Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

plastic slider chain tensioners are used on bazillions of off-road
motorcycles...

"Old Nick" wrote in message
...
Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

.........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

you could fit a complete tensioner assembly intended for a vintage type
trials motorcycle..........try BJ racing
"Old Nick" wrote in message
...
Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

.........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

Subject: Chain tensioner ideas
From: Old Nick
Date: 24/03/04 06:41 GMT Standard Time
Message-id:

Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Plastic tensioners are the standard method for cam chain drives in engines but
of course it's clean and well lubricated in there. Also such tensioners are
only used on the slack side of the chain. If you need to tension the drive side
of a chain the tensioner will have to withstand a fair amount of force. A
sprocket on a substantial bearing would seem to be the only way. Given that you
might as well make two.


Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
I'm not at all sure why women like men. We're argumentative, childish,
unsociable and extremely unappealing naked. I'm quite grateful they do though.

"Old Nick" wrote in message
...
Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

I did see a plastic tensioner some while ago that would work for you. I
looked like a thin walled plastic sprocket that sits between the two chain
runs. It is compressed to an oval shape and pushes the two sides of the
chain apart.
Hope I have managed to describe it OK.

John

I did see a plastic tensioner some while ago that would work for you. I
looked like a thin walled plastic sprocket that sits between the two chain
runs. It is compressed to an oval shape and pushes the two sides of the
chain apart.
Hope I have managed to describe it OK.

John


You could also make a floating tensioner like this
http://www.tonysbuggypage.btinternet...tensioner.html

John

"Old Nick" wrote in message
...
Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

.........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?


Check these simple tensioners, I like the simplicity, sold through Lovejoy,
so they're surely available through a local bearing distributor.

Good luck

Kai St-Louis

If you can avoid anything that turns the rollers on the chain, you may
get a little better life in a dirty environment. Even though the
bushings are hardened (and sometimes the rollers, sometimes neither in
really crappy chain), you have a steel against steel wear point.

We use what we call a "follower wheel". Basically, it's a UHMW wheel
with a bump that sticks out for some guiding between the chain sidebars.
The bump doesn't stick out quite to the point of touching the rollers.
The sidebars of the chain sit on the shoulders of the UHMW follower
wheel. Sidebars can wear down quite a lot and still not cause sprocket
engagement problems whereas if the rollers wear even a little, you can
start having problems.

I'm not sure of the speed of the chain or the overall tension so cannot
say if UHMW would be adequate for your application. A spring system
will probably be enough to apply the tension you need.

Oh yea...go as large as possible on any tensioner so that the chain
doesn't have to bang it's way around a small diameter bend.

Koz

Old Nick wrote:

Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************* *** sorry

.........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

On Wed, 24 Mar 2004 11:48:26 -0800, Koz
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

If you can avoid anything that turns the rollers on the chain, you may
get a little better life in a dirty environment. Even though the
bushings are hardened (and sometimes the rollers, sometimes neither in
really crappy chain), you have a steel against steel wear point.


Yeah. I was thinking about this. Chain wear is the biggest problem,
not some bit of plastic. But as you say, a static piece of plastic
will turn the rollers.

We use what we call a "follower wheel". Basically, it's a UHMW wheel
with a bump that sticks out for some guiding between the chain sidebars.
The bump doesn't stick out quite to the point of touching the rollers.
The sidebars of the chain sit on the shoulders of the UHMW follower
wheel. Sidebars can wear down quite a lot and still not cause sprocket
engagement problems whereas if the rollers wear even a little, you can
start having problems.


I'm not sure of the speed of the chain or the overall tension so cannot
say if UHMW would be adequate for your application. A spring system
will probably be enough to apply the tension you need.

Fairly slow. It comes of a 3" sprocket on a 500 RPM PTO on a tractor.


Oh yea...go as large as possible on any tensioner so that the chain
doesn't have to bang it's way around a small diameter bend.

Yes. I thought of this when I considered a ball bearing (now discarded
as an idea). If the tensioner does not use a sprocket, too small wheel
will cause a constant chattering.
************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

On Wed, 24 Mar 2004 07:03:59 GMT, "Jon Grimm"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

plastic slider chain tensioners are used on bazillions of off-road
motorcycles...

OK. That's a good indication they would probably be OK. AS I said in
another reply, wearing abit of plastic makes much more sense than
wearing out chain.

************************************************** ** sorry

..........no I'm not!
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Does Bill Gates dream of electronic sheep?

On 24 Mar 2004 08:49:54 GMT, a (Dave Baker) vaguely
proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email


Plastic tensioners are the standard method for cam chain drives in engines but
of course it's clean and well lubricated in there. Also such tensioners are
only used on the slack side of the chain. If you need to tension the drive side
of a chain the tensioner will have to withstand a fair amount of force. A
sprocket on a substantial bearing would seem to be the only way. Given that you
might as well make two.

hmmmm...yes. When I was farting about with the thing yesterday, I
realised that I cannot expect to control the tight side of the chain.
I may have to redesign the frame a bit :-. I expected to be able to
"squeeze" the chain through the frame, but this would take a serious
sprocket setup on the "working" side. Better to give the chain more
clearance, and only tension on the slack side.



Dave Baker - Puma Race Engines (www.pumaracing.co.uk)
I'm not at all sure why women like men. We're argumentative, childish,
unsociable and extremely unappealing naked. I'm quite grateful they do though.

