Nor-Star Kingfisher Re-make

[Rob_P]

OK calm down this first posting is very premature.

I'm still re-designing and this is just a quick look at the potential hardware list and the enevitable trying to make it all fit.

I no longer have the original boat and I'm trying to re-design along the construction method favoured by LJ Rowell of Aerokits. The original design was pretty heavy and used 1/2" curved ply chines that I'm unable to create / get right first time around. Also the original had 1/4" thick side decks.
The re-design will feature two, 1/8" x 1/4" stringers back to back to form the chine and gunwale stringers.

The overall dims are approx 24" long, 8" beam
I'm planning on a std direct drive Graupner Speed 500 (1799) $10.50, RPM no load = 17,600, No load A = 1.5A, Stalled = 9A, Max efficiency = 66%.
Graupner single articulated UJ
Graupner prop shaft & tube (Have already checked the length).
Graupner rudder, two sizes shown on the layout, currently undecided which I will use.
I will have a go at building a water cooling set up for this one.
Battery power will be from six sub C cells configured as two 3 cell packs for ease of install. Maybe 3600mA.

I'm still not happy with the spacing around the motor as currently its pretty hard up against the forward bulkhead, also I have had to excavate a fair amount of the keel in order to make the hardware fit. At the moment Im looking at the front bulkhead and wondering if I should cut a big opening in it. While that would dramatically improve access. Its a lost potential air pocket that could keep the hull afloat in the event of a problem.

Rob

[toesup]

Nice looking boat there Rob.... :)

Something that strikes me... If you are working in CAD, have you tried enlarging the model to make fitting the motor / other bits in a little easier?.

As long as the model has a 'keel' of some type around the motor area (could you laminate some ply 'locally' below the motor mount?) i dont think lowering the motor in the boat would be a problem. It would certainly help to lower the C of G and get a better angle on the tube.
Would a flexible tube drive shaft be any advantage?.

The rudder looks really BIG!.... :eek:

Looking forwards to seeing more of this one come together... I think others on here like the look of that 'style' boat too... ;)

[toesup]

I've just had another thought Rob... :o

Would turning the motor round, so its facing forwards above the shaft / tube and going a 1:1 gear / belt drive give you more room?..
Thinking something along the lines of the motor / shaft arrangement in Mustang Sally...
http://www.rcgroups.com/forums/attachment.php?attachmentid=1411701

Would a 'Jet' drive fit?... :eek:

[Rex R]

of late I've been thinking that a wire drive* would be useful for solving some of the straight shaft headaches and yet still allow reverse.
*uses a piece of 1/16" music wire for the shaft.

[Rob_P]

Toes / Rex,

Thanks for your input. I find this all a bit of a compromise. While I'm pleasantly suprised by the "excess performance" of the FPB, I have learned that maybe 10 cells were over the top weight wise, hence I want to come down to a less volt hungry motor. Also following the feedback it was thought a Speed 400 may not have enough power & a Speed 600 would be too heavy and phyically even more of a struggle to fit.
The g/box on the FPB moved the motor weight too far forward. Hence I'm staying with a Speed 500 on only 6 cells and direct drive.

As it turns out the spare prop tube I have is pretty much the exact length for what I need.

If I go bigger, the boat will be heavier & I'll need a new prop tube, based on that I'm thinking of proceeding as designed.

I have just picked up some 1/4" x 1/8" spruce and I'm pleased with how flexible it is.

Rob

[toesup]

I have just picked up some 1/4" x 1/8" spruce and I'm pleased with how flexible it is.


As long as you wet it and clamp it down so it takes the twist of the chines Rob.. ;)

[Rex R]

not trying to push you into it...but a 380 size inrunner would sit further down in the vee :)(something in the 2400-3000kv range). course that might be a tad pricy for your tastes

[Rob_P]

Here we go.....

Lets hope the build is a little quicker than the FPB.

Rob

[toesup]

Here we go.....

That looks like a very good start Rob..

I shall be keeping an 'eye' on this thread for sure...

Any ideas on color scheme yet??... :p

[Rob_P]

Toes,

The colour scheme on the original box lid was, red decks, white sides & red below the waterline. They also had the name KINGFISHER in black lettering on the sides.

Mine was pretty similar but on the sides I had a race number and a Union Jack just ahead of the transom.

No firm plans yet for painting this one but I was thinking red below the water line and gloss white all over. Perhaps Callie could do me a race number, some flames and a Union Jack for the sides but thats a long way off.

