Tie Rod Ends used as hinge Question

[raul segura]

I'm looking at car tie rods as a source for a hinge, but have no experience with them.
I'm sure it depends on type/brand etc.

Would they be very stiff or due they ark relatively smooth ?
Due they have any shake to them slightly loose or are they snug with no play ?
About how much radius / pivot would I expect from one ? (not necessary)
I'm looking to make swing arms for part of a router Duplicating machine The same idea as the one pictured but smaller.
At a price significantly less than a rod + two bearings it would be much more feasible for me.
Ive got several Ideas in mind but all depends on price and parts available and tie rods should be very sturdy, I would think.

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Thanks,

[Dennis Ford]

Very interesting idea, I have never used tie rod ends on anything other than a vehicle. I do remember that the new ones I installed were fairly stiff with no play in the motion.

[Thomas Bank]

I'm not sure that a tie rod end will work as you want it to in this application. Take a look at this illustration:

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The ball joint allows the pin to not only rotate, but also to pivot. I can't see how that would allow the stability you'd need in something like a duplicator where you'd want one side to exactly follow the movements of the other side.

In an automotive application, the range of movement of the wheels in steering is constrained by their own attachment.

But perhaps I'm not understanding where you are suggesting to use the tie rod ends in your application.

[raul segura]

Thanks for the picture Thomas My supposed Idea is to build a set of V frames pictured below in blue, at the point it would have ball socket to move R/L.
At other end it would have two sockets tide together, welded or bolted ? I think it would work much like a wish bone ? These will swing like a door.
The up down motion would be another part of the build along with sliding forward and back. The joints would be adjustable so I could right my lack of precision.
Dennis Ive thought of using wrench hinges from HF. bicycle parts and used (exorcize machines lots of cheep metal there) etc. but it seemed that those designes may have to much play and the easiest retro fit and most brutal one would be the car parts, 9.99 at auto part store.

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Iv added a picture of the forward/back slide I may use.

[Thomas Bank]

Ok, now I understand better. Yes, the triangulation you have there will keep the rod ends from moving out of plane. But I do think that the rod end isn't exactly suited for that - more bulky and hard to connect to than it would need to be.

For another image:
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That is going to be a bit difficult to incorporate into the structure as your drawing shows.

I recently picked up a few weldable barrel hinges (http://www.hardwaresource.com/hinges/SPECIALTY+HINGES/Weld-on+Hinges+-+Welding+Hinges/Welding+Hinge%2C+Two+Piece+Steel) for a project. The 4" hinges with 440# capacity should be more than enough to do the trick and will cost you less than $5 apiece.

[raul segura]

The main thing I was looking for was the tight fit of the hing to shaft. The ball/socket came to me because of the precision joint the robust build was a secondary thought. I understand it takes very little free movement to through the system off. I would much prefer a simpler design to work with.
Very good then, are thoughts hinges accurate ? They look very handy.
Thanks for the help,

[mike holden]

Raul,
I am not clear on how you intend to use the tie rod ends, but you are aware that neither end is supposed to rotate in a tie rod, yes?
Mike

[Thomas Bank]

The barrel hinges are very snug. I couldn't exactly tell you how much "slop" you'd have in your application once you figure in the leverage of the arm because I haven't used them in anything even remotely similar.

But Mike is correct. The "stiffness" that Dennis mentioned is because the ball isn't designed to rotate in the socket around the axis of the threaded portion, but to be able to pivot perpendicular to that axis to keep the tie rod from binding.

[raul segura]

The design should be a little weighty, but wont be loaded but with a small router. I'm lifting the swing arm from this video which gives you an idea Mike.

http://www.youtube.com/watch?v=mqUtlIP81rI&feature=related

Ill pick up a few hinges and a tie rod to run some tests. I may just have to save the trouble and order blocks and rods.

Thanks all ,"FOOD FOR THOUGHT" If I get any were with this Ill try and post the finished piece.

[Scott T Smith]

Have you looked into sperical rod ends (aka spherical ball joints), instead of automotive tie rod ends?

http://www.mcmaster.com/#spherical-ball-joints/=dkab8p

[raul segura]

Never thought of using. The ones Ive seen are very small and loose (big box store). The Mc Masters look very enticing Id assume they don't rattle, the pricier ones have roller bearings. Using these would obviously make things go along much faster. Ill have to take a better look at my metal pile and these rod ends.They'll run me about the same as car parts, but much faster build.
Very good Scott.

[ray hampton]

I not trying to hi-jack your thread but do ROBOT arms rotate similar to the way that you want ?

[raul segura]

hi-jack away ,
Trying may hand at a copy carver, duplication machine,etc. Most slide this one would slide and swing cutting price. There are several interesting builds on Youtub.
Actually need a series of linear bearings/rods, but I thought using a hing set up would be cheaper, at least for part of the build. A nice tight hing would due the trick. Going the CNC slides and rods would be road kill for my intentions unless I could make some money out of it. Id assume something robotic would break the bank too.

[ray hampton]

hi-jack away ,
Trying may hand at a copy carver, duplication machine,etc. Most slide this one would slide and swing cutting price. There are several interesting builds on Youtub.
Actually need a series of linear bearings/rods, but I thought using a hing set up would be cheaper, at least for part of the build. A nice tight hing would due the trick. Going the CNC slides and rods would be road kill for my intentions unless I could make some money out of it. Id assume something robotic would break the bank too.

buying a robot would break the bank but if you could study how the robot works and build the engraving arms yourself

[raul segura]

Yes Id agree, if I use the modern method it would be much easier on labor,and design, at the moment though I have more time than money and Im all about sweet equity even if it fails to pay out half the time. Not much of a business sense I suppose.

Any how , unless anyone has any more ideas on a hinge design I think I have enough to think about for the the moment. I thank you all for the help, I try not to take any thing for granted so I will review. Thanks again.

[Thomas Hotchkin]

Raul
You can get sperical rod ends designed for large aircraft flight control use that do not need lubrication and have right or left threads, they could work as a turn-barrel for adjustment. Tom

[sullivan mcgriff]

new tie rods are really stiff and the taper would be hard to work with, you could use a bike head tube or bottom bracket if you have those laying about, the heim joints are nice too but a bit pricy, round ball bearings are only a couple of bucks and are easier to use.

[raul segura]

I had taken a good look at the bike parts as I have two identical bikes, but one of the kids left one out to rust badly. I would have taken that rout. The spherical are nice to, but also pricy. Ive gone with what is available and cheep, the rods I tested some for shape and stiffness and there all stiff ! So I fit them to the drill press and added some rock polishing compound in three grits. They are soft now and only $6 + each. As I will be welding I can get around the taper connections. The difficult part so far has been finding left hand threaded nuts. Wew. Ive also picked up the swing arms, two orders of H.P.'s crow bars they come in three per set, also cheep I think and should be plenty strong. The nice thing about the tie rods is that they are beefy and should last. The next thing to pick up will be the long rails. Ive picked out some square fence posts at Lowes 12+$ for 2"x7ft pipe. Plus a bunch of nuts and bolts that come with each post. Compare that to the stuff they have stocked for regular use. I agree though the bicycle parts would have been real nice.

Ive had to put this aside for some time as the wife has things that need fixing. But Ill post pictures once I get to the fabrication part.
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Here is one I found on e-bay the other day sold for a total of $560.00 with router.