Topic: Omra Makara D Class (Read 185450 times)

martno1fan · « **Reply #450 on:** March 01, 2008, 08:47:38 am »

Is this the radio you have? if so change it for FM now dont run an AM radio or your loveley boat will sail off into the blue yonder and smash into something at full tilt i guarantee you.If it doesnt happen first time its only a matter of time AM is renowned for glitches especially with an elec ignition system.
http://cgi.ebay.com/Futaba-Attack-2ER-2-Channel-R-C-System-AM27_W0QQitemZ350029886292QQihZ022QQcategoryZ34063QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Blagmeister · « **Reply #451 on:** March 01, 2008, 08:59:55 am »

Hi Fellas. Many thanks for the prompt replies.

Stav - I was using a separate F/safe but it was not getting a consistent signal and would not work so I took it out of the loop. I bought the Tx/Rx set at the Warwick show last Nov. Prolly not the best place to buy one but I was tempted by the offer...

Danny - thanks for the compliments and the offer of a lend of a spare set. The more I think about it, the more it sounds like a Tx problem which would explain the f/safe I got from BigTee not setting properly. If it wasn't getting a strong enough signal from the Tx then of course it would keep failing as it was designed to do! I'll have it to bits this morning and see if I can see anything like a dry joint or something. I'll try your suggestion with the vaseline too. Re: the foam, I am going to put some more in as soon as I have got everything else snagged but until I have a fully functioning system, I thought I'd leave it out just to make access that little bit easier. I have plenty left so once everything is functioning properly, it will be out with the silicon sealer and then a bouyancy fest!

Webby - It is a 40Mhz AM system so having said that, I think you are probably right and a better system might be in order. As you say - shame to spoil the ship for a ha'porth of tar!

Simon - glad to hear that your R143F works ok with Nimh. I think that whatever I go for, if I can get something with a built-in failsafe then it makes sense to do so.

Mart - good advice and thanks.

Conclusions are that it sounds like the Tx might be on the fritz, then again it could be the receiver. The separate failsafe I have won't work with the current setup due to the anomaly. There is some ambiguity with the whole setup therefore I shall replace the system. Off to Brum now..... Let you know how I get on later.

Cheers!

Phil

Bill D203 · « **Reply #452 on:** March 01, 2008, 09:48:03 am »

40Mhz AM is not good news. :( Best off luck with your maiden voyage on Sunday

Don't forget to take a video cam with youu.
All the best. Bill

Bill D203 · « **Reply #453 on:** March 01, 2008, 10:30:27 am »

Hi Martin.
All Done ready for a run Sunday morn. Lets hope it stays sealed up

martno1fan · « **Reply #454 on:** March 01, 2008, 10:49:15 am »

Hi Phil best change the radio to fm also with failsafes if there is a lack of power in the battery they will kick in so make sure you runa 5 cell hump pack for your rx,the bigger the cells the better also.Another thing too is run a y lead in yoiur setup between rudder servo and battery this ensures a full 6 volts gets to the rudder servo at all times

.There are some decent cheap fm radios arround if you dont want to spend more on a futaba fasst system ,but i find the fasst system great and not having to worry about clashing with others is a bonus too.I got my 6ex from the states for less than a hundred quid shipped almost new and it works great.Mines intended for helis so has 6 channels ,bit overkill but it was a good price so went with it,it has 6 model memory which comes in handy and also a built in failsafe

.Just dont go spektrum as they have issues on water or some have,futaba fasst systems dont

.That said if you wanna save money get a decent fm radio you can pick them up for arround 50-75 quid.I was running a cheap hitech zebra radio with not problems at all i just chose to go to the fasst system to save messing with crystals .

martno1fan · « **Reply #455 on:** March 01, 2008, 10:53:51 am »

Quote from: Bill D203 on March 01, 2008, 10:30:27 am

Hi Martin.
All Done ready for a run Sunday morn. Lets hope it stays sealed up

Looks good Bill if it were me id runsome elastic band a zip tie or anything from one fastener to the other to stop them popping off in a flip

.Hope it works good for yaa ,my tupperware box is about same size and the lids very strong and water tight in tests ::) tip for yaa stick a tampon or two in the radio box to soak up any water that might get in and that will keep things dry hopefully

.checkout my build thread for my stepped vee some videos on there of it too.
http://www.modelboatmayhem.co.uk/forum/index.php?topic=5984.0

Blagmeister · « **Reply #456 on:** March 01, 2008, 08:34:28 pm »

I'm a happy bunny now!

