# 51/64" Guide Bushings



## jschaben (Jun 21, 2009)

I've been following some of the recent threads concerning the use and value of guide bushings and got real interested in the possibilities. The one thing that puzzles me is where did the 51/64" size come from?
I made up a matrix similar to the one Bj posted last week crossing all my guide bushings and straight bits with the resulting offsets. The offsets I get with that bushing are kinda odd to be obviously useful. Yet, almost all bushing sets include that one but omit the 3/4" and I have only found a couple of sets that include the 1". 
Seems to me that both the 3/4 and 1" are more useful. 
The only thing I noticed about the 51/64" bushing is that most offset values are in n/32". 
Is that the key??


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## bobj3 (Jan 17, 2006)

Hi John

Not to sure why, but I always turn that the one down to a good size..

The best set I have found is the one below,it's the right price and it comes with most of the guides..the 1" one is the one I use most of the time 

- Harbor Freight Tools - Quality Tools at the Lowest Prices


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jschaben said:


> I've been following some of the recent threads concerning the use and value of guide bushings and got real interested in the possibilities. The one thing that puzzles me is where did the 51/64" size come from?
> I made up a matrix similar to the one Bj posted last week crossing all my guide bushings and straight bits with the resulting offsets. The offsets I get with that bushing are kinda odd to be obviously useful. Yet, almost all bushing sets include that one but omit the 3/4" and I have only found a couple of sets that include the 1".
> Seems to me that both the 3/4 and 1" are more useful.
> The only thing I noticed about the 51/64" bushing is that most offset values are in n/32".
> Is that the key??


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## jschaben (Jun 21, 2009)

bobj3 said:


> Hi John
> 
> Not to sure why, but I always turn that the one down to a good size..
> 
> ...


Hi Bob, thanks for the quick response. That is a good price on that set and the sizes look right to me also. :happy:

I was kinda looking for a set with shorter noses but I got a hacksaw. Would like a set with <1/4" noses as I like to use 1/4" stock for one-off templates.


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## bobj3 (Jan 17, 2006)

Hi John

You're Welcome ,,Like you I wanted a set 1/4" long , the hack saw will do the job but if you have a small pipe cutter ( the 2" long one made for copper pipe in tight corners) it will do a better job  nice and clean and true clean cut, then all you need to do is use the rem on the cutter (on the bigger cutters) to rem it out 

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jschaben said:


> Hi Bob, thanks for the quick response. That is a good price on that set and the sizes look right to me also. :happy:
> 
> I was kinda looking for a set with shorter noses but I got a hacksaw. Would like a set with <1/4" noses as I like to use 1/4" stock for one-off templates.


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## jschaben (Jun 21, 2009)

bobj3 said:


> Hi John
> 
> You're Welcome ,,Like you I wanted a set 1/4" long , the hack saw will do the job but if you have a small pipe cutter ( the 2" long one made for copper pipe in tight corners) it will do a better job  nice and clean and true clean cut, then all you need to do is use the rem on the cutter (on the bigger cutters) to rem it out
> 
> =========


Hi Bob - Thanks for the suggestion. Guess with only two of us in here this won't be a thread hijack.
I have both the mini cutter and the standard pipe cutters but I think the guide wheels are a bit wider than I would like. Haven't got a lathe, that would make things to easy. I was thinking about a way to chuck them in a drill and use a hacksaw to turn them off. Die grinder with a metal cutting wheel would also do it. Soon as I get my air compressor back up.
This isn't a big deal at the moment anyway, hehehe, will probably do my usual and procrastinate until it is:haha:.
By the way, I was going to ask you: How big a cam board do you recommend? I was thinking in the neighborhood of 12x18 or 18x24. 18x24 is about the max before becoming problematic with storage for me. I did make a 1-1/2" dowel, playing around trying to get used to big bits, had a 3/4 roundover bit and a 2x2 that weren't doing anything.  How thick did you make the cams?
I've just about got the hardware assembled. At 40-50 cents per for t-nuts and 0.75-$1 for button head cap screws locally I had to do some serious hardware shopping to get those acceptable.
Thanks again


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## bobj3 (Jan 17, 2006)

Hi John

Board size can be anything you want to be, the bigger the better, the one I have is 18" x 22" ..it has a block on the bottom side so I can drop it in to the router table, no clamps needed to hold it...

The cams are form 3/8" thick to 1 1/2" thick ,I just about always put some scrap stock under the project board,in that way I will not cut into the cam board..

The tee nuts and socket cap screws let the net do the work for you and you can pickup them at your door step..

McMaster-Carr
Tee Nuts, Nuts, Fasteners - McFeely's - Wood & Deck Screws, Supplies

Chucking up the guides in the drill press will be hard one..lathe would be nice..

