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Experimental Tungsten Carbide Yeti Hinge Pins

the_ocho

Quarry Creeper
Joined
Jun 5, 2011
Messages
206
Location
Salt lake city
Update. Tungsten doesn't work, I am now moving on to 01 tool steel.



With all the want for better hinge pins out there I figured I would let you in on a litte experiment I am working on. I have seen this done before by another person but I don't recall who it was and I remember they didn't say too much about it other than they were trying it.

I bought 6" of 3mm C2 Tungsten Carbide rod, and a package of 1/8" RC air plane wheel collars to retain the rods. The total was under $20 on amazon.

I'm thinking that the hardness of the Tungsten will protect the surface of the pin so it wont scratch up and bind. The second thing is the hardness of the Tungsten wont let it deflect or bend. the downside is since it is so hard it is brittle, if I hit something hard enough to bend the pin it will probably just break. The experiment side is finding out if it is too brittle or not, I mean for less than $10 a pair I can afford to make new ones every once in a while. Given where the pin is located I don't foresee a direct impact from anything that could cause it to shatter, I also don't see my RPM arms being strong enough to put enough shear load on the pin to break it.

QQ8PzgR.jpg

Ignore the shock tower and o-rings this is the only picture I have of the supplies before started working.

Here are my stock pins next to one of the cut Tungsten pins. the bends are just from jumps and bouncing off rocks. The difference in how the suspension cycles is night and day.
Lfy7leh.jpg


How I retained the pins, the collar keeps it from coming out the front and the spot in the chassis where the factory nut used to be keeps it from sliding back.
Qv2MAhp.jpg

kTUuvtd.jpg


The Tungsten is a pain to cut as I was expecting. it took about 2-3 minuets with a 4.5" cut of wheel to make one cut. Not something I would even attempt with a dremel and impossible with hand tools.


FWIW my yeti is a basher and has a PRO4HD 3000K, MMP, 7955 servo, BM trailing arms, Vanquish steering, STRC hubs/shock tower, RPM lower arms, Traxxas turnbuckes for the rest of the front suspension, and under drive gears with 500K oil in the front diff.
 
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^ Down jump,about 5-6 feet and hit a log. I wasn't mad at it for breaking...

The tungsten is from McMaster and is "Ultra-Hard" Rockwell C79.
 
Tungsten carbide is apparently too brittle. I'm ordering grade 12.9 M3x60mm screws to try out. Coupled with the sleeves I made, RPM arms, and STRC hinge pin mount I doubt I'll bend or break one again.

Good experiment though, thanks for sharing.
 
I have tried carbide and hss with the same results as the broken tungsten,to brittle.

Currently using spring steel, havnt sheared a pin yet. I havent pulled them out to inspect....if it isnt broken,dont fix it:mrgreen:that and I am lazy and lack the time to do so.
 
Tungsten carbide is apparently too brittle. I'm ordering grade 12.9 M3x60mm screws to try out. Coupled with the sleeves I made, RPM arms, and STRC hinge pin mount I doubt I'll bend or break one again.

Good experiment though, thanks for sharing.

I haven't tested mine yet but based off the conditions the other person said when it broke I wouldn't be mad either. I also have RPM arms that flex ant take way more impact than stock arms do. for less than $10 a pair they may work out to be a good solution. I do plan on trying some tool steal if I cant make this work

I have tried carbide and hss with the same results as the broken tungsten,to brittle.

Currently using spring steel, havnt sheared a pin yet. I havent pulled them out to inspect....if it isnt broken,dont fix it:mrgreen:that and I am lazy and lack the time to do so.

I think the spring steel may be a good way to go. It will flex but should return to its normal shape. I wonder if they are still straight. The whole if it aint broke don't fix it is why my pins were so bent, I though they were good but man do straight pins make a difference in how the suspension cycles.
 
I tried picking up some O1 tool steel rod but don't have the tools to heat treat it properly. Without heat treating it, it's just soft steel, softer than the factory bolts. Spring steel may work well, especially if you use an aluminum hinge pin mount and sleeve it for rigidity. With the right equipment, you could take O1 rod and heat treat it to different hardness levels (including spring) and see which works best.

I haven't run across 3mm spring steel rod yet. Where would I find this?
 
Oh don't mind me guys, I'm just re-filling my popcorn bowl and popping another top...

This it the best thread right now, lots of, not only fabulous ideas, but real world experimenting!!! No PC geek physic lessons by arm chair scientists and/or thoughtful or wild speculation!

You guys are my heroes! Once you finish bashing and testing, not only will i get to enjoy some Yeti carnage pictures along the way, but I should have my Yeti finished and ready by then, just in time to implement whichever of these ideas is the best fit for me.


Many thanks for the hard work and more importantly for sharing the findings"thumbsup""thumbsup"
 
This is basically spring steel I guess, but how about music/piano wire? I use it for CVD pins and it's super hard but not brittle. You can buy straight pieces of it or coiled up (like I use for pins) I might try it if I start bending hinge pins.
 
I tried picking up some O1 tool steel rod but don't have the tools to heat treat it properly. Without heat treating it, it's just soft steel, softer than the factory bolts. Spring steel may work well, especially if you use an aluminum hinge pin mount and sleeve it for rigidity. With the right equipment, you could take O1 rod and heat treat it to different hardness levels (including spring) and see which works best.

I haven't run across 3mm spring steel rod yet. Where would I find this?

I just remembered my sister has a kiln at her house, she fires her pottery at 2200F so the 1400-1500F required to harden the 01 steel should be easy. tempering would be a easy as its only 350-500F. getting it to quench properly may take some practice though.

Looks like I may have to cut some rod and send it out to here to try out
 
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Yes, and treating it in the right atmosphere is also key. Can't just heat it to a temp and figure to get the right temper.

You'll need to pack it in something carbon rich.
 
Yes, and treating it in the right atmosphere is also key. Can't just heat it to a temp and figure to get the right temper.

You'll need to pack it in something carbon rich.

I can make up for not being in the proper environment by limiting the time that the piece is at temperature. since the cross section of the pin is so small I don't have to hold it at temperature, I can quench as soon as I hit 1500F. By limiting the time I am able to limit the amount of carbon that is lost in the outside surface. Yes it isn't perfect or ideal but i'm not building a space ship here either. People have been treating their own knife blades in their garages for years. If it all fails I am not worse off than before using stock pins.
 
I tried picking up some O1 tool steel rod but don't have the tools to heat treat it properly. Without heat treating it, it's just soft steel, softer than the factory bolts. Spring steel may work well, especially if you use an aluminum hinge pin mount and sleeve it for rigidity. With the right equipment, you could take O1 rod and heat treat it to different hardness levels (including spring) and see which works best.

I haven't run across 3mm spring steel rod yet. Where would I find this?

i am using 1/8" spring steel drilled out the arms and what not to fit.
 
Well this lasted 10 minuets haha
tx6pcWZ.jpg


I just ordered 36" of 1/8 01 tool steel. lets see if I can get the heat treating process close enough.
 
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