Help with speed controller

[TROUBLEMONSTER]

Hi, I haven't put a radio in a boat in over 12 years and only have experience with the old resistance type controllers so I need you guys help. I am getting ready to build the tianjie salvarille anchor handeling tug. I am installing 2 graupner 400 motors that draw 10 amps max. I was thinking of using 2 viper 15 speed controllers. I found them for $50 each if anyone knows where I can get them for cheaper please let me know. Also what size fuse shoud I use to protect the circut. I will be using 7.2v rc car packs because of limited space and I have them already. I am also looking for a good 4 channel or more radio that won't break the bank. I would like to be able to purchase multiple receivers for the radio to use in future boats so I won't have to have more than one radio. Any tips on this set up will help. Thanks Shane

[HoaRC]

It's nice to see someone interested in tugboats. You are very welcome to ask for help here and on other forums. I will do my best to share what I've learned from converting the Dickie Seaport Tugboat (http://www.modelboatmayhem.co.uk/forum/index.php?board=125.0) . Tianjie salvarille anchor handeling tug sounds like an interesting project and I'd be curious to see where you take it. Can you post a link to the tug? Please excuse the red NO! and WRONG
messages below. :D

I am installing 2 graupner 400 motors that draw 10 amps max WRONG! NO! NO! NO! :D SPEED 400 6V Motor is For planes; it is too fast for a tug boat.

Graupner 400 FREE RPM : 25.8k will blow the fuse and fry the ESC!

Really, tug boat motors spin at only 3k (FREE No Load RPM). the 25.8k will not be faster than the 3k as both will reach your boats top speed!!!

By all means, use any of the vac-u-tug motors. Nobody else sells direct drive tug boat motors, but them. They run cool and draw little amps. :p I have the $17 5-pole motor in my Seaport tugboat..http://i203.photobucket.com/albums/aa36/Stevelum_2007/Dickie%20Seaport%20Workboat%20Tugboat%20RC/P1010084.jpg (http://www.modelboatmayhem.co.uk/forum/index.php?topic=10228.msg108668#msg108668)


I was thinking of using 2 viper 15 speed controllers.

These are good waterproof esc's and the pro's on modelboatmayhem use them a lot although you don't need: fail safe, 12volts and the adjustable features. You can just as well use a 7 volt rc car or boat esc (no airplane esc's) rated for 10 or 15 Amps. Your motor should not draw more than 1 amp if you pick your RPM/propeller size correctly. My tugboat motor runs for 3 hours+ on one 2 Amp 7v nimh battery!!! http://www.vac-u-boat.com/Motor545.htm


what size fuse

Your motor's should not draw more than 5A, so a 5A or 10A fuse would be fine i guess.

a good 4 channel I own 4ch and 2ch AM Radios and it seems they all make the servo's tremble and jitter which means extra wear tear for the servo gears. My Airtronics FM radio does not jitter servos at all! So i'd go with FM even though it's more expensive also because less modelers use the FM frequency which equals less chance for interference.The jittering does not interfere with manuevering at all. If it's easy to take out the servo and replace the gears, go with AM as both the transmitter, receiver, and crystals are much cheaper and have the same range.

I will be using 7.2v rc car packs

A neat trick is to make hidden charge plugs on the outside deck of the boat so that you don't have to take the battery out or disconnect deans plugs to charge them. Basically any rc car pack is fine if you have a low rpm motor with the right sized propeller.

[toesup]

WRONG! NO! NO! NO! :D SPEED 400 6V Motor is For planes; it is too fast for a tug boat.
Graupner 400 FREE RPM : 25.8k will blow the fuse and fry the ESC!


By all means, use any of the vac-u-tug motors. Nobody else sells direct drive tug boat motors, but them. They run cool and draw little amps. :p I have the $17 5-pole motor in my Seaport tugboat.. (http://www.modelboatmayhem.co.uk/forum/index.php?topic=10228.msg108668#msg108668)

I own 4ch and 2ch AM Radios and it seems they all make the servo's tremble and jitter

A neat trick is to make hidden charge plugs on the outside deck of the boat so that you don't have to take the battery out or disconnect deans plugs to charge them.

Basically any rc car pack is fine if you have a low rpm motor with the right sized propeller.

I dont know where you get your figures from HoaRC, but the Graupner Speed 400 (From the Harbor Models website) has a free load RPM of 16400.
The Speed 400 would be ideal for small boats, especially in pairs and with carefull use of the throttle, would have plenty of power at the prop.

Any car motor can be used direct drive in a boat.. and they dont necessarily have to be car motors either..
Tower sells the Tamiya 'basic can' motor....
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXPML4&P=7

I own several 2 and 4 channel RC units, both AM and FM and NON of them jitter. If they are 'jittering', i would suggest you look at your setup's carefully to make sure you have no binding in your controls, and the Rx aerial is away from the ESC and motor.

It is sensible to disconect the Deans Plugs, or any other plug that connects your batteries to your electronics when not in use. This ensures that non of your electronics (including plugs, switches, wiring, etc) is LIVE.

