HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 03, 2013, 04:13 PM
Registered User
Joined Sep 2013
27 Posts
Build Log
A minor projekt....

Some background info about my deep V project I started last weekend. This hull I got for my birthday more than 20 years ago. Back then i put a size 40 watercooled nitro engine in with octura double rudder and straight axels. I also bought an 3 blade x650 propeller from octura. The boat run pretty good with that for a while under that season. Apart from some wobbly tendencies at higher speeds.
When I did some service to the engine all of the bolts to the coolinghead snapped. Since it was a cheap OS copy nitro engine , the cooling head and cylinderhead was somehow integrated with eachother leaving me with a broken engine. So the RC boat went on the shelf for some years .
Until last week when I thought i'd throw the faulty engine away and go for brushless motor and so to speak revive the old hull for some good old racing.
I ordered a Jaguar 3640 1700kv and some spare parts from different hobbysites that I found. I didnt want to spend huge amounts of cash so flexaxle, rudder, 6s lipo, charger, 200 A ESC and stingerdrive I bought from HK, brushless motor and propeller from OSE.

When I inspected the hullbottom I took a steel ruler and quickly found out that the hull wasn't straight at all. It had a bump on one side and a hook on the other.
So i dug into this forum and read about faulty hulls that behaved strange when in water and with some speed. My hull was behaving strange all those years ago when I got it up to speed. Thats where I am right now, with a faulty hull and stuff on its way.

A lot of text to read but I hope you manage it
Will add pictures but im writing this on the Nexus 7 and its camera sucks. And it autocorrect my text so I have to edit this.

Brushy
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 04, 2013 at 01:56 AM. Reason: Autocorrect sucks...
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 03, 2013, 04:48 PM
Registered User
Joined Sep 2013
27 Posts
Pictures

Some pictures to accompany the massive text
Name: 20131003_232112.jpg
Views: 35
Size: 153.0 KB
Description: Hull
The hull ...

Name: 20131003_232247.jpg
Views: 26
Size: 154.1 KB
Description: Hook
The hook...

Name: 20131003_232343.jpg
Views: 25
Size: 209.1 KB
Description: Bulge
And the bulge...
Brushy is offline Find More Posts by Brushy
Reply With Quote
Old Oct 04, 2013, 02:55 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
4,517 Posts
Hi Brushy,

What size is the hull?

Reason I ask is that a 3640 motor could be too small if the hull is in the 25 - 30"range.
Unless ofcourse if this is the motor in question, than it's no issue at all:
http://shop.rcboatbitz.com.au/index....oducts_id=1548

Assuming the hull is polyester and you have a good access to the interior, the hook and bulge could be corrected for the biggest part by heating up the section in question and clamp it between two blocks until is has cooled down again.

Perhaps adding some glasscloth and epoxy on the inside if required to stiffen the hull and some filling and sanding on the outside.

Regards, Jan.
pompebled is online now Find More Posts by pompebled
Last edited by pompebled; Oct 04, 2013 at 03:02 AM.
Reply With Quote
Old Oct 04, 2013, 04:11 PM
Registered User
Joined Sep 2013
27 Posts
Hi Jan !
Thanks for reading the story and inputs

The hull is 930 mm or 36 inches long. And I have got the motordata wrong its an
3674 1700kv jaguar motor.
That was an good idea to apply to the hull by heating it and straighten it, but unfortunately its not good access interior wise.

And the engine support from the old nitro engine is plastered good into the hull bottom, tried to remove that yesterday but only a small fragment came loose.

I decided to order this hull instead
http://www.hobbyking.com/hobbyking/s...y_1075mm_.html
Will the 3674 be sufficient powersource for that hull with 6s LiPo?
Old hull will be fixed later for another project.

Brushy
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 05, 2013 at 08:46 AM.
Reply With Quote
Old Oct 05, 2013, 07:35 AM
Registered User
Joined Sep 2013
27 Posts
More infos and stuff

Propeller I intend to use is this one
http://www.offshoreelectrics.com/pro...od=cnc-4614350
46mm or 1.81" with total pitch of 2.54" for 4.76mm/3/16" axle.

Battery for now is 2250mAH 6S Turningy LiPo, will testdrive with that and buy larger
capacity later maybe 2x 5000mAH 3s serial connection or 2x 5000mAH 6S in paralell connection.

//Brushy
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 05, 2013 at 08:56 AM. Reason: New info
Reply With Quote
Old Oct 05, 2013, 01:12 PM
Registered User
Joined Sep 2013
27 Posts
Took a picture of the motor

Name: 2013-10-05 16.37.54.jpg
Views: 43
Size: 285.0 KB
Description: Brushless motor
Brushy is offline Find More Posts by Brushy
Reply With Quote
Old Oct 05, 2013, 05:19 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
4,517 Posts
Hi Brushy,

It turns out your 'jaguar' is a leopard...

