Steering worm and gear wheel

[Boston Lodge]

I am looking for a steering gear and worm wheel for an 8" scale Burrell tractor. I have looked at the dimensions of one for a 6" Savage and as the gear wheel is 3.687" across the teeth, it is possible I could adapt this. Has anyone got anything of similar size?
I am in fairly urgent need as I cannot steer my engine at the moment and the cost of having one made to the current specification is prohibitive.
Has anyone got anything out there that I can consider please?

[carl_byrne]

Please see my reply to your previous thread. Without the information I requested I, or anybody else, cannot really help you.

Cheers
Carl.

[basil JNR]

Originally Posted by Boston Lodge

I am looking for a steering gear and worm wheel for an 8" scale Burrell tractor. I have looked at the dimensions of one for a 6" Savage and as the gear wheel is 3.687" across the teeth, it is possible I could adapt this. Has anyone got anything of similar size?
I am in fairly urgent need as I cannot steer my engine at the moment and the cost of having one made to the current specification is prohibitive.
Has anyone got anything out there that I can consider please?

Does the 6" devonshire one not fit? maybe worth speaking to adrian

[Boston Lodge]

Originally Posted by carl_byrne

Please see my reply to your previous thread. Without the information I requested I, or anybody else, cannot really help you.

Cheers
Carl.

Thanks for your reply Carl. The gear wheel is 2 1/2" across the teeth with a shaft size of 1 1/2" It has 25 teeth and the worm wheel turns 20 times for one complete revolution of the gear wheel ( not sure how you would work out the ratio). The worm wheel on the steering shaft is bored out 5/8" diameter There is room for a bigger gear wheel up to 3 1/2" and the centre could be machined to fit the shaft. I realise I am not going to get an exact match to the original but I am hoping that someone has something that could be adapted to fit.

Michael

[carl_byrne]

Hi Michael

I have a few small worm/wheel gearboxes. I'll root them out and see how the dimensions of the gears compare with those you have given.

Cheers
Carl.

[Boston Lodge]

That would be great Carl, thank you.

[carl_byrne]

Hi Michael

I have looked through the gearboxes I have. The closest ratio I have is 30:1, not the 20:1 you need. My other boxes are 60:1 and 120:1 - not in the right ball park.

I have had a look through various suppliers of stock gears. Judging by the sizes you have given you need to source gears of 2.5 or 3 Mod - or imperial DP equivalent. I suspect metric/Mod will be easier to find and cheaper.

This company is worth looking at :-

https://www.rargears.com/gears/worm-wheels

This website gives the dimensions of wheels/worms they supply. Assuming your existing worm is single start, your wheel must be 20 teeth to give you a ratio of 20:1. However you state it has 27 teeth, so something doesn't tally here.

Don't forget you also need to confirm the 'hand' of the worm - get it wrong and you will be turning the steering wheel anti-clockwise to steer to the right! Incidentally, a friend had a Series 1 Landrover which had opposite hand steering ! An interesting driving experience !

Is the drawing available? If so, what are the original specifications?

Sorry that I can't help you directly.

Regards
Carl.

[Boston Lodge]

Hi Carl,
I appreciate your help. I will have a look at the quoted website and see what they have. Sadly there are no original drawings for my engine. Your friend with the Series 1 Land Rover had an interesting time! Some years ago I was operating a Fowler ploughing engine named Margaret built in 1870. You steered it from a step outside of the footplate using a vertical shaft and this steering wheel had to be turned left to go right etc. much concentration needed!

Thanks again

Michael

[carl_byrne]

He drove the Series LR like that for 5 years, even passing 5 MOTs. In those days the driver used to stay in the car during the test, helping the tester - so it went unnoticed.

Good luck with sourcing a worm/wheel.

Regards
Carl.

[steamy1]

Originally Posted by Boston Lodge

I am looking for a steering gear and worm wheel for an 8" scale Burrell tractor. I have looked at the dimensions of one for a 6" Savage and as the gear wheel is 3.687" across the teeth, it is possible I could adapt this. Has anyone got anything of similar size?

Is "3.687" across the teeth" the diameter?


You may be able to use a stock spur gear and make a worm to suit.