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[mrzippy]

Hope you guys are up to speed with your Tx sticks !  Lol.
you have serious horse power in this model, way more than its earlier ic. incarnation, I suspect its going to fly - literally !!

My 33" Swordsman's brushless is a fraction of the size and power of your Javelin's motor, yet easily faster than its original 40 glow -
it managed to eat a stock prop tube's plain brass bearings after a couple of runs,
replaced with a race spec ball raced top end, lead teflon bottom end version which seems ok to date.

Paul

[Stuw]

Bob,


Thanks for that guidance for the rubbing strip repair. I did utter a few choice words but in the grand scheme of work to be done it’s minor!


Paul,


Thanks for the info. I am only planning to run this on 2S but have 2 batteries to offer endurance. At 1900kV that should give me about 14000 rpm no load and I’ll likely limit max output via the Tx. As my mount base will be screwed into the bracing ribs, it will be removable. Should this power plant prove too much, I’ll probably swap it out for an outrunner of lower kV. I’m planning to use a 5mm shaft with brass bearings only so I won’t go higher on the rpm (to start with  )


Regarding your Swordsman, I take it that’s the one that won an award on another thread on here? Looks great! Very tidy and neat inside. Did you use white plastic for caulk effect and use cherry on the deck (I’ve read it somewhere on here I think?) Getting ideas for another build but have never planked.

[zooma]

Hope you guys are up to speed with your Tx sticks !  Lol.
you have serious horse power in this model, way more than its earlier ic. incarnation, I suspect its going to fly - literally !!

My 33" Swordsman's brushless is a fraction of the size and power of your Javelin's motor, yet easily faster than its original 40 glow -
it managed to eat a stock prop tube's plain brass bearings after a couple of runs,
replaced with a race spec ball raced top end, lead teflon bottom end version which seems ok to date.

Paul

 


Hi Paul,

I have been running Rapier1 (same hull as the Javelin) with similar power (maybe more?) for over a year now, it is good and fast but I have had no problems running it with a plain bearing M5 shaft.

The shaft was taken out at the end of last season and checked to find that it had zero wear - no play whatsoever.  I was surprised and (almost) disappointed as I have two sets of spare M5 bearings ready to drift in and use if the originals start to show any signs of play.

The shaft was put back into the tube with some fresh flexi-shaft type marine grease and I will check it again at the end of another seasons running.

The only problems I have had with premature wear on a plain bearing shaft is when running the smaller M4 size of shaft and not using a good quality marine grease to make sure it is never allowed to run dry.

The smaller M4 shaft can "whip" when given too much power and this can also cause accentuated bearing wear.   The same problem can occur when using an over-long shaft and is why I never have any excess shaft inside the engine bay.

A ball-raced shaft needs checking carefully if it is being used with a high speed brushless motor.  I prefer to use a good quality plain bearings M5 shaft for this purpose - every time!

My fast craft that run with flexi-shafts need to be stripped and re-greased after ever session.
 
Using an M5 stainless steel shaft with plain phosphor bronze bearings should be safe (when kept clean and lubricated with the correct type of marine grease) for use with the fast brushless motors that we are using (or going to use) in our Javelin hulls.

I hope to be running my Aerokits Swordsman later this year with this same sort of brushless power and a plain bearing M5 shaft.  The Rapier is a bigger boat, so I will check to make sure I only use as much power as I need in the Swordsman.

Stay safe,

Bob.

[zooma]

I managed to finish making the replacement front hatch cover last night, and the fit is not too bad, so I just need to trim the side over-hang on both of the new hatch covers and they should look a little better than the ones that came with the model when I bought it.

Thinking a bit more about the prop shafts, I remember replacing a ball race on a prop shaft many years ago and was pleasantly surprised at the choice and wide variety of optional replacement bearings.

The variety of available high speed bearings and different types of "zero friction" shielding etc from specialist bearing suppliers was quite an eye opener and should make it possible to fit a bearing that is more than capable of handling our brushless motors if the original bearing should suffer from any wear.

Maybe currently available ball-raced prop shafts come with high speed bearings as standard?

