Redesigned TC Rods!!

[BlackBeaut]

Ballsy... especially on a combo machine

But the 1mm max. depth of cut sure makes for some boring hours going back and forth! I guess I'm learn to be patient using this machine though, whenever I try to push things it screws up and I'm back to square one.

 

Ah, Zen and the art of Machining! There could be a book in that

 

Cheers,

Rob

[Guest remix240z]

Great looking tc rods azcarbum and blackbeaut.

 

Blackbeaut - What kind of workpiece holding device are you using to clamp your clevis? As for milling out that slot, I agree with you on making a smaller slot and then moving out little by little to get your desired width. Going through once with a 12mm end mill will definitely cause chatter marks at the end of that clevis. As rontyler mentioned, climb cutting is the way to go. Might need to adjust your spindle speed and feed rate also.

 

You also might want to try this technique, if you're still getting chatter marks.

-Mill through a little over half way on the slot.

-With the end mill still in the slot, clamp down a piece of metal the same width as the slot.

-Then mill the rest of the way through.

NOTE: Make sure the spindle will not interfere with the clamp. Just be careful.

[RTz]

But the 1mm max. depth of cut sure makes for some boring hours going back and forth!

 

 

Damn... hats off to you!

[gretchen/jason]

Looks similar to my rods but mine have not sure how to spell it heim joints with aluminum front controll arms nice job there on those rods . But i got mine from Arizona z car and theire chrome moly tube rear arms .

 

Jason

[Mike Mileski]

Brian, what is that pivot end thing called and where did you find it. I'm helping a friend build a sand rail and we're looking at an application that could use something like that.

 

Mike Mileski

Tucson, AZ

[azcarbum]

I Had already been working on removing the "dogleg" in my new LCA design. I should have some pictures this week. Nothing special, pretty much like the CAD that "BlackBeaut" design shows.... The TC will now mount directly to the LCA.

 

I know there has been some expressed concerns about the use of the clevis to link the two. Even though I don't think it would of possed any issues for the design, I'm looking into a solid rod end to bolt directly to the arm. This should eliminate any question of strength in regards to this connection.

 

Once I have pictures I'll post.

 

B.

[jeromio]

Brian' date=' what is that pivot end thing called and where did you find it. I'm helping a friend build a sand rail and we're looking at an application that could use something like that.

 

Mike Mileski

Tucson, AZ[/quote']It looks like an inner tie rod from a 280ZX R&P. You should be able to get one at a regular old auto parts store.

I know there has been some expressed concerns about the use of the clevis to link the two. Even though I don't think it would of possed any issues for the design, I'm looking into a solid rod end to bolt directly to the arm. This should eliminate any question of strength in regards to this connection.

I'm having a hard time imagining what you're refering to. In order to maintain adjustability, the connection betw. rod and LCA has to pivot, yes? Are you talking about changing from clevis to some fancier pivoting "rod"?

 

I presume the complaint against the clevis is the load on the pin. With braking, you would get quite a lot of force on that pin. Perhaps something like a heim would be preferable, where the pin (or bolt) would be much thicker.

[tube80z]

I presume the complaint against the clevis is the load on the pin. With braking, you would get quite a lot of force on that pin. Perhaps something like a heim would be preferable, where the pin (or bolt) would be much thicker.

 

No, the issue isn't the pin (bolt), it's really what's the best way to resist bending at this point. Few people will ever see this as an issue unless they use the car rally hard on a track. A better way to resist bending is to use a solid rod end and a wider spacing for the mount. Just adding a lower dog leg to the standard clevice will generally keep the bending from happenning.

 

You don't want to put a heim in this location as it will allow an addition degree of freedom. Once you overcome the forces putting tension on these parts from car weight you will get a wheelbase/caster change. In practice this is seen as severe wheel hop under braking. Double lower balljoints can be done but you have be careful how things align.

 

Cary

[1 tuff z]

bri, pics coming soon?

