info, he ships to the UK.
Thanks to anyone who replies, any links welcomed.
Russ.
Regards, Jan.
12-12-2004 | 10:23 AM
#3
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RE: Going for the tripple
Russ,
I can give you some ideas about one of your questions. I'm not aware of any ESC that's designed specifically to handle three motors (doesn't mean they don't exist, though). There are some new versions now that do handle two motors, no idea if they would fit your requirements though. Probably the most common method of using ESCs with three motors is to use two ESCs. One handles the two outboard motors, the second handles the middle one. Depending on the boat, some make the center motor an 'on/off' thing and only control the two outboard motors with an esc. The third motor only being there for speed, if that makes sense. The rattings of the ESC used for two or more motors has to be large enough to handle the current requirements of both motors. It really doesn't make any difference how many motors are connected through the ESC as long as it's rattings aren't exceeded. That brings up another problem though. The motors have to be the 'same' (not particularly by brand, but in their current requirements. 'Unequal' motors mean one will get hotter than the other, and their speed won't be the same, which leads to directional control problems.).
- 'Doc
PS - If I remember correctly, the two motor ESC is made by 'Electronize'. (Don't count on my memory though!)
I can give you some ideas about one of your questions. I'm not aware of any ESC that's designed specifically to handle three motors (doesn't mean they don't exist, though). There are some new versions now that do handle two motors, no idea if they would fit your requirements though. Probably the most common method of using ESCs with three motors is to use two ESCs. One handles the two outboard motors, the second handles the middle one. Depending on the boat, some make the center motor an 'on/off' thing and only control the two outboard motors with an esc. The third motor only being there for speed, if that makes sense. The rattings of the ESC used for two or more motors has to be large enough to handle the current requirements of both motors. It really doesn't make any difference how many motors are connected through the ESC as long as it's rattings aren't exceeded. That brings up another problem though. The motors have to be the 'same' (not particularly by brand, but in their current requirements. 'Unequal' motors mean one will get hotter than the other, and their speed won't be the same, which leads to directional control problems.).
- 'Doc
PS - If I remember correctly, the two motor ESC is made by 'Electronize'. (Don't count on my memory though!)
12-12-2004 | 01:07 PM
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From: bournemouth, UNITED KINGDOM
RE: Going for the tripple
Firstly thanks,
to pompebled, it's a small world although im in the uk i spent all of june in makkum (?) and stayed in sneek, went to cafe triade most nights - do you know of it.
im not at home at the moment but i have pics of the hull, it has a nitro setup with a jet drive installed - a previous poject that never saw the water but the hull is identical, do you have an e-mail address to send it to ? or can i attach pictures on this site ??
I see your point on the scale speed, i worked at sunseeker for a few years and there superhawk 50 was a tripple set in a triangular formation on the transom, with counter rotational props, perhaps a 2 setup would be more beneficial.
the drives that i have in mind have no rudder they use large flat bladed props and pivot at the transom, all drives are linked together externally to stop them wandering, perhaps looking at www.sunseeker.com will help - my explanation is poor, the predator 80 and above have a arneson (surface piercing drive) option.
i had the idea of just the center prop cutting in a 1/4 to 1/2 throttle with the other two cutting and at 3/4 - full, giving a turbo effect, but also making it easy to bring home / launch expecially if batteries are low.
talking of batteries, if they were up front, i could also use them as ballst to trim the boat when its in the water planing, helping to keep the bow down - i wont be racing this hull, its just for my ammusement
thanks to you both for the advice on the esc's it makes sence, 600 speed motors seems the norm, how does the different turns / windings affect performance, how do you pick the best / match it to the boat - is there a tried and tested meathod.
if any one want to se pics of the hull for ideas e-mail me at [email protected]
thanks,
to pompebled, it's a small world although im in the uk i spent all of june in makkum (?) and stayed in sneek, went to cafe triade most nights - do you know of it.
im not at home at the moment but i have pics of the hull, it has a nitro setup with a jet drive installed - a previous poject that never saw the water but the hull is identical, do you have an e-mail address to send it to ? or can i attach pictures on this site ??