After much debate this morning, I grasped the nettle and went out and bought a nice new 2.4 Ghz Futaba 6EX setup. What a difference!! Much better. No problem with range now! Having said that, I think you need a degree in electronic engineering to set the damn thing up! At least I got it most of the way there and it all seems to work ok. So, a little fettling later and Jnr and I thought we'd sneak a quick half hour in over at Kingsbury before it got too late in the day.

Well it runs! Takes a bit of starting [always seems to need about 3/4 choke to start it, even when warm then I need to idle it at about 1/3 throttle for it to stay running after knocking off the choke]. The first chuck resulted in a stall so it was out with the club rowing boat. I tried again and managed to get a bit further this time before it stalled. It seemed not to want to open the throttle. I could run it at about 1/3-1/2 throttle and as long as I didn't change the throttle setting it was okay. Running very wet though at this stage and the engine seemed to be hunting and the prop cavitating. I got a few laps in at this setting though at least before it stalled. As soon as I opened the tap a bit it fluffed to a stop and it was out with the rowing boat again. I figured it might be running too rich so I leaned off the H screw a bit and blimey! what a difference! It frightened the life out of me! It sat up screamed and round the lake so I backed it off a bit then and again it stalled after a few laps.

I think the carb settings are all to cock but as I don't really have a clue with these engines, any advice anyone has to offer would be useful. It handles very nicely though, runs straight and true, no prop walk but a bit of porpoising. Strut angle may need a tweak but again, those in the know could prolly do with seeing it.

Regrettably no video footage of this maiden, but I don't really consider it it's first "official" outing. I'll try again tomorrow and with a bit of luck get some video footage. Incidentally if any of you guys are off out tomorrow with your boats, if you let me know ASAP, I'll try and get to you with it so I can pick your brains re: the setup but failing that it's back to Kingsbury and a bit of trial and error.....

At least it didn't sink!

Cheers

Phil

Bill D203 · « **Reply #457 on:** March 01, 2008, 08:57:15 pm »

Hi Phil
Well done on your maiden trip. I Will be out at Stevenage in the morn having fun with mine. Let's hope my new radio box stays water proof. I tip my boat over lasat week at Brentwood. This was when i found out maplin water proof boxes an't . Radio,Engine, fuel tank was all under for 20 mins . Not what I had in mine for a fun day out.

Blagmeister · « **Reply #458 on:** March 01, 2008, 09:01:54 pm »

Unlucky Bill. Sorry to hear that. Hope you have finally managed to get it sorted. Do you have a rescue boat at Stevenage? 20 Mins is a long time for a radio box to go swimming. I think I managed to get out to mine today in about 5 mins of it stalling each time. [Not that it was underwater of course but having the rescue boat at my disposal made a rotten situation into a half decent one if you know what I mean].

If you let me know the details of where and when you are likely to be at Stevenage I may see if I can convince SWMBO that I may need to get up early tomorrow to go testing...... Just make sure the rescue boat is to hand!

Cheers

Phil

bigtee · « **Reply #459 on:** March 01, 2008, 09:33:21 pm »

hi phil , good to here you got her on the water

i take it you are running a standard zenoah / 644 carb combo ? what is your oil / fuel ratio ( how much oil to 5 lts of fuel )

the amount of oil will have a big effect on setting the carb up , but a starting point is 1.5 on the L and 2 on the H

another good tip is to take out the choke complety ( starting not a problem just choke using your finger ) this will help to get more air

into the engine and help it breath better

let me know if i can help

tony

Bill D203 · « **Reply #460 on:** March 01, 2008, 09:34:04 pm »

Hi Phil
You would be very welcome to come along and join us. We have the use of the lake from 9-12 . Yes we do have a boat with a very helpfull young member of our club who needs the practice. The entry to the lake off a road called" Six Hill Way" If you go on the OMRA site and look up the meet on the 4th May there is a map there to find us. We are allowed 5 car lake side parking, but we can short out something if you come down all that way. Will send you a email ASAP with my moblle . Look forwards to seing you. Bill.