[Careless]

i'd like to know what would make me buy your TC rods over these ones here, from tech-toy tuning?

 

http://cgi.ebay.ca/Datsun-240Z-260Z-280Z-Tension-Control-Tie-TC-Rods_W0QQitemZ200025217762QQihZ010QQcategoryZ42609QQrdZ1QQcmdZViewItem

 

 

is the clevite that you put on the end that mounts on the LCA neccessary, or even as strong as these from T3... i know it allows added caster, but what about the strength!?

 

because in all honesty, i'd rather buy something that has had input from a board such as this, than the ones from T3...

[RTz]

because in all honesty' date=' i'd rather buy something that has had input from a board such as this, than the ones from T3...[/quote']

 

 

If my opinion matters... Those don't really do anything for me. The heim bracket pushes the pivot point farther forward than Brian's. The farther forward the pivot is, the more caster change you'll have as the suspension reciprocates. Also, becuase of the caster change with movement, the angle between the LCA and the TC rod MUST change. With tech-toys design, the TC is clamped solidly... that means things must bend to accommodate the caster change. Brian's design has a pivot for this reason.

 

HTH.

[JMortensen]

The farther forward the pivot is, the more caster change you'll have as the suspension reciprocates.

True, but IME having the TC on a clevis like that and being able to run a larger amount of caster was a big improvement over stock, poly, or GMachine setups I ran previously. When you're talking about 1" difference in the length of the arm (guessing since the tie rod end end also moves the pivot forward from stock probably an inch) I don't know that the difference in the caster sweep is going to be that huge an issue. I can say that the clevis type worked very well for me. My lastest setup moves the TC bucket back and strengthened it to run a rod end with the stock length arm, but that was a big project and is above and beyond "necessary" IMO, although it does truly fix the problem you describe.

Also, becuase of the caster change with movement, the angle between the LCA and the TC rod MUST change. With tech-toys design, the TC is clamped solidly... that means things must bend to accommodate the caster change. Brian's design has a pivot for this reason.

I don't like the way you worded this part. I know what you mean, but I don't think the argument you make is really true here. The bolt through the clevis gets locked down once the caster is adjusted, so there is no pivoting of the clevis "as the caster changes with movement". The impression I get from reading your post is that the clevis can change its angle because it is left loose at all times.

 

With the TTT, AZC, and Mike Kelly's old TC rods, one simply needs to loosen the J bar where it connects to the control arm when the caster is set, then lock it down again. I had mine made for me but they were similar to the clevis type that AZC sells, and I was able to run 5.5 degrees without any binding of the J bar to the control arm. If there was binding, I already had a plan to deal with it. It involved drilling out the holes in the control arm or the TC rod to make them larger and allow for more angularity. Not hard to do, and accomplishes the same thing as the clevis. The important bit is to loosen the bolts that attach the J bar to the control arm when the caster is adjusted, or the clevis bolt in this case. If that is done I don't really see an advantage to either design.

[RTz]

True, but IME having the TC on a clevis like that and being able to run a larger amount of caster was a big improvement over stock, poly, or GMachine setups I ran previously.

 

I couldn't agree more... Brian's are also adjustable so I'm not seeing your point.

 

When you're talking about 1" difference in the length of the arm (guessing since the tie rod end end also moves the pivot forward from stock probably an inch) I don't know that the difference in the caster sweep is going to be that huge an issue.

 

Agreed' date=' probably not a huge issue. But I don't want any more caster change than necessary. I fail to see the advantage of the heim and combined with it being farther forward just doesn't excite me.

 

I don't like the way you worded this part. I know what you mean, but I don't think the argument you make is really true here. The bolt through the clevis gets locked down once the caster is adjusted, so there is no pivoting of the clevis "as the caster changes with movement". The impression I get from reading your post is that the clevis can change its angle because it is left loose at all times.

