Red car in Iowa

Hi Rod, I totally missed this thread. I'll be watching carefully, as I'm using the Holinger MFT as well. I have gone exclusively with the compressor and paddles insterad of the shift-cut lever like you've got there. I'd be fascinated to see which ratios you've chosen.

Keep up the great work.
 
Hi Rod, I totally missed this thread. I'll be watching carefully, as I'm using the Holinger MFT as well. I have gone exclusively with the compressor and paddles insterad of the shift-cut lever like you've got there. I'd be fascinated to see which ratios you've chosen.

Keep up the great work.
I'm doing paddles too!
 
^ good catch - doesn't matter for mock-up, but it is out of phase and it will matter when it is ready to drive.
 
Interesting question. Why does phase mater? Further, what would be in phase? I’m going to go have a look at mine. I didn’t know about this.
 
Phase is very important otherwise the joints will bind as they are not on a natural axis to each other. It also causes stiffness in the system and could potentially lead to wear or breakage.
 

Neil

Supporter
Interesting question. Why does phase mater? Further, what would be in phase? I’m going to go have a look at mine. I didn’t know about this.
Gale, if the U-joints are not phased correctly, the rotation won't be the same angle from input to output as you rotate the shaft through 360 degrees. The rotation slows down and then speeds up.
 
mathematically - a universal joint is unlike a CV joint. As you bend the joint, while the input shaft moves at a constant velocity, the intermediate or output shaft rotates a sinusoidal velocity, which is to say, + or -, depending on what phase of rotation the joint is in. So if you keep the final output shaft in the same phase as the input shaft, it doesn't matter what the intermediate shaft is doing in between. Out of phase, you double the variation, so it's ++ or --, depending on what part of the phase it is. That would lead to stiff/loose parts of the rotation, corresponding to a fast and slow steering rack. Wouldn't be nice when countersteering a slide for instance. In Phase means the forks on the outboard portions of the universal match ie they are both vertical/horizontal/clocked the same.
 

Terry Oxandale

Skinny Man
So, after all of that, my question is how much will this really matter in a steering set-up. Higher rotation rates seen in driveline applications make is much more obvious than much slower, and variable impacts in steering angle. Any slight changes (assuming they will be very slight) would be accounted for or adjusted by the driver, and I would hazard a guess that 80% of the drivers out there wouldn't notice the difference between the two (in phase vs out of phase) in terms of feedback to the wheel.
 
How much this will matter is up to the driver, and the deflection angles in the universals - see the link below. But if you have two 30 degree joints out of phase, you are looking at approximately 40% difference in shaft speeds peak at 90 degrees, well within the steering angle range you would expect to use correcting a slide, for instance. I'd think that would tend to make the car less pleasant to drive, especially with a non power assisted steering system where the car pushes the driver further into his/her strength envelope. With bigger angle deflection, it becomes quite a bit worse. All this is not a deal killer, but if the solution is just to clock one universal 90 degrees from where it was, it's a no cost improvement, certainly easier than chasing down bump steer.

 

Terry Oxandale

Skinny Man
Rod,

My set-up is very similar to yours. On the street, or on the track, I've never felt anything sketchy about the feel, or observed issues at any angle of wheel turn. Mine are phased, and angles are very similar.
 
^ if they are phased, it's nearly irrelevant what the angles are, as long as the universals don't bind.
 
Yes it matters.....heaps. I recently did a drive shaft shortening for the Formula Junior. Due to the shaft tube sizes being about 2 mm different in dia, I spent a considerable time and effort getting them straight and true before I tacked the 2 shafts together......BUGGER I forgot to phase them and was only about 1/4 of a turn out of phase .......the shaft was un usable due to vibration other than a perfect sample for the drive sh
DSCN6973.JPG
 
That's a cool little ride! LIke the scallops, perspective makes it look heaps bigger than your Mick Laren.
Motorcycle powered?
 
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