Drag Knife - Securing Material

Why not simple duct tape on all 4 sides?

Hi, yes I had considered this but I'd prefer to have the cut pieces to stay secure and not move about once they are cut/free. I was concerned that given the SC drag knife has a plastic head (trying to think of a better word) in contact with the material it could cause a larger or thinner sheet of material to buckle as it twists and turns, or that once a piece is cut out it could move the piece away into another toolpath. Perhaps these are unfounded concerns. Has anyone tried this, thanks.

Ah, I see, then yes, that sticky pad would be good.

From what I see on youtube, people use duct tape, even on big machines.

Just try it before expending money on the sticky pad.

Surely the best solution would be a vacuum table?

Not too difficult as a DIY project.

MDF vac bed - you can put 2 or 3mm MDF down on the Vac bed - or build this into the vac bed and it will work a treat. The material will be held through the MDF. sounds mad.. but works well

I've done a lot of work with both the Stepcraft and Donek drag knives, and I would say Rory's right - a vacuum table is really the only way to go.

If you fix only around the edge, I've found the knife will warp the material enough to snag on it and... destroyed work sheet. I've not tried contact adhesive - I cut 100 - 200 pre-printed A3 sheets in a go, so prepping and peeling each one would be a nightmare.

You can get great results with a basic vac table - clamping and releasing takes seconds, and the work sheet is held over its entire surface area. Seriously - you'll save yourself hours and hours!

For the Stepcraft dragknife I use a 3mm MDF sheet on the vac table as a spoil board - enough vacuum permeates to hold the sheet firmly. You MUST be careful though to make sure that the sheet you're cutting is ABSOLUTELY FLAT. If there are any 'bubbles', ridges or raised areas, the knife will snag on them and will rip your worksheet... I know through bitter experience. I spent hours trying different depth settings on the knife, different Z pressure etc. before realising that the worksheets were not clamping absolutely flat. I now use a wooden bar as a squeegee to make sure that the sheet is seated properly.

The table of my particular Stepcraft is not sufficiently flat to use the Donek knife with an MDF spoil board (the Donek does not have a spring-loaded mechanism to compensate for uneven depth). Unfortunately both the Stepcraft MDF table and my vacuum table itself have a pronounced downward bow towards the middle - approx 1.5 mm. But I use the Donek successfully for cutting 2mm Plastazote foam, using a 3mm galvanised rubber mat for the spoil board. This works well enough for the foam, but not really for paper - you really need a hard cutting surface for that.

I also made a little jig to zero the Stepcraft dragknife exactly on the corner of a paper sheet. Most of the cutting I do is on pre-printed sheets, so the dragknife must align with the print registration to get consistent results. I'll post some info on that and a DXF in another thread.

All the paper and foam for this packaging is cut on the Stepcraft.

Hi guys,, i'm trying to figure out if buyig a stepcraft could be a good shot for my need. One of the things i'd like to do is cuttin dry glass fibre with a drag knife, if i use a vacuum table could the hoover give enoght clamping force (at least for a while) or do i need to buy one of those pumps?
thanks