Compass Boat Models Marlin

[Kmot]

Preface: http://www.rcgroups.com/forums/showthread.php?t=972953

Problem solved, and the Marlin was delivered today.

The first thing I did was connect the battery and test the electronics. Everything worked, so out it came.

I have J-B welded some brass tubes in the heatsink of the esc, and attached brass cooling tubes to the brush tabs on the motor.

I have removed all the silly Marlin decals, that made the boat look toyish. It looks much better without them.

I need to decide where I will install the water pickup. The prime location unfortunately would require the tube to go through the battery tray. So I am thinking about alternative methods.

Pic's to come later.

[Kmot]

Pics:

[Kmot]

Fooling around with it some more, I found that the steering servo and rudder tiller arm can be accessed by peeling up the faux wood floor sticker and then the ABS cover plate lifts off. I found by playing around that the rudder shaft can spin inside the lock collar. That is because there is no flat cut into the shaft. Another maintenance item to take care of right away.

The rudder must be removed to get the prop shaft out. Once I got the rudder and propshaft out I could see that there is no lube at all on either shaft. So this is a maintenance item that should be performed before the hull ever hits the water.

I did not think at first that a coil around the can would clear the floor of the motor mounting base but I tried one and it does fit. So now it will have a full water cooling system consisting of water cooled esc, brush tabs, and motor can.

[Kmot]

The Marlin is finished and has even undergone a swimming pool test.

I ground a flat on the rudder post. I greased the propshaft and installed it followed by the greased rudder post. I installed all the electronics and then I installed an Octura water pickup (because I had it on hand already) and finally installed a brass tube for the water discharge. Then I cut various types of silicone and plastic tubing for the water system.

I then turned my attention to the interior appointments. I painted the upholstery a navy blue, matching to the side stripe on the boat. I replaced the plastic steering wheel with a spoked wood wheel and lastly I made an instrument panel decal and affixed it to the dash.

I ran it in the pool at various speeds until the 1800 NiCd battery pack was drained. I then quickly removed the boat from the water and checked the esc and motor for heat. Both were about ambient temperature.

I should get it an open water sea trial tomorrow at Hansen Dam.

"This concludes my report." Takayashi

[gpzy]

You made quick work of her, looking forward to seeing her on the water at the "Dam"

[avidjeepr]

Nice, We will get some shots of it tomorrow splashing around. :D

[Aerominded]

Looks like an intersting boat, Kmot!

I can't think of a better way to spend the first day of the year than running some boats! :)

[woodybob]

Mods look great Tom.

[Kmot]

Thanks guys. For $50 it is a good value.

For anyone who doesn't want to go through the trouble of water cooling it, I was thinking a small vent cut in the front and rear of the cabin would let the hot air created by the esc and motor escape and prevent the thermalling the guys who bought these before were experiencing at Hansen.

[MILLERTIME]

Look'n good Tom!!!

[jeepers1940]

Nice bargain buy there, Tom, and good practical mods to it. I'm just not sure how much sheetboat ramming that ABS hull is going to be up to. :D
Oh, Happy New Year to ya.
Bill

[norgale]

Just how much of a problem was the heat? I would think the manufacturer would have done something about that if people were having a lot of trouble with it.

[Kmot]

It apparently was quite a problem for the two gents who were running them at Hansen. One of the fellows installed water cooling and solved his problem. I guess the other fellow just grins and bears it.

[Predreadnut]

Nice job Tom, the minute I saw that boat I thought that would look soo much better without those stickers. If that motor ever quits on you or heat is still a problem, you can install my favorite motor a Traxxas Titan 14.4v. It has an internal fan, and running on 7.2v gives you good speed with little or no heat problem. Will be waiting for the action pictures. :)

[Kmot]

Thanks Tim! I have used the Traxxas Titan in many boats, and I agree with you that it is a most excellent boat motor.

Here are plenty of on the water shots, thanks to woodybob. And a video also. :D


http://wavelit.com/media/1193/Compass_Boat_Models_/

[pkboo]

Good value Tom, looks great on the water! Eugène

[graphixman]

Great job Tom :)

[nocal707]

I'm having one of these delivered next week and would like to do similar mods.
Thanks for the pics and info.

[nocal707]

The video is gone. I'm still waiting for my boat in the mail.

[Kmot]

The video is gone.
Yeah, Wavelit went down the toilet and became part of Ebaum's World.

