HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 20, 2012, 05:35 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
4,822 Posts
Discussion
Mono 1 tinkering

Though my 25"Xcalibur with a 1700KV outrunner on 3S runs nicely with a 45K prop, it's not quick enough to win a race, as I've discovered last season...

So I went trough the drawer with spare motors and mounted a Turnigy B3640 3900KV, which I fitted with a watercooler.

Today was the proptest; I started small with a Tenshock 33 mm twoblade, as 38000 rpm under load is nothing to sneeze at and I wanted the blades to stay on the hub.
Failure; too small, with an endless acceleration fase, eventually getting up to speed when I had to throttle down for the turn, as I ran out of canal.
Next a 34,5K, slightly larger, slightly less slow off the mark, still too small.
The 36K did the trick and the boat ran very quick, I'm estimating about the speed of my Arowana.

Keeping the boat upright proved to be a challenge, as the older design of the stepped hull wasn't up to this kind of speed while being so much lighter than the 700 motor/12 NiMH days.

Even running slightly wet I couldn't prevent several back flips running into the wind at full blast.

The hull is designed to turn right easily, which in it's overpowered state means I have to steer left to run straight, even with the driveline offset to the right.

At this speed this means the right side is lifted up, causing a horrible running attitude, resulting in a flip as the boat stumbles over the bow when the speed gets high enough.
I didn't time the runs, as I changed props frequently, but my guestimate is that the runtime won't be long enough, not really a problem, as the boat can't even corner properly at this ludicrous speed.

It is fun though, bolting over the canal with a screaming motor, attracting lots of kids with their dads, who find it very cool (untill they ask you what it costs to go that fast).

I'll try a timed run on glass water, with a little chop I won't be able to keep running for an entire lipo charge...

So the next motor is the Turnigy B2845-3600KV, a bit less rpm and hopefully a better handling boat.

I'm also considering this one on 2S:
http://www.hobbyking.com/hobbyking/s..._Inrunner.html

Suggestions are welcome, keep in mind either 5000mAh 2S, or 3300mAh 3S are the max weight allowed and the runtime should exceed 6 minutes.

I'm even considering refitting my old MHZ Flash, which handles better at speed due to the runpad I added.

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 20, 2012, 06:42 PM
Closed Account
Joined Jul 2006
1,474 Posts
Jan

Here's what you don't like; skip using stepped boats! Now being you live in Europe, home of the best selection of rc boats, there should be one for you. What size boats do the rules say are max beside the time limit?! No Step 1! Hint; the flat area of no step; fill the flat area so the keel is 1 level which will aid in cornering by 50%. Mine has Feigeo 3583 kv on 2S with a 632 and corners great with no turn fins or rim tabs. Lipos are in saddle pack with cg at 30%, just a suggestion. I extend my outside strakes to transom. Jan you quote( those pesky No Step 1 ).
Mikedown is offline Find More Posts by Mikedown
Last edited by Mikedown; Mar 20, 2012 at 07:00 PM. Reason: Suggestion.
Reply With Quote
Old Mar 21, 2012, 02:20 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
4,822 Posts
Hi retoabcr,

You are right, the Nostep 1 are the boats to beat at the moment...

My mono 2 hull is a non stepped Arowana, so I know how well such a hull behaves, but as I've 'grown up' with stepped hulls, I value the extra speed a step can give you.
As I have to work with weight limitations on the Lipo, I'm trying to squeeze the most out of the capacity available.

Speedwise I'm there, now to find the compromise that will give me the 6 minutes runtime.

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Old Mar 21, 2012, 06:38 AM
Is life for real?
pkboo's Avatar
Almere The Netherlands
Joined Sep 2006
1,320 Posts
Hey Jan, sounds like my scorpion in my first season, straight runs excellent, be behind somebody or try taking corners and youre all over the place Youve seen my Zoom, no step low in the water, three bladed 37mm on 2S, just have to get that annoying vibration out now to run with a 2 bladed 39mm! Boo
pkboo is offline Find More Posts by pkboo
Reply With Quote
Old Mar 21, 2012, 05:12 PM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
4,822 Posts
Hi Boo,

I did a timed run with the same motor tonight, just over five minutes, but with a silly grin om my face; the boat is scaringly quick, barely controlable, not suitable for competition, but great fun!

Running a lipo charge in one go did raise the temperatures a bit, but nothing serious:
- Motor 45C
- ESC: 42C
- Lipo: 44C

I have a 2200KV outrunner on it's way, but until that arrives, I'll give some other motors a go.

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Old Mar 22, 2012, 03:38 PM
Is life for real?
pkboo's Avatar
Almere The Netherlands
Joined Sep 2006
1,320 Posts
Kid!

Ah, you've let the Kid in you come out again huh!

Those are good numbers! I get about 50% higher numbers on the 3s Lipo with a 31mm on the MM and fearing the summer, I can't go lower on the prop. If everything goes well, I'll race Hengelo with these numbers and change motors after that. I can't go top speed 'cause it really flies , I get the 6 minutes by playing around 3/4 speed I'll have to check the rigger how it runs with almost the same setup as the MM or go 2S with a bigger prop or changing motors after Hengelo

I'll have the same setup as always on the Mono I, I have a bigger chance at the oval due to it's top speed, you've seen it I need to find out why it vibrates with a 2 bladed prop, I've ordered some flex links from Gundert and adding additional bearings and will be testing around Easter ...gotta finish with the rigger in time

See you soon, Boo
pkboo is offline Find More Posts by pkboo
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log 1/2 Scale 72" Mono TGKconnectors Racing Boats - Electric 121 Mar 01, 2013 10:04 AM
Discussion Tinkering with a PC power supply conversion BrownEyedFool Batteries and Chargers 18 Mar 22, 2012 12:34 PM
Discussion Dragon Boats, Shark Mono 1 ep won't work when battery is connected _Hammer_ Racing Boats - Electric 14 Jan 11, 2012 10:44 PM
well here i am tinkering again.......this time, AT-6 derailed Foamies (Kits) 2 Jul 03, 2005 10:28 PM
Format Tinkering Sure Gets Annoying aeropal Site Chat 5 Feb 18, 2005 10:26 AM