Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: 1 2 3 4 [5] 6 7   Go Down

Author Topic: new petrol powered deep v mono scratch build!!  (Read 26183 times)

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #100 on: April 02, 2007, 02:54:21 PM »

Glenn i dont think ill be racing any time soon im just in this for some fun at our local lake with my son,i may yet build another one that way we can race each other with identical boats and engines. how do you think she went then?.remember this engine is running a standard muffler with no pipe and just a bigger carb to help get a few more rpm.
Logged

od boating

  • Guest
Re: new petrol powered deep v mono scratch build!!
« Reply #101 on: April 03, 2007, 01:42:58 PM »

hi
 nice to see boat in the water at last!  doesn't go bad for a coffin fitted with a hedge trimmer (only joking) ::) good to see a boat built for the price of a good epoxy hull. keep up the good work
 i see fleetwood  is still as windy as ever
       regards Steve
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #102 on: April 03, 2007, 02:07:58 PM »

Hi steve thanks for the err compliment  ::) this boat will move on out once shes dialed in, this strimmer motor revs high and i will be getting  a pipe on it in the summer ,my mates hydro forming me one whn he gets a water pump sorted to do the job.The boat will do over 30 maybe mid 30s with the motor as it is with the walb carb on it.A mate has the same engine in one and hes gps,d it at 35 in very rough conditions 12" chop  :o rather him than me.Yes fleetwood hasnt changed its still windy ,if you think those conditions were bad you should have seen the big lake it was scarey.All in all i payed about 150 to get this boat running thats including radio gear  ;D,i payed 15 quid for this engine brand new and i got lucky as all the walb carbs are a straight fit.If i get bored of the stock motor ill get it ported a little before i probably fork out for a zen.By the way this boat runs better than those blue fishy knock offs on ebay with more hook in them than peter pans mate!!.With a zen i know this hull will do 50 mph plus as ian webster has the same hull ,i changed the design of this hull considerably too by myself and she runs very straight and true with no vices so far .If any show up when speed increases time will tell but im sure that can be sorted with trim tabs if needed maybe turn fins also.Im also thinking of using this hull to make a fibreglass one by making a mould off it first,the bare hull weighs 7 lb so a zen in there would deff make it move!!.
Logged

w3bby

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Helsingborg, Sweden
Re: new petrol powered deep v mono scratch build!!
« Reply #103 on: April 03, 2007, 02:45:55 PM »

A zen will make it move, above and beyond the limits of the design  ;D

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #104 on: April 03, 2007, 03:07:16 PM »

A zen will make it move, above and beyond the limits of the design  ;D
not my design lol  ;D serriously though anything above 40 to 45 would be more than enough for me,but thers no harm in pushing the envelope a little hehe.
Logged

glennb2006

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 434
  • Location: Newcastle
Re: new petrol powered deep v mono scratch build!!
« Reply #105 on: April 04, 2007, 05:01:41 PM »

Aye, seems to go OK, I think I am with Ian, Zenoah would maybe be a bit much for it. Maybe buy a Zenoah and keep a look out for a second hand hull?

I remember years back upgrading a boat from a 6.5cc to a Webra 61 (10cc), despite the instructions telling me not to, it was an absolute pain, really, really fast but so unstable as to not be safe and fun anymore. Actually had to slow it down to turn it!

It used to crash for fun after that upgrade.

Glenn
Logged

w3bby

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Helsingborg, Sweden
Re: new petrol powered deep v mono scratch build!!
« Reply #106 on: April 04, 2007, 05:17:19 PM »

Got me wrong guys, stick a zen in there and it will fly, mine did. It was fast and stable with a full mod 260 but could be difficult to keep on the water in a wind. I adjusted my balance point with a chunk of stainless L profile and it was good to go.

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #107 on: April 04, 2007, 05:39:59 PM »

Aye, seems to go OK, I think I am with Ian, Zenoah would maybe be a bit much for it. Maybe buy a Zenoah and keep a look out for a second hand hull?

I remember years back upgrading a boat from a 6.5cc to a Webra 61 (10cc), despite the instructions telling me not to, it was an absolute pain, really, really fast but so unstable as to not be safe and fun anymore. Actually had to slow it down to turn it!

