Mechanical Drive Component ID, please?

Thread Starter

Barnaby Walters

Joined Mar 2, 2011
102
I need some help identifying this shaft component. I'm new to mechanical engineering and don't know what anything is past 'thread', 'bearing' and 'bushing', and I don't have any catalogues I can browse through until I find it.

With insert screwed in.


With insert removed, loose.


It seems to be some kind of laterally screw-adjustable bushing. There is a housing about 40mm long that is glued into the body of the instrument, into which a threaded insert is screwed.

I'm pretty sure it's not a tapered bushing, as it doesn't actually make contact with the shaft, it seems to just serve to hold a roller bearing inside against a wider portion of shaft. The bearing seems to be registering off the insert housing.

The photos are rather bad (damned iPad camera) but you can just about make out the fact that it's threaded.

Can anyone tell me a) what these are called, and b) the name of a good (preferably UK or European) supplier of this kind of drive component?

Many thanks,
Barnaby
 

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shortbus

Joined Sep 30, 2009
6,878
What is the 'instrument' that it is used on? Some time knowing the context some thing is used in can help.
 

Thread Starter

Barnaby Walters

Joined Mar 2, 2011
102
What is the 'instrument' that it is used on? Some time knowing the context some thing is used in can help.
Pretty much the only instrument I know of that has a shaft — a hurdy Gurdy. Making sure the wheel is perfectly round and does not vibrate about is vital to the playing action. I'm currently drawing up plans for one.

I'm so lucky I can't complain about the iPad camera.... I don't have one.
Ha ha ha. :)

Not the most helpful of responses though, you have to admit ;)

Cheers,
Barnaby
 

strantor

Joined Oct 3, 2010
5,025
a retaining nut? If I understand your description, the object pictured is threaded on the outside and screws up against a thrust bearing (not pictured, inside) and just hold it in place? I would call it a retaining nut.

...but then it's not really a nut if it is threaded on the outside...

...might be up to the manufacturer what that thing is called.
 

shortbus

Joined Sep 30, 2009
6,878

shortbus

Joined Sep 30, 2009
6,878
The actual part may be proprietary to the original maker. Most of the kits and parts sold on line use either plain brass or nylon bushings without the threads.
 

Thread Starter

Barnaby Walters

Joined Mar 2, 2011
102
:) When you said instrument, I thought you meant like a electronics test instrument.

You may want to go here and ask this question - http://www.gurdy.co.uk/forum/index.php?sid=21335e470406b5e59cdcbe17a9607212

Some where in my mess I have a set of plans for one. Came from GAL http://www.luth.org/plans/ethnic.htm#plan49

As the poet Donovan once said "Came singing songs of love.
Hurdy gurdy, hurdy gurdy, hurdy gurdy, gurdy he sang."
That actually looks like a pretty good set of plans, as commercially available gurdy plans go.

Yep, I'll ask the original maker what it is and where he got it. If it is a custom part, it's very highly polished!

Most kits do use a plainer system, but equally it's extremely difficult to find a kit thats any good! I have heard positive things about parts from hurdy Gurdy crafters in the US though.

I actually don't think it's such a bad camera. My cellphone camera is much worse.
Well, it's adequate. Has a surprising amount of benefit over my point and shoot — quicker to use the photos, excellent editing facilities, video with decent sound, 10 hour battery life. But not a great camera :)

Cheers,
Barnaby
 

shortbus

Joined Sep 30, 2009
6,878
It probably is used to adjust the end play of the shaft and act as the bearing. I'd bet that the shaft has a step on it that the threaded bushing goes against. Then you adjust it in or out to control the end play.

Custom made or one-off parts made by a craftsman are almost always smoother and more "polished" than off the shelf parts. Because the craftsman puts pride in his work that a production machine can't.

The GAL plans are usually taken from historic instruments.
 

Thread Starter

Barnaby Walters

Joined Mar 2, 2011
102
It probably is used to adjust the end play of the shaft and act as the bearing. I'd bet that the shaft has a step on it that the threaded bushing goes against. Then you adjust it in or out to control the end play.
Yep, you're right. As I said earlier, the component I have yet to identify pushes a roller bearing up against the stepped shaft. The shaft doesn't actually touch this component at all, but the roller bearing registers off it's housing.

Custom made or one-off parts made by a craftsman are almost always smoother and more "polished" than off the shelf parts. Because the craftsman puts pride in his work that a production machine can't.
I'm familiar with the finish a craftsman can get, being one myself :) But I'm pretty sure this is moulded, it's got that kind of semi-gloss to it.

The GAL plans are usually taken from historic instruments.
They certainly look pretty good. I've drawn up my plans from scratch (using standard soprano scale length), but I've sent them off to the gurdy maker who made the instrument pictured to see what he thinks. I'll ask him what the mystery component is too!

Cheers,
Barnaby
 
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