[nocal707]

Got it, ran it. Doesn't get too warm on the stock battery. 7 cell heats it up prettty good. I'll have to have it water cooled... OR, i'm going to get one of those traxxas motors for it.. one of the fan cooled ones.. is it still possible to water cool those motors? Also, do you have any idea what mods might be necessary to run such an engine, do you think it would just be a bolt in/direct replacement deal, or not?

I was also wondering where one would find the metal tubes you jb welded into the heat sink?

Last but not least, how to grease the prop shaft? I'm a newb, so as much as a vague step by step is all I would need. Oh yea, what kind of grease should I use - that would be easy to find around town?

Thanks so much!

[Kmot]

The Traxxas motor can be water cooled just like the stock motor. Solder some tubes onto the brush tabs.

I don't know if the Traxxas motor will be compatible with the stock esc. It may work, it may burn it up.

The tubes used in the esc are simply short pieces of brass tube. You can get the brass tube at hobby shops.

To grease the prop shaft you must first remove the rudder. Refer to my pictures in this thread. After you remove the rudder you can disconnect the shaft from the motor and pull it out. Use white lithium grease, or even Vaseline will do.

[nocal707]

I guess removing the rudder and disconnecting the shaft from the motor is what I have to figure out. Didn't see anything in the instructions regarding this procedure, however, I did notice they recommend greasing the shaft.. :)

Thanks.


edit: got the rudder out.. got the nut and prop off.. now what? :confused:
edit2: Looks like there are small allen screws that couple the coupler to the motor shaft and prop shaft.. i'm guessing I have to loosen the prop shaft screw to slide the shaft out.

[Kmot]

The Allen screws are referred to as "grub screws" and they are metric, needing a 1.5 Allen driver to remove them.

Yes, loosen them and slide the prop shaft out. Wipe some Vaseline or other light grease on it and slide it back in. Wipe off the excess that squeezes out. Retighten the grub screws. Attach your proppeler and nut and then reinstall the rudder and tighten it. Stick the decal back down. If you wreck the decal, they gave you an extra one in the decal sheet provided with the model.

[nocal707]

Done and Done. Dug through and tried about 20 allen drivers till I got the right one. Just did pretty much exactly what you said. Thanks. I'm going to order the traxxas marine titan motor tomorrow. I will also look for the best esc I can get at a reasonable price. I noticed in the instructions that they recommend using a 7 cell for increased performance, they don't say anything about the engine and esc getting burning hot though, which they do. I will probably water cool the new engine and esc and report back later. Thanks again for all the excellent help.

[nocal707]

I'm wondering if there are any other propellers that would work with this model other then the stock replacement. The stock replacement is on backorder, not sure how long it's been on backorder. I'll attempt to find out when I might be able to get a replacement.. http://www.hobbypeople.net/gallery/151281.asp

[Kmot]

I believe the shaft size is 4mm. And it is a dog drive. So you need to look for 4mm-dog drive props. Measure the width of the stock prop. I don't remember at all what it is. Probably 40mm or less.

Some props:

http://www.offshoreelectrics.com/categories.php?cat=16

[nocal707]

I installed a traxxis titan marine motor tonight. My girlfriend was kind enough to solder everything up. I'll see how it performs tomorrow and if it runs any cooler. Wish me luck.

[Kmot]

My girlfriend was kind enough to solder everything up.

Better hang on to that girl! :D

[MILLERTIME]

My girlfriend was kind enough to solder everything up.

Does she have a sister?

[Kmot]

:D :D

[Aerominded]

Does she have a sister?

LOL!!!

[nocal707]

Does she have a sister?
Indeed, however, her sister's a basket case, and further more - can't solder.

On another note, the marlin performed great with the new traxxas titan. It was a direct replacement. It has a higher top speed (if that's what one's going for) and runs much cooler. The cooler running temps probably help the battery last a bit longer too. I plan on getting a 2200mah nicad if not a larger mah nimh battery.

I don't even think I need to worry about water cooling or replacing the esc at this point. Maybe now i'll start work on my paula III.

I took a vid today, i'll try to upload it tomorrow.

[Kmot]

Excellent!

Be aware, that if you go to a larger capacity battery, you will not only get longer run times, but you will also generate more heat in the motor and esc due to them being used for a longer period of time between cool downs. ;)

[nocal707]

vid quality kinda stinks
This was the 1st time out with the new titan motor.
I don't remember it being as loud today either.
http://www.youtube.com/watch?v=X_8MmsblcOY

[norgale]

Nice vid Nocal. Boat looks great and has some decent speed too. Nice going. Pete

[nocal707]

thanks.
I forgot to add a link to this other shorter clip;
http://www.youtube.com/watch?v=9pPGMtJN7rE&feature=channel_page
in this vid. i'm running in a pretty shallow area of the river with much quicker current.
Yesterday the wind came up pretty good and there was some pretty nice chop, I was bashing it around with the 8.4v 7cell and it tracked well but was jumping all over, pretty sweet!

