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[tonyH]

Sorry Bob! I think you may have got the one I had that Steve exchanged for me, thankfully very quickly. Yes, the replacement is spot on!

[zooma]

Sorry Bob! I think you may have got the one I had that Steve exchanged for me, thankfully very quickly. Yes, the replacement is spot on!

Nah - Steve wouldn't  send out a returned item knowing it to be defective........but I do know that you only said that to try and wind me up   .......and further added to the story by letting me know that the replacement that you received was spot on 


I called Steve this afternoon and he offered to replace my Micro Flex coupling straight away, and this time I have asked for both ends of the coupling to be plain bored with no thread in either end as I suspect that this may be a potentially better way to ensure accurate alignment?


As usual, Steve was "on the ball" and said he would make the replacement straight away this afternoon and get it in the post to me.


You cant get a better service then that !  I am very pleased 

[tonyH]

Curses, foiled again Moriarty!

[zooma]

The replacement MicroFlex coupling bored 5mm at the motor shaft end and bored 4mm at the prop shaft end arrived from Steve this morning. It has been fitted into the boat and it looks good.

I also fitted a better steering arm to the rudder (bought previously from modelboatbits) and adjusted the ESC so everything is now ready to go.

Remora will be given her first "wet test" on the lake at Southport this week and if all goes well the motor, coupling, ESC and steering servo will be stripped out of it next week so the inside of the hull can be painted.

Progress at last for this slow build Remora.   

[tonyH]

Gulf colours .....with an attitude problem!

[zooma]

Tony - your mention of Gulf Colours has given me a thought.


I could cover the French Blue with a paler shade of blue and see what that looks like?


Failing that, I could be drifting back towards the “in house” red/white/black colours again , but a change would be nice if I can find some colours that work for the model.

[zooma]

………and maybe some strakes would look good too………..

[zooma]

Remora was taken to the Southport club lake today and everything worked OK but produced a couple of snags that I need to take care of.
Firstly the boats performance (speed wise) could best be described as “adequate”. My wife thought it was “rather sweet” and actually had a drive when I needed to pop back to the car for something!
Various props will be tried, but basically I think the boat lacked a little “umph”, but a new motor with more power would need a prop shaft upgrade to 5mm and the engine mount cutting out to accommodate a more conventionally front mounted motor.
With 3 cell LiPo power I expected a better turn of speed.
A comparatively minor snag was another leaking alloy motor mount that caused water to be pumped into the engine bay. The same thing happened with Rapier1’s maiden voyage (!). I will try smearing some Araldite on the threads of the two brass nipples and hope this fixes the leaks.
The positive side was that the boat looked good on the water and steered beautifully as expected from a boat designed by Vic Smeed for use in steering competitions!
 

[canabus]

Hi Zooma


What motor, ESC and prop have you got on the boat ???


I use 4mm drive lines on all but two of my boats.


3/16" on the Crash Tender 46" and installing one in Spooky because of the length  of the shaft.


Canabus

[zooma]

Hi Zooma
What motor, ESC and prop have you got on the boat ???

I use 4mm drive lines on all but two of my boats.

3/16" on the Crash Tender 46" and installing one in Spooky because of the length  of the shaft.

Canabus

Hi Harry,

I have a Turnigy 3536/6  1250KV rear mounted out-runner (see photos on this thread) with a SeaKing 90amp ESC (shown in photos) powered by a Turnigy 5000mah 20-30C LiPo 11.1volts (also in photos) and I was using an S40 prop.

An X35 prop was tested, but this made very little difference.  I was hoping it would allow the motor to rev more freely, but now I am thinking that the motor is revving a much as it is going to do, so I will try a bigger prop next time.

Now I have returned home I have wiped some 24hr Araldite around the threads of the two brass nipples that screw into the water-cooled alloy motor mount to fix the leak and I have found that I can (just about) squeeze an X45 prop onto the prop shaft without it touching the underside of the hull or the water pick-up (but it is tight) and I am hoping that the motor has enough torque to turn this prop and push the boat along a little bit faster!

If the bigger prop does not improve the speed then I will have to cut out the motor mounting platform so that I can remount it further back to allow a more conventional choice of out-runner motor with a front mounting.  This will give me plenty of choice as I have a few out-runners to choose from that I know will shove this lovely little Vic Smeed design along at a much brisker pace............but I am disappointed by the lack of "power" that this Turnigy 3536/6 1250KV has to offer.

I definitely expected a better performance from this motor!

Stay safe,

Bob.

[canabus]

Hi Zooma


Banggood have a Surpass C3542-1250(850Watts) and 1450kv(1050Watts)which both handle up to 4S.


