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[Buccaneer]

I have just completed a Caldercraft Talacre Coaster that I picked up on EBay and today gave it it's first Sea Trial. Basically it goes alright but I require full power to get even a reasonable speed from it. It came fitted with an MFA Geared Motor, 11:1 Ratio, and a 36mm four bladed propeller. I have fitted a 7.2V 4300 mAH Battery Pack and an Action P80 ESC. The maximum prop size I could fit would be 44mm. If I were able to remove the motor, which looks like a somewhat doubtful option, I have an MFA 2.5:1 which I could slot in, or I am considering a Mabuchi 555.

I have a number of other Tugs and Merchant ships so I have a rough idea of what performance looks right but this one definitely under performs. I would be interested to hear from other Talacre owners about what they have fitted, or any thoughts from anybody else.

John

[Tug-Kenny RIP]

I have built the Talacre and used an MFA 500 motor direct to the prop with no gears and it went quite realistically on the water. 

There is a build blog on here somewhere.  I'll have a look for you.

Cheers

ken

[Kipper]

I have a Billings Nordkap, it's very close to the Talacre's dimentions & runs nicely at scale speed, with a bit of 'oomph' in hand for get out of trouble speed, it's powered by a good ol' Mabuchi 555 on 12v, running a 40mm 3 blade brass prop.

I also have a Model Slipway 'Dutch Courage' tug, it is getting twin Mabuchi 555 power, swinging 60mm 3 blade props in fixed korts & they don't struggle to give above scale speed. 









Your Photobucket pictures are missing!?!
Try direct from your computer as long as they are under 200K.   I find that 150K is satisfactory
 Ken

[roycv]

Hi Buc...The 555 driving direct will do the job, the gear reduction you have now on a relatively small prop, as you have found, is ineffective.
If you can measure the current taken when prop is in the water you should be looking for about 2 to 3 amps to give 15+ Watts of power.
regards Roy

[malcolmfrary]

The previous owner probably thought that if the real thing turned its prop at a given speed, so should the model, hence the rather silly gearing.  The usual advice for better performance is "smaller prop", but in this case a larger prop an a lower gear ratio would be the answer.  For scale looking performance, the techy answer is a scale prop turning at full size speed TIMES the square root of the scale.

[Subculture]

Aim for a shaft speed of 4000-5000RPM. That should give you a decent speed without overcooking things.

[Martin (Admin)]

Send me the photos, I'll post them for you! 

[Colin Bishop]

The 2.5 gear reduction should be OK.  11:1 is far too much.

Colin

[Kipper]

Missing pics 

[Buccaneer]

Problem solved, I hope. Thank you to everybody for their contributions, many thinking along the same line as me. I ended up fitting a 3 Blade 40 mm Propeller and the 2.5:1 Motor. Fitting the motor was a 'challenge' (That's the nice way of putting it!) Removing the mounting bracket by undoing the four bolts was not on as these came up through a wooden base that had been epoxied to the hull and two of the nuts were just not accessible by spanner. Then I had a bright idea, why not just change the gearbox. This fell apart when I found out that the gearboxes were fixed with different size bolts. Finally by removing the gearbox, then the retaining ring that holds the motor onto the mount, I was able to extract the motor. Repeat the process in reverse with the 2.5:1 motor and we were there. I just need a calm day at the pond to see how it performs, but whatever the result I think this will probably be as good as it gets.

John