It used to crash for fun after that upgrade.

Glenn
i was gonna say same as ian on that this boat is as stable as houses mate i wont have any fear of sticking a zen in there and after seeing some new hulls recently that garry  pope was hoping to race i know which one id rather have!! ;D heres the second run enjoy i did ,oops sorry officer i never saw that buoy lol
http://http://www.youtube.com/watch?v=JEFk5rwwMPc
Logged

w3bby

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Helsingborg, Sweden
Re: new petrol powered deep v mono scratch build!!
« Reply #108 on: April 04, 2007, 11:39:51 PM »

Time to hit the loud button Martin and open it up, stop pussy footing around  ;)

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #109 on: April 05, 2007, 08:31:23 AM »

Time to hit the loud button Martin and open it up, stop pussy footing around  ;)
Haha gimme a chance man i dont think she will go much faster just now till i get the prop walk sorted as i had full left rudder on most of the time at full speed!,! even so id say shes pretty fast considering im not running a zen.Once i get a pipe sorted im sure speed will be much better along with a few porting mods i have planned in the future.If i decide to live on the edge ill buy a zen and have some more fun,i said when i built this boat id be happy with 25 mph and shes well over that allready maybe over 30  so im chuffed to bits as this engine cost me 15 quid lol ;D.Hopefully next time at the lake the duck feeding brigade wont be watching and i can ignore the ducks instead of slowing down for em or avoiding them hehe!!.Swans are another matter them things dont move for nothing >:(.
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #110 on: April 11, 2007, 12:01:39 AM »

well prop walk is almost sorted i only need a little left trim on the rudder to keep straight so maybe another washer to angle the prop a bit more left will sort it out.i ran her this morning in rough water and wow she really loves it!! heres a pic of her also a guy i met had a speed gun he was running his rc car in the car park and he timed it at 35 mph which was good considering the 10" chop at one end of the lake.
Logged

omra85

  • Guest
Re: new petrol powered deep v mono scratch build!!
« Reply #111 on: April 12, 2007, 10:48:40 PM »

Hi Martin
Glad it's up and running and 35mph - not bad at all :o :)
Don't try to tilt your shaft, what you're getting is torque reaction.  The prop is pushing anti clockwise making the boat try to go clockwise.  This causes it to run to the right - it happens with them all!
The cure is to add weight to the left hand side in the form of stick on lead weights as used by tyre companies for balancing alloy wheels, (try pleading with your local KwikFit).  The sprips are 80 grams for a full strip but you may not need it all.  Try sticking one strip inside the boat about level with the back of the engine where the side meets the bottom (as low as you can get).
This way does not affect your steering which angling the prop will.
Danny
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #112 on: April 12, 2007, 11:00:18 PM »

Hi Danny ive shimmed the strut allready ,only 1 mm and it helped a bit but ill try the lead weight how much weight would you think id need?.I have lots of lead here im sure i can fix some in there somehow.Any reason you say level with the engine and not at the transome?.
Logged

Martin [Admin]

  • Administrator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 19,056
  • Location: Peterborough, UK
    • Model Boat Mayhem
Re: new petrol powered deep v mono scratch build!!
« Reply #113 on: April 12, 2007, 11:09:32 PM »


Well done sir.

Martin.
Logged
"This is my firm opinion, but what do I know?!"    -   Mayhem FaceBook Group!

w3bby

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Helsingborg, Sweden
Re: new petrol powered deep v mono scratch build!!
« Reply #114 on: April 12, 2007, 11:19:15 PM »

Any reason you say level with the engine and not at the transome?.
Best effect without changing your balance point, your balance point(front/back) is probably around the engine.

omra85

  • Guest
Re: new petrol powered deep v mono scratch build!!
« Reply #115 on: April 12, 2007, 11:19:53 PM »

Hi Martin
If you've got your own lead then great, just make sure it stays stuck on!
As for the amount, it will vary as no two boats are the same.  Try 100 grams for a start as yours is a big boat.  You can adjust it depending on the effect.  The reason for putting it at the centre of bouyancy is that it will not try and 'twist' the boat which it does if you put it at the transom.