Depending on the displacement of the boat, a 7.2v car pack may not be enough ballast for a boat and a SLA battery may be more of an advantage. Both from a ballast point of view and also for run time.

[toesup]

I was thinking of using 2 viper 15 speed controllers. I found them for $50 each if anyone knows where I can get them for cheaper please let me know.

I am also looking for a good 4 channel or more radio that won't break the bank.

Hi Shane.
The Vipers should be ok with the motors and setup you have described. You may want to think about watercooling them if you plan on doing a lot of recovery / towing work though. Look at the heatsink, the middle channel will accept a brass tube for watercooling.. ;)
As for 'cheap'.. that seems about the average price...

Tower carries the Futaba Skysport (Dont let the name fool you) 4YF which is available on 75mhz.. and is priced at $129.99
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEFJ4**&P=ML

[HoaRC]

Toesup, you may be right, I am just sharing my own experience, and it's not the be all end all of course.


Any car motor can be used direct drive in a boat..

rc car motor absolutely cannot be used in a tugboat...

rc car motor + speed boat hull + speed boat propeller works BUT

rc car motor + tug boat gull (displacement hull) + tug boat propeller will overheat

Speed 400 (From the Harbor Models website) has a free load RPM of 16400

It will work with a speed boat prop, but not with a tugboat prop.

While it would be fairly easy to just "drop in" a Speed 400 motor, I wouldn't consider doing that before experimenting with props first. A powerful "380 size" motor like the 400 would overpower the hull and likely need a smaller prop or gear reduction to be of any use as a work boat. It would drain a 1,500 mAh battery in about 15 minutes. It would likely run hot, require cooling, and a mount that would not melt under the heat. Feel free to experiment but read the following first.

http://www.vac-u-boat.com/Modifications.htm
http://www.vac-u-boat.com/Motor545.htm
http://www.vac-u-boat.com/FAQ.htm#where

[toesup]

rc car motor absolutely cannot be used in a tugboat...
rc car motor + speed boat hull + speed boat propeller works BUT
rc car motor + tug boat gull (displacement hull) + tug boat propeller will overheat

It will work with a speed boat prop, but not with a tugboat prop.


So Scoot the Springer, a push tug, is incorrect?

Incidentally, Scoot won the Foss Cup (Small class) last weekend..
http://www.rcgroups.com/forums/attachment.php?attachmentid=2019233

[HoaRC]

That's a nice boat :p What is the runtime of this tugboat above? :confused: Can you post specific motor/propeller tugboat combinations on 7volts with links plz?

[toesup]

What is the runtime of this tugboat above?

Can you post specific motor/propeller tugboat combinations on 7volts with links plz?

About 3 hours on a pair of 6v 4.5ah gell cells.

Probably...
Try http://www.modelboatmayhem.co.uk/ ,'Tugboat kits' from the menu

[nick_75au]

Hi Troublemonster,
I think the ESC is fine, the motors will be fine as well but I would be inclined to put them through some form of gear reduction, If the props are 35 mm in dia aim for a RPM of around 5000 at the prop. So if the Spec is 16 000 RPM gear it 3:1, this will give you the desired loaded RPM. A "Maxx" gearbox is something I use and is designed for the 400 motor, Cant find them but here are some others that will work.
http://www.hobby-lobby.com/gear400.htm

Fuse's, I use Automotive blade fuses because I get waterproof holders for free(lucky me) :) ), I would start with a 3 amp fuse test then increase until fuses stop blowing under normal conditions up to a 10 amp, a seperate fuse for each speed controller, if that size fuse continues to blow then there is a problem somewhere else in the setup. I would think a ball park figure would be 7.5 amp with that motor and gearbox on a 35mm prop,

You could go the same route as my Springer :cool:

Regards
Nick

[LtDoc]

Radios. I think it's a fairly good idea to stick to a well known 'brand name' for several reasons. Parts availability and the warranty (with new radios) are two pretty good ones. A two channel radio is about as 'minimal' as you can get. More control channels usually make for more construction/control options which is certainly nice... to a point. I'd love to have a system that does 4 or 5 thousand control channels! Absolutely no idea what I'd use them for, but it'd be nice to have, wouldn't it? A 4 or maybe 6 channel radio is probably about 'standard', sort of. It's also nice to get your hands on one to see what they 'feel' like. Not the easiest thing in the world to do, but certainly nice if you can. Remember all those 'accessories'! Like battery chargers, batteries, crystals, etc, etc. It's a very safe bet that if a manufacturer sells a transmitter, they also sell receivers (extra ones). Or just make the one receiver removable (like us cheaper R/C'ers do??).
Motors.
Will an R/C car motor work in a boat? Yes, most of the time. If it's one of the 'hotter' motors, less turns, bigger amp draw and rpm, probably not as well as slower motors. Lots of 'wiggle room' there. I've used a '400' sized motor in a tug boat before. No particular problems. If the top speed is too fast, just don't go there. Also nothing wrong with gearing a motor down a bit.
Fuses.
Determine maximum current draw with both motors. Do a 'stall test' on one of them, multiply by two, and you've got the max for the fuse size. 'Better' would be less than that max current draw. Don't want to stay in a 'stalled' state very long. Max stalled current draw is 10 amps? Use an 8 amp fuse, or maybe a 7 amp'er.
- 'Doc

(Just for 'grins', go look at the parts page at "Vac-u-Boat". Handy place to find a few things, not just motors. Or boats. Or ducks. Maybe even an alligator or two?)