It runs at scale speeds pretty nicely as well.

[nocal707]

If anyone gets one of these, GLUE the thumb stick things into the controller. One fell out and is lost forever now :(
Also, I noticed I overheated the stock ESC on the traxxas motor while running the 7 cell 8.4v battery. I lost contact with the boat for nearly a minute before It came back to life.

[nocal707]

Yesterday at the river my wonderful girlfriend happened to look down on the trail down to the beach and viola, spotted the steering stick. I was pretty amazed. I guess it was not lost forever after all, score!

On another note I got a 2000mah nicd and included 5 hour nicd/nimh charger for like $14 shipped off thEbay.

[Kmot]

I think you have bitten the r/c boat bait, hook, line, and sinker! :D

[MILLERTIME]

Nocal,
Does she have a sister?
I've lost all my marbles, maybe she can help me find them.

[nocal707]

Indeed, however, her sister's a basket case, and further more - can't solder.
lol. how many more times ya gonna ask miller ;)

Yea, boats are fun!
They make the river that much more fun.

[nocal707]

ran it in pretty heavy 'seas' today. I don't know how high the gusts were, but they were blowing the boat all over at times. Definitely some chop to say the least. Doesn't seem to be an issue for the Marlin. Dry interior the entire time.

I ran the 2000mah nicad after the 1800mah stocker. Eventually over heated and didn't want to do anything (steer, move,etc.) for a few minutes. Let the ESC cool off in the breeze with the hatch off for 5min (long enuff to go pee). Problem free from then on.

I think i may want to switch to the proboat 40amp esc.. but i'm worried that esc will overheat and shut down just as much if not sooner. I'm not sure. I don't know how many amps the stock esc. is rated up to, and I'm not even sure if amperage is the issue? Is that what creates heat?

Either way it's still getting too warm and shutting down IMO. Probably because I have a nicer motor, right? The motor runs cooler since it's fan cooled, the esc gets as hot if not more so then before(on the stock motor). Perhaps water cooling the ESC and the motor (while I'm at it) will do the trick. Not sure.

$0.02


edit: included is a pic of the Marlin cooling down/recovering beached ON a make shift jetty. It was windy enough to blow it down(up) river if it was not sheltered, beached or not. I think the ducks like it.

[Kmot]

Perhaps water cooling the ESC and the motor (while I'm at it) will do the trick. Not sure.


Go read post #9 again. ;)

[jemdesign]

Kmot,
I picked up a merlin on the sale and just now trying it out ( my first boat). Did you take the flux ring off the motor? and if so shouldn't it be there? I have a 8 cell 3000mah nimh I tried and it goes great but do you think it will burn up the motor or esc? Tonight I will be installing the water cooling for sure.
Thanks

[tim slocum]

nocal707, nice video, you just gotta love that Titan!!! The Marlin looks like alot of fun. I think your Marlin and my Titan powered Classic runabout would be a good race. Im using a blue esc with a titan and a 30mm Octura prop with no heat problems.

Millertime, I dream of the day I find a woman who loves rc boats, model RRing, rock music and ah .......me.

[Kmot]

Did you take the flux ring off the motor?
Yes, if installing a cooling coil it is my opinion it cools the motor better with the flux ring removed. The flux ring increases torque and at the same time decreases RPM. You can run with it or without it.

I have a 8 cell 3000mah nimh I tried and it goes great but do you think it will burn up the motor or esc?

I am pretty confident it will, yes. I believe that ESC is rated for 7 cells max.

[woodybob]

So...ahh...what's a flux ring?

[tim slocum]

If you go with the Proboat blue esc, its rated at 12v and only $39.99. I have heard someone at the LHS that used the blue esc on 14.4v without any magical blue smoke, but no promises. :)

[Kmot]

Pat, it is the removable, extra piece of metal that is sometimes found on a can motor. It is designed to make the metal around the magnet area thicker, and hence the name "flux ring" because it creates more flux because of more metal mass.

[MILLERTIME]

It's kind of like a flux capacitor, only it looks like a ring.

Ha ha.