Rob

[mr.boat]

Rob P,
when do you take a break? you've just finished one and started another straight away. Definitely keeping busy

[Rob_P]

Mr Boat,
Take a break? with two children (4) & (2) I have more workshop time after they have gone to bed than free time to go and sail the boat.
Perhaps that will change when they get older?

Progress so far, both gunwale stringers in place. While the method of building inverted on a board means its relatively easy to build a straight / square model, the down side is that you don't get to clean up the excess glue until the model is removed from the board. Ugh! Nasty.
I glued the chine stringer to the bow of the keel and B1, then while pulling them round to B2 got scared and quickly cut and inserted some gussets to the back of the chine stringer to help prevent them pulling away from the bow.
Currently glueing the inner chine to B3. Temporary clamps hold the chine to the transom.

While building the FPB, on one location, I got into a bit of trouble as I had not left enough depth on the keel to butt the bottom skins into. With this in mind I added some extra depth to the keel for this one. Looks like I have gone over the top and will have plenty of triming back to do.

[toesup]

While the method of building inverted on a board means its relatively easy to build a straight / square model, the down side is that you don't get to clean up the excess glue until the model is removed from the board. Ugh! Nasty.
I glued the chine stringer to the bow of the keel and B1, then while pulling them round to B2 got scared and quickly cut and inserted some gussets to the back of the chine stringer to help prevent them pulling away from the bow.

With this in mind I added some extra depth to the keel for this one. Looks like I have gone over the top and will have plenty of triming back to do.

Ahhhhh.. thats where you learn not to use too much glue Rob. Just a dab of CA will hold the pieces together until the hull is released from the board, then go round all the joints with the CA again to give some 'glue fillets'.. ;)

With some wetting and clamping down prior to glueing, the chine stringers should take the shape quite easily.. If they wont take the shape as you glue from the bow backwards, just wet them, clamp and let them dry. You could even wet them again now they are in to take out some of the 'stress' in the shape.
By the way, is it the angle of the pic or does the chine stringer 'starved horse' between B1 and B2? (at B2) ...

The extra depth to the keel is a good idea. Even though it means some work after the skins are on, at least you have something to butt up the skins to. I made the same error on the Sea Nymph... but not on the Hornet ;)

[Rob_P]

CA - I'd heard a rumour that it was not 100% waterproof. I use it while building aircraft but I'm not a fan of the stuff. I don't like the fumes.

I'm not sure what you mean by a "starved horse".
What has happened is that I ran the chine straight between the bow and B1. Between B1 and B2 the chine starts to curve outward and rise up to B3.
I'll admit it does not look good but we cant judge until the second stringer is on and its all sanded.

[Rob_P]

Well the chines are on and 99% sanded and I ran into a problem.

Where the chines run into the bow, the edges onto which to glue the bottom skins were very narrow. As a result I imagine that trying to glue a skin to it sucessfully would be difficult.

I looked at adding an additional strip of material below the chine to allow the width of the joint face to be widened but in the end opted just to block fill.

Not ideal and I will still apply a skin over the block.

When it comes to fitting the skins what is the preferred method, sides skins first followed by the botoms or vice versa?

[Aerominded]

Sides first, bottoms second- (either way, works though!) then use a small plane to trim the edges... that would be my vote! :)

your block solution should work fine! :) Looking good!

[toesup]

Sides first, bottoms second- (either way, works though!)

Either way Rob, my prefered method is bottom, sides, top....

I would of gone the Rowell way at the bow, run the bottom skins up to B1, add the sides and then block in the bow area.
Your way should work, but possibly going sides first may give you more area to glue the bottom on to?... :confused:

[Rob_P]

I was able to pick up some supplies this morning from my LHS including some hardware for the water cooling.
I was a bit suprised regarding the design of the water scoop, in that the tube is straight down and not cranked forward at the inlet. I hope Octura know what they are doing.

Also picked up some brass tube to make the cooling coil 5/32"(3.97mm) x 0.14 (0.355mm). I'm hopefull that it will be a close enough match to the inlet and outlet connections.

[Rob_P]

Provisional hardware install and alignment.

[Rob_P]

Home wound cooling coil.
May try and tighten them up a bit later.
I stopped the coil short so I didn't block the vent in the can.

