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[2772e]

Phil,

By the sounds of things there is a flaw in the mould, all the marks are in the same places, a mate of mine got his a couple of weeks ago and we have compared, pretty similar. His however has been rubbed through in a few places and gel filled afterwards. Its all going to be painted anyway so don't worry to much about it.

Paul does not like stringers!

I fitted as per his recommendations to begin with. OK for two races then all came apart. Took another 3 attempts to get them in and solid. Most of my early race problems were with that type of mount, both on the radio box and the engine.

For whats it worth i will always fit stringers. Weight is not a problem with this boat. I have to add weight in rough conditions and am thinking of adding more strength/weight/glass fiber in the rear anyway. Big dissadvantage is if you want to run a different engine, some are 5 inch and some 6 inch. Stringers add strength front to back and dissipate the loads of the engine. The feet cracked my outer gel coat where they flexed. Mine are 5mm marine ply, 2 inches high and glassed in all the way. With a solid glassed in bow bulkhead.

Always here to help.

BW

Simon

[Blagmeister]

Sound advice if you ask me Simon! Thanks!

I had a feeling that those flaws must be in the mould and like you say, they are going to get filled and painted anyway so I am not going to lose any sleep over it.

As for the stringers, I had my own thoughts about going down the route of mounting directly to the hull and was a bit twitchy about it, so I think I will go down the stringer route.  Did you beef up your transom incidentally?

Had you thought about using anything other than ply for the stringers? [I know Paul doesn't like 'em as he suggests that they can get soft after a season or two of getting damp, hence the thought of using a more modern material such as some kind of composite or plastic for example.] Certain types of acrylic sheeting are fuel resistant and a 5mm thickness should provide more than adequate strength I would have thought.  I was curious as to whether anyone had ever tried it before as it would seems to address the drawbacks Paul seems to suggest are prevalent in wooden stringers.

Any thoughts?

Phil

[bigtee]

hi phil
been using carbon stringers for a long time now with no problems , as simon says added weight is not a problem and the added advantage of the stiffness with the stringers will ne a real help , also  beaf up the transom area arround the rudder and strut mountings
here to help !!!! :)

tony 

ps simon , its done !!!!, just got to put it back together for you   

[Blagmeister]

Hi Tony

Thanks for that. I guessed that someone out there was already doing something along those lines. Next question then Tony, is how expensive is carbon as a material to buy in a form that lends itself into making stringers?  I have been mooching around the www and I can find plenty of places that will flog me carbon sheet, but they all seem to want to divest me of a limb or two in the process.

Can you tell us how you go about it?

All the best

Phil

[2772e]

Phil,

I did not beef up the transom, not that much hanging off it. When i built it originally i went for a strut. I have now changed to a stinger. Our other one has been beefed up with 5mm ply, that will have a z drive hanging off it though!

I would think that if the wood is sealed properly it should be ok. Marine ply does last, probably longer that the boat will the way we run.

I like the 5mm plastic idea, best of both worlds, do you really need the carbon?

BW

Simon

[Blagmeister]

Hi Simon

As you say, going by the way the boats are run, it's probably a bit moot as to whether to worry about the stringers going soft!  I am not convinced about whether my idea for using acrylic would work - I may have to do some testing but as this is going to be the first boat, of a couple [one for me and one for the lad], then I suppose this one can be a bit of a test bed.  I might start some resistance tests to fuel on some acrylic this weekend though. Carbon is a great idea as it is light, strong, inert and easy to work with. I am not sure about the VFM though!

What made you switch from a strut to a stinger incidentally?

Cheers

Phil

[2772e]

Phil,

More adjustments, up down, in and out! Intersesting post by Martin on set up. Well worth reading. I have suffered with a bit of porposing when running on calm water on my own.

This was my first big petrol boat so it was suck it and see. I am sticking with the Makara next year but want to start tuning her. Where there is adjustment you can tweek.

She's running at about 39 mph and i want to get her up to the mid to high 40's. Dont think the hull will stand much more. Just need that bit of extra zip when passing.

At least thats what i am going to have a go at. I dont run a turn fin or trim tabs

Simon

[bigtee]

phill
the carbon i lay up myself ,epoxy in the summer on a peice of glass .cut it up as i need it

simon your boat will do more than 50 in race trim now but you are right about the hull not standing much more , the 35 in mine is a real hand full !!!!! ::)

[2772e]

T,

Keep it on the QT!

[omra85]

So Simon's been having a bit done on the side! 

Scoop ......  are you listening!   You should just about be able to let the cat out of the bag before the start of the season 

Simon, the hard bit is when it's just a BIT faster than the one in front, and you have to go round the outside (as you know!)
So if it will now do 50, you're in for an easy life 

Phil, never use acrylic on anything in the boat (even the radio box lid) as it cracks at the first hint of vibration!  It would certainly crack if used as an engine mount!  The only stuff of that type you could use is Polycarbonate (Makralon) which will resist cracking but is an absolute bu**er to bond.
If you notice, almost none of the 'glow' boats have stringers because you need a much bigger tank than a petrol, which usually takes up the whole width of the boat.  If your hull is standard polyester, the mounting post method possibly supplemented by an extra thickness of glass under the engine area, will last ages (or until you slam into your first buoy - a large lump of metal decelerating from 50 to nil in less than a foot ......... ) 

If you go down the 'non wood' stringer route - carbon, on its own, is very brittle and subject to shear fractures.  The best would be a 'sandwich' of carbon (for stiffness) and kevlar (for strength).  You would have to use epoxy resin for layup and use the same resin to bond to the hull.

Good luck with the build.