[mrzippy]

Good to hear you are fully aware of any transmission issues, as Bob rightly states mine suffered shaft whip.
To add some background history if I may - the model was a new build way back in 2009 as an experiment into brushless in a boat,
outrunners becoming common place in aero's, but shrouded in mystery - we weren't aware of KV's? etc and only used Nimh's,
Lipo's were considered a black art and were to be avoided at all costs they might expolde !!

I jumped in blissfully unaware with what seemed huge at the time, a purple Overlander Thumper 42x50 600kv, using 2 packs of 7 cell Nimh's,
Graupner 40/42mm 2 blade race props and it was a huge dissapointment - no speed due to lack of revs.
I was advised to fit the biggest 4 blade Prop Shop brass steam prop I could squeeze in, a 50mm and it made a huge difference,
the outrunner having lots of torque to swing a chunky prop.

Realising more revs were required (inrunners weren't around in those days) I ftted a 42x40 1050kv outrunner and this made a huge difference,
equally as quick as a my old OS40 glow Swordsman, and this was the (tiny motor by modern standards) motor that blew the bearings -
hence my concerns for the beasts you guys are now fitting.

I did eventually work out my original 42x50 600kv outrunner produced just over 1hp,
the hot OS40 on a pipe would just about manage .8hp, I dread to think how much power you guys are packing into your Javelins?
its giving me ideas about electrifying my old ic. 40" offshore Gancia that's very similar to a Javelin.

Stuw re planking - Swordsman's cherry with white holly caulking and 1.5x Sea Hornet is spruce with white plastic,
I recommend going all wood because plastic strips will not sand easily and require scrapping with a cabinet scraper (large snap off knife blade)
to make them flush.
You spend hours sanding away to a nice level surface, pause and the plastic seems to spring back up above the surrounding timber !
please ask any questions, happy to pass on my experiences.

regards Paul

[zooma]

Hi Paul,

Thanks for sharing your experiences of powering your Swordsman with brushless motors and for making the comparison with the same model when it was powered by your OS40.  I also ran an Aerokits Swordsman with an OS40 Marine for a while before switching to a Merco 61 (twin plug) Blackhead but to be honest the OS 40 was a really good performer and it ran nicely too!

I found your thread really interesting to read as the only (very limited) knowledge that I have with brushless motors has been gained from using them in my own models and by observing how well others have performed (or failed to perform) in their r/c boats.

My previous experience with ic engines is remembered fondly,  and although I wish that it was still possible to run ic powered boats just about anywhere (as we were able to do "in the good old days"),  I have to admit that running r/c boats with the latest generation of brushless motors is a lot less hassle, and we suffer from no loss of performance!

You were one of the "pioneers" of running brushless motors in r/c model boats and so your early  experiences with your Swordsman are well worth sharing here.....and your Gancia is only an inch longer that a Javelin so it would be good to compare results if you do decide to re-fit it and get it going under brushless power!

Enjoy your weekend,

Bob.

[tonyH]

Front Hatch stuff......

[Stuw]

Paul,


Thanks for all that info on your pioneering brushless power. Also for the info on planking. I’ve got ideas for a future project so may well PM you in the future if that’s ok?


Bob,


Your front hatch looks a great fit. 


Meanwhile back in my workshop, I’ve been slowly progressing with the motor mount. To allow the motor and it’s water cooled mounting to be completely removable (should I deem it too overpowered) I have added some M4 marine stainless bolts into threaded inserts.  Once the brace ribs are bonded in and the motor mount bonded to its 9mm ply baseplate, I can still unscrew the 4 bolts and remove the motor quite quickly.


I am also deciding to beef up the rudder tube support by adding some ply blocks. Made out of some offcuts of my 12mm brace rib wood.


None of it bonded in but making steady progress.

[zooma]

Stuw - your Javelin will be Nukeproof by the time you have finished reinforcing it so substantially.


Even the rudder shaft should be able to withstand a first wave strike 

[Stuw]

Indeed     Thanks for pointing me towards the chunky plywood. I’m getting a bit carried away with it!

[zooma]

Indeed     Thanks for pointing me towards the chunky plywood. I’m getting a bit carried away with it!

You might need somebody to help you carry the boat if you get too carried away with the use of heavy weight ply reinforcement 


.........it does look good though........

[Stuw]

A bit more progress over the last couple of days. 