************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

On Wed, 24 Mar 2004 13:10:25 -0000, "John Manders"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email


I did see a plastic tensioner some while ago that would work for you. I
looked like a thin walled plastic sprocket that sits between the two chain
runs. It is compressed to an oval shape and pushes the two sides of the
chain apart.
Hope I have managed to describe it OK.

John


You could also make a floating tensioner like this
http://www.tonysbuggypage.btinternet...tensioner.html


Tricky! Unfortunately, while it's very elegant, it allows too much
movement of the whole chain on both sides for my purposes. But handy
to remember for other times....
************************************************** ** sorry

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On Wed, 24 Mar 2004 14:41:25 +0800, Old Nick
vaguely proposed a theory
.......and in reply I say!:
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Thanks for all the food for thought, guys.
************************************************** ** sorry

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remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

Old Nick wrote in
:

Back to my post hole digger. I want to spring-tension the main drive
chain (5/8"). I was wondering if anyone has any useful ideas about
putting a chain tensioner together. Part of the reason is that I wll
have to use 2, because the chain fouls the mounting (my build :- ) if
I just tension one side.

I have thought of actually using a little sprocket, or a ball bearing
on a shaft (no drive needed, of course). But there was one picture
that appeared to simply use a piece of plastic! Presumably delrin, or
some other slippery, hard material? It looked quite narrow. I assume
it sits only on the chain rollers.

The chain is in exposed, dusty conditions, I might add. That was why
the dragging plastinc idea did not appeal.

Any ideas appreciated.
************************************************** ** sorry

.........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?


whatever you use on the drive side to run against the chain, you really
should think about a ratcheting or hydraulic locking method of keeping
the tensioner tensioned. The idle side has no real pressure on it
(unless it's reversing), the drive side does. A spring taunt enough to
adequately control whip at start/stop may put too much added load on the
chain.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

On Thu, 25 Mar 2004 01:02:51 GMT, Anthony
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

I have modified the whole frame that the chain runs in. I will only
need to tension the slack side now.

Thanks for all the help, guys. I realise I am not going to directly
use it all. But the bit about the drive side having all that force
decided me to "simply" (BAH! It never is!G) mod the setup a bit.


whatever you use on the drive side to run against the chain, you really
should think about a ratcheting or hydraulic locking method of keeping
the tensioner tensioned. The idle side has no real pressure on it
(unless it's reversing), the drive side does. A spring taunt enough to
adequately control whip at start/stop may put too much added load on the
chain.

************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

On Wed, 24 Mar 2004 13:07:06 -0000, "John Manders"
vaguely proposed a theory
.......and in reply I say!:
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It's called a roll-ring. I foun d it in a search. If it works as
dedigned, I reckon discovering it _had_ to be an accident! It looks
brilliant. I bet they manage to charge too much to make it a world
beater!

hmmm...made by Renood. So it's not some flash in the pan! I rang
Ren0old this morning before I had read the blurb. They did not mention
this product. I laugh and say "This is Australia"....

Unfortunately I need to make the chain path narrower, not wider....

I did see a plastic tensioner some while ago that would work for you. I
looked like a thin walled plastic sprocket that sits between the two chain
runs. It is compressed to an oval shape and pushes the two sides of the
chain apart.
Hope I have managed to describe it OK.

John


************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

On Wed, 24 Mar 2004 09:03:33 -0500, "Kai St-Louis"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

You seem to have forgotten the URL?

Check these simple tensioners, I like the simplicity, sold through Lovejoy,
so they're surely available through a local bearing distributor.

Good luck

Kai St-Louis


************************************************** ** sorry

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On Wed, 24 Mar 2004 14:41:25 +0800, Old Nick
vaguely proposed a theory
.......and in reply I say!:
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Ok. I went to the local ag shop today. They understand us RAG (rough
as Guts) backwards...errr backwoods...engineers! They have a 10 tooth
sprocket, with pressed (sweated?) in bearing, which simply mounts on a
threaded 1/2" rod. You then use two nuts (with locks if needed) to
move the bearing along the rod to line up with your chain, and lock it
in place with the nuts. No pressing etc. $18 or so for the sprocket
and bearing. I supply the spring loading.

I like the sprocket as it feels as if it disturbs the rollers on the
chain least, and wears least. Sprockets are what chain was made for.

Again. Thanks for all the replies. This one suits me this time, but I
have other applications coming up. Some of the other ideas are most
interesting.
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Sorry about that!!
here it is

http://www.lovejoy-inc.com/motorbases.htm

Regards,

Kai


"Old Nick" wrote in message
...
On Wed, 24 Mar 2004 09:03:33 -0500, "Kai St-Louis"
vaguely proposed a theory
......and in reply I say!:
remove ns from my header address to reply via email

You seem to have forgotten the URL?

Check these simple tensioners, I like the simplicity, sold through
Lovejoy,
so they're surely available through a local bearing distributor.

Good luck

Kai St-Louis


************************************************** ** sorry

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On Fri, 26 Mar 2004 15:08:47 -0500, "Kai St-Louis"
vaguely proposed a theory
.......and in reply I say!:
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Sorry about that!!
here it is

http://www.lovejoy-inc.com/motorbases.htm

Ahah! Yes. Thanks. The farm shop had those. They were Aud$100 or so
each! Nice simple idea, but why not a nice simple price?

........because they can???
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