Routing Grooves

[SteveF]

i have a friend that has thrown me a small job
mdf 18mm
wants it grooved 3mm deep x 10mm wide x 10mm spacing between each groove
how would you do quickly? accurately? Safely?
assuming you had any equipment apart from cnc

Steve

 

[Cordy]

Perhaps make a jig on THESE lines only longer of course

 

[paulrockliffe]

Single pass with a router using a 10mm cutter - though this is an unusual size, so I don't know if they exist.

Then the key to doing these quickly is to be able to reference the next pass off the previous one, so some sort of custom guide that has a 10mm x 3mm key to sit in the groove and position the router where the next groove goes.

Might not even need the guide clamping in place, which would save some time. If it does, fix the clamp(s) to the guide so that they are quick to reset.

 

[Phil Pascoe]

3mm x 10mm? You'll be lucky to find the cutter, I'd think.

 

[marcros]

a 10mm cutter will be easy enough to get wont it?

 

[Woody2Shoes]

I'd buy a Trend CRB 7 (or I'd make something similar). The technique is one of the seven shown here (using the first slot as a reference for the second). Just like the router table solution mentioned above but upside down! https://www.youtube.com/watch?v=gdGQi22kUC8

10mm router bits are easy enough to find - trend do them, or LIDL/ALDI if your timing's right. e.g. http://www.screwfix.com/p/trend-double- ... 19mm/32974

Cheers, W2S

 

[Phil Pascoe]

By the nature of a groove I presumed he meant with rounded corners not like a housing. A groove to me is round bottomed.

 

[marcros]

ah, i never thought of rounded bottoms.

 

[Phil Pascoe]

I could be totally wrong, of course. My wife says I usually am.

 

[sunnybob]

ah, i never thought of rounded bottoms.

Strange, i rarely think of any thing else.

 

[novocaine]

depends how many groves, if it's 10 max I'd measure and mark then reference of 1 face.
if it's 50 across an entire face I'd make a fence which references of the last groove. as said though, if it's a rounded bottom I'd make the reference 1mmx10 so it sits down but doesn't interfere to much, you can always trim the edge if needed.

oh, I'd also use the edge of the base plate for reference not the cutter.

 

[WellsWood]

ah, i never thought of rounded bottoms.

Strange, i rarely think of any thing else.

Beat me to it Bob.

This is easy to do with just a straight edge clamped to the workpeice. Work out the offset from router base edge to cutter and use this dimension to find your first mark, mark both edges at 20mm intervals from your first then just move the straight edge one mark at a time. Done in no time once you've got your 10mm cutter

 

[SteveF]

Thankyou all

I think the straight edge and 20mm intervals will do for this job
and flat bottoms
Steve

 

[Sheffield Tony]

if it's 50 across an entire face I'd make a fence which references of the last groove.

Do you not get a sort of Chinese whispers effect ? If you have any slop, is groove 50 likely to still be straight ?