Demtech Pro-Wedge VM-20 Operator's Manual page 18

Rev. F, December 2020
Note 1:
Make sure if using a split wedge with an air channel pin, that the notch is cut in the
end of the doubled-up piece of material as it is detailed on the material template. This is to
allow clearance for the air channel finger when the material set-up piece is in place.
With a Phillips screw driver remove lower frame chain cover to expose the
lockdown bolt for the front lower contour roller (#4, Figure 6).
Using a 6mm Allen wrench, loosen the lockdown bolt and then temporarily
adjust the front lower contour roller down, clockwise, away from the wedge
using a 4mm Allen wrench on the end of the roller (this will give you a fresh
starting point and you will make a final adjustment on this roller later).
Using a 13mm open end wrench, loosen the lockdown bolt (hex head) for the
rear lower contour roller (#3, Figure 6). You can now adjust the height of the
wedge by adjusting the rear lower contour roller up or down with a 4mm Allen
wrench at the end of the roller. Once the desired position has been achieved,
tighten the lockdown bolt (hex head) then check the adjustment again to make
sure it did not move when tightened.
Note 2:
The most important adjustment is the positioning of the wedge in relationship to the
lower nip roller (#2, Figure 6). The distance between the lower tip of the heating wedge and
the lower nip roller should be slightly more than the thickness of the material you will be
welding. The distance is set by adjusting the rear lower contour roller (#3, Figure 6) up or down.
Note 3:
When adjusting the lower contour rollers (#4) and (#3) rotate them both to the
right (counterclockwise) and up so that in their adjusted positions the rollers are closest to the nip
roller (#2). Also because the rear contour roller (#3) is forcing the wedge up against the upper
contour roller spring tension, you may notice the roller will still spin with your fingers. This is
normal. The amount of resistance of the roller when turning it with your fingers does not matter.
Note 4:
The lower contour rollers are mounted to the lower frame on eccentric cams that thread
onto the lockdown bolts. When adjusting, you may need to work the 4mm Allen wrench and the
6mm Allen wrench for the front contour roller (4)) or the 13mm open end wrench for the rear
contour roller (3)) simultaneously to rotate the roller smoothly.
Warning!
If the rear lower contour roller is adjusted too high, there will not be enough clearance
for the top sheet to travel through the welder and it will be pinched between the top of the heating
wedge and the upper nip frame. This will result in loss of welding nip pressure and an inconsistent
weld.
Pro-Wedge VM-20 Operator's Manual Page 15