I am running the 1450kv on 4S with a 32mm 2blade prop in the Old Speed boat and it's quick.


The 1250kv ones are in the little Huntsman and Corona Cabin Cruiser on 3S with 30mm 3 blade props.


I have had the Huntsman on 4S and planning on changing it to the 1450kv because the hull will handle it no problems!!!


Canabus

[zooma]

I have just noticed that the 4mm plywood fillet that I used to "fair-in" the space between the prop shaft and the underside of the hull has split away from the hull.


This fairing is held between the shaft and the underside of the hull with 24 hour Araldite and I have used this method to hold similar shaft fairings on to every hull I have ever made and used since 1964, and even those that used large vibrating two strokes petrol engines and high reviving glow engines have never failed!


I doubt that the "less than impressive" performance that I have witnessed from this Turnigy 3536/6 1250KV motor would be enough to worry a good bond like this so I can only guess that there is some undetected vibration or movement that has caused this hairline split?


This is the only model boat that I have fitted one of the thin stainless steel Perkins prop shafts into.  I chose this shaft because it would look "neat" on this Remora (and and it has a 4mm inner shaft that again I thought would suit this model well.


The alignment of the shaft/motor/coupling is spot-on so I know that there is no problem here that could contribute to any excess vibration and I was using a brand new MicroFlex coupling that should help to keep everything running vibration free.  The shaft itself was "rolled" on a flat surface and it is absolutely straight and the whole motor/coupling/shaft assembly turns nice and smoothly.


Maybe the thin stainless outer tube has allowed the 4mm shaft to whip - despite the lack of excess power, good alignment and free turning drive train?


It is certainly an unusual thing to see on any of my powerboats, so having checked everything is OK I have re-bonded the shaft fairing back into place again and I will see is it moves again as I give this motor another chance to perform before scrapping it and changing it for a different motor such as one of the excellent Surpass motors as suggested by Harry in his last post.

[tonyH]

The split and the "Gentleman's Runabout". Not the normal Zooma pace!
Bob sent me a short film of Remora running. If anyone wants to see it, send me a PM and I'll forward to e-mail address.

[zooma]

An old 2BA prop shaft was found in the workshop this afternoon, so I cut it down to 11"" and fitted a pair of 5mm phosphor bronze bearings so I have a 5mm prop shaft ready to replace the 4mm one I have fitted now - if I need to fit a more powerful motor.

[madwelshman]

Bob,


Could it be that the Araldite just didn't take properly, maybe a slightly greasy surface preventing full or proper adhesion?

Remora looks good on the water, even if performance isn't up to expectation quite yet. 


You'll get to the bottom of it I'm sure.




Will

[zooma]

Bob,

Could it be that the Araldite just didn't take properly, maybe a slightly greasy surface preventing full or proper adhesion?

Remora looks good on the water, even if performance isn't up to expectation quite yet. 

You'll get to the bottom of it I'm sure.

Will

The hull and the fairing were both raw wood at the time they were Araldited together so the bond should have been OK, but I have repaired it now and hope it will not split away again.

Performance wise it is OK - but my TID tug is almost as quick(!) - so I am hoping to find an improvement with the least work.  More work takes time away from my other projects but I would like to see it move with a little more pace so I will do what works to improve it.

With a 5mm prop shaft now made and ready to use (if needed) a bigger motor could be fitted, but I will try the set-up that I have first with the X45 prop and hope it will work.

Cutting out the existing alloy water-cooled engine mount and motor plate to fit a front mounted out-runner involves fairly major surgery, so if it comes to this I will change the shaft to 5mm to make certain that I don't have to "butcher" the hull for any other reason in the future.

Using this 35mm rear mounted Turnigy 3536/6 1250KV motor was a mistake - I hadn't reckoned on it being such a poor performer.   I should have stuck with my usual mix of using the alloy water cooled mount - positioned to accept a front mounted out-runner and a 5mm prop shaft.  A rock solid combination that can cope with anything I could ever want to fit.

I may see if I have a 4cell LiPo that could spark some life into this Turnigy 3536/6  1250KV motor.  With a 35mm motor like this that has a 1250KV rating it should work very well in this lightweight hull on 3 cells (or two cells) so maybe it is just a faulty motor?

Does anyone know what the /6 after the 3536 designation means?

[madwelshman]

I was going to ask if you had a 4s battery that you could try, to see how much of a difference it makes.
The extra voltage should give some useful extra rpm.


Keep at it Bob, you'll win.


