Hegner Spares

[Harbo]

The bearing link on my 1996 Multicut 1 has sheared - am I correct in thinking spares can only be obtained from Hegner 'cause it 'aint cheap?!
And why are they made from plastic?

Rod

 

[CHJ]

....And why are they made from plastic?

Rod

Don't know the specifics of the machine design but often linkages are designed as a weak point that will shear or wear rather than causing a major component failure elsewhere in the chain.

 

[martinka]

....And why are they made from plastic?

Rod

Don't know the specifics of the machine design but often linkages are designed as a weak point that will shear or wear rather than causing a major component failure elsewhere in the chain.

Exactly what someone from Hegner told me when my cracked.

Harbo, where did it break? I cut a small strap of thin metal to put round mine and fastened it to the plastic with small self-tappers. that was about 6 months ago and it's still working OK, but I did put new bearings in it. I also made a new one from aluminium, but considering the time it took me to make it, it's really cheaper to buy a new one, and less hassle of course.

And yes, they are only available from Hegner, unless anyone knows different. I don't know if Axminster do spares for their Hegner clone, which may or may not fit newer Hegner models, but I think the older saws had a shorter link arm. Might be worth measuring the length between centres and giving them a call. If it's had a lot of use in its time, the bearings may be notchy, so it might be time to change it anyway.

 

[Harbo]

One end has sheared off on two pieces.
A new one costs £25.
It did occur to me that I could probably make one out of Aluminium if I had the right thickness but then I noticed the bearings are enclosed within the plastic? Perhaps Loctite might work?

Rod

 

[CHJ]

....Exactly what someone from Hegner told me when my cracked.
.....

Then I wonder what is the setting/usage that causes it to fail, and can it be adjusted/avoided, or if this is a regular 'norm'.

If so how many times can a new component be fitted before the next stronger component in the chain fails instead due to accumulative fatigue.

(Probably nothing at all relevant in the machines lifetime, just my warped train of thought having spent a lot of my time considering failure points in aerospace components.)

 

[Harbo]

With a Hegner and perhaps other saws, the weakest element would be the blade?

Rod

 

[martinka]

I'm guessing, but the bearings get notchy over time because the top one only rocks, it doesn't revolve. If it gets stiff it will begin trying to twist the link arm and eventually break it. Maybe.

I made the bearings a press fit in the ally link arm I made. The original looks like it has the plastic pressed in over the bearings to hold them in place, but in fact, the nut and washers will hold it in place, and that's what it is doing on mine.

What's the distance between centres on your link arm?

 

[Harbo]

It's just under 30mm - I measured it quickly with a scale rule.
The link is 6mm thick.

Rod

 

[martinka]

I thought as much. If it had been same as mine I'd have sent my spare alloy one for you. A couple of mm difference would have been OK, but 25mm difference is too much.

 

[beech1948]

Cast your own plastic replacement.

see:----http://owwm.org/viewtopic.php?f=1&t=141311&hilit=plastic+casting

to see how.

Al

Mod edit:- URL

 

[finneyb]

The Axminster clone has a exploded parts diagram and list at the back end of its manual http://www.axminster.co.uk/media/downlo ... manual.pdf

Would let you see if it was the identical construction to your Hegner and then if Axminster was cheaper for the spares

HTH

Brian

 

[Harbo]

Similar but I suppose it's down to measurements?
Bearing spacing is 30mm

 

[martinka]

Looking at the diagram, I suspect the length of the Axminster one will be same as the Hegner Multicut 2S ones, which I think is 52mm.

edit: I just checked on the Hegner website. The Multicut 1 centres are (Hegner says approx) 28mm and the Multicut 2 is 52mm

 

[Harbo]

I might have a go at making one - my friend has a Milling machine if my little Unimat is too small?
The existing bearings look OK and can be replaced later if not?

 

[martinka]

I might have a go at making one - my friend has a Milling machine if my little Unimat is too small?
The existing bearings look OK and can be replaced later if not?

I've never seen a Unimat in the flesh, so to speak, but I don't see any reason why it couldn't be used. Thinking back, I'm sure I must have bored the holes in the lathe. The bearing holes are obviously the most important, the rest could easily be done by hand. There's a photo of the one I made in this thread.
The new bearings cost me about £2:50 each at a local supplier. I did buy a pair from ebay but they seemed to have used some black gunge instead of grease and the bearings would hardly turn. You get what you pay for I suppose.

 

[Harbo]

I actually used a ⅝" drill, which worked out just right for a tight fit for the bearings and some 6mm Ally.
Shape achieved using a hacksaw and some files.
Machine up and running again

Rod

 

[martinka]

Good to hear you got it sorted, Rod

 

[Harbo]

Thanks - I can now get on with cutting brass - clock making

Rod