# Collar to work clearance



## DaleFiorillo (Oct 30, 2017)

What is a safe clearance between the end of the collar and the work surface? 1/16, 1/32, or 1/64 ?
I made a great offset chart for my 3 bit/7 bushing kit, but when it came to pattern thickness my
lack of experience with bushings stopped me. The collar lengths are 5/32, 5/16, 9/16, and 3/8. 
Of course my favorite template material is 1/4”. I can see some serious grinding in the near 
future!


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## DesertRatTom (Jul 3, 2012)

I have a short set, all about 3/16ths, so they are clear of the workpiece automatically. With 1/4 inch MDF for your pattern. For loinger bushing collars, use thicker MDF for patterns, or grind the collars down. Of course, with most patterns, you're using a bearing as your guide and pre cutting most waste away on the workpiece with a band saw or jig saw.

There are other uses where a bushing is good, but you must also make certain the collet is centered in the base or you will have wandering lines unless you keep the router oriented the same way throughout the cut--that's if the collet, bit and bushing are not centered


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## DaleFiorillo (Oct 30, 2017)

While I’m buying that 5/8 Forstner bit tomorrow I’ll get some 1/4 sheets of MDF and play
around til the sub-base parts arrive. 
Thanks


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## DesertRatTom (Jul 3, 2012)

DaleFiorillo said:


> While I’m buying that 5/8 Forstner bit tomorrow I’ll get some 1/4 sheets of MDF and play
> around til the sub-base parts arrive.
> Thanks


I think that's the best way to learn and gain proficiency before working on expensive wood.


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## JOAT (Apr 9, 2010)

DaleFiorillo said:


> Of course my favorite template material is 1/4”.


Tried 1/4". Once. My templates/masters are now always made from two layers of 1/2" plywood glued together. All in all much easier setup, and I think much safer, and easier to maneuver, as plenty of material to get a good grip on.


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## hawkeye10 (Jul 28, 2015)

JOAT said:


> Tried 1/4". Once. My templates/masters are now always made from two layers of 1/2" plywood glued together. All in all much easier setup, and I think much safer, and easier to maneuver, as plenty of material to get a good grip on.


Theo are you saying you make templates out of 2 layers of 1/2" ply? That is one inch!!!


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## JOAT (Apr 9, 2010)

hawkeye10 said:


> Theo are you saying you make templates out of 2 layers of 1/2" ply? That is one inch!!!


Some people call them templates, others patterns, I call them masters. And yep, they are one inch thick. I have been doing them that way for years and years. And they work very well for me. I also tried double stick tape, and rubber cement, to hold them to the piece being routed, once each. Now I nail my masters to the part being routed, been doing that for years and years too, and that works very well for me too. 

Here is a picture of three of my old masters, all one inch thick. If you look close, you can see the nail pilot holes drilled in the lower right master, doesn't look like I had drilled them in the other two, or maybe just can't make them out.


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## tomp913 (Mar 7, 2014)

Maybe it makes a difference if the template/pattern/master (seems to me we had a discussion about terminology not too long ago) is internal or external? The patterns I made for my turtles were made of 1/2" MDF, but I screwed them to the blanks and used a top-bearing pattern bit to trim them to finished size - I would agree that the thicker pattern may be a better choice in that application. However, I think that 1/4" hardboard or MDF is good for an internal template where the template guide is riding along the inside and, more importantly, there is usually much better support for the router base - although a it's probably a wash in either case if an extended/oversize base is used on the router.

The floor/base of my turtles has notched cutouts for the various appendages and I made a template to cut the notches. Used scrap 3/4" plywood, biscuit joined the legs and then tied everything together with a top layer of 1/4" hardboard - never been accused of skimping on fixtures. It worked OK, although it was slow, and I messed up by not making the legs long enough to give me an adequate lead in to the notch. The notches direct off the bandsaw were too rough so I came up with the final iteration - laid out the finished size of the notch and roughed out the fixture on a piece of scrap 1/2" ply. Then tacked some scraps of 3/16" edge banding around the profile and trued up the notch from the other side with a bottom- bearing trimmer bit. This was the keeper; roughout the notches on the bandsaw - I leave enough material in the corners so that the bit cuts a clean radius in the corner that matches the round-over bit I use when finishing the various parts - and then clean up the notch using the template.


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## JOAT (Apr 9, 2010)

tomp913 said:


> Maybe it makes a difference if the template/pattern/master (seems to me we had a discussion about terminology not too long ago) is internal or external? The patterns I made for my turtles were made of 1/2" MDF, but I screwed them to the blanks and used a top-bearing pattern bit to trim them to finished size - I would agree that the thicker pattern may be a better choice in that application. However, I think that 1/4" hardboard or MDF is good for an internal template where the template guide is riding along the inside and, more importantly, there is usually much better support for the router base - although a it's probably a wash in either case if an extended/oversize base is used on the router.enough to give me an adequate lead in to the notch.


Similar to how I do mine, except my masters are 1", and nailed on. My router is in the table, with a top bearing bit. I use the 1" masters for inside routing also. Use the master, mark the inside -of the blank, drill a hole or two, rough cut with a sabre saw. Tack the master down, and have at it. The 1" master not only give a better grip, but I can buy nails just long enough that I can smack them flat on the master (not usually done)I, and they will still not penetrate the blank, quite. The 1" also means I don't have to be so precise on where the bearing rides on the master 

I managed to dig up one of my old masters, that was used for routing inside a blank. I don't find it any different from routing the outside, just a couple more steps first. Works for me, and like I said, been doing this stuff for years, and no issues. Oh yes, I also put any pertinent information on my masters - the reason it says flip, is because these are outside pieces, so needed a good side of the plywood on the outside, hence the flip. You can clearly see the nail pilot holes drilled in this. Many more than actually needed, usually, but every once in awhile the nails will start dancing out, which means not enough nails - sometime just whacking them flat works, but usually just use more nails, then it's easier to pry the master off, rather than working on fully driven nails.. And no nail holes show on the finished whatever. Never tried screws, and don't plan to.


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