# Why do threaded guide bushings have right-handed threads



## sandyalexander (Jul 19, 2009)

Like many of those reading and writing here, I have seen my guide bushing come loose: it ruined both the bushing and my dovetail template.

Looking more closely at the bushing I realized that it floats somewhat relative to the base. That means that as soon as it starts to bear against the template guide, that pressure is transferred to the shaft of the bit and will cause the bit to start binding within the bushing. The friction of a 1/4 in shaft rotating clockwise inside a 1/4 in bore then more or less instantly unscrews the bushing from the ring nut securing it to the router base, if it can. Remember that rotating the bushing clockwise is equivalent to rotating the ring nut counter-clockwise.

Bicycle manufacturers recognized this problem many decades ago, and so right-side pedals have left-handed threads securing them to the crank. That way the pedal's rotation relative to the crank doesn't unscrew the pedal when its bearings start to rust.

If threaded template guides were built with left-hand threads, the bit's rotation would tighten the nut rather than loosening it. We might still need vise grips to get the nut off, but at least we wouldn't need to use them to put the nut on!

Sandy


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## bobj3 (Jan 17, 2006)

Hi Sandy


Router Bushing Spring Washer
Router Accessories

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## xplorx4 (Dec 1, 2008)

You have made a good point, I will have to check out B J's post in a bit.


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## sometimewoodworker (Feb 13, 2009)

bobj3 said:


> Hi Sandy
> 
> 
> Router Bushing Spring Washer
> ...


There is an interesting study with video if the effects of vibration, admitedly the used a helical spring washer not a crinkle washer, that showed that the anti vibration washer caused the bold to loosen very much sooner than with no washer. 

Bolt Science Web Site

The only way they found was to use a lock nut.

While there is no data that shows the effectiveness of a crinkle washer in this situation I would be dubious of its usefulness.

The best way would be to size the bushing and base to eliminate any play.


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## Charles M (Apr 10, 2006)

They are right hand because they rub against a template and with correct feed direction the pressure of the template against the guide will cause it to tighten. The bit should never contact the guide.


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## Bonehead V.2 (Aug 23, 2009)

I'm sorry gentlemen, but you are all incorrect.

The threads are that way because that router was meant to be used in the southern hemisphere where things turn in the opposite direction.


Glad I could help.


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## Old_Chipper (Mar 30, 2009)

It's all about dollars and cents. Cheaper to setup and manufacture RH threads than LH. Has to do with the tooling and machine rotation.


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## bobj3 (Jan 17, 2006)

say what hahahahahahahahahaha

It's a counter balance thing because the earth swings to the left.. hahahahahahahaha

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Old_Chipper said:


> It's all about dollars and cents. Cheaper to setup and manufacture RH threads than LH. Has to do with the tooling and machine rotation.


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## BigJimAK (Mar 13, 2009)

+1 on Charles M's post.

Sandy, if your bit can touch the inner edge of a particular guide with a particular bit installed then one of the following is true: 

* the bit is oversized
* the guide is undersized
* router has excessive runout
* the setup allows excessive movement of the base in relationship to the bit, or most likely
* the baseplate that holds the guide is not perfectly concentric with the bit. Bases have a small amount of "adjustability" in them and should be centered for very close tolerances. Various companies sell kits for this, if you do not otherwise have the means to do so. Either that or your router base hole is oversized and should be replaced (no big expense).

The bit should be incapable of touching the guide (at least without dropping it or some extraordinary force).

Charles says it correctly, the threads are right handed because when moving the bushing against the edge of wood (where it should rub) in the correct direction, it tightens the threads. From what I hear on here, people who need to use guides in the other direction add a drop of (non-permanent type) loctite to the threads to ensure they don't come loose prematurely.

Charles M (above) is our resident Freud employee (thanks for being here, Charles) and is giving you the serious answer.

It's tough to beat BJ's answer though!


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## Gene Howe (Jul 10, 2007)

I'll bet BJ's solution is the best one....his usually are! 
I just wrap the threads with Teflon tape.


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## rtunas (Jul 14, 2009)

It all has to do with the old adage of righty tighty lefty loosey. Therefore in order to tighten it there must be right hand threads. I remember the old days when on my 63 Pontiac I had left hand lug nuts on the left and right hand on the right. Bot were people confused with that one.


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## levon (Sep 14, 2008)

"Charles says it correctly, the threads are right handed because when moving the bushing against the edge of wood (where it should rub) in the correct direction"

doesnt the guide move in both directions depending on routing the outside or inside of a template?