[Rob_P]

Progress to date:
Side and bottom skins added to the hull & provisional sand.
The oversize depth of the keel center member proved to be a very usefull feature for setting up clamps while glueing the bottom skins in place.
Next steps rather than just run my normal bead of resin to form a fillet on the internal seams, I'm planning to add glass fiber strip over the seams to re-inforce the joints. This is not because I have had a problem with previous builds, I'm just curious to see how it will turn out.

I will do the internal glass fibre before trimming back the keel.

[HS93]

Its looking great as usual Rob takes me back , Just a quick question when that kit came out where the chines made of ply, its just that I dug my old NOR STAR crash tender out the othere day and when looking inside it came back to me that they where plywood about 5/16 thick and cut on a band saw , unlike the old Aerokits. but it made the building dead easy.anyway hope to see this going soon

Peter

[Rob_P]

Peter,
You are quite correct, the thick ply chines is how the Kingfisher was designed too.

There are a few reasons why I opted for the stringer method:
* Trying to get the curvature right could be tricky.
* The cost of the wood for the chine. It was pretty thick & due to the curvature would need to come out of a fairly large piece.

If I wanted to make "easier" to assemble kits then the pre curved chine would be the way to go. So far I'm quite happy with the way my light weight solution worked out for me.

Rob

[Rob_P]

Update, I have given it much thought and I'm coming down in favour of giving the glass fibre a miss. I fear that things could get ugly pretty quickly plus the fact its electric & should not be too highly stressed.

I have added some stools to the rear section to support my radio plate.

I applied tape to protect the future joint faces and applied three coats of fuel proof to the inside of the hull. I did it now because when the cockpit sides are its going to be more difficult to reach all areas.

The keel has been provisionally planed / sanded down. I have left a little taper up toward the prop tube.

Once again Its apparant that during fitting the bottom skins there was approx a 1/32" gap in places between the edge of the skin and the side of the central keel former. Rather than fill with "wood filler", I prefer to use 15 min epoxy glue. I apply tape to each edge of the "crack" then knife the glue over the tape to fill the crack. After a few mins but before the glue has cured, remove the tape and viola ! the crack is filled with resin
and no mess.

Rob

[Rob_P]

Update:
The cut out in B2 had been boxed in so that I get an extra 1/4" + 1/8" of depth behind the motor. This will make connecting to the motor terminals much easier. I decided to fill in the opening to gain an extra air tight bulkhead just in case the worst happens.
Working on the cockpit sides I added locators for the bench seat and the dashboard.
The cockpit sides have been glued in place along with the side deck support strips.
Also fitted is the curved tops to bulkhead 2 & 3. The former at the back of the hatch has also been fixed.

[toesup]

Thats beggining to look nice Rob!.. :)

Do you think the construction method works for this boat?... and would work well for other boats too?..

[Rob_P]

Ralph,

Its all falling together very easily especially after I tried your trick of cutting the bulkheads with flat tops to allow it to be built upside down on a board. For a hull with side and bottom skins its such an easy construction method I would be reluctant to try any thing else.

Currently fitting the deck side skins and building the rear hatch.

The scary job will be the front deck which needs to butt up to the back edge of the dashboard. I can see that I will be doing a lot of fine tuning on the radius tops for B1 & B2 to get good alignment.

Rob

[Rob_P]

Preparing to attach the bow deck.

I will need to take apart the rear hatch cover for some reason its not sitting down properly on one corner.

[Aerominded]

Very nice! :)

[Rob_P]

Aero,
Thanks for your comments. I really do feel like the photos are very hard on the model. To the naked eye the resin beads and a lot of the glue marks are hardly visible. Its such a shock to see them stand out so much in the pictures.

Rob

[Aerominded]

I know exactly what you mean, Rob, re: photos! :) Your boat does look great! :)

[toesup]

I really do feel like the photos are very hard on the model.

I know what you mean there Rob, especially as the wood / ply is soooooo white. I always reduce the scale of the pics so you cant see the :censored: up's... :o

Looking nice though... :)

[Rob_P]

Bow deck fitted and provisional sand. Its starting to look how I remeber it now, which is a good thing.

Still need to work on the rear hatch to make it sit properly and fit the stern deck

[nick_75au]

I always reduce the scale of the pics so you cant see the :censored: up's... :o

His Secret is revealed :p

Rob, looking good :cool:

Nick

[Rob_P]

I'm just back from a trip to Fl, hence no progress last week.

