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[likeomg]

Hello all,


I have a graupner Atlantic challenger I've destroyed both belts on.. originally its a T5 11 to T5 23


I have searched various places for a suitable replacement, being a belt, gears or anything (my option is to go direct drive currently but it's a shame on a original unmolested boat)


the shafts both motor and jet unit drive shaft are 5mm,


any thoughts on a suitable gear supplier?

[ChrisF]

SHG Model Supplies do a range of pulleys and belts.

Chris

[derekwarner]

So if the motor speed and [jet rotor or propeller] selection are stock with the drive belts as standard, you shouldn't be prematurely chewing out belts


Is the motor + belt reduction + the jet drive one package?, or have you selected a jet drive as a separate add-on component?

[Any belt failure is the result of thermal or and mechanical stress]

Looking at your installation, we see both motors are [assumed] as spigoted, however have been secured @ 3.00 and 9.00 o'clock


This underload could cause the motor axis to flex downwards causing stress within the belts [on the motor side]


It would appear, that the 2 x motor securing screws could be relocated to 12.00 & 6.00 o'clock, which would stiffen the motor axis


Assumed again that the belts must be slipped over the motor belt pinion,when the motor is loose, then repositioned in the spigot and motor locked up?


Derek     

[Martin (Admin)]

Also see this build thread: https://www.modelboatmayhem.co.uk/forum/index.php?topic=46975.0

 

[mrzippy]

MFA/Como Drills would be the obvious toothed belt and pulley supplier to the modelling world.

However HPC Gears at Chesterfield supply anything gears, pulleys and belts wise - provided one understands the technicalities involved !
I recently replaced a slipping Meccano pulley and belt two stage reduction drive on my stern wheel steam launch,
with more substantial toothed belts and pulleys from HPC.

Lots of technical info on their website, most of it going straight over my head - I'm not an engineer,
therefore I took the model along and HPC's technical guy went into action with micrometers, vernier and calculator,
measuring shaft centres, pulley diameters etc.
He returned from the stores half an hour later with the exact components -
one pulley requiring minor drilling to the correct shaft size, excellent service, but not cheap!

Would be interested to know how they produce toothed belts to exacting dimensions ?
I cannot spot any signs of joints in the reinforced nylon material ??

[tonyH]

Totally agree with Mr Zippy regarding pulleys/belts/gears etc.
Is there any movement on the current setup to be able to adjust the tension or are they fixed and will only use the graupner bits? If that's the case you'll probably be better off using route 2....direct drive.

[likeomg]

Hi guys, few things


- the above pic is one I just quickly googled, my boat is in storage.


I believe the belts weren't 100% aligned which caused them to put unnecessary stress on them - I was probably running 9 also believe it's near impossible to get them to have no play due to the design, I did buy thrust bearings etc in a way to pin them into place.


the 'gearbox' mounting is also fairly flexible, I understand what your saying Derek but there is flex in the whole unit...


I was thinking just 2 gears direct with no belt, it's a tiny impeller I think 30mm and I can adjust the rpm from different cells / motors.


I have had a thought tho - just securing the 3mm fibre glass plate I was going to mount everything too with silicone sealant, I've used it for the battery trays in my 110mph boat and so far no movement, this is a slow scale boat so should work and also far less permanent than silicone


this would then form the platform to mount things to, keeping the hull original.


I have 2 motors, 4x couplings 5mm - 4.75 and will run some Flexi cable to count for any misalignments and keep vibrations down

[TomHugill]

Theyre much better on dorect drive but it do have two spare belts in their packets if you want them

[likeomg]

Hi Tom, I will take the belts - you don't happen to have any other spares do you?


Will send a pm,


I will also try and run direct drive... just without gluing anything etc.

[likeomg]

Made this, lines up pretty well and the stainless was only in place while the glue cured, it will be replaced with 4.75mm Flexi.


motors are 1521 1y Neu, and hoping to run without water-cooling on 3s. the esc is OSE raider 150amp if the 1577 KV is too much at 3s I will either source some 2s or just limit the TX to a safe %.

[TomHugill]

It should rip on that setup! I would definitely advise water cooling though

[Fastelectrics]

Have a look at GT2 belts and pulleys on ebay or bangood.com. They are normally used on 3d printers but could be put to work on model boats.

[likeomg]

I appreciate the comments on water-cooling, it's just that in the current setup, the water-cooling jacket won't fit, without the alignment is perfect. I did create a spacer but still it was maybe 2mm away from fitting - oops.


I believe the motors should be fine, they are after all big, 40x96mm motors, I won't be pushing this boat fast at all, I have other boats for going fast.. (more of which hopefully over the next week)

[likeomg]

Well, as things usually do with me, it escalated quickly.


bought a second challenger, with gearbox complete. I plan to remove the original belts and pulleys, convert this one to direct drive and keep my original one as is - original.

[likeomg]

It was very rough around the edges - still is and could do with a new paint but



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And converted to brushless, Neu 1521 1577KV on 3s to start.
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Still need to make some battery mounts once they've arrived.