As it's a four pole motor, it will run rather cool, but the cooling jacket is too short for my liking, I'd rather use the 55/60 mm long jacket to get a more even cooling of the can, even if this means either omitting the rear support ring, or making a longer epoxy/carbon base to accommodate a longer cooling jacket.

Something you must change, is the position of the outlet; this needs to be on the highest point of the jacket, as it is in the picture, you'll have air trapped on the highest point, reducing the cooling capability of the jacket, leaving you with the infamous 'part motorcan cooling'...

As you can see on the HK site, a bigger motor is adviced for such a large hull, even the 4074 has to work hard in this hull, I fear the 3674 will suffer, or leave you with a sluggish boat, due to the relative small prop.

Regards, Jan.
pompebled is online now Find More Posts by pompebled
Reply With Quote
Old Oct 05, 2013, 09:45 PM
Registered User
Australia, VIC, Blackburn North
Joined Feb 2011
825 Posts
The jacket will be fine. The restriction of the rear ring mounting is the issue on these size mounts.

I run a 4082 with that same length jacket in my Genesis and have no cooling issues at all and also my recommendation for a motor. 4082 1600kv on 6S.

As for the outlet, Pompebled is right, you need the exit point of the jacket the highest point.

This is a 3674 2000kv in a 30" Hydro. See the cooling pipes from the motor? Pipe comes from the rear, up to the ESC (That isn't there), then into the lowest jacket nozzle, out and into the mount then out the side.

mozzyrocks is offline Find More Posts by mozzyrocks
Reply With Quote
Old Oct 06, 2013, 07:58 AM
Registered User
Joined Sep 2013
27 Posts
Hi Jan and mozzyrocks !

Thanks again for helping what seems like a total noob = ME
And yes ive bought a leopard motor but wants to call it jaguar ...strange lol

When i ordered the leopard i wanted a bigger coolingjacket but it wouldnt fit, so
I went for the 50mm one.

Hmm it seems like I have to order a bigger motor then , cause i dont want a sluggish boat ...I aim for speed

Mozzyrocks... what about a 4092 1480kv or 4092 1730kv or should I go for the 4082 1600kv?
Both are still working with 200A ESC.

Lefts me wondering if bought the right hull and if its a good setup...
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 06, 2013 at 09:56 AM.
Reply With Quote
Old Oct 06, 2013, 11:43 AM
Registered User
Australia, VIC, Blackburn North
Joined Feb 2011
825 Posts
Quote:
Originally Posted by Brushy View Post
Hi Jan and mozzyrocks !

Thanks again for helping what seems like a total noob = ME
And yes ive bought a leopard motor but wants to call it jaguar ...strange lol

When i ordered the leopard i wanted a bigger coolingjacket but it wouldnt fit, so
I went for the 50mm one.

Hmm it seems like I have to order a bigger motor then , cause i dont want a sluggish boat ...I aim for speed

Mozzyrocks... what about a 4092 1480kv or 4092 1730kv or should I go for the 4082 1600kv?
Both are still working with 200A ESC.

Lefts me wondering if bought the right hull and if its a good setup...

Hahahaaa, here's my Genesis (Which I'm sure people are getting sick of seeing) with that motor I mentioned with an Octura X440/3 on 6S.

My hull runs with two 6S 800+ gram packs in parallel. This was before I hit a downed tree and split the hull which I'm now getting up and running again.

First run of Genesis after rebuild (6 min 20 sec)
mozzyrocks is offline Find More Posts by mozzyrocks
Reply With Quote
Old Oct 06, 2013, 11:57 AM
Registered User
Joined Sep 2013
27 Posts
Quote:
Originally Posted by mozzyrocks View Post
Hahahaaa, here's my Genesis (Which I'm sure people are getting sick of seeing) with that motor I mentioned with an Octura X440/3 on 6S.

My hull runs with two 6S 800+ gram packs in parallel. This was before I hit a downed tree and split the hull which I'm now getting up and running again.

http://www.youtube.com/watch?v=rAmS2hyvxaY
Looks like a neat setup and good speed, i guess your answer is 4082 1600kv then ?
Brushy is offline Find More Posts by Brushy
Reply With Quote
Old Oct 06, 2013, 12:11 PM
Registered User
Australia, VIC, Blackburn North
Joined Feb 2011
825 Posts
Not at all.

I only show you what mine does. I have no idea of the actually speed and this is not full throttle yet as I run out of room.

The new place I found is 2.5 times larger than this lake, but, I won't get on it for a little while yet.

I will also be trying this same boat on 8S with this motor, but, changing ESC to a SF 240 HV ESC capable of 12S.

The motor can handle 9S and a max of 120amps, so, I think it may be ok.

8s or 29.6v x 1600kv = 47360RPM.