Before I went away I was able to attach the front window frame, Fix the rear hatch so that it sits properly, build the rear deck and attach a finishing skin to the transom.

Next jobs will be 1/8 x 1/4 rub rails and 1/8 x 1/8 spray rails full length of the chines.

[Rob_P]

I'm in the process of adding 1/8 x 1/8 spray rails along the full length of the chine and I have a question.

Should the rails be sanded to match the angle of the bottom skins?

Due to the angle of the side skins, the outer corner of the rail projects down below the bottom skin and due to the shape of the hull I imagine that this may produce turbulence and drag.

Any comments?

Hand sketch to illustrate my point.

[toesup]

I'm in the process of adding 1/8 x 1/8 spray rails along the full length of the chine and I have a question.

Should the rails be sanded to match the angle of the bottom skins?


At the bow i would leave the rails 'full' and square... as the rails progress towards the stern, sand them in to match the angle of the bottom skins..

Like i did on the 'Huntress' (Nymph) build.

Bow:
http://www.rcgroups.com/forums/attachment.php?attachmentid=1859300

Stern:
http://www.rcgroups.com/forums/attachment.php?attachmentid=1859302

Its coming together nicely by the way Rob, looking good! :)

[Rob_P]

Ralph,

Thanks for the comments, your response makes sence but I'll take a look at how much meat I'll have left. I suspect in some areas they could be left pretty thin. If I already knew where the water line crossed the spray rail at the bow I'd be a lot happier.

You are right, I think its looking quite quite sporty and so far has been a pretty easy build.

Rob

[toesup]

Thanks for the comments, your response makes sence but I'll take a look at how much meat I'll have left. I suspect in some areas they could be left pretty thin.

I think you will find that with the 'twist' in the spray rails as they follow the chine, you wont have to sand away that much as you get towards the stern.

[Rob_P]

Latest pics of work in progress.
Chine spray rails & gunwale rub rails added.
Decided against the mast on the rear deck but added some exhaust pipes instead.
Have made some drop in seats.
Cooling water outlet added, (not shown).
Its getting close to paint time, but there is still a fair amount of clean up to do & I still need to do something with the dashboard.

Rob

[toesup]

Cooooooooo.. that looks real nice Rob!.. :D

Those spray rails worked out ok... ;)

[Rob_P]

Toes,
Thanks for the comments.

I did as you suggested regarding the spray rails and I'm very happy with the results, thank you for your assistance.
I think my exhausts are a bit over the top, they will be framed in the boat colour and the base plate by the pipe outlets will be matt black.
I picked up a really nice Bosch key chain at a trade show which is in fact a steering wheel. Its perfect scale for the boat but just too heavy to mount high up on one side. Not quite sure what to do, I doubt if I'd be able to do a decent job replicating lighter version in ply.

Toes - What are you working on?

Rob

[toesup]

I picked up a really nice Bosch key chain at a trade show which is in fact a steering wheel. Its perfect scale for the boat but just too heavy to mount high up on one side. Not quite sure what to do, I doubt if I'd be able to do a decent job replicating lighter version in ply.

Toes - What are you working on?

Have a look at some of the lightweight wheels in the LHS.. something to do with air-planes i think ;) they can be altered to look like steering wheels..

Me?..
Oh.. a barge for the Springers http://www.rcgroups.com/forums/showthread.php?t=958022
a Springer to finish and gearing up for a 'scale' build...

I also fancy a tug / speedboat crossover... hmmmm :rolleyes:

[Rob_P]

Almost a month since the last update and not much progress to report.
I have purchased an Mtronics 25A Maribe Viper ESC and have a set of (6) 3500mA sub c cells on the way. Hopefully they will be here sometime next week.
The boat was covered in three coats of white epoxy primer but that is gradually disappearing as I wet sand with a 320 grit pad.
I have not done a thing yet regarding radio install but that should be fairly straight forward. The only pain is that rather than have one six cell pack it will be made up of two three cell packs enabling me to get the weight further back.
I will hold off painting the hull until I do a float test with the cells to work out where the waterline will be.
Rob

[Rob_P]

Well the rush is off on this one as the pond is frozen and will be for some time.

I am proceeding with the hardware install. Rather than buy a standard 6 cell pack, I built my own. The object was to get the weight towards the back of the boat and the easiest way to do this was to split the pack into two, three cell packs.

The Rx and ESC are located on the radio board and framed for a snug fit. The board is cut away below the components to aid ventilation. Now the install is near complete its looking llike the c of g is at 36% when measured from the tip of the transom.