martno1fan · « **Reply #461 on:** March 01, 2008, 09:54:39 pm »

Congrats on your first outing Phil glad you got a new radio too

,on my stock zen i run 16/1 mix full synthetic oil.My needles are 1 3/4 low and 1 to 1 and 1/4 on the high.That should get it reving and keep it running

.Heres a nice tool to help work out your fuel mixes too

.
http://www.beta.id.au/2%20Stroke%20Fuel-Oil%20Ratios.htm
heres a vid of my boat running,this was her fifth run with a bigger prop than im now running.
http://uk.youtube.com/watch?v=X_KNprezP00

lgosdset · « **Reply #462 on:** March 02, 2008, 03:08:12 am »

is the fishing rod in that video to retrive the boat incase it stalls mart? If so genius idea.

martno1fan · « **Reply #463 on:** March 02, 2008, 01:07:12 pm »

Quote from: lgosdset on March 02, 2008, 03:08:12 am

is the fishing rod in that video to retrive the boat incase it stalls mart? If so genius idea.

Yea thats the idea ,works good for close in any further than say 30 -50 mtres and its dificult to reach.its just the butt end of the rod, an old sea rod and big real 30lb line with some cord attached to it via a loop which is threaded through the tennis ball and knotted the other side.My mate also built a rescue boat using an electric boat and some plastic tubing and some insulation foam to make the rig float simply drive out collect the dead boat and push it back.It works great too heres a apic of a similar one.

Blagmeister · « **Reply #464 on:** March 02, 2008, 02:38:05 pm »

A big thank you today for Bill for inviting me down to the Stevenage club for a bit of testing and tuning. That side of things went well and the carb settings are much better and the boat now runs for as long as I want and is throttling much better too. A bit more testing should see it perform as it should. The CoG needs a bit of work as there is too much weigth aft [probably thanks to my over-engineered radio box] and the nose definately needs some weight as it was lifting like mad in a head wind, so much so that I had to back off the gas quite a bit.

One thing didn't quite go to plan though. I was getting a little enthusiastic with things and in view of the spray that was getting into the hull, I thought I'd run with the lid on. [Bear in mind that I hadn't as yet fitted any flotation to the lid and the tin of spray glue I was going to use to stick the foam to it was jammed into the forepeak acting as temporary ballast. I did another run with the lid on and it was going very well - lap after lap completed with no sign of anything untoward....... Right until the lid came off. And then sank.

Bugg*r...

Quote

The hatch fixing is a combination of brackets which hook under the trailing edge of the front of the engine bay opening coupled with an adapted aluminium 50mm door bolt which was tapped out and a M4 bolt fitted. Seems to be secure enough.

Evidently not secure enough! You live and learn... Back to the workshop!

Cheers

Phil

w3bby · « **Reply #465 on:** March 02, 2008, 03:45:14 pm »

Quote from: w3bby on February 29, 2008, 04:53:14 pm

Two observations: I can't tell from the photos if you have buoyancy attached to your cowl, last thing you want is to watch it disappear beneath the waves if it happens to pop off :(

Quote from: Blagmeister on March 02, 2008, 02:38:05 pm

Right until the lid came off. And then sank. Bugg*r...

I did try to save you from that one... Other than that it sounds like you had a good day at the lake

Blagmeister · « **Reply #466 on:** March 02, 2008, 04:19:23 pm »

You did indeed Webby and so did Danny too! In my defence, I have to say that even though I was mindful of the possibility, [and I thought it was a slim one, AND I only intended to be out for a minute or two with the hatch on], I was enjoying myself too much to worry about it! A classic dose of over-enthusiasm! ::)

* Blagmeister shrugs

Cheers!

Phil

martno1fan · « **Reply #467 on:** March 02, 2008, 04:27:22 pm »

Congrats mate seems like your getting there pitty about the lid

,have you done the broom test as regards balancing the boat.balance should be arround 30 -32% from the transom on most boats.if balance is ok and fronts still rising you can either use trim tabs if you have them to correct it or alter the prop angle a tad ,also tucking the rudder in a touch will make it run a little wetter.

