# Specialist bit needed for making spectacles



## jwmspencer (Jan 15, 2014)

Hi, 

I am designing a range of spectacles. 

To insert the lenses, the frames need a groove around the inside of each eye hole. 
This groove should have a v shaped profile. I would like to cut this groove using a router table with a router bit that has the correct profile. Ideally this router bit would have a bearing so that I can run it around a template. 

However I cannot find any router bits like this (Please see attached drawing)

Any ideas where I could get something like this? Your help would be greatly appreciated. 

Thanks
Jack


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## DaninVan (Jan 1, 2012)

Hey, Jack; welcome!
There was a very similar thread/question running here a few months back. There was a lot of discussion; hopefully another member with better archive skills (than me) can dig it out for you.


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## Semipro (Mar 22, 2013)

Welcome to forum Jack

http://www.routerforums.com/router-...yeglass-lens-groove.html?highlight=spectacles


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## jwmspencer (Jan 15, 2014)

Thanks guys! Really helpful, I will look through that thread now.

Jack


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## mark greenbaum (Sep 26, 2010)

I have made eyeglass frames from 14KY & 18KY gold, and I used a Busch 90 degree diamond setting burr. You could equip the shank with a small set collar to act as a bearing.

12 Pieces HSS 90 Degree Hart Bur Assortment

This is similar to what I daily used to cut seats for diamond, and what I used to route the groove for the lenses. I did not use a bearing guide (just went carefully slow, and used patience). I hope this helps.


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## jdowney (Oct 9, 2010)

There was a similar question a few months ago... a Hart burr seemed like the way to go on that one too.

If it's a one off project, best to do it with a burr freehand. Not that hard really. If it were some kind of production project, then a bearing guided bit is how I would go too. I'd use a flush trim/v-groove bit, with some sort of holding jig designed to the dimensions of the bit.









I would also cut the inside groove first, then trim and shape the frames (maybe that discussion was in the other eyeglass thread). Easier to hold the work in a jig if it's not shaped yet, and re-cutting a groove in a blank is fairly easy compared to shaping the wood frame down. If something goes wrong routing (no, that never happens to me either! :laugh: ) then all the shaping work isn't wasted.


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## jdowney (Oct 9, 2010)

DaninVan said:


> Hey, Jack; welcome!
> There was a very similar thread/question running here a few months back. There was a lot of discussion; hopefully another member with better archive skills (than me) can dig it out for you.


http://www.routerforums.com/router-bits-types-usage/43776-rabbeting-router-bit-bearing-sets.html

Here it is. Easy to find when you only have a dozen or so posts to look back through 

I see now that thread is where I remembered the bit from  I'd seen them for years but assumed it was some kind of laminate bit and they never really registered.


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