But do pickup one of the small pipe cutters it's makes it a easy job,you can grind off a little bit of the cutter so it's right at 1/4" 

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jschaben said:


> Hi Bob - Thanks for the suggestion. Guess with only two of us in here this won't be a thread hijack.
> I have both the mini cutter and the standard pipe cutters but I think the guide wheels are a bit wider than I would like. Haven't got a lathe, that would make things to easy. I was thinking about a way to chuck them in a drill and use a hacksaw to turn them off. Die grinder with a metal cutting wheel would also do it. Soon as I get my air compressor back up.
> This isn't a big deal at the moment anyway, hehehe, will probably do my usual and procrastinate until it is:haha:.
> By the way, I was going to ask you: How big a cam board do you recommend? I was thinking in the neighborhood of 12x18 or 18x24. 18x24 is about the max before becoming problematic with storage for me. I did make a 1-1/2" dowel, playing around trying to get used to big bits, had a 3/4 roundover bit and a 2x2 that weren't doing anything.  How thick did you make the cams?
> ...


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## RustyW (Dec 28, 2005)

I have a Pat Warner video in which he shows how he shortens guides. He uses a square wood block with a hole on one side that the threaded end of the guide fits snugly into. Then he uses a disk sander, with the block keeping things square. He then follows up with a de-burring tool. I imagine this would be very quick with brass, in the video he's using a steel guide, and it still goes pretty fast.


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## jschaben (Jun 21, 2009)

Good idea Rusty. I already have a block that will hold a locknut pretty tightly, mistake I can use for a change. Just thread each bushing into it. 50 grit belt in a belt sander ought to make short work of a brass bushing, along with a round file and a mill file to deburr. :dance3:

Thanks for the references Bob. I beat McFeely's on eBay for t-nuts, $6 for 200 1/4" but I think that was a shot in the dark deal. Just got lucky. McMasters looks good for button head cap screws though. Got some 7/8" coming at 18 cents including shipping but that was the longest the guy had. I'm thinking I'll make 3 sets of 10 cams; 3/8", 3/4" and 1-1/4" thick. I've already got a jig to drill the holes in the cams with a router and am makiing a jig to drill and relieve the board for the t-nuts, also with the router.:dance3::dance3:

Hmmm, I really do need a second plunge router....


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## bobj3 (Jan 17, 2006)

You're Welcome John

Good price on the tee nuts 

To keep the price down you can use 10-24 x 1 1/2" Allen cap screws and tee-nuts but 1/4-20 will work just fine..

By the way they make a tool for deburring ,it works on just about anything and a great tool to have around the shop I use it all the time,on many projects, that's removes that little sharp edge,,,clean..on plastic,steel,alum.brass,copper,stainless steel, hardwood, etc.

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jschaben said:


> Good idea Rusty. I already have a block that will hold a locknut pretty tightly, mistake I can use for a change. Just thread each bushing into it. 50 grit belt in a belt sander ought to make short work of a brass bushing, along with a round file and a mill file to deburr. :dance3:
> 
> Thanks for the references Bob. I beat McFeely's on eBay for t-nuts, $6 for 200 1/4" but I think that was a shot in the dark deal. Just got lucky. McMasters looks good for button head cap screws though. Got some 7/8" coming at 18 cents including shipping but that was the longest the guy had. I'm thinking I'll make 3 sets of 10 cams; 3/8", 3/4" and 1-1/4" thick. I've already got a jig to drill the holes in the cams with a router and am makiing a jig to drill and relieve the board for the t-nuts, also with the router.:dance3::dance3:
> 
> Hmmm, I really do need a second plunge router....


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## BigJimAK (Mar 13, 2009)

Geeze John... Hijacking your own thread! <g> Seriously, I'm starting to think through building a cam table myself, so appreciate all the questions you are asking and thank you for any future ones! 

Bob, I'm starting to fully grasp the need for a seemingly (initially) obscene number of routers. I'm working on a prototype for a hallway bench, so I'm developing the templates. I have 3 routers but all three have bits set up in them and I'm far from settled on my template design.

<Putting on my male chauvinist hat and starting to grunt> Some women say "you can never have too many pairs of shoes". So it is with routers!

Bob, on your most router-intensive project, how many routers have you had concurrently set up bits . endge guides / bushings at once? I don't *really* want to collect routers but once thought 3 routers would be enough... no more.


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## bobj3 (Jan 17, 2006)

Hi Jim

Can't have to many routers 

"had concurrently set up bits"
Well I have 7 router tables and 3 hand routers setup ,I use them all at the same time so to speak.. like a little kid going form toy to toy..:dance3:

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BigJimAK said:


> Geeze John... Hijacking your own thread! <g> Seriously, I'm starting to think through building a cam table myself, so appreciate all the questions you are asking and thank you for any future ones!
> 
> Bob, I'm starting to fully grasp the need for a seemingly (initially) obscene number of routers. I'm working on a prototype for a hallway bench, so I'm developing the templates. I have 3 routers but all three have bits set up in them and I'm far from settled on my template design.
> 
> ...


