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Routing purfling ledges above 0.210"
https://luthiersforum.com/forum/viewtopic.php?f=10101&t=55466
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Author:  flemsmith [ Fri Jan 20, 2023 4:22 pm ]
Post subject:  Routing purfling ledges above 0.210"

Not a routing expert. Normally use the StewMac bearing set. Tried to order a rabbeting set, but they all use bearing ID's of 3/16" rather than the 1/4" ID of the Stew Mac bearings. I was hoping to get to 0.225" but for now I don't know how to do it. Appreciate any advice, Roy

Author:  bobgramann [ Fri Jan 20, 2023 5:24 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

You might try getting a rabbeting bit that will do .250”. Enlarge the bearing with tape (or with a metal sleeve if you get lucky) until only .225” of the bit can cut. If you use tape, check it often.

I got a rabbeting bit set just for that purpose. The cutter was too big to fit through the baseplate in my laminate trimmer. I don’t remember how I cut the ledge that time.

The other thing that I have done for the bigger purfling ledge was to use a 1/4” spiral downcut bit with a bearing edge guide on the laminate trimmer. That approach requires a lot of attention to the orientation of the router and bearing as you go around the guitar.

One other approach would be to use the smallest bearing that you do have to cut the biggest ledge you can and then finish it off with a gramil and a chisel. I haven’t done that, but it ought to work.

Author:  flemsmith [ Fri Jan 20, 2023 6:26 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

Good ideas, thanks. For now I'm trying to figure out if I can make 0.250" work. I do have the Rabbeting set. Roy

Author:  J De Rocher [ Fri Jan 20, 2023 6:47 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

This older thread on the same topic might help: http://luthiersforum.com/forum/viewtopic.php?f=10101&t=48399&hilit=deep+channel

Author:  Ken Lewis [ Fri Jan 20, 2023 7:59 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

I don't know where it came from but I have a bushing that fits into quarter inch bearings and makes them usable on the
three sixteenth shafts. I'm thinking it came with some bearings I purchased once upon a time. Maybe check some online bearing
suppliers, you may find something.

Author:  Woodie G [ Sat Jan 21, 2023 7:49 am ]
Post subject:  Re: Routing purfling ledges above 0.210"

The type of sleeve Mr. Lewis mentioned may be found at McMaster-Carr: search for 'reducer bearings' - you'll find dry-running harsh environment sleeves with 1/4" OD and 3/16" ID. Best practice is to buy an additional SM bearing of each size you wish to use on the LMII or other 3/16 bearing ID and install a reducer sleeve in each one.

Author:  flemsmith [ Sat Jan 21, 2023 12:43 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

Excellent inputs, thanks all! I was looking at McMaster, but didn't know what to call the 'bushing'. That should work perfectly!

Author:  Colin North [ Sat Jan 21, 2023 1:59 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

Gotta love this forum!

Author:  Clay S. [ Sat Jan 21, 2023 7:53 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

Bob Gramann wrote:
"I got a rabbeting bit set just for that purpose. The cutter was too big to fit through the baseplate in my laminate trimmer. I don’t remember how I cut the ledge that time."

For bits too large to fit through the hole in the base plate we would make a new sub base out of Corian or plexiglas or plywood and either drill a center hole with a hole saw, or for a tight "zero clearance" fit drill a hole large enough for the bearing to pass through and then slowly lower the bit into the sub base and allow it to cut its way through the material. It's possible to do that with the factory sub base but it usually eliminates the possibility of using template guides.

Author:  bobgramann [ Sat Jan 21, 2023 8:56 pm ]
Post subject:  Re: Routing purfling ledges above 0.210"

Yeah, I was too lazy at the time to make another special purpose base. That one would have had to be another doughnut base—too much trouble at the time.

Author:  bluescreek [ Sun Jan 22, 2023 6:25 am ]
Post subject:  Re: Routing purfling ledges above 0.210"

I use my set and I have a 1 and also a 1 1/4 in bit this affords adjustments to anything you need and then some.

Stew macs set as short on doing the full 45 series

Also there are different binding and purflings out there so take not to what you need.

we use a 19 pc set and the bits are extra but are worth it.

Author:  Bryan Bear [ Sun Jan 22, 2023 9:17 am ]
Post subject:  Re: Routing purfling ledges above 0.210"

I have cut the binding channel first and run the bearing in the binding Chanel to cut wide purflings. I suppose I can get away with this because I use laminates solid linings and don’t have any gaps so if I cut through the side wood for the bj dings I’m still riding on hardwood with no gaps.

Author:  dzsmith [ Sun Jan 22, 2023 11:17 am ]
Post subject:  Re: Routing purfling ledges above 0.210"

You may want to see if MLCS has a solution.Image


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