[TROUBLEMONSTER]

Thanks for the info guys. I will be going with the Viper ESC's from Loyalhanna dockyard as I have not heard anything bad about them. I still have not chosen a radio yet. I have a old 2 chanel Futaba that is about 14 years old and still kicking so I will probably stick with that brand the tower hobbies price looks like about what I would want to spend. I will check with the hobby shop next time I go to New Orleans to see what they have I know they carry Futaba. They are the closest hobby shop to me and I like to buy from them even if its a few dollars more. I am thinking of cooling the electronics with some type of fan. The instructions calls for 380 / 400 size motors so that is why I ordered them. Does anyone know if the vac u tug motor is the same size as a 380? The Salvarille has a nice built in motor mount that I would like to keep. I am aslo thinking of adding multiple batteries if needed I have too many 7.2 race packs not to use them. I am still in the planning phase so any more info will be greatly appreciated.

[Shaun Hendricks]

These were the stats HoaRC was looking at:

http://www.hobby-lobby.com/speed400.htm

Yes, I wouldn't run that motor in a scale boat without a gearbox either. It could run well in a FE boat direct drive or even run a small jet drive.

(EDIT: Ignore the following since you've already ordered. Leaving for future reference.)

This puppy could probably spin a small tug prop no problem:

http://www.allerc.com/product_info.php?cPath=7_112&products_id=2653

It can toss around an 11" aircraft prop on 7.4v. You could probably take it up to a 3" boat prop at that voltage. It would certainly drive a pair of smaller props with the gearbox on it. It would need a 1.6:1 down gearing to hit 5000 rpms. You could probably just use a 1:1 tranny and be fine.

Here's the ESC for it:

http://www.allerc.com/product_info.php?cPath=7_112&products_id=2663

Under $50 and brushless.

Warning: This would likely require some in depth reworking of the tug drive system so not for the uninitiated. It might be best to stick with the tried and true methods others have recommended to avoid any hassles.

[HoaRC]

Thanks for the info guys. I will be going with the Viper ESC's from Loyalhanna dockyard as I have not heard anything bad about them. I still have not chosen a radio yet. I have a old 2 chanel Futaba that is about 14 years old and still kicking so I will probably stick with that brand the tower hobbies price looks like about what I would want to spend. I will check with the hobby shop next time I go to New Orleans to see what they have I know they carry Futaba. They are the closest hobby shop to me and I like to buy from them even if its a few dollars more. I am thinking of cooling the electronics with some type of fan. The instructions calls for 380 / 400 size motors so that is why I ordered them. Does anyone know if the vac u tug motor is the same size as a 380? The Salvarille has a nice built in motor mount that I would like to keep. I am aslo thinking of adding multiple batteries if needed I have too many 7.2 race packs not to use them. I am still in the planning phase so any more info will be greatly appreciated.


If you ordered the 380 motors as Toesup said above you'll be fine with the small propeller. Propellers are easy to change and plastic ones are cheap so you can experiment to see which works best. The vac u tug also sell the 380 size motor, http://www.vac-u-boat.com/TugMotorUpgrade.htm Mine is the 540 size motor and it works fine, I just never tried the 380. You can buy the propeller and fittings from them too and read a detailed how to guide about ballast and leaks. I used marine grease in the prop shaft and silicone under the deck. Read the vac u tug website how to's for the best info.

I am thinking of cooling the electronics with some type of fan tugboat motor and esc will run cool if the motor/prop is correct.

The pdf pages are here: http://www.vac-u-boat.com/Vacutug.htm

[HoaRC]

Is this the model you are getting?

SALVIRILE TUG – COMPLETE KIT

1/75 SCALE

26” X 7”

http://www.loyalhannadockyard.com/TJSALVIRILE.htm


http://www.loyalhannadockyard.com/TJSALVIRILE_files/image001.jpg http://www.loyalhannadockyard.com/TJSALVIRILE_files/image006.jpg

[TROUBLEMONSTER]

Yes that the boat. I have had it for over a year now and haven't started it yet. I was tied up for a year babysitting two new real boats under construction with very little time off. I am back offshore working 14 days on and 14 off and my 5 year old has just started school so I have some time on my hands to start building it.

[HoaRC]

If I had a $500 boat on the shelf, I'd turn it into a lazy relaxing 1-2 year long project. I'd clear up the desk and shelves for the parts and enjoy building it a couple of parts at a time. Whether you build it quickly or slowly, you will sure get tremendous satisfaction.

[TROUBLEMONSTER]

I definatly will enjoy the build its a very nice kit I hope I can finish it in less than a year or two. I have been itching to start it but as I mentioned I didn't have much time off in the last year. I ordered the viper ECS'S and a 4 channel hitech radio from Loyalhanna dockyard so I will soon have everything I need to get started. Thanks for the info I will try and post pictures when I start.