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## harrysin (Jan 15, 2007)

Correct answers are scattered throughout this thread, so to summarise, template guides are more commonly used with female templates and that being so the router goes in a clockwise direction, tightening the thread. A guide/cutter combination should allow lots of clearance, the main benefits being that you can see what the cutter is doing and the swarf does not compact and create heat.
After writing the above, I must remind all members that I personally think that these threaded Brass guides should be melted down for scrap. They don't compare for safety and overall superiority with the ONE PIECE guides which are usually made from steel. Makita, Hitachi and several other wise makers of routers have long since gone down this path, I'm hopeful that one day even Bj will agree with me! (I'm always the optimist)
Take a look at this 50mm one piece guide that I made from alloy, the material is unimportant, the one piece compared to the three piece guides is completely SAFE, no chance of flying apart, as they are prone to.


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## dutchman 46 (May 23, 2007)

Hello Bob! Just curious, Where abouts in Mich are You, I come from Holland Mi. That (rightie,tighty) term has got me in trouble more that once. Have come close to breaking a few things as well.


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## jschaben (Jun 21, 2009)

levon said:


> "Charles says it correctly, the threads are right handed because when moving the bushing against the edge of wood (where it should rub) in the correct direction"
> 
> doesnt the guide move in both directions depending on routing the outside or inside of a template?


Hi Levon - Actually, makes no difference whether you are on the inside or outside of the template, routing direction, relative to the bit/bushing are the same.
*Right hand rule*.

By the way Harry - both thumbs up on your new signature:sold:


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## bobj3 (Jan 17, 2006)

Hi Walter 

All I say how do you do inlays with that tank of a guide.

- Harbor Freight Tools - Quality Tools at the Lowest Prices
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http://www.youtube.com/watch?v=1kXOg23pGeA
http://www.youtube.com/watch?v=MS4AmNQ34wY

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harrysin said:


> Correct answers are scattered throughout this thread, so to summarise, template guides are more commonly used with female templates and that being so the router goes in a clockwise direction, tightening the thread. A guide/cutter combination should allow lots of clearance, the main benefits being that you can see what the cutter is doing and the swarf does not compact and create heat.
> After writing the above, I must remind all members that I personally think that these threaded Brass guides should be melted down for scrap. They don't compare for safety and overall superiority with the ONE PIECE guides which are usually made from steel. Makita, Hitachi and several other wise makers of routers have long since gone down this path, I'm hopeful that one day even Bj will agree with me! (I'm always the optimist)
> Take a look at this 50mm one piece guide that I made from alloy, the material is unimportant, the one piece compared to the three piece guides is completely SAFE, no chance of flying apart, as they are prone to.


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## Marco (Feb 21, 2009)

I'm glad this thread was started because I was too embarassed to come out and ask how you keep your guide bushing nut tight?................ I figured being a newbie I was doing something wrong which still may be true. With that said I do know how to tighten a nut and after the second time of the nut coming loose I know exactly what it sounds like when it becomes loose.......... the second time it came loose it was almost catastophic for a body part.... fortunately it only took out a bit and a bushing.

For now I will go with the teflon tape and keep an ear out!


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## levon (Sep 14, 2008)

hi Marco,

you can have these shipped to you pretty reasonably from atlanta or pick them up when in atlanta.

Router Accessories


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## harrysin (Jan 15, 2007)

bobj3 said:


> Hi Walter
> 
> All I say how do you do inlays with that tank of a guide.
> 
> ...


I'm not sure if this reply of yours was for me Bob, MY name being HARRY, but if it was Bob my dear, dear but stubborn friend, then look at the last two shots and tell me which one makes more sense, the large one that allows perfect vision, or the small one which gives no view of the cutter. As for the type of inlays that YOU refer to, they appear to be rather limited, most of the examples that I've seen are basic things like bow ties. These following shots from a few of my previous projects, all done using various large template guides are to illustrate to beginners, the wide variety of ways in which to take away the plainness of a project.


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## allthunbs (Jun 22, 2008)

Marco said:


> I'm glad this thread was started because I was too embarassed to come out and ask how you keep your guide bushing nut tight?................ I figured being a newbie I was doing something wrong which still may be true. With that said I do know how to tighten a nut and after the second time of the nut coming loose I know exactly what it sounds like when it becomes loose.......... the second time it came loose it was almost catastophic for a body part.... fortunately it only took out a bit and a bushing.
> 
> For now I will go with the teflon tape and keep an ear out!


Hi Marco:

Now, you've opened the proverbial can of worms. Almost every router comes with the ability to implement templates, except some sort of idea how to do it. The other frustration is that it seems that no template guide will fit another router. Some routers use large threaded retaining rings, others use two or three screws and yet others complicated bayonet bases. If you have three different routers, it is conceivable that you'll have to get three different sizes or types of guides. 