Of course, the VERY BEST way of curing this is to put a wedge underneath the right of the boat at the transom.  The effect of the wedge will increase the faster you go through the water and have less effect when you slow down which is the exact opposite of the torque effect you're trying to cure
The lead effect is constant whatever the speed so at slow speed the boat will tend to steer slightly left.  However, it's a LOT easier to adjust lead weights rather than a wedge!
Add or take off lead, then trim the rudder AT FULL SPEED so that the boat runs straight. When you bring it in, the rudder should be dead centre.
Cheers
Danny
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #116 on: April 12, 2007, 11:20:19 PM »

Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #117 on: April 12, 2007, 11:22:44 PM »

cheers Danny any pics of this wedge your talking about?.
Logged

omra85

  • Guest
Re: new petrol powered deep v mono scratch build!!
« Reply #118 on: April 12, 2007, 11:25:02 PM »

Don't go there - unless you REALLY have to ;D ;D
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #119 on: April 14, 2007, 01:08:13 PM »

Don't go there - unless you REALLY have to ;D ;D
LOL maybe not !!
Well ive added a cpl of turn fins to the transom too so ill test them sometime tomorrow hopefully.I made them myself from aluminium and theyre nice and sharp so hopefully wont cause too mkuch drag.Ill let you know how she runs with them and hopefully ill have a new video to show you guys .
Logged

omra85

  • Guest
Re: new petrol powered deep v mono scratch build!!
« Reply #120 on: April 14, 2007, 09:57:05 PM »

Looking VERY professional Martin - nice job.
Danny
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #121 on: April 15, 2007, 06:55:42 PM »

Looking VERY professional Martin - nice job.
Danny

cheers mate ,well i took her out agian today and for some reason she just wasnt getting up and going id say 1/2 speed i was cursing thinking the turn fins were causing too much drage etc.i brought her in adjusted the prop angle tried her again then she stalled  :(.then when starting the enine again on the stand she just wouldnt rev then this guy said do you want me to tune it for you so i said be my guest thinking let someone else have a go lol.wow in two seconds she was reving well so i tossed her back in and the difference was amazing she leapt up on plane and she was getting faster and faster the longer she ran.he said another 1/8 turn should make another big improvement and so it proved.he also said he thinks my no name chinese weedy is in fact a zenoah!!all in all im chuffed to bits with the speed of this thing now.that said she still doesnt like left turns and still drifts right a bit so ill add more weight to the left next time.sorry no video this time the wife took the camera walkabout.
Logged

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #122 on: April 20, 2007, 12:06:20 AM »

hi guys heres an update took her out yesterday and she was going well in very rough water and wind then oops she flipped lucky no damage and alls running again now.have a look and a laugh ;).http://http://www.youtube.com/watch?v=RIiugpqf2lw
Logged

2772e

  • Simon
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 452
  • The Sea Shall Not Have Them
  • Location: Colchester, Essex
Re: new petrol powered deep v mono scratch build!!
« Reply #123 on: April 20, 2007, 07:13:14 PM »

Hi Mart,

Looking good, well done.

35 mph for a hedge cutter is going some,(dont run over the lead ;D) look forward to seeing her go on a calm day.

I am off for my maiden voyage tomorrow so fingers crossed.

Keep up the good work.

Regards

Simon ;)
Logged
Rubbin is Racin!

martno1fan

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,506
  • Location: Blackpool
Re: new petrol powered deep v mono scratch build!!
« Reply #124 on: April 21, 2007, 09:40:38 AM »

Cheers Simon good luck with your first trip to the lake hope she goes well for yaa ,dont forget the video camera  ;).yea speeds pretty good and turns out the engine is probably a zen copy according to a guy who tuned her for me at the lake last week.His mate owns a mower shop and hes seen a few of these engines and says they are good.I can vouch for that as she certainly moves out and gets up on plane very fast ,she even flies and does barell rolls too lol  ;D. she should be even faster when i get the pipe made.
Logged
Pages: 1 2 3 4 [5] 6 7   Go Up