Managed to bond in the brace ribs for the LIPO tray and then once set, removed the tray and built the side supports.
Bonded in the supports for the ESC and rudder servo mount.
Once dry removed servo plate and cut hole for servo.
Rudder support sanded and chamfered slightly and then glued in.
Rudder servo in and linkages set up
Rudder travel limited to about 30 degrees for the moment


Placed an order for some more birch ply of various thicknesses for the hatch covers and replacement rubbing strip section. As the delivery cost was quite high I decided to order a load more for Javelin 2! (Hot off the press - Javelin 2 may become a Rapier!!)

[zooma]

Another Rapier ?

That will be cool - a new member of the Rapier fleet will be very welcome and nice to see. 


There were a lot of Javelins sold, and the breed continued under the Streaker name, but not so many Rapiers were ever sold and so it did not have its production continued in the same way.

[zooma]

I finally finished making both the replacement front and rear hatch covers yesterday and the fit is not too bad - well a little  better than the under-sized ones that came with it - but they were beautifully painted - and mine probably won't be!

I am not sure whether to add any air intake scoops to the front hatch cover (or cab sides) and ventilation slots or louvers to the rear cover.......or just leave them plain?

Maybe I should take a look at some pictures of some real off-shore powerboats from the 1960-70 time period and see if I can pick up any ideas from them?

Some Javelin models have lumps on the rear hatch (not sure what these are supposed to be) and a large central scoop on the front hatch. The front scoop that was fitted to this one looked OK and had the inlet vents on the sides (rather than open at the front) to help prevent any unwanted water getting scooped up in rough water.

I don't think I need any working air intakes with the water-cooled brushless motor mounts and w/c ESC - but they may look better than leaving the hatch covers plain.

[tonyH]

Hatches complete!

[Stuw]

I finally finished making both the replacement front and rear hatch covers yesterday and the fit is not too bad - well a little  better than the under-sized ones that came with it - but they were beautifully painted - and mine probably won't be!

I am not sure whether to add any air intake scoops to the front hatch cover (or cab sides) and ventilation slots or louvers to the rear cover.......or just leave them plain?

Maybe I should take a look at some pictures of some real off-shore powerboats from the 1960-70 time period and see if I can pick up any ideas from them?

Some Javelin models have lumps on the rear hatch (not sure what these are supposed to be) and a large central scoop on the front hatch. The front scoop that was fitted to this one looked OK and had the inlet vents on the sides (rather than open at the front) to help prevent any unwanted water getting scooped up in rough water.

I don't think I need any working air intakes with the water-cooled brushless motor mounts and w/c ESC - but they may look better than leaving the hatch covers plain.

They look a very good fit to me.


The rear lumps are dummy vents for an engine in the rear I’m guessing. The are streamlined at the front but just solid blocks of wood. They also feature on the Lesro Arrow where some have reversed them to make them intakes. On my version as per the box art photo they are solid dummies.


When I was in the early stages of thinking about what to do with my restoration I thought about emulating something like the attached photo. The vents are more shaped. Was thinking of highlighting them with trim tape or similar.

The front hatch intake was open to let air into my engine bay. I did however drill an exit hole for my exhaust on the side and opened up the front cabin to get more air in for my modified glow motor. Never had any water in there from memory as the bow was up at speed!


I like the dummy vents as they add a little feature to the shape but too much detail would be lost once they are moving at speed!

[zooma]

This evening I have been trying to work out the best route for the water cooling system in the Javelin.

The water outlet that was fitted in the old hull when I bought it was mounted very high (just under the deck) and the previous owner had cut the plastic water tube off more or less in line with the end of the brass outlet pipe before he sold it so I needed to remove it and fit a new longer length - or that is what I thought I would be able to do!

As this part of the hull is hidden behind the inside wall that runs between the bulkheads, it was almost impossible to reach up inside to touch the remains of the pipe and tube  - never mind pull it off of the nipple and fit a new length of tubing to connect from the water-cooled motor mount!

The solution was to drill the old brass outlet tube out and plug the hole with some tight fitting dowel.

A small section of the inside wall was cut away so that I could reach inside to bond the dowel plug in place.  A new outlet position was then drilled in the more normal (mid hull side) position and the cut-away was shaped to make it easy to fit or remove any water tubing to a new outlet nipple in the future!

