slippery

hi, i'm a second fix carpenter on house building sites and i spend hours cutting the scribe joitns in skirtings with my chopsaw, then my tennon saw for the straight cut, then a coping saw for the curve. The type of mould is ogee, made from mdf and i only ever cut the right hand side of the board.I had a bit of a try today to make a jig, but don't know where to start, do i need a flush cutter with a bearing or a guide bush? any ideas??

Advertising

Mike

Slippery, the ideal design might be to create a sleeve to slide the molding into with a stop block. The top of the sleeve would be cut to the profile you need, then trim using a pattern following bit. This is a different type of flush cutting bit, the bearing is on the collet side of the bit instead of the far end like a flush cutting trim bit. I am guessing you make a slight relief in the back side of your cut to allow some adjustment? Use wedges and some 1/4" plywood to make a "ramp" at an angle so your router is fully supported at whatever angle you need for relief. If you design your jig with a second pocket you can make guide slots for using a hand file to define any sharp corner details. Another thought might be to use Rotozip bits which could self guide on the smooth part of the shaft. Either way i would use a hardwood edge for your guide, or perhaps some UHMW plastic?(available at Woodcraft) Once you have this jig worked out you can have an unskilled laborer make your cuts freeing you for other things.

__________________
Mike

Mike

The more I thought about it the more I liked the idea of using UHMW with the Rotozip bits. Since they are small diameter they cut more accurate, and they are faster since they are removing less wood. The spiral cutting edges should slice very cleanly with excellent chip removal. The UHMW plastic is self lubricating and should be a dream for your guide, it is easy to work with too. Add in the cost savings realized from the lower bit price and I think this is a real winning idea.

__________________
Mike

slippery

yes i think you've solved the problem of how to do it except that the skirting is made from 18mm mdf and one of the problems i had in my trials was that it was too big a cut for a small bit (needed for the smallest part of the mould) if i have to re set the depth two or three times per cut, it may not prove worthwhile. I am a bit green to routering and iv'e never heard of a rotozip, do you think they can handle the job?

bespokec

Sounds like a top method have you got any pics that might give me a better understanding of this method ?