[nocal707]

Kmot,
I picked up a merlin on the sale and just now trying it out ( my first boat). Did you take the flux ring off the motor? and if so shouldn't it be there? I have a 8 cell 3000mah nimh I tried and it goes great but do you think it will burn up the motor or esc? Tonight I will be installing the water cooling for sure.
Thanks

I can overheat the stock esc on a 7cell nicd. I can overheat the stock esc on a 2000mah 6cell nicd. I think an 8cell 3000mah nimh will definitely overheat the esc pretty quickly if not fry it all together. Even with water cooling I think they still might get real hot. Please, let us know how it goes.

I think the stock esc might be able to handle my 2000mah 6cell nicd if water cooled.

The hull might be able to go a bit faster if the water is like glass. However, with the titan motor and a 6cell battery, the boat can go much faster then scale. It will start bobbing around when maxed out. Any faster and I think you might need trim tabs to keep it from bobbing all over the place. Either that or more weight up front, something?

[jemdesign]

I installed the water cooling following Kmots method along with greasing the shafts. I also left out the flux ring. Getting the salt out of the coil was the worst part. Could I have packed it in to tight?
I did try the 8 cell 3000mah nimh battery before the cooling went in and I did not get thermal shutdown but I checked it after about 10min and the esc and motor were do not touch hot. The boat with 8 cells went quite fast but I will not use that in fear of burning something up. I will try a couple of 1100 mah 7 cell nimh in parallel and see how that goes. Do you think with the water cooling 7 cell 2200 will be a problem?
I am going to do a test run later to check out the cooling.
Thanks for all the help

[Kmot]

"My Opinion"

This is supposed to be a scale cabin cruiser sport fishing type boat. Not a speed racer. On 6-cells the speed is excellent, and even faster than "scale". IMHO, trying to run faster motors, higher voltages, etc is counter productive. You will also learn that going fast costs money, in the burned up motors and ESC's you will be going through.

My Opinion is to just leave the powertrain stock, add water cooling for extra reliability, and call it a done deal. :)

[jemdesign]

Point well taken. I agree and I was just trying to use the batteries I had. The 8 cell came out of a multiplex magister and it will not go in the marlin again.
The cooling mod is a cool project and I am sure it will work great. I think the overall look of the boat is great. The next is to put lights on it for night cruises. I will post pics of the light set up as soon as I do it in the next few days.

[nocal707]

Lights, night cruising!!! Definitely post up pics of that as soon as it's done. I plan on adding lights and water cooling in the near future as well.

It's hot out, I'm done with my errands and gardening - off to the river!

[nocal707]

I realized it might be a crappy factory solder on the tamiya connector that's causing my marlin to cut out. It won't do it so much while it's running as much as it will after I let it 'recover' for a few seconds, I go to take off again, and nothing. I tap the connection and viola, off it goes.

On another note i'm wondering how well these boats will run on 6v and if running two large mah 6v packs together will give you crazy long run times at scale speeds.

[jemdesign]

Nocal, sounds like that makes sense. You seem to have more thermal cutoff's then most. Time t get the girlfriend and the soldering iron out.

I put the lights on and the only thing is the green is a lot brighter then the red. Other then that I am pleased with the setup. 3mm leds look fairly scale. The white all around is on the top of the radar arch. These lights look much better and brighter in person. I took some pics.. they came out crappy since I used low light in the room to show off the lights. This weekend I will shoot some in the water shots at night which will come out much better.

[Kmot]

Cool deal on the night/nav lighting! :)

[nocal707]

Today my friend gave me 3 7.2v 1100 niMH rc18t sport packs. One powered the marlin pretty well, pretty good run time. These packs are 1/2 the size of a stock battery. I'm thinking about running them in parallel so i'll have something like the equivalent to a 2200niMH pack. I'm curious what my run times and top speed will be like with said arrangement.

The 2000mah nicd I got WITH wall charger(5h) off ebay for about $15 shipped is also capable of charging nimh batteries, so i'm in luck.

[Aerominded]

Like the nav lights, Jem... running at dusk/night is fun!

[defranci]

Hobby People has the Marlin on sale for $59.99. Didn't see the ending date for the sale.
http://www.hobbypeople.net/gallery/151175.asp

[seadog985]

fun little boat. i got one about a year back for the wife when they were on sale for $59. i added water cooling, a trinity monster stock motor and a duratrax speed control. the motor and esc came from a little used car :) when you punch it from a standing start it will almost jump out of the water. am thinking about trying the stock prop from my sv27 though heat might be a problem. my wife likes it.