Air gap query

[Wildvine1066]

Ok so we have a really old Cincinnati guillotine which we cut upto 15mm x 2000 wide steel plate put through a decoupling line. Today I set the blade at 10% of our thinnest material we cut which is 6mm. I set it at 0.6mm in at the ends and .05 in the middle. The problem I’m having is I’m getting bad bur straight away on my 8mm, 10mm, 12mm, 15mm. This is with a new blade in. Can anyone give me some tips regarding what air gap I should be altering it too please

 

[Wildvine1066]

I used to set it at 17 thou each end and 15 thou in the middle and never really had any issues but been told this is too small an air gap

 

[sako243]

Over such a wide range of thicknesses shouldn't you be adjusting the gap dependent on the thickness?

I've no real experience using them but I had to build a controller for a large Kingsland KTSL guillotine (used for 4m cuts on up to 6mm steel) and it had hydraulic adjustment to alter the blade gap and it was varied often between the thinner 1mm stuff and thicker 6mm stuff.

Depending on the material type they also adjusted the rake angle to produce cleaner cuts.

 

[Welderpaul]

Our blade gap adjusts from 1 to 10mm. If you forget and leave the blade gap too large it just acts like a pressbrake and folds the material over.

I can't see one blade gap suits that full range of material thicknesses?

 

[sako243]

The rule of thumb I was told by the guys who operate it is that you should have a line halfway through the thickness of the material. The first half is cut by the blade the other half is sheared off. That's the optimal setting as others will wear the blade quicker or won't result in as clean a cut.

 

[Wildvine1066]

Yes it will be getting modified for hydraulic air gap adjustment in the near future as it is a very old guillotine but for the past 15 years we have cut upto 15mm x 2000mm even 20mm at one point, but I used to set it at 17 thou at both ends and 15 thou in the middle. We had a firm called simach from Scotland come down and that’s what they told us to set it at. It was cutting fine and finally ended up with bur off the blade becoming blunt. Just this time I’d though I’d go with 10% of the thinnest material we cut now which is 8mm but on the first cut it had bur, maybe I’m best resorting back to 17 thou which is 0.432mm