The guide will fit into the base plate. The bit will protrude through the guide. Take a 1/4" thick strip of plywood or wood, set the router on top of it, butt the guide up to the strip and push the bit through the template guide. If the router were turned on, you'd be cutting a groove dictated by the position of the strip. Neat tricks here. Search the forums for "Template Tom" (Tom O'Connell) and and HarrySin (Harry Sinclair) for a myriad of their, and others, creations.

There are two basic philosophies of guides, brass and steel. 

The steel often rely on an external attachment method. For example, my M12V used to have two tabs and the guide was attached to those tabs with screws. I think in the photos that Harry shows, the router there is his Makita. It attaches the guides in the same way that the Hitachi does. However, my 2nd M12V is for table and large bit use and I've taken off the tabs to give me a huge hole to allow for the large bits.

Steel threaded guides with steel nuts will never hold tight. They will always work loose. That is just a property of steel and why lock washers were invented.

The other philosophy is brass and the method that Rob Rosendahl may have pioneered. This method has been picked up by LeeValley. I've not tried to interchange the parts but it might be possible. Maybe Deb may have tried it.

Brass on brass does not seize. When thumb tightened, the brass has sufficient friction that it won't move. Should the bushing get dislodged somehow, the brass, being soft, will not damage the bit, instead it will take the damage. Because the brass will take the damage, the potential of injurious shrapnel is much reduced. I've never had a brass guide fail.

Not all brass is equal. There are manufacturers that consider Porter-Cable routers to be some sort of standard. PC uses a 1 3/16" steel template guide. LeeValley makes brass 1 3/16" guides and the largest is 1". The problem with this size is the depth of cut. There will be instances where the bit is just a tad short of what you need. The Porter-Cable philosophy will obstruct the collet causing a shortened depth of cut. 

Alternatively, OakPark and LeeValley both make 1 3/4" template guides. I've standardized on the 1 3/4" guides. The 1 3/4" guide fits into a 1 1/2" hole with a 1 3/4" shoulder. The collet will fit inside the guide thus not restricting the router's depth of cut. They allow for greater visibility and more sizes are available. Harry swears by his 40mm brass guide for his Makita and OakPark has a 1 1/2" guide that is only 1.9 mm off that. The OakPark system cannot handle anything larger than the 1 1/2". 

Now, there are adapters that will allow you to add brass template guides to other manufacturers philosophies. Harry had one of these fail on him. He was not happy. He has a non-OakPark baseplate to which he attached an adapter to accept the brass guides. The adapter came loose, not the guide. The moral of the story is don't mix steel with brass. Buy or make the OakPark baseplate and use only the 1 3/4" brass guides. 

In summary, buy only brass guides and locking rings. Brass sticks to brass and doesn't come loose when finger tightened (so the experts say.) Brass, should it come loose, will take damage but won't damage your bits. There are several router manufacturers that make steel template guides. I really don't know why. I think they feel they own a stable of products and don't need to know too much about any particular one. There are actually vendors that sell them too. One of the problems you'll encounter is that the template guide will get in the way of the collet chuck. The solution is to make the template guide larger so the collet fits within the locking ring. There are only two organizations that recognize this fact, OakPark and LeeValley. Both make the 1¾" OD template guide.

I welcome any comments to this. I sort of extracted it from my notes and feel that there's more to the story but I haven't got all of it, yet.


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## istracpsboss (Sep 14, 2008)

Good write-up, Ron. 

I'm never quite sure why there is a prejudice against steel bushings, unless you are talking of ones that are retained by locking rings that might work loose. I noticed the ultra large one we looked at last week fell into this category. 
Trend, for example, make steel bushings that are secured by two countersunk screws and I've never had those come loose, particularly as I put a Nyloc nut on the back of them.

Cheers

Peter


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## harrysin (Jan 15, 2007)

Yes Ron, a pretty good summary of what has been said in the past. I'm still however waiting for someone to tell me what's wrong with the super safe versatile Makita/Hitachi system which tradesmen here have running most of the day with no possible chance of a guide coming loose, plus of course the ability to make any size required very easily. The first shot is of a guide that I fabricated from Aluminium, the disc is from a very old computer hard drive. The other shots show that three piece Brass do get damaged, this one I repaired for a fellow member. You might ask how come I have a set of the Brass guides that I condemn so vehemently. The answer is simple, I would never condemn something that I hadn't extensively tested.


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## bobj3 (Jan 17, 2006)

Hi Harry

Sorry
Must have been a Freudian slip ,when I see your name Walter's face comes to mind and his mind set...
I still don't see your inlay set or did I miss it..

By the way Ron your wrong on many points about the guides, PC is the base for all the guides in the states, Oak Park is not the same as the RWS they are the users of the OP products..not the makers..
Many of the funky routers from over the pond have the funny guide set ups , in the states once the plate is set we don't need to reline the guide if we switch one out ...unlike the funky routers...