Next steps will be to finish the sanding and then drop it in the bath tub to establish a water line for final paint.

[Aerominded]

Nice installation, Rob! :)

[Rob_P]

Thanks Aero ! It could be cleaned up a little more but its always a compromise. Neat wires tend to be too short for easy maintenance.

After the performance of my Fast Patrol boat, I wonder if I have cheaped out too much on this one as its a Speed 500 on only a six cell pack. I have already assembled a collection of four fast "X" type two blade props to try and gain the best performance.
The sizes are 32.5mm, 42.5mm, 47.5mm and 50mm diameters.

[toesup]

Nice and neat there Rob... :)

Are you going to watercool the ESC too?..

[Rob_P]

Toes,
This has always been a mystery to me.
So far my two other boats have each used the oversized 40A Mtronics and it does not even get warm. This time I'm direct drive and only using a 25A ESC so I expect it will get warmer.
I may try and hook up my wattmeter and run it in the bath tub (holding onto it) and see what current I'm drawing on each of the props. Not accurate but an indication of how close I am to the 25A.

[Rob_P]

The painting is near complete now. It would have been quite a bit sooner but originally I painted the foredeck red and it didn't look right. So it took a lot of wet sanding and re-painting to bring the colour back to white.
Its all brush painted with Nelsons epoxy.
The remaining tasks include getting some custom cut decals from Callie, re-installing the hardware and windows

I also want to do an instrument panel and may get around to that later on today. I have also made a steering wheel but will have to review how much it will obscure the motor fixing screws.

When it comes to installing the water inlet and rudder tube, is it the norm just to bolt them up in place? On my other boats I have always epoxied in place.
Rob

[Rob_P]

Decals added

[toesup]

Decals added

Its looking the 'part' now Rob...

[Rob_P]

Thanks Toes,
Still a few little jobs to sort out:
Another rub down and coat of clear.
Maybe paint over the brass water outlet.
Locate the ariel / antenna,
Glazing.
Not happy with the motor mount screws, I may change.

But apart from that... and the weather..... its nearly there.

Rob

[Aerominded]

WOW!!! She looks great! Very sporty paint scheme!!! :) Looking forward to warmer weather in Grosse Pointe so we can see her in the water! :)

Nice Job! :D

[Rob_P]

Thanks Aero, hope the warmer wearther comes soon. We had another 2-3" of snow today.

I'm very keen to see how it performs.

Perhaps a better name would have been "Signal 2"..... :^)

I'm already planning my next build...

Ron

[toesup]

Perhaps a better name would have been "Signal 2"..... :^)



LOL at "Signal 2"... I wonder if the US readers get that Rob.. :rolleyes:

[Aerominded]

LOL at "Signal 2"... I wonder if the US readers get that Rob.. :rolleyes:

Hee hee, it is not "computing" with this US reader! ;)

I do like the colo(u)rs though! :)

[toesup]

Hee hee, it is not "computing" with this US reader! ;)

I do like the colo(u)rs though! :)

It's to do with the colo(u)rs Mr Aero..
http://www.scienceandsociety.co.uk/results.asp?image=10318768

[Rob_P]

Thats right, when you squeeze a tube of Signal 2 toothpaste it emerges from the tube as white with red stripes...
I think they used a special nozzle & a tube within a tube to keep the red and white paste separate.

[Rob_P]

First test

[toesup]

First test

Well?... and?...

C'mon Rob... we need a 'report' as well as the nice pics... :D

[Rob_P]

Toes,

Sorry no time yesterday to write any notes.
All in all it was sucessful and I was happy with the outcome. It was realtively lively, stable in tight turns and got onto a plane easily.
I did screw up regarding prop selection. I bought a few two blade types in the 40mm range but I did have one at 32mm dia and this was the best of the group. My next size up was a 40mm but it did not rev out well so I assume the current loading was higher. I will see if I can get any more props in the 30mm size range and see what else I can squeeze out of it.
I do have to remind myself that unlike my Fast patrol Launch, this is only a 6 cell.

Something else I did was fabricate up a little lite ply Tranmission console. This simply straddles the keel over the UJ. The UJ is in line with the side windows and I had maybe applied too much lube to my proptube as the grease was leaving a black spray line on the inside of the hull. My little console prevents any of the clean parts getting sprayed with grease.

Rob