 

I think were talking about the same thing... we just have different opinions. No matter how tight the clevis bolt is, there is no way for me to imagine that it wouldn't rotate with even a small load. I'm not implying "leave it loose". However, I think torquing it to oblivion won't do anything either. *IF* there is caster change during travel (from a non-ideal location of the rear pivot point) then I don't see how it could NOT rotate. The angles must change. So something either has to flex, pivot, or break. Its possible I'm looking at this all wrong... If you type REAL slowly, maybe it will sink in

[RTz]

I think were talking about the same thing... we just have different opinions.

 

Jon,

 

I'm beginning to think I am wrong about the angle change during travel. I believe you are correct.

 

Forgive?

[JMortensen]

Jon' date='

 

I'm beginning to think I am wrong about the angle change during travel. I believe you are correct.

 

Forgive?[/quote']

Not a problem.

[chelle]

Wow, the parts look great guys.. almost enough to get me to consider going that route.. I was figuring this winter maybe we would upgrade the whole front end to a tube frame, but with parts like this maybe we can keep the front sheetmetal, I was thinking we would go with 4 complete Strange struts with big brakes... I like azcarbum's strut assemblies, with all we spent on our car I do want to go with the best available parts

Chelle

[Careless]

Jon' date='

 

I'm beginning to think I am wrong about the angle change during travel. I believe you are correct.

 

Forgive?[/quote']

 

it it because you realized the entire shock/strut assembly would have to rotate for it to change the angle?!

 

that's what im thinkin right now, so im not sure if it's right or not, but im sinking this info in.

 

My lastest setup moves the TC bucket back and strengthened it to run a rod end with the stock length arm' date=' but that was a big project and is above and beyond "necessary" IMO, although it does truly fix the problem you describe.[/quote']

 

Pics? im trying to envision the mods to the TC mount, since the car will go to it's bare frame in due time.

 

Wondering what you did to the stock TC's or who made the TC's too.

[JMortensen]

Grab a beer, it's a long one: http://forums.hybridz.org/showthread.php?t=106974

[RTz]

it it because you realized the entire shock/strut assembly would have to rotate for it to change the angle?!

 

Actually, I just imagined a one piece A-arm with its inner mounts parallel with the longitudinal axis of the car. Pivot the A-arm up and down... no need for its 'leg' angles to change right? Now, spin the whole A-arm assembly in a horizontal plane (so its rear mount is far outboard). Pivot the arm again... stilll no bind. It now just travels an arc that would promote caster change... BUT the angles between the legs don't change.

[jeromio]

In another thread, a similar design using inner tie-rods for the TC pivot was panned as being undesirable (vs., in that case, a customized mono-ball) die to moving the pivot out towards the wheel.

 

What are the specific disadvantages of this pivot movement? I fail to see any intuitively.

 

I can see the advantages of lining up the vertical axis of pivot with that of the LCA. For instance, on my car the LCA pivot was moved up 13/16", but the TC was left alone. If I exaggerate this in my mind, I can see that braking could induce extra dive in the front. Therefore, and I think this was explained in Jon's thread (already referenced once in this thread), moving it up maybe even past the point of parity (for example, moving TC pivot up 1.5"), might create a resistance to brake induced dive.

 

However, I am not able to analogize movement of the pivot in the X or Y directions as having any particular negative affect, part from the obvious potential reduction in suspension travel or binding in the extremes.

 

Looks to me like picking up some Escort inner tie rods

(LENGTH= 13.34 in.; OUTER THREAD= M12x1.25R; SHAFT DIA.= 0.560 in.; RACK END THREAD= M16x1.00R) for $30/ea ($70 ttl w/ shp)

some hockey sticks made 3/8" plate (with 3 holes drilled) and a pair of female clevis ends:

for $9/ea, prob'ly $25 w/ shp. Maybe add $8 for the generic dust boots.

 

So, just a wee bit of effort and less than $100, I can reduce (eliminate) the possibility that my currently doubly poly bushed TC rod will snap. I can also move the pivot up to remove the pro-dive geom. I introduced when I raised the LCA pivot.

 

Any holes in this theory of mine?