I see your point on the scale speed, i worked at sunseeker for a few years and there superhawk 50 was a tripple set in a triangular formation on the transom, with counter rotational props, perhaps a 2 setup would be more beneficial.
the drives that i have in mind have no rudder they use large flat bladed props and pivot at the transom, all drives are linked together externally to stop them wandering, perhaps looking at www.sunseeker.com will help - my explanation is poor, the predator 80 and above have a arneson (surface piercing drive) option.
i had the idea of just the center prop cutting in a 1/4 to 1/2 throttle with the other two cutting and at 3/4 - full, giving a turbo effect, but also making it easy to bring home / launch expecially if batteries are low.
talking of batteries, if they were up front, i could also use them as ballst to trim the boat when its in the water planing, helping to keep the bow down - i wont be racing this hull, its just for my ammusement
thanks to you both for the advice on the esc's it makes sence, 600 speed motors seems the norm, how does the different turns / windings affect performance, how do you pick the best / match it to the boat - is there a tried and tested meathod.
if any one want to se pics of the hull for ideas e-mail me at [email protected]
thanks,
12-13-2004 | 08:20 AM
#5
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RE: Going for the tripple
Russ,
In general, the lower then number of turns or windings in a motor, the faster is runs. It also means that current is used much faster so that the run time from a particular sized battery is shorter than for a motor with more windings ('there ain't no such thing as a free lunch', kind'a deal). Is there a formula for figuring all this stuff? Probably, but I have no idea what it is, except that it is NOT simple. It would have to take the shape/type of hull and everything in the drive system into account. I'm just too lazy! The 'easy' way is to look around and find out what 'everyone' else is using and how it performs. (Not exactly the answer you were looking for, right?)
Have fun...
- 'Doc
In general, the lower then number of turns or windings in a motor, the faster is runs. It also means that current is used much faster so that the run time from a particular sized battery is shorter than for a motor with more windings ('there ain't no such thing as a free lunch', kind'a deal). Is there a formula for figuring all this stuff? Probably, but I have no idea what it is, except that it is NOT simple. It would have to take the shape/type of hull and everything in the drive system into account. I'm just too lazy! The 'easy' way is to look around and find out what 'everyone' else is using and how it performs. (Not exactly the answer you were looking for, right?)
Have fun...
- 'Doc
12-13-2004 | 02:48 PM
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From: bournemouth, UNITED KINGDOM
RE: Going for the tripple
thanks, will use the info, its postponed till nxt year now i stuffed my t-maxx into a lampost yesterday so im going to rebuild that first because i use it allot, but now its approaching winter here ill move into the garage and start construction.
i assume youve build quite a few boats, do you have any pics ?? would love to see your work
russell
i assume youve build quite a few boats, do you have any pics ?? would love to see your work
russell
12-13-2004 | 04:01 PM
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RE: Going for the tripple
Russell,
" i assume youve build quite a few boats, do you have any pics ?? would love to see your work." Uh, no you wouldn't - LOL! Six or eight boats really isn't a lot, and they're mostly 'scale' anyway. I learn by making mistakes (stupid and expensive, but what can I say?). I'm happy (I think?) to say that I've learned something each time I build something. That means I only make the same mistake two or three times before I learn better. For example, never use an expanding glue to stick the bird shot, used as weight, in a sailboats keel. You'll be cleaning up the oozing glue for a month! Or, never use 'Elmer's Wood Glue' to seal a stuffingbox to the hull. I know it is NOT water proof...now! Or, never try feeding ducks from the deck of a balsa constructed boat. Shut up, just don't ask! Or, electric motors WILL run when submerged. Another one of those 'don't ask' things...
- 'Doc
" i assume youve build quite a few boats, do you have any pics ?? would love to see your work." Uh, no you wouldn't - LOL! Six or eight boats really isn't a lot, and they're mostly 'scale' anyway. I learn by making mistakes (stupid and expensive, but what can I say?). I'm happy (I think?) to say that I've learned something each time I build something. That means I only make the same mistake two or three times before I learn better. For example, never use an expanding glue to stick the bird shot, used as weight, in a sailboats keel. You'll be cleaning up the oozing glue for a month! Or, never use 'Elmer's Wood Glue' to seal a stuffingbox to the hull. I know it is NOT water proof...now! Or, never try feeding ducks from the deck of a balsa constructed boat. Shut up, just don't ask! Or, electric motors WILL run when submerged. Another one of those 'don't ask' things...
- 'Doc
12-14-2004 | 05:58 PM
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From: bournemouth, UNITED KINGDOM
RE: Going for the tripple
fair comment, but if theres no one to teach then we all do the same, i spent £500 building a nitro boat with jet drive and twin fuel tanks in a racing hull only to find i knackered the motor trying to start it (first one ive ever seen) then i found out that the unchangeable prop in the drive would never relaese the power of the engine - total missmatch, that one is sitting on my shelf in the garage never run, so this time im going to get the mechanicals right before even starting the build hence all the questions, once i know what im ftting is right ill be living in the garage playing till its done, hope the misses doesnt mind - i know she will, but what the hell its what flotes my boat. iff you want to see some pics of my orniment um i mean nitro boat attempt then just ask
russell.
russell.
