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[Tim_M]

Nice to know we're keeping people entertained! Thanks for your interest.

George, pm sent

[ooyah/2]

Kiz & Ramon
 
 My problem is that to post pics on the forum my MAC needs Windows and I have to mail them to my Lap top and then to the forum which is rather a long method.
 However as a test I am trying to post a resized pic  of K7 showing the lift dimensions so I hope it works and if so I can then post pics of the Sponson angle of attack.
 
 Test didn't work I shall try again via Laptop tomorro

 
 George.

Just to let you see that this old Clydeside hammer and chisle engineer is trying to catch up on I.T.
No1
Here is the pic of the sponson angles on my 1/12 th scale K7 which are not the same as D.C's full size K7 but they work and certainly lift the boat off of thwater and onto the plane.
No2
 
Wishfull thinking.

[Tim_M]

Now, that's cool picture!

[Tim_M]

Dunnit.

The stbd sponson has been dropped 20mm at the front. The boom is now sticking out of the top so I'll need a power bulge; I can just pretend I modelled an earlier version.  (I decided not to go into the hull to drop the boom as the structure inside there is pretty complex and there was a good chance of wrecking something). The mod is not pretty but it is strong (large blocks going right onto the original sponson internal structure).

I won't post a picture of the present state of repair. Let's just say, like all surgery, it will look OK when the swelling goes down

[klz]

I agree that is a cool picture 

[Ramon]

George if that's a problem please don't struggle with it - it was just that I have been enjoying following every post twixt you and Tim and didn't want to miss something 


I agree too - a novel picture indeed 


Ramon

[ooyah/2]

George if that's a problem please don't struggle with it - it was just that I have been enjoying following every post twixt you and Tim and didn't want to miss something 


I agree too - a novel picture indeed 


Ramon

Ramon & Kiz,
It's not really a problem, just a round about way to post pics so I shall keep you all informed but remember it's Tim's thread and he will be posting pics on his progress as it develops.
Thanks for looking on.

George.

[ooyah/2]

I was just having a thought on some of the problems encountered while running my K7.
 
Some cracks began to appear on the top of the hull which I have deduced are caused by the constant buffeting of the sponsons on the water at high speeds.
These are attached via a 3/8" dia Ali tube passing thro' the hull and the Sponsons attached at ether end and I assume that it's the deflection of the Ali tube causing the hull to crack on top. The pics only show the cracks on the Port side but since these pics were taken the cracks are now the same on the starboard side.
 
Pics No 1-2-3 show the cracks and No 4 shows the inside of the hull.

On reflection if I was to build another K7 I would re enforce the inside , Port & Starboard with a piece of 1/4" ply bonded into the sides to give some support and to stop the flexing.
At this late stage it's impossible to get inside to do anty re enforcing, the yellow object up front is the E.S.C. and it's wedged in to prevent any movement.
If anybody is considering using a Touchwood K7 I would recommend this strengthening to be done, you must remember this kit is for display purposes and the Fibre glassing is quite poor.
I hope that the pics come thro'
George.

[Tim_M]

George, did the decals come with the kit? I have some paper for making decals but haven't yet found the right artwork. Do my eye's deceive me or is one of those union flags upside down?  (They are different but I wouldn't know which one is right, by the way  )

Hey, Those cracks are just a sign that you've enjoyed your model!!

[ooyah/2]

George, did the decals come with the kit? I have some paper for making decals but haven't yet found the right artwork. Do my eye's deceive me or is one of those union flags upside down?  (They are different but I wouldn't know which one is right, by the way  )

Hey, Those cracks are just a sign that you've enjoyed your model!!

Hi Tim,
Yes they come with the kit but as I only purchased the hull and the sponsons I had to buy them as well, think the cost of transfers were a ridiculous £8.

I never gave the flag a thought so I have just Googled images  and it looks very similar to the transfer so I suppose Google has it correct.

I sure have had some fun with this K7, much more heart stopping than a Steam boat !!!!!!!!

Mind you when I sail my flash steamer I have to go and have I lie down to recover after running it.
George.

[Tim_M]

I googled it. The one on the right is correct. Another piece of useless information 

[Tim_M]

There's a bit of a lull in proceedings here while I wait for my new ESC to arrive ('up to 45 days' ). I wanted to add a water cooled heatsink to my ESC while the glue was drying on the sponson mods. When I stripped it down, I decided that the soldering was very scruffy where I had repaired it after the previous 'meltdown' and there was a good risk of causing a short if I put metal anywhere near the board.  After a massive struggle, I managed to get two wires stripped and re-fitted. On the third one, I dislodged a tiny chip and (of course) lost it.  Subsequently, Castle Creations explained that it's impossible to do DIY repairs on their boards as you need specialist equipment to deal with the solder. They are not wrong there! Anyway, if anybody has the skills and access to the right equipment, an 80A ESC is yours for the cost of a stamped addressed jiffy bag (PM me). Be aware that I have almost certainly damaged it beyond repair and there is a chip capacitor missing!

