Hegner help!

[Cornish JackParticipant @cornishjack]

[Cornish JackParticipant @cornishjack]

G'day all.

I have a Hegner scroll saw which hasn't been used for a few years. Needed to do some 'brown stuff' cutting and purchased a couple of packs of Sandvik blades. So far, I have broken SIX of them and not yet cut any wood!! The blades snap each time on powering up the machine. Has anyone any thoughts on possible remedies. I have used the saw in the past with no problems and the blade attachments are pretty basic. The blades are metal cutting but, since they haven't actually come into contact with anything, I don't see that as an issue.

TIA

Rgds

Bill

[Keith LongParticipant @keithlong89920]

Bill

Just a thought, have you checked that the top arm is free to move over the same stroke length as the lower – sounds as though the blade is getting seriously over tensioned somewhere in the stroke.

Can you wind it through a stroke or two by hand rather than applying power straight off to see if there is any binding?

Keith

[Martin WParticipant @martinw]

Bill

You say that you have used this to cut brown stuff in the past, with the same type or similar blades, with no problems. As you say that you are using the same or the same type of blades then has the return arm mechanism become too stiff or slack after lack of use or has it had a knock and become misaligned somehow.

If the return arm/spring is not maintaining tension on the blade then it is possible that the blade is becoming loose at some point in the cycle and the system is snatching the blade tight causing it to fail. If too tight then the blade will be over tensioned with the same result. Does the return arm have free movement for the complete cycle of the blade movement, is there a stop and if so is this adjustable to accommodate various blade lengths?

Just a few ramblings while I await my instructions from SWMBO for the afternoon's activities.

Regards

Martin

 

Edited By Martin W on 14/04/2012 12:39:43

[Cornish JackParticipant @cornishjack]

Thank you Keith and Martin.

Never really had a close look at the 'workings' but have assumed ("Don't assume, CHECK!&quot that the return arm is the top one and the drive is direct to the lower attachment. If so, the top arm APPEARS to be free to move and the blade tension adjuster has been set to give a nice 'ping' (technical term!) when tapped. The basic principle of these things is such that I wouldn't have expected much to go wrong. I don't have a handbook for it (bought 2ndhand) so don't have a reference for problem areas. The blade holders are rectangular steel clamps which have 'wedges' to seat on the ends of the arms. Possibly I'm clamping the blades slightly off vertical and inducing stress? Will try again.

Rgds

Bill

[KWILParticipant @kwil]

Go to Hegner UK website, there are illustrated parts breakdown diags that may help.

http://www.hegner.co.uk

[Cornish JackParticipant @cornishjack]

Thank you KWIL. That could be most useful. Just an update – I have at last managed to cut wood again!! No idea what caused the improvement, although I stripped the main bits, oiled the bearings and took great care lining up the blades in the clamps. Still managed to break two more blades but that particular job has been completed

Thanks to all

Rgds

Bill

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