Bill D203 · « **Reply #468 on:** March 02, 2008, 06:15:43 pm »

Hi Martin.
The radio box seems to of held up. Got to do a bit more work on the exhaust coupling then I think my winter trails will be over.
Phil's boat is going in the right direction. The nose was a big high and prevented the boat from going full chat. Putting a bit of extra weight in the front end did very much improve things. I don't run any trim tabs on mine and it is very steady in the water. So it must be down to the heavy radio box in the rear which needs a bit of countering.

Bill D203 · « **Reply #469 on:** March 02, 2008, 06:19:44 pm »

PS I meant to add Well done Phil for a nicely turned out boat. Pitty about the top but IF it dose wash up we will let you have it back. You are welcome at Stevenage any Sunday morn where help is only a conversation away.

martno1fan · « **Reply #470 on:** March 03, 2008, 04:44:17 pm »

Glad to hear it worked out mate,best way to balance the boat is not to add weight been there done that ,maybe a bit of down angle on the drive will help but first try angling the rudder in towards the transom a tad that will bring the nose down a bit depending on how bad it is i guess.Maybe moving the fuel tank forward would be best idea rather than adding any more weight?.but def try the rudder thing.
Mart

Bill D203 · « **Reply #471 on:** March 04, 2008, 05:47:28 pm »

Hello
Is there any on out there has a 1/4 scale servo for sale?? If yes email me with how much you are looking for. If not it will be a trip down to Hobby Store.
Bill

ids987 · « **Reply #472 on:** March 06, 2008, 03:07:54 pm »

Quote from: martno1fan on March 03, 2008, 04:44:17 pm

Glad to hear it worked out mate,best way to balance the boat is not to add weight been there done that ,maybe a bit of down angle on the drive will help but first try angling the rudder in towards the transom a tad that will bring the nose down a bit depending on how bad it is i guess.Maybe moving the fuel tank forward would be best idea rather than adding any more weight?.but def try the rudder thing.
Mart

Mart,

If by angling the rudder in, you mean the tip of the rudder further forward than the top of the rudder, I think you've got it the wrong way round.
The rudder, and anything else touching the water at the transom end will tend to lift the transom, and therefore bring the nose down. Angling the tip (bottom / submerged end) of the rudder in (nearer the transom) will tend to direct some of the water flow up the rudder, and reduce the lift from the rudder, therefore raising the nose. This will be most pronounced in turns, but should have a similar but lesser effect with a straight rudder (assuming that the front to rear cross section of the rudder is wedge shaped). Angling the rudder the other way (tip further back than the top) will produce more lift from the rudder - therefore raising the transom more, and pushing the nose down. Again, this will be more pronounced in turns, so angling the rudder outwards to lower the nose is likely to result in "bow steering", and spinouts.

As regards balance point, my opinion (mostly gut instinct) is that this should be positioned so that the boat flies at the right attitude when it comes off a wave, and lands at the right attitude. For a deep vee, surface driven, this should be slightly nose up. If this is right, but it porpoises, I would try and adjust it out with driveline adjustments or trimtabs. If it flies wrong, adjust that first, then trim the driveline etc. If it flies wrong, it will be horrible in the rough (personal experience there). It's quite hard to test without rough water though.....

Still working on getting my new AA boat to handle, but having trouble getting enough time on the water without breaking anything.

Ian

martno1fan · « **Reply #473 on:** March 06, 2008, 09:38:23 pm »

Ian your completeley correct mate ,sorry if i confused anyone i angled mine forward a tad to raise the bow as mine was running wet and digging in in the turns dont know how i made that mistake ::).i meant to say angled back of course dohh.

2772e · « **Reply #474 on:** March 08, 2008, 07:53:43 am »

Ian,

Ling time no hear mate.

Whats happening with you, Bill has been over a few times to play. Thought you might have come with him?

See you soon.

BW

Simon

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Author Topic: Omra Makara D Class (Read 185450 times)

Blagmeister

Blagmeister

Blagmeister

bigtee

lgosdset

Blagmeister

Blagmeister

ids987