Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: overthesea on July 16, 2017, 12:48:31 am

Title: Cog wheels
Post by: overthesea on July 16, 2017, 12:48:31 am

Hi Folks,
Am building a model boat and the prop shaft is very low in the boat. Between the centre of the shaft and the keel I have just enough room (5/8 inch or 12mm) to fit a cog wheel on the end of the shaft.  Can anyone please tell me where I can obtain cog wheels of 24mm dia with a 4mm bore, or pulleys to make it belt driven, again pulley to have 4mm bore.
Thanks very much for reading and hopefully answering my question.

Title: Re: Cog wheels
Post by: derekwarner on July 16, 2017, 01:20:20 am

 %) morning OTS........hope the weather is fine in the IofW...I am sure fellow UK members will offer a number of sites closer to you, however these guys in USA have a very comprehensive range  :-)) that will fill your requirements

Derek

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjg7M73wozVAhUGKJQKHau6AhwQFggmMAA&url=https%3A%2F%2Fwww.servocity.com%2F&usg=AFQjCNF_VIoFwmsFF99X1w82r2yicwIJUA

Title: Re: Cog wheels
Post by: imsinking on July 16, 2017, 08:28:57 am

Belt drive will be easier to do , no need to worry about meshing and with a jockey wheel in your set up tightness is easily adjusted .
Bill

Title: Re: Cog wheels
Post by: Mark T on July 16, 2017, 08:39:09 am

I think that I may also have a similar issue with my next build; if I do I was going to try these people


http://www.ema-models.co.uk/index.php/mechanisms/toothed-pulleys-belts/toothed-pulley-14-teeth.html


Its the correct bore size for what you want but they do other sizes too.  Good luck  :-))

Title: Re: Cog wheels
Post by: Klunk on July 16, 2017, 09:03:25 am

https://www.mfacomodrills.com/timing_belts_timing_pulleys/timing.html


These also do cog and chain sets

Title: Re: Cog wheels
Post by: Seaspray on July 16, 2017, 10:57:53 am

Belt drive is easier here is my setup on the Meteor

Title: Re: Cog wheels
Post by: Colin Bishop on July 16, 2017, 11:20:58 am

I prefer belt drive too but try to ensure that the pulley on the motor is smaller than the one on the shaft. This will gear the prop down and allow the motor to run more efficiently.

Colin

Title: Re: Cog wheels
Post by: Dave Cook on July 16, 2017, 11:43:54 am

A belt would be far superior in this application no back lash to worry about and a lot smoother than gears.
There is a company in the UK called hpc transmissions they have a huge range .
Regards Dave

Title: Re: Cog wheels
Post by: overthesea on July 16, 2017, 10:21:46 pm

Hi Dave Cook/Colin Bishop/Mark T/imsinking/derekwarner-decoy and Seaspray.
Thanks to everyone for your answers.
To Seaspray==Am I right in assuming that the two tooth pulleys are the same size in the pic?
To derekwarner-decoy. Weather on the island is very nice at the moment, probably hotter here than where you are at the moment.
Once again many thanks to you all.
overthesea.

Title: Re: Cog wheels
Post by: Seaspray on July 17, 2017, 08:50:17 am

Yes they are 1:1   :-))

As i was only turning a 4blade 35 mm prop this suited the model If I get into trouble I've plenty of spare revs to get out of it

Title: Re: Cog wheels
Post by: overthesea on July 17, 2017, 09:25:29 pm

Hi Seaspray,
Thanks for answering my query.
Regards
overthesea.

Title: Re: Cog wheels
Post by: Seaspray on July 18, 2017, 10:30:31 am

Hi overthesea

If its any help I got my pulleys and belt from HPC Gears Ltd. Unit 14, Foxwood Ind Est. Chesterfield. S419RN
01246268080

I spoke to the technical department and got good advice as I had a very compact area to fit pulleys and belt in.

 30/08/07 was when the were bought and cost £31.47  including p&p £7.60  not cheap