This job took far longer than it should have done as I spent far too long trying to pull the old length of tube off of the outlet pipe whilst reaching in-between the side skin and the inner wall before I gave up and realised that it would be far better to make this outlet pipe easy to access in the future by chopping out a small section of the inner side wall.

Some jobs just eat up the hours  - one of the joys of restoring old boats!

[ChrisF]

Not only when restoring old boats but when building new ones as well Bob!

Chris

[tonyH]

Water, water everywhere........except where you want it

[zooma]

The first picture shows the original high position of the water outlet - I couldn't reach up in-between the side wall and the side skin enough to remove the old tube and fit a new length so I plugged it and drilled a new one a little lower and a bit easier to get to.


The new cut-out in the inner side wall allows easy access to the new position water outlet and gave me enough space to plug up the original hole too.

[zooma]

I had an old tin of Leyland non-drip gloss paint in a nice bright red colour that had been lurking in the garage for at least a few years, and it still had some paint left inside it, so last night I decided to paint the inner surfaces of the hatch and cockpit openings with it as I thought it may look OK.

I got carried away...the next thing I know is that I started to paint the cabin...and then the decks....and then the hull sides.......so now I have a red boat!

The initial thought was that this was only some old paint (and the tin had been opened many years ago), so it would make a nice first gloss coat over the pink undercoat that could be rubbed-down when dry - ready to give it a nice finish with some decent paint!

As I was painting the hull some of the paint came out a bit thicker than it should (old paint!) and it took a bit more brush work to smooth this jelly-like paint out enough to look less lumpy.  At that stage I wish I hadn't started!

This morning I was half afraid to go out to the shed (workshop) and see what I had done!

As I (somewhat apprehensively)  looked around the door, the boat did not look anything like as bad as I expected it to look, and as I checked it over it really was not "too bad", so I think I will leave it until after the initial water testing is completed and see what I think about it then.  This delay will also give the paint plenty of time to harden-up so I can sand it back with fine sandpaper (or wet and dry paper perhaps) to improve the surface.....

I did note that the the instructions on the tin suggested that this paint should not be stirred - so I didnt.....but it is old paint so maybe I should have given it a good stirring, and perhaps that would have also mixed-in the thicker paint that I scooped-up on the brush from time to time?

This is a nice bright coloured paint and I think it could look good on the Javelin, so another thought that I have it that maybe I could add a little white spirit to "refresh" this old paint little and after a good stirring it may be good enough to use again.

Has anyone had any success in trying to revive old non-drip gloss paint in this way?

[zooma]

As a change from the Turnigy 3648-1459 out-runner that I have been using in Rapier1 (same hull as the Javelin) I would like to try a Surpass in-runner as I have been very impressed with the performance of the ProBoats that run with in-runners and I would like to see how well an in-runner (with a comparable diameter can to the Turnigy) would perform in my Javelin hull.

I have a choice of three different Surpass in-runners and any advice from users of in-runners like these would be appreciated.  I am using a standard size alloy water-cooled motor mount, so changing from one type to another (including out-runners to in-runners) would not require any changes to the hull or the mountings.

The power from the Turnigy out-runner is very impressive but the run times are about 7 minutes from a 5500mah 55C 2 cell pack, and I would like to see if I can get a reasonable performance from an in-runner but with an improved run time.

The following 36 series Surpass in-runner choices are available for me to try:-

Surpass 3764 - 1580KV.
Surpass 3764 - 1900KV.
Surpass 3764 - 2250KV.

I have found that there is very little performance difference when using S55, X55, S50 or X50 propellers on the Turnigy 3648-1450 motor, but guess that an in-runner could be a little more sensitive to prop changes due to not having so much torque?

Any advice from those that have run comparable in-runners in hulls this sort of size (39") would be appreciated.

[tonyH]

Sorry about the delay!

[canabus]

Hi Zooma


The 3648-1450kv works better on 3S and is a beast on 4S !!!
Try series up the 2S batteries if the ESC can handle it and drop to a 40mm prop to start with.


Canabus

[Stuw]

Hey Bob that’s distinctive red paint! If I got my finger out and finished my Javelin I could give you some useful data on the inrunner that I have at 1900kV!