Danny
(water's going to be FULL of Makara sparkies next year)  ::) ::)

[2772e]

Evening Danny,

Just fishing! Thought if i threw the right bait i would catch something.

I reckon that there will 8/9 Makara's running next year! Pushing 3 heats in D at some events i suspect. Someone is doing quite well i think!

These old boats still look the part and will look good in a crowd.

BW

Simon

[martno1fan]

Glad you liked the setup info i posted Simon ,by the way those hulls regularly run in the 50 mph range with the right setup .At least thats what the guys in the states are getting,my mate has an appache and his runs almost 60 thats with a fully modded engine done by one of the top guys in the states.He says its uncontrolable at that speed though so id say 50 is more than enough  .By the way you can buy a propper appache for the same price as those  makaras you know?,why buy a faulty one when you can buy an orriginal pluss the guys not nice to deal with either as you know.the cat my friend bought was horrific ,holes in it hooks ,twists you name it there wasnt a straight line anywhere on it.Its so obvious to me hes using faulty moulds ,several of you have the same faults on your boats? speaks for itself i think.

[Blagmeister]

Phil,

More adjustments, up down, in and out! Intersesting post by Martin on set up. Well worth reading.

Been looking for that topic, but not sure which one you mean..... Any chance of a linky?

TVM Simon.

Danny, thanks for the advice. I am still in 2 minds as to which route to go down with the engine mounting method.  The Makara hull needs beefing up either way imho, as there is loads of flex in the undersides and a bit of extra stiffness wouldn't hurt. I don't think the extra bit of weight will make that much difference to overall performance to be honest either.  So its either gonna be stringers, [which I have to say I am leaning towards at present] or a load of extra lay-up and glassed in posts, [which I am not overly confident at being able to pull off successfully].

In writing that, I think I just made a decision........ stringers it is! 

Thanks for helping me to focus my mind!!!

Cheers

Phil

[martno1fan]

Phil go back to the last page i posted a link to some info on setup etc,makes interesting reading mate.By the way have you guys seen those Sg motor from Italy yet? one of those in an appache will hit 60 mph ive seen a few on another site.HERES A LINK TO THE SG SITE THERES A CPL OF VIDEOS OF BOATS RUNNING THEM TOO these things are awesome.if i find the vids of the sg powered appache ill post a link ive seen it somewhere.
http://www.sgracing.it/ita/home_it.htm


http://www.sgracing.it/ita/video/vid1.wmv

http://www.sgracing.it/ita/video/ACLazerVideo.avi

[martno1fan]

heres the link to those setup tips.
http://www.modelpowerboat.com/RC_Boat_Hull_Attitude

[Blagmeister]

Thanks for posting those clips Mart. Those engines do indeed look awesome. Not sure the bduget will run to one of them this time around though!!

Thanks also for the linky. I shall read and inwardly digest!

cheers

Phil

[w3bby]

........ or a load of extra lay-up and glassed in posts, [which I am not overly confident at being able to pull off successfully....

I used posts in the L ynx and stringers in my Sigma and have to say that I prefer using posts as you have more options as to where to mount everything else that goes into a boat. However both these hulls are epoxy layup and therefore more flexible allowing the hull to absorb the point loadings of posts without cracking or separating.
Polyester hulls, in particular the gelcoat, are stiffer and more likely to crack under point loading. Judicious use of larger patches of extra glass under the posts to spread the load could reduce the likelihood of hairline cracking and separation on these hulls.

[martno1fan]

Stick to stringers and just slot the holes for and aft with a dremmel that way you allways have adjustability to change your balance point if needed  .The stringers will also add stiffnes to the big hull you have which i bet flexes like mad been poly?.Not sure what the price of the sg is to be honest but its probably arround the price of a full mod zen but maybe Ian can clarify that one?.I know one guy who runs in omra has an sg in one of his boats not sure if hes raced in omra with that one yet though,if hes arround maybe he can let you know how they run.You cant go wrong with a zen for reliability though and theres lots of mods you can do or have done if needed.Good luck with it  .

[w3bby]

Not sure what the price of the sg is to be honest but its probably a round the price of a full mod zen..........

I wish, nowhere near..... in Sweden 15000sek but you get the pipe..... http://www.gasolineracing.se/shop/product_info.php?cPath=42_48&products_id=50&language=en

[martno1fan]

Not sure what the price of the sg is to be honest but its probably a round the price of a full mod zen..........

I wish, nowhere near..... in Sweden 15000sek but you get the pipe..... http://www.gasolineracing.se/shop/product_info.php?cPath=42_48&products_id=50&language=en

Cummon Ian i was only about a $1000 out lol 

[AC RAZOR 45]

well i must say the makaras are coming out in force now ,it seems a very popular hull,and not something out of the ark as i once heard,as for the sg £1000 ,and it sits in 6 inch rails,don mauro, in the states runs one in his ac razor 45 and it was clocked at 75 mph,well i have some more money to burn so i am now building a 60" cat that actually measures 58" it will be run with sikk power of course, will start the thread with pictures soon....i think a makara club is long over due...AL

[pete_486]

yeah a MAKARA club sounds good.
oh and by the way ive seen that cat of Al's and with the sikk in it that thing will purr

Pete

[AC RAZOR 45]

DONT YOU MEAN THE WOODY EATING WILD CAT WILL ROARRRRR

[Blagmeister]

Well, [gulp] it's leap of faith time!!!

I'm just off to drill a big hole in the transom...... [stuffing tube]. First time I've done this and I'm keeping my fingers crossed that I don't s*d it up!

Here we go!

[/me goes off to the workshop clutching offset diagrams.....]

 

[Bill D203]

Makara Club. YES YES YES! How about our own D Class only OMRA Days!!!