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Blackstone gear box linkages

Proper Job

By Proper Job
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David Mack Veteran II

David MackDonate to Canal World

Posted
Posted

Can I suggest that if you're thinking of having some made specifically for connection to lever operated gearboxes, that you go for a bigger reduction that the standard GU kit? I'm not sure, but from memory they were about 1.5:1 reduction though might have been 1:1. I can check later if you don't have one to hand.

 

Tim

 

Looking at the photos in the links I posted, the gear ratio on the bevel gears looks to be about 3:1.

 

If I remember I will count the teeth on Fulbourne's gears when I am next on the boat.

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alan_fincher Veteran II

alan_fincher

Posted
Posted

Can I suggest that if you're thinking of having some made specifically for connection to lever operated gearboxes, that you go for a bigger reduction that the standard GU kit? I'm not sure, but from memory they were about 1.5:1 reduction though might have been 1:1. I can check later if you don't have one to hand.

 

Tim

 

Looking at the photos in the links I posted, the gear ratio on the bevel gears looks to be about 3:1.

 

If I remember I will count the teeth on Fulbourne's gears when I am next on the boat.

My impression is that it is between the two, and probably pretty damn close to 2:1.

 

This picture of Chertsey's is best I can find.....

 

ChertseyGears2.jpg

 

I think there are 15 teeth on the small gear, and about double that on the big one.

 

I have driven Chertsey, and with the lever arrangements it has at the bottom, it all works superbly, with not a lot of force required on the Parsons box on the PD2.

 

I would not have thought the Lister box that radically different that the same ratio should not work well on that, but obviously design and lengths of levers at bottom is also a factor. Halsall (with a Lister) has exactly the same gears, but I have not driven it to see how stiff, or how much travel.

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David Mack Veteran II

David MackDonate to Canal World

Posted
Posted

 

 

 

My impression is that it is between the two, and probably pretty damn close to 2:1.

 

This picture of Chertsey's is best I can find.....

 

ChertseyGears2.jpg

 

I think there are 15 teeth on the small gear, and about double that on the big one.

 

I have driven Chertsey, and with the lever arrangements it has at the bottom, it all works superbly, with not a lot of force required on the Parsons box on the PD2.

 

I would not have thought the Lister box that radically different that the same ratio should not work well on that, but obviously design and lengths of levers at bottom is also a factor. Halsall (with a Lister) has exactly the same gears, but I have not driven it to see how stiff, or how much travel.

 

Agreed. Looking at that 2:1 is probably right. In which case something like these would be a pretty good off-the-shelf equivalent, though at £75 (plus VAT) they aint cheap!

 

For something that looks reasonably close to the original with out the cost and hassle of getting a genuine handwheel copied you can get a Chinese version cheaply on Ebay.

 

$_57.JPG

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alan_fincher Veteran II

alan_fincher

Posted
Posted
There are several million things I would want to do to my boat before I mucked about with the gear lever.

 

You can't see the potential issues with gear rodding that has to be pushed so far forward into the cabin that you can't reach it again when you want to take it out of gear?

 

Or which pulls so far back in reverse you can't have the cabin doors shut?

 

Fair enough - nobody is making you consider altering yours!

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Timleech Veteran II

Timleech

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Posted

 

You can't see the potential issues with gear rodding that has to be pushed so far forward into the cabin that you can't reach it again when you want to take it out of gear?

 

Or which pulls so far back in reverse you can't have the cabin doors shut?

 

Fair enough - nobody is making you consider altering yours!

 

The Hotel Boat 'Jupiter' was like that for many years, successive captains learned to live with it ;)

 

Tim

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George94 Experienced

George94

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Posted

 

You can't see the potential issues with gear rodding that has to be pushed so far forward into the cabin that you can't reach it again when you want to take it out of gear?

 

Or which pulls so far back in reverse you can't have the cabin doors shut?

 

Fair enough - nobody is making you consider altering yours!

 

Perhaps you could just alter the lever ratio. Or put in stops to prevent excess travel. I would exhaust the simple remedies before taking such drastic action as you propose.

 

My (JP3 - Blackstone) lever travels about a foot from neutral in each direction, and that works fine. But I do have a wider boat.

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FadeToScarlet Veteran

FadeToScarlet

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Posted

 

The Hotel Boat 'Jupiter' was like that for many years, successive captains learned to live with it wink.png

 

Tim

 

The clutch rod on Spey is like that- there's a convenient piece of string clipped onto the edge of the slide, so you can reach for the string and pull it rather than having to have arms like Mr Tickle.

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davidg Community Regular

davidgDonate to Canal World

Posted
Posted

One way, probably the simplest, of altering the clutch rod travel is to pivot a vertical rod off the bottom of the boat in line with the gearbox operating rod and about 6-8" behind it with a horizontal link between the two. The vertical rod then moves through a smaller angle to get the required travel on the gearbox operating rod (compared to the angle the gearbox operating rod moves through) and when this is projected up to the connection to the clutch rod it gives a shorter travel.

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MoominPapa Veteran II

MoominPapa

Posted
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One way, probably the simplest, of altering the clutch rod travel is to pivot a vertical rod off the bottom of the boat in line with the gearbox operating rod and about 6-8" behind it with a horizontal link between the two. The vertical rod then moves through a smaller angle to get the required travel on the gearbox operating rod (compared to the angle the gearbox operating rod moves through) and when this is projected up to the connection to the clutch rod it gives a shorter travel.

 

Like this:

 

gears2.jpg

 

MP.

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madcat Experienced

madcat

Posted
Posted

Looking at the cost of new gears has anybody any bright ideas of what might be scrapped which could produce a suitable set or several second hand ?

The bracket could be fabricated and welded maybe .

 

I remember Boris doing something to the gear linkage on our first boat which reduced the travel no end.

 

I can't remember that the travel of the gear rod on Shad was that great, one to be looked at if anybody is at Ellesmere Port. Don't forget to take loads of photos.

 

FWIW I currently prefer the gear wheel system , once you get your head round which way to turn the wheel when looking backwards it's great. The gear wheel is also handy to hang a wet donkey jacket on to dry overnight , it's away from the stove but in the warm zone. I've dried my beret on it in the past too.

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Timleech Veteran II

Timleech

Posted
Posted

Looking at the cost of new gears has anybody any bright ideas of what might be scrapped which could produce a suitable set or several second hand ?

The bracket could be fabricated and welded maybe .

 

I remember Boris doing something to the gear linkage on our first boat which reduced the travel no end.

 

I can't remember that the travel of the gear rod on Shad was that great, one to be looked at if anybody is at Ellesmere Port. Don't forget to take loads of photos.

 

FWIW I currently prefer the gear wheel system , once you get your head round which way to turn the wheel when looking backwards it's great. The gear wheel is also handy to hang a wet donkey jacket on to dry overnight , it's away from the stove but in the warm zone. I've dried my beret on it in the past too.

 

Jack legs for semi-trailers.

 

Tim

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