Choosing Optional 0, -1mm, and -2mm Hinge Pin Braces

[RustyUs]

I like all the setup information in the back of the manuals of the newer platforms. Explaining the aspects of Ackermann; active tow; bump steer; roll center, etc., etc., etc., and the different parts/plates/inserts/spacers used to adjust things. I've look, and look everywhere for info about using the different optional hinge pin braces, that are now offered on the new platforms, and what they do. Is it simply just shifting the hinge pin inserts up and down? What situation/condition/advantage is best for each?

Is there somewhere out there in the interwebs, that I can be schooled on the subject?

 

[Billl DeLong]

https://www.teknorc.com/wp-content/uploads/2014/06/Set_Up_Guide.pdf

 

[RustyUs]

Yeah, no. I'm talking about hinge pin braces themselves. I'm assuming the 0, -1mm, -2mm blocks are used to adjust the height of the inner hinge pins? If so, then lowering the inner hinge pin (as shown in picture below) lowers the roll center. Correct?



EB48 2.1 block options

SCT410 2.0 block options

 

[nub]

I've wondered what the -1mm and -2mm is also. -1mm or -2mm of what?

 

[davidg]

Following

 

[Billl DeLong]

Okay, there's a lot going on and I'll do my best to break down each.

The inner suspension pins which go into the A-B-C-D blocks are going to tune Sweep/Kickup/Toe/Anti-Squat

The optional blocks are going to lower the pill insert -1mm lower from stock to extend your tuning window if you need to go farther lower than the stock block will allow.



A-B Blocks will tune Sweep and Kickup:

C-D Blocks will tune Rear Toe and Anti-Squat:

On the outer suspension pins there are 2 holes of the hub which tune for LRC (Low Roll Center) or HRC (High Roll Center) which is discussed here:
https://www.competitionx.com/rc-tuning-guide/rc-suspension-tuning-guide-axle-height/

The only reference to 0mm/1mm/2mm is the offset for the thickness of the hexes which tune track width:
https://www.sodialed.com/rc-setup-tips/hudy-off-road-setup-book

Clear as mud? Ha!

 

[Billl DeLong]

If you get lost with setup, go back to box stock, then use this guide here to prioritize your changes being careful to make only 1 change at a time as you go down the list in each section of recommended changes to address a tuning option:
https://www.competitionx.com/rc-tuning-guide/rc-quick-setup-guide/

 

[RustyUs]

Okay, there's a lot going on and I'll do my best to break down each.

The inner suspension pins which go into the A-B-C-D blocks are going to tune Sweep/Kickup/Toe/Anti-Squat

The optional blocks are going to lower the pill insert -1mm lower from stock to extend your tuning window if you need to go farther lower than the stock block will allow.....

I'm trying to keep it simple for my head. I get everything that you mentioned. It's the greater range of vertical pill adjustment with the optional hinge pin braces that I never dealt with before. I added my thoughts in picture below represented with Lower Hinge Pin and dashed lines. If everything else stays the same, and I lower the inner hinge pin, then I would be lowering the roll center a bit....

 

[Billl DeLong]

I'm trying to keep it simple for my head. I get everything that you mentioned. It's the lowering of the inner hinge pins that I never dealt with before. If everything else stays the same, and I lower the inner hinge pins, then I would be lowering the roll center a bit....
View attachment 9987

You need to be more specific because the front/rear inner hinge pins are completely opposite between kickup or anti-squat, neither has anything to do with roll center.

I recommend using the guide I referenced in post #7 to keep things simple.

 

[RustyUs]

I guess I got to stop listening to Ray Munday then.(sarcasm)

To adjust the roll centre, the most sensitive adjustments are raising and lowering the height of the pills (inner lower arm), the upper link inner ballstud, the upper link outer ballstud, and the height of the axle in the hub (which our cars have had since the B6 series introduced the concept). Changing the ride height also affects the roll centre.

Ray Munday wrote just one of the few articles that popped up in my search for inner hinge pin/roll center adjusting.

Onward and upward.

 

[Matthew_Armeni]

If you raise or lower the A and B block together by the same amount you will raise or lower your front roll center. If you raise or lower the C and D block together by the same amount you will raise or lower your rear roll center.

 

[Billl DeLong]

The context of roll center is generally addressed across the plane with the arms where the upper turnbuckle links are of the main concern. Assuming you maintain the same kickup and anti-squat (KU/AS) angles then I would agree that you'd effect the roll center ever so slightly, but any changes you make to the angles along the plane of the chassis length (KU/AS) are going to override the effects you might feel from the roll center change. I try not to mix these together because it over complicates recommended tuning guide reference points.

*** UPDATE ***

The more I think about it, maybe consider the B and D blocks for roll center but A and C blocks for referencing KU/AS

 

[Matthew_Armeni]

The context of roll center is generally addressed across the plane with the arms where the upper turnbuckle links are of the main concern. Assuming you maintain the same kickup and anti-squat (KU/AS) angles then I would agree that you'd effect the roll center ever so slightly, but any changes you make to the angles along the plane of the chassis length (KU/AS) are going to override the effects you might feel from the roll center change. I try not to mix these together because it over complicates recommended tuning guide reference points.

*** UPDATE ***

The more I think about it, maybe consider the B and D blocks for roll center but A and C blocks for referencing KU/AS

If you are center dot on both C and D blocks and then move both down .5mm (double dot down on the 8th scales and single dot on the EB410 based platforms), keeping the anti-squat (AS) settings the same, you'll lower the cars roll center and it makes a pretty noticeable difference in the cars handling. I don't change it very often because once I found the setting I like it makes it feel like I'm driving another car.

 

[Billl DeLong]

If you are center dot on both C and D blocks and then move both down .5mm (double dot down on the 8th scales and single dot on the EB410 based platforms), keeping the anti-squat (AS) settings the same, you'll lower the cars roll center and it makes a pretty noticeable difference in the cars handling. I don't change it very often because once I found the setting I like it makes it feel like I'm driving another car.

I agree that this change will effect the roll center but most folks are going to adjust the upper links which offer a far wider tuning range, I would only touch the pills to adjust roll center as a last resort once the tuning window on the upper links have been maxed out.

FWIW, once I got my base setup figured out, I've never touched my roll centers since, when I visit new tracks I only adjust sway bars and ride height to tune for varying grip. No need to overthink it

 

[Skynet5]

I’d be keen to understand where the cog is of the 2.1 front and rear and also what the axis line is through the front and rear roll centres when everything is kit.

I struggle to know if I’m neutral or if I have a positive or negative inclination.

I could work it out with my ride height and middle holes on the tower, if I knew where the cog was.

I’m definitely over thinking…but it’s part of the fun for me.