I have been working on re-aligning the sponsons. When I designed the model, I had to use my imagination. I made the planing shoes a little wider (not wide enough, it turns out) and I also increased the angle of attack. That was a mistake and the effect was to lift the bow far too early, burying the prop deep under water where it couldn't work properly. I'm now down to about 5 degrees incidence (thanks, George) so we'll see how that goes. Don't worry that the mod looks a bit flimsy. The booms are attached to the internal structure of the sponsons; the power bulges are cosmetic (not very cosmetic, I'll grant you).

I've also been working on the MkII design on the computer. I have so far made what I believe to be an accurate conversion of the Nexus plan into 3D. Now I am working on modifying (a copy of) that model to correct some of the things that are wrong in the plan and to add 'un-scale' features that are needed to make the model work (no rear wedge, modified planing shoes etc.). I enjoy computer modelling pretty near as much as working on the bench. Everything fits perfectly, the glue dries instantly and the finish is perfect  Oh, and you can 'undo' your mistakes.

MkI still has a big role to play. I need to find the best position for the CG, tune up the sponsons and check out the prop angle. Once she's up and running sweetly, I will have the information I need to put into MkII.

One of the biggest mysteries to me is what is the best angle for the prop. The current set up has 'a bit of down'. I reckon it's about 8 degrees and that is the minimum I can get with the shaft completely straight. I have the opportunity to play around with that because I'm using a flex shaft and strut. I would rather like to use a straight (rigid) shaft in MkII. The minimum angle I would be able to achieve with that would be around 5 degrees (and that is using a very long shaft). If that turns out to bee too much then I will use a flex and strut again.

I understand that the Octura X4 props have 'medium lift'. If anyone has experience of these props and how to set them up properly, now would be a good time to share it! (Please)



 

[John W E]

 
will this be of help to you ? from the real plans of Bluebird

aye
john

[Tim_M]

Hey, thanks John! That's brilliant!

I'm using a combination of the Nexus plan, photo's in 'The Bluebird years' and photo's on line. (especially those on the Bluebird restoration project website. You drawings are a huge help. I shall download them before the internet breaks 

Rgds,

[Leovilla]

Its now approaching 20 years since I did all the development work to get the very first Touchwood K7 to work. Time goes past too quickly.(I also did the development work for the working Touchwood K4 and K3)
Having got the first K7 to work  I prepared a set of intruction to Touchwod which were sent out with the kits. Early version had a modified 540 hot motor on a geabox. I later converted it to brushless power but never got around to doing an ammended set of intructions for Touchwood however I did help a lot of people privately on lin via e mail.
The kit was too heavy and I replaced the heavy fin/seat and sponson planing wedges with my own made from lite ply. My grandson now owns the model and recently the family cat kocked it of the top shelf in his bedroom resulting in some minor damge but the sponsons remained intact due to how I built it.I have recently run it with a hot Leopard motor on 2S lipos(lighter than nim cells) and its sill very fast, much too fast for an 8 year old.
 
I have followed this thread with interest and its good to read interest is still out there.
The original sponsons on the full size boat had a chamer to reduce the wetted area. I spoke to ken Norris the designer of Bluebird 20 yeas ago and he said the chamfer idea was a mistake. After listening to him and in the knowledge we cannot scale water all my Bluebird models, including the big gas trubine one on youtube, dont have the chamfer  and I believe thats why they run well. I have 4 a various scales..
By the way. If using an Octura X series prop the shaft needs a bit of down angle and the cetre of the prop needs to be on the same horizontal plane as the rear most part of the sponson planing suface. The COG is important, about 20% of the distance between the rear part of the front planing wedge and the centre of the prop. Too far back and it will run tail heavy.
 
Cheers
Ernie Lazenby

[Tim_M]

Ernie, I'm honoured!
As the acknowledged 'guru' of K7 models and all things fast I'm delighted that you have been following the thread (and probably chuckling as you watch me stagger up the learning curve). I corresponded with you way back in 2001 or thereabouts and you offered me advice then too.

I shall continue to develop the model I have following the advice I receive on this forum, which has been invaluable and then move on to MkII (a lighter version incorporating all the modifications from the start). I plan to make that a very 'open' project from the initial design stage onwards so that others can contribute. I will follow guidance and, who knows, perhaps some of my own ideas may be of interest to others.

PS. Love the turbine job. I really don't know how you build models that good!

Thanks for your interest and best wishes,

[ooyah/2]

Tim ,
The bulges on the forward sponsons don't look too bad, in the early development of K7 there were very large bulges on the forward sponsons as shown on a pic that I have in a book when D.C. tried Lake Ullswater in 1956 and these were obviously dispensed with at future development, In Touchwoods cat there is a pic of these bulges
( http://www.touchwoodmodels.com/water-speed-record-models/1-43-bluebird-k7.html ), please keep us posted on developments.

ERNIE.
it's so good to read that you are following this K7 thread, you were such a help when I built mine especially the article in ASTEC Models.
I think it was in 2002 that we spoke at Windermere when I had my flashsteamer there, pity it didn't perform particularly well at the time but it now has a new engine but it's just too fast to run it on R/C. at 40 + mph and at 26lbs all up weight.

I do hope that you are felling much better and glad that you are in the background to advise on building and running a K7,
Keep well.
 George.

