Worktop jig

[HomerG]

Hi all, new to using a worktop router jig and just purchased a HIB Topform jig and made a few 90 deg mitre joints.

Something slightly puzzling, the jig makes good joints but when bolted up, consistently leaves a 3mm gap at the back of the left/right section. In other words, once the back worktop is pushed up to the wall there is a 3mm gap between the left or right sections and the back wall.

It's not too much of a problem but I wondered if this is normal/acceptable. I can't imagine that a CNC machined jig, no matter how cheap can be out by this amount. In all other respects it is spot on.

Also, as the jig is slippy melamine onto slippy worktop, I find that I can't guarantee that it won't move slightly whilst routing. I'm using quick-grip type clamps but they do apply a fair amount of pressure. Best to use G clamps and pads?

Thanks.

 

[foxhole]

Gap is almost certainly down to movement during routing, need to be solid ,new clamps, quick action are fine if good quality.

 

[steveuk]

it defo sounds like the jig is moveing. i only ever use G clamps, with plywood packers to avoid damge to the face side.

Steve

 

[rxbren]

maybe the peg holes are out by a few mm

 

[HomerG]

Knew I'd cause confusion by trying to explain in words so here's a drawing.

Untitled

• HomerG
• 25 Apr 2013
• 1

Hopefully you can see the offset at the back of the female part. Now, this comes out very consistently at 3mm. The jig doesn't move in the direction that would cause this. The male part is referenced by the dowels against the postformed edge, the female part by dowels against the cut edge and they don't move. The jig only moves in a way that would open or close the join, if you see what I mean.

Maybe I'm being a bit anal about this as the joins are good, don't even need any filler. If you think it shouldn't be happening though, I'll contact the manufacturer.

Thanks again.

 

[kbdiy]

Being even more anal - from my days in the kitchen fitting business this was known as a 'butt & scribe joint'

 

[Harbourwoodwork]

What size:
guide bushand router cutter? are you using

 

[HomerG]

Just standard 30mm/12.7mm. I think it must be the jig.

 

[Harbourwoodwork]

The router cutter and guide bush could be out of sinc or it could be a iffy jig ,compare it with another jig