Slo mo Shun

[Bob Abell 2Participant @bobabell2]

Hello Phil

 

Thanks for your kind wishes

 

Slo Mo is ready for another run tomorrow, only hope the weather is better than today……..We`ve got lashing rain at the moment

 

Liked your video……..Very professional ending!

 

We went a drive out to Llanberis yesterday, but the weather turned foul after lunch

 

Bob

[Phil Winks 1Participant @philwinks1]

Thanks for that Bob. I’m starting to get to grips with the editing software, unfortunately “photobucket” converts to a different media type on upload and for whatever reason doesn’t doesn’t maintain the aspect ratio, the original file on my computer is in 16:9 wide-screen format and quality is much better. That 1st power boat looks so tall on the photobucket version maybe I need to try U-Tube?

 

 

Phil

[Ian GardnerParticipant @iangardner62867]

Hi Phil,

I was interested to hear of your problems uploading videos- I have the same problem. I shoot in widescreen, edit in Windows MovieMaker in widescreen and it displays on my computer in 16:9 but when I upload to You Tube or any other site it shows up in 4:3 (or whatever it is). If you get to the bottom of it before I do I would love to know how you solved it. There are tags you can add on You Tube but  although giving w/s they stll cut bits off. It’s driving me nuts!

 

I liked your video by the way- just what it’s all about and  I know how hard it is to keep a swift boat in shot!

 

I would have liked to know more about the craft in the video, especially the fast ones. Was the blue one a yacht tender that was featured in a magazine a while ago?- can’t remember the name of it.

 

I hope you have set a precedent for uploading video to this site! You might like to have a look at the Fireboats website to see some of mine.

 

All the best,

Ian

 

[Bob Abell 2Participant @bobabell2]

Test sailing No 2

 

A lot better today, but still not on the plane!…………..Actually, it did just once when we were not aiming for it…………..But it wouldn`t repeat the action

 

The motors have lots of power but they  consume their energy, blasting the water backwards…………..as though it was pushing against the bank.

This is probably the problem…….too wide an area……..perhaps a vee shape down below might split the water resistance

 

The roar of the engines is very impressive……..Doesn`t need a sound unit at all

 

An interesting problem…………Now thinking about water cooling and scrapping the fans and I think a vee up front will improve things

 

Bob

[Phil Winks 1Participant @philwinks1]

hi Bob should’ve read this before answering your email. (just knew you’d have smile on your face) that certainly looks better. I think that mod I found on mayhem may help lift it a little more also from these pics the aft end does look low so a weight shift fwd may help as may a slightly smaller prop to get even more revs out of the motors. the fans are definatly sapping significant power in my humble opinion so water cooling looks to be a must lukily those esc’s are convertable I believe. Personally I’d try the balance issue and prop change 1st then if more front end lift is needed try the sponson mod. Ripple strakes under the bow might smooth things out in that area. on the prop issue don’t forget they are surface piercing are they not? so the answer surely is massive revs but take your time on the throttle to avoid aerating. the rooster tail wake is inevitable though. remember the full size took a very long run to get to WR speed.

 

Phil

 

 

[Phil Winks 1Participant @philwinks1]

Hi again Bob just had a thought about getting the aft end up on the plane and it simply involves a couple of simple spoilers (off design I know) fitted level with the props to either side and angled to lift the back as speed increases they could prob be made adjustable to allow you to experiment with the best angle. I’ll give you a ring later to discuss when you’ve a moment if you want.

 

Phil

[Bob Abell 2Participant @bobabell2]

It`s obvious the craft is behaving like a Bulldozer………………When it should behave like a Snowplough!………So it needs a snowplough shape underneath

 

The motors are working too hard at the moment and getting hot…….just shifting water……..once the boat starts picking up some speed, the airflow should come into it`s own!

 

If I can find some brake tubing, I`ll make a start on the water cooling

 

That`s the plan, chaps………Bob

[ashley needhamParticipant @ashleyneedham69188]

Phil, are we talking trim tabs here?

 

A full width extension covering the props may help possibly to counter the aeration issue.