[Tim_M]

Still waiting for the new speed controller to arrive, The tracker says it's in the UK (and has been for well over a week). No doubt sitting in a customs shed somewhere.......

So, meanwhile I've started work on the design of the MkII version. I decided to re-model it from the original plans (rather than the Nexus version) at 1/8 scale and add certain adjustments to make it work as a model. No rear wedge. The sponson shoes are angled at 5 degrees and are 62mm wide at the step. These measurements may change when I see how MkI runs. The steps are set 30mm from the bottom of the hull. I think that's enough to clear non-scale ripples. I have compromised on the front booms as I want to use some 20 x 15 aluminium tube I have in the garage and it's a tad too big to go inside true scale booms. Also, I have the top of the sponsons horizontal, not sloping down. Stand off scale. If you don't like it, stand further away .

What I have so far is the 'plug' that I will carve up to create the basic frames. I think it's reasonably accurate (remembering I'm going for stand-off rather than true scale) but if anyone can see any glaring errors, now is the time to shout!

[nigeltyoung]

Hi Tim,

I have just found this topic and what a great build. I am now subscribed and looking forward to see how your K7 develops even further!

At the moment I too am building an RC 1/12 K7 and will hopefully get a heads up on running issues from your excellent reports - good luck and looking forward to more progress.

Nigel

[Tim_M]

The speed controller (Aquastar 160A water cooled), programming box and cooling jacket for the motor arrived yesterday. Yay!

Unfortunately, they didn't come with instructions. The online instructions are incomplete and in Chinglish. I've read a few reports of these things blowing up on the bench so I'm waiting for HK to clarify just what I plug into where and what I do to make the motor turn. I've found them pretty good in the past so we'll see how that goes.

I have to say the ESC looks well-made (from the outside). Good quality wires supplied as well. If it performs as well as it looks, we're on to a winner!

Lots of draws on my time this week but the water is looking closer.........

[Tim_M]

Phew! The motor's turning. No sparks, no bangs, just a drop of sweat and some palpitations as I connected the battery. I had to make a slight mechanical mod to my Rx because the plug would not fit my 40 year old JR gear. (They don't make 'em like that any more. Just as shiny as the day it was bought and it looks really classy!). I can sleep again.

So the power train is sitting on the bench, ready to go back in with new plumbing. Everything is just about ready for another trial. Am I going to get on the water this weekend? Methinks the weather has other ideas.  Never mind. My very belated birthday present from #1 daughter arrived today. An airbrush kit with compressor! Just have to learn how to use it...............

All in all, a good day.

[Tim_M]

And she's off! Bluebird has had her first run without breaking down. That doesn't mean without breakage.......

Went to the lake this morning only to find that the model yacht club were in residence. Given that they have been sailing there for 100 years or more, I thought it better not to intrude. After lunch, despite the dodgy weather (windy) we set off again.

Bluebird now has a new speed controller and the planing shoe angles reduced to 5 degrees. Straight away, the difference was obvious. No more tail dragging and the prop started to surface pierce on about two clicks of throttle. At 1/4 throttle, she was planing and at half throttle running straight, clean and smooth. And rather too fast for my liking!

I tried full throttle a couple of times and whilst the speed was impressive, the stern started to leap about a bit. Could be that I have too much 'down' on the prop or maybe it was just that the water was way too rough for high speed running. One thing is clear. I have ample power and the boat runs 'easy' now.

I still have a bit too much throw on the rudder but I can turn that back on the Tx. Most of the twitchiness is actually down to bad driving. I have the eye-hand coordination of a snake. (Which is why I gave up aero modelling many moons ago. At least with a boat you can stop to get your head sorted out). I have set the water outlet high up so I can see if the cooling is working. It isn't, so that is something to look into.

Now, the yacht club had left two marker barrels in the lake. Quite small, bright orange. You couldn't possibly hit one of those, could you? Damned thing was like a wood magnet. I clipped it once, slowly, and then went back for another go at high speed. That's gonna take some glue. I think it's the 'you go where you are looking' syndrome that causes bikers to ride into trees and horse riders to dump themselves in hedges. You should never look at the obstacles!

There's a scrappy video here: http://youtu.be/dhnnJWXCJRI

[ooyah/2]

Hi Tim,
It's good to hear that you have your K7 running true and straight, not so good that the glue bucket will have to be brought into play.
For some reason I can't access your you-tube vid, keeps saying access denied.
The pic of the boat running looks fine but the water is a bit rough and this can cause the tail dancing but please take care on rough water or it will take off at full throttle and it's imperative that you cut down rudder throw, another cause of tail dancing due to twitchy fingers.

In your thread asking advice on setting up your E.S.C. you say that the motor shuts of immediately you pull the stick down, I would leave it at that as it will act as a very efficient brake to stop the boat in emergencies, especially when heading straight for orange markers or swans !!!!!!!!!

George.

[essex2visuvesi]

Youtube Video says it is private :(

[Tim_M]

Sorry chaps,
I posted on Mayhem while the video was still uploading. It took nearly two hours!

Should be OK now; I've just viewed it.