Will

[zooma]

I was going to ask if you had a 4s battery that you could try, to see how much of a difference it makes.
The extra voltage should give some useful extra rpm.


Keep at it Bob, you'll win.


Will

Thanks Will,

I do have a 4 cell LiPo that will fit.  Sadly it has an XT90 plug fitted as it is used on a fast boat where I would normally choose this size of plug. I only have an XT60 plug on the ESC for the Remora as I never considered this boat ever needing so much power just to get it to move along at a reasonably brisk pace.

I can solder-up an XT90 - XT60 converter, but I do wonder if I am just failing to accept that this motor is a bit of a "flop".

With a decent 35 size motor my Rapier fly's along on just two cell LiPos - and that is a much bigger and heavier boat with a V hull that needs much more power than this lightweight "flattie" to push it along.

Sadly, I am thinking that the Turnigy 3536/6 is an unexpected poor choice - but I don't know why this motor is such a wimp!

Does anyone know what the /6 part of the motors description is?

3536 presumably refers to the motor width and length - but what does the /6 refer to?

In the old style (non-brushless) model car racing motors this would refer to the number of windings on the armature and /6 would give a very aggressive motor, but the winding on this brushless motor are very fine - and it is certainly not an aggressive motor 

[canabus]

Hi Ye old Zooma


As the diameter is the same , the length of the motor makes up a lot in power.


The longer the motor will get more power because of winding length.


Checking out the motor specs and comparing to others !!
The Watts on the specs is on the higher voltage and dropping voltage losses power.


Comparing two  motors:-


The Banggood Surpass C3542-1450kv 1050Watts on 4S .


The Hobbyking 3648-1450kv 1600Watts 0n 6S.


The 3648-1450kv on 4S is far more powerful than the C3542-1450kv on 4S.


Canabus

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[zooma]

Hi Ye old Zooma


As the diameter is the same , the length of the motor makes up a lot in power.


The longer the motor will get more power because of winding length.


Checking out the motor specs and comparing to others !!
The Watts on the specs is on the higher voltage and dropping voltage losses power.

Comparing two  motors:-

The Banggood Surpass C3542-1450kv 1050Watts on 4S .

The Hobbyking 3648-1450kv 1600Watts 0n 6S.

The 3648-1450kv on 4S is far more powerful than the C3542-1450kv on 4S.

Canabus

I just found and checked the small manufacturers slip of paper that was included with the Turnigy D3536/6  1250KV

voltage range  7.4 - 15v

1250KV(rpm/v)   1250.

Max Pull 12670g.

Motor size  35 * 36mm.

Max Power  496watt.

The last line of the spec sheet says it all.  Max Power 496watt.

It is a officially a weakling! 

[canabus]

Hi Zooma
It would not pull skin off a custard !!
The Banggood C3542-1250 or the 1450kv has the beans !!!


Canabus

[zooma]

Sadly I have to cut the engine mounting plate out of the Remora as I made it to accommodate this rear mounted motor so the water cooled engine mount is in the wrong place to accept the more normal front mounted motors!

The motor plate that the alloy mount is bonded onto needs to be cut out of the hull and a new one made to position the mount in the right place,

This is not a mistake that I will make again as it will make a lot of work that could have been avoided..........this is getting to be a bit like one of my restoration jobs - but this time in a hull that I have newly built   

[zooma]

This afternoon I cut away the engine mounting and removed it from the hull.

A new plywood plate to fit into the hull with a replacement alloy water cooled motor mount was made, but with the motor now being further away from the bow the very shallow angle of the prop shaft specified by Vic Smeed in his hull design made it very difficult to fit.

The old motor mount sides have been cleaned-up and fitted onto 1.5mm plywood and the remans of the original hardwood mounting have been chiseled back to give a bed to laminate this new motor mount onto, and this has made it possible to retain the original prop shaft angle.

For now the 4mm prop shaft will remain, but the 5mm shaft that I made to replace it will be ready to fit if the 4mm shaft fails to handle the new motors improved power output.

When this new mount has been installed it will then be possible to swap to almost any other out-runner or in-runner motor brushless motor and experiment to find the most suitable match. I am thinking about starting with a Turnigy 3542 1250.  Surprisingly, no printed information sheet was supplied with this motor, but it is the right size and shape so it should perform a lot better than the removed Turnigy D3536/6 1250KV motor - and if it does not, it will be a quick and easy job to unscrew it from the mount and replace it with something else.

[zooma]

The new mount has been Araldited in and when it is dry it will be given a coat of glass fibre and chopped matting to keep it in place.

[tonyH]

The new mount etc.