 

Copper water cooling coils filled with water will be heavy!!

 

Bob, i would investigate the cheap and easy fixes first before more alterations of a more permanent nature. Weight distribution, loss of cooling fans , some different props, ordinary x pitch items, or even plain 3 blade items…never know! (and easy and cheap to experiment with)

 

 Ashley

 

 

 

[Phil Winks 1Participant @philwinks1]

Hi Ashley water tubes etc are not going to add that much weight esp if the pipe runs are kept as short as possible.

 

 Brake tubing is only very narrow bob I’ve tried it and to be honest you need a bigger bore I’d look for some 5/6mm annealed thin wall copper or ali tube. Maybe you already know this but to anneal ali is easy simply run a black permanent marker along it then heat in a large flame until the marker pen goes clear and allow to cool!

 

The spoilers idea is to create a bit of lift, a bit like trim tabs I think. Basically flat plates that can be lowered into the water at the desired angle to push water down and the boat up.

 

The idea of a shelf fwd of and under the props would surely cause to much turbulence those props are designed to run up to1/2 out of the water, aren’t they? So the aeration issue is confusing.

 

Hot motors suggest an overloaded motor,  aeration surely unloads the prop (air is thinner than water) so the fans and prop size must come into question again! Do the motors heat up when run with the props in the air for an extened period, say 5 mins??

 

Phil

[Bob Abell 2Participant @bobabell2]

Thank you for your common sense advice, Ashley, but……………

 

Don`t think a prop change is any good, having spoken to the prop man…….and they don`t use two bladed props without good reason

 

For most of the test sailings we`ve had, we`ve gone for more weight in the back to give the illusion of getting up the water incline and onto the plane. but now think we should keep the boat level and deflect the water wall, sideways. At the moment, we`re trying to get over the water barrier!

 

More later…….Bob

[Bob Abell 2Participant @bobabell2]

This is what I mean by a Snowplough effect…….Two thin strips meeting at the front like a pointed hull…….to deflect the water sideways…….instead of trying to climb over!

 

Any comments on this super idea?

 

Bob

[Phil Winks 1Participant @philwinks1]

I’ll need to think about that Bob. and while I’m doing so have a look and see if you’ve seen these photo’s before they I think suggest that Billings merely guessed at the bow/sponson intersection the v of the bow sect seems more pronounced and leaves a gap for water to pass either side and into the void supplying the props with a lovely clean compressed stream of water prior to getting on the plane. what do you think.

 

 

Phil (possibly opening a whole can of worms)

 

 

The LInk

[Bob Abell 2Participant @bobabell2]

Dear Worm Can opener

 

Thanks very much for the latest batch of photos to confuse the confused!!

 

Luckily, my latest snowplough deflectors do not over – lap the contraversial void section, so the cover mod can be removed quite easily

Look again at the rear section in action!………Look at the side wave and the trough in the prop section………the bulldozer effect is such that the hull as made hardly any headway….so the props have washed the water away instead…….leaving a trough!

 

So now convinced the water barrier has to be deflected!…………..QED

 

Bob

[Phil Winks 1Participant @philwinks1]

I’d have to agree with you now Bob also the “shelf” thingy above the props(adjustable of course) and maybe a curtain like affair along the sides of the rear sect projecting down about an inch to keep water under the aft of the boat (tunnel it to  the props) also given their proximity to  the surface when you down size the props you might want to consider surface piercing ones, they are still very efficient when fully submerged and suffer less loss as they come close to the surface. not too much pitch either I think. something else I’ve picked up is that if or when you remove / alter the infill between the sponsons make sure the inner edge of the sponsons is a sharp corner (no rounding at all) apparently it helps a lot when turning.

 

 

Phil (the can opener)

[Bob Abell 2Participant @bobabell2]

Hello Phil………………..So we see “eye to eye” at long last!

 

All those little tips you`ve just mentioned will be fitted ASAP!

 

And here`s something we made earlier, in true Blue Peter style……

 

Rock on Tommy!…………….If this don`t work, I`ll eat my EMBC hat!