Veritas®
http://www.leevalley.com/wood/page.aspx?c=2&p=41776&cat=1,43000,51208
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harrysin said:


> I'm not sure if this reply of yours was for me Bob, MY name being HARRY, but if it was Bob my dear, dear but stubborn friend, then look at the last two shots and tell me which one makes more sense, the large one that allows perfect vision, or the small one which gives no view of the cutter. As for the type of inlays that YOU refer to, they appear to be rather limited, most of the examples that I've seen are basic things like bow ties. These following shots from a few of my previous projects, all done using various large template guides are to illustrate to beginners, the wide variety of ways in which to take away the plainness of a project.


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## jschaben (Jun 21, 2009)

I dunno, my limited experience seems to have been just the opposite of everyone elses. I have never had a steel bushing come loose but I have had brass bushings I had to retighten after every pass. I use the wave washers on the brass ones all the time now and they work very well. 
The only thing reason I can think of is my Hitachi M12VC, that I had the problem with, has a steel guide adaper. Maybe something about steel on steel resists slipping and brass on steel doesn't want to hold as well.
I haven't had any such problem with the Freud 1700 which uses a brass adapter. Then again, I don't use the steel bushings much anymore since I got a set of short barrel brass.


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## allthunbs (Jun 22, 2008)

istracpsboss said:


> Good write-up, Ron.
> 
> I'm never quite sure why there is a prejudice against steel bushings, unless you are talking of ones that are retained by locking rings that might work loose. I noticed the ultra large one we looked at last week fell into this category.
> Trend, for example, make steel bushings that are secured by two countersunk screws and I've never had those come loose, particularly as I put a Nyloc nut on the back of them.
> ...


Hi Peter:

A steel nut will work loose from the bolt under vibration and temperature variations. Lock nuts and and lock washers have long been in use specifically for just such a reason.

Personal experience dictates that metal to metal requires a positive locking in order to be secure. I've had bicycle bolts come loose that were not securely locked. I don't take chances. They hurt too much.

Next, a steel template guide will damage a bit contributing to the shrapnel propelled by a bit traveling at 22,000 rpm. This means that the guide will sustain damage, the bit will sustain damage and both will create shrapnel.

Brass guides are soft. They can be finger tightened and will hold nicely. I've not had anything brass come apart by itself. As well, should the brass contact a spinning bit, only the brass becomes shrapnel and the bit remains undamaged.


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## Marco (Feb 21, 2009)

Ugh Ron, I may have opened the can of worms but I didn't empty them on the table and finger my way through it looking for the Red Wigglers! (lol) .............. I was surprised and disapointed at the lack in depth of cut with the PC guide bushings............. 

Thanks for the link Levon I think it's the same link as Bob provided on this thread or it might have been on another but either way I believe a washer is a must for my brass PC guide bushing locking nut............... I assumed my bit was ate up by the guide bushing and nut when it came undone.... hopefully there is some goody left on it.......... I'll look at it with a calm eye later


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## harrysin (Jan 15, 2007)

"Hi Harry

Sorry
Must have been a Freudian slip ,when I see your name Walter's face comes to mind and his mind set...

I'm going to take that as a compliment Bob.


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## istracpsboss (Sep 14, 2008)

allthunbs said:


> Hi Peter:
> 
> A steel nut will work loose from the bolt under vibration and temperature variations. Lock nuts and and lock washers have long been in use specifically for just such a reason.
> 
> ...


It's as I thought. All the PC type ones I have are brass. My steel ones are the Trend type and fit more securely. I guess you don't see those so often over there. I understand the problem you have with the PC ones.

Cheers

Peter


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## bobj3 (Jan 17, 2006)

The true PC guides are steel sold by PC as a standard item..

I have many of the funny steel guides that fit the funky routers but I just don't use them, just a real PITA to use.. and to re-line up on dead center.

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## harrysin (Jan 15, 2007)

Bob, for three years I've been trying to wean members off using template guides in the table, in favour of using them hand held in plunge mode. However I can't see a problem in routing a concentric step in a router mounting plate so that the sensible one piece guides can be fitted accurately and quickly into the router plate, in which case the thinner steel ones would excel.


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## bobj3 (Jan 17, 2006)

Hi Harry

I must say using the guides in the router table is the way I like to use them most of the time..
The router table holds the router for me ,it's just one more thing I don't need to think about..just like a table saw so to speak..
The hand power saw has it's place in the shop just like a hand held router..but when it comes to a push the router table will excel the norm..

Many buy a router and than move up to a router table must be something to it..it was the same way for me..  and many others I think..then if you add the guides it opens a new world to the router table.. 


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