I may only get one run in before it lets go. OR it may run quite reliably on that setup.

Either way, I WILL be getting a GPS in the boat for these next runs. I just HAVE to know how fast this thing really is!

I will be moving onto something like a HPR or MHZ 60-70" twin set up for my next boat.


For the record, Brushy, my boat is 1040mm from tip to rudder and 230mm wide and weighs 4035grams or 4.035kgs. Based on that weight, if you can get yours under that weight on a similar setup, it'll be faster. This runs very cool too. ESC , motor and batteries all come out at about 25C.
mozzyrocks is offline Find More Posts by mozzyrocks
Last edited by mozzyrocks; Oct 06, 2013 at 12:50 PM.
Reply With Quote
Old Oct 06, 2013, 04:26 PM
Registered User
Joined Sep 2013
27 Posts
Well where I live its soon to be winter in another month maybe so the season for me comes quickly to a halt.

Worst nightmare must be to end up in the woods when theres no more lake.


Interresting ... hull as is weighs in at 2780gr,motor as I have now weighs 315 gr
ESC 132gr Testbattery is 369gr but only a 2.2A 6S battery= 3596 gr without other hardware.

Did a calculation at radiocontrolinfo.com with hullsize and leopard engine
it turns out that i need to run boat with 10s swordfish 240A ESC and
Leopard 5698 4d 835kv on leopard homepage it says 6500 W max 42V and 150A. It also features 8mm axle .
More interresting that program suggest same motorconfiguration for your hull
mozzyrocks.

It also suggest that 4082 1600kv should be used on 840mm hull and 5S
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 07, 2013 at 06:10 AM.
Reply With Quote
Old Oct 06, 2013, 11:30 PM
Registered User
Australia, VIC, Blackburn North
Joined Feb 2011
825 Posts
Quote:
Originally Posted by Brushy View Post
Well where I live its soon to be winter in another month maybe so the season for me comes quickly to a halt.

Worst nightmare must be to end up in the woods when theres no more lake.


Interresting ... hull as is weighs in at 2780gr,motor as I have now weighs 315 gr
ESC 132gr Testbattery is 369gr but only a 2.2A 6S battery= 3596 gr without other hardware.

Did a calculation at radiocontolinfo.com with hullsize and leopard engine
it turns out that i need to run boat with 10s swordfish 240A ESC and
Leopard 5698 4d 835kv on leopard homepage it says 6500 W max 42V and 150A. It also features 8mm axle .
More interresting that program suggest same motorconfiguration for your hull
mozzyrocks.

It also suggest that 4082 1600kv should be used on 840mm hull and 5S

That is by no means correct then.

You've seen mine run with that motor on 6S and I can honestly say that adding that 5698 motor and 10S it will surely weigh over 5.5kg and may not even fit under the canopy.

This setup runs nice and cool too. What on earth is that calculator???

I can only imagine what it would state for a big hull like a MHZ or HPR.

Actually, I had a look at 'Cat Setup' and they only show setups for single motor drive.
Stupid!!!
What about twins?? Bahhhh, any site that doesn't cover all facets is crap in my eyes!
mozzyrocks is offline Find More Posts by mozzyrocks
Reply With Quote
Old Oct 07, 2013, 05:55 AM
Registered User
Joined Sep 2013
27 Posts
Quote:
Originally Posted by mozzyrocks View Post
That is by no means correct then.

You've seen mine run with that motor on 6S and I can honestly say that adding that 5698 motor and 10S it will surely weigh over 5.5kg and may not even fit under the canopy.

This setup runs nice and cool too. What on earth is that calculator???

I can only imagine what it would state for a big hull like a MHZ or HPR.

Actually, I had a look at 'Cat Setup' and they only show setups for single motor drive.
Stupid!!!
What about twins?? Bahhhh, any site that doesn't cover all facets is crap in my eyes!
Calculator only takes hullsizes 500-1300mm and if you
throw in 1300mm it cant suggest any motor.
Anyway i'll mount the 3674 1700 I have and prepare motormount for 4082 later. Can't wait for the hull to arrive from NL ..and the other stuff. If im lucky I can assemble and testdrive before winter and icywaters .
The calculator: www.radiocontrolinfo.com that I have used to look at what motor would fit
Brushy is offline Find More Posts by Brushy
Last edited by Brushy; Oct 07, 2013 at 06:09 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion DIY projekter - Projekter udviklet af Dennis SpookiePower DK FPV 254 Mar 12, 2014 02:57 PM
Discussion CAD Projekt - Gimbal GoPro3, BLDC pirzol Multirotor Talk 0 Jul 12, 2013 06:46 PM
Gallery Arado Projekt jimsky Your Plane Photos 0 Jul 23, 2004 07:56 PM
Gallery Arado Projekt jimsky Your Plane Photos 0 Jul 23, 2004 07:55 PM