 

I`m highly delighted to discover that a straight edge has settled down nicely to fit the hull contour!……………..That can only be an good omen!

 

Bob……….Highly delighted!

[Phil Winks 1Participant @philwinks1]

Rock on Bob just be carefull what you say about the Hat or I may have to post you the ketchup to make it palletable LOL

[John Christopher1Participant @johnchristopher1]

Hi Bob,

 

I have been following your build of this excellent model since you started posting and what a great model it is but I think you are going on a down hill spiral here..A plaining hull needs two things, it needs power and it also needs to be light, you have the power to get it on the plain but I think adding all this extra weight is going to make the model too heavy. I think it may be too heavy now and thats why you are having problems. May be the solution is to lighten the model rather that adding more weight to it.

 

Just my opinion for what its worth…

 

 

 

 

 

[Bob Abell 2Participant @bobabell2]

Hello John……….Thanks for popping in………………A new face at last!

 

I realise the model is heavy…………..but there`s no way of removing any sensible amount of weight……………..and I know the motors are down on power………….We all knew that on day one!

 

I could have gone down the Brushless LiPO route. but that was strange technology to me and there were so many scare stories associated with it too…………….and our pond committee frown on crazy high speed boats anyway…………..so that`s that!

 

If my model was a destroyer of the same weight and power etc……it would fly!…….due to the pointy bit at the front………………..hence my latest modification

 

I just want the model to shake off it`s sluggishness, then I`ll be happy

 

We`re almost there…………………..Bob

[Phil Winks 1Participant @philwinks1]

Hi John, as Bob says so nice to have a fresh face/voice/point of view. Bob is right though, he’s just a tad past the point where this one can be made any lighter. So making it slippier is the simplest route now! In Bobs defence I would like to point out that the hull is prob as light as could’ve been made in woo,. and his main aim of produceing a truly scale look, has been exceded in spades. As for the motors being underpowered well, my opinion is, only just if at all. Although I’d love to get some telemetry in her, and see exactly how many horse’s are actually battling the waves, so to speak, as I think we’d all be suprised, a little at least.

 

 

Phil

 

PS cleaned the workshop (shed) and cleared the decks this morning Bob, but no sign of mr P Pat! still it’s early days yet prob tomorrow

[Paul TParticipant @pault84577]

Bob

 

You could fit small hydrofoil type stub wings under the bow to give the model that extra lift.

A bit like the Aussie winged keel that upset so many people a few years back.

 

 

 

Paul

Edited By The Fat Controller on 24/03/2010 15:04:49

[Bob Abell 2Participant @bobabell2]

Hello Paul…….Welcome back me o` fruit pie!

 

Thanks for the little tip……………Phil and me have been discussing similar topics especially the flaps that your lifeboat have got on at the back end

 

But to be honest, we`ve deliberately and wrongly weighted the back end down and it fact for the last session of tests we actually had five bottles of pop in the back!

 

I`m convinced now that the snowplough idea will be a tremendous improvement…….Just waiting for the glue to dry

 

Bob

[Phil Winks 1Participant @philwinks1]

Hello Paul, Bob surely you’ve got the front end lift sorted haven’t you and that “snowplough” will provide some more I’m sure! Its definately the stern that needs attention now lift without fetching the props too high is what I reckon your looking at so the shelf/trim tab idea should help can’t wait to see the affect it all has! So when’s your next planned exscursion?

 

 

Phil

[Bob Abell 2Participant @bobabell2]

Hello Phil

 

If the snowplough shape works, the rear trough may not appear?

 

But downward facing trim tabs should be quite simple to make and fit……or a small float box at the back?

 

And I could also move the batteries forward

 

Next sail could be Saturday morning?

 

Still waiting for the glue to set!……………….Bob

[Phil Winks 1Participant @philwinks1]

Good Good stuff you don’t hang about do you mate.

 

 

Phil

[Bob Abell 2Participant @bobabell2]

Just discovered this website, they market 1/6th scale Shovelnose kits…… (Slo Mo`s)

 

………………http://www.rcboatcompany.com/

 

Bob

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