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## bobj3 (Jan 17, 2006)

Hi John

I forgot to say I started to use the 1 1/2" guides ( the OP type) for many of the template project, they come at 1/4" long as a default item..
It's not a big deal to drill the hole out so they fit the same plate, router table and hand routers..

1-3/4" Brass Template Guides - Lee Valley Tools
http://www.leevalley.com/wood/page.aspx?c=2&p=51208&cat=1,43000
http://www.routerforums.com/project-plans-how/10818-bogydave.html
============


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## BigJimAK (Mar 13, 2009)

Lee Valley also makes brass router plate inserts (essentially guides w/o the lip) in a variety of inner diameters if you desire to have the base supported nearer the bit. I've attached a picture.

They are available starting around 1/4" holes and up in 1-1/2" 1-3/4" Router Plate Inserts - Lee Valley Tools and 1-3/16" 1-3/16" Router Plate Inserts - Lee Valley Tools diameters. For handheld use you may want the added visibility of a large bit opening but in a table you may want it closer to minimize your stock catching on the far edge.


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## TWheels (May 26, 2006)

To get back to the subject, 51/64 is the imperial equivalent of 2 cm. Harry would have picked up on this situation immediately. Are there 51/64 guides available in 1 1/2 in diameter to fit the Oak Park base plates?


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## jschaben (Jun 21, 2009)

mftha said:


> To get back to the subject, 51/64 is the imperial equivalent of 2 cm. Harry would have picked up on this situation immediately. Are there 51/64 guides available in 1 1/2 in diameter to fit the Oak Park base plates?


Thanks Tom.... Never occurred to me to check that aspect. 
I dunno about the big ones. I just started looking at the Lee Valley offerings when BJ and Jim referred me there.:thank_you2:


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## BigJimAK (Mar 13, 2009)

mftha said:


> To get back to the subject, 51/64 is the imperial equivalent of 2 cm. Harry would have picked up on this situation immediately. Are there 51/64 guides available in 1 1/2 in diameter to fit the Oak Park base plates?


 
Not in the 1-1/2" size, at least not at LeeValley or Oak-Park.. LV's 1-3/16" sets have it though.


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## BigJimAK (Mar 13, 2009)

Ever since this thread got going, whenever I see a 51/64 guide bushing advertised I come back to the question: Why 51/64"?

I know that it's mighty close to 20mm (.01" over), but 25/32" would be even closer (.006" small). It's *such* a strange dimension. Nevertheless this bush probably does (or did) have a use at one time. Like many things, once someone thinks of the answer, it'll likely be obvious to all.

While surfing through the MLCS web site today I again ran across them. Specifically,I noticed that the ID of these is 5/8", which seems common across brands. Could it be something about the 5/8" ID that led it to being added in the original set? When we use bushings with templates, we register off of the outside, but there's nothing intrinsically impossible about working off the inside dimension. For example, this bushing would fit over a 5/8" cylindrical tendon, permitting center-drilling.

I don't have a clue what the connection might be but I thought maybe if I raised that perhaps something being important about the 5/8" dimension, one of you more experienced folks out there will come up with it.

How does that old saying go??? Curiosity killed the cat...?


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## jschaben (Jun 21, 2009)

Hi Jim - yeah, I posted this one a long time ago. To me, a 7/8 bushing would make a lot more sense. Why the 51/64 is included in virtually every set is also beyond me. h34r:


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## TwoSkies57 (Feb 23, 2009)

_*Apparently popular hinge mortising kits work with standard 3.5" door hinges and 1/2" straight bits when used with the 51/64th OD, 5/8" ID router guide bushings.*_

shamelessly copied from BT3CentralForums


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## bobj3 (Jan 17, 2006)

Hi Guys

At one time Sears Craftsman and PC set the mark for many fixtures, I recall seeing a old manual that listed the 51/64" guide for the sign making kit and the door butt hinges, the long 51/64" guide was needed for the Craftsman sign making jig if I recall..

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## bobj3 (Jan 17, 2006)

Hi Harry

Well I got yours in the mail late today from HF, it's going out Wed.  if I can get out in the SNOW to the POST OFFICE.  yep snow in Denver on Wed.

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## harrysin (Jan 15, 2007)

bobj3 said:


> Hi Harry
> 
> Well I got yours in the mail late today from HF, it's going out Wed.  if I can get out in the SNOW to the POST OFFICE.  yep snow in Denver on Wed.
> 
> =========


That really is appreciated Bob, my right index finger is stiffening, holding it over the PayPal button!
Snow at this time Bob, I reckon that you should seriously consider moving to warmer climes, like here in Western Australia!


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## BigJimAK (Mar 13, 2009)

Those make sense...


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