Fabricating Custom Knuckles with plate steel (Page 3/7)
Will JAN 22, 04:24 PM
The caster induced camber gain happens in slow turns with high steering angle. Higher speed turns with less steering angle still need camber gain to keep the tire effective with body roll.
cam-a-lot JAN 23, 07:20 AM

quote
Originally posted by zkhennings:

and no I think it was doing 0.15" steps not an inch at once, but at those corners once you are in the final passes it chatters because it is close enough that the chatter at the bottom since the endmill has to have decent stick out, it causes it to chatter along the whole length.





Why would you buy a new CNC for hobby jobs? I know of dozens of usable, full 3 axis CNC mills for sale for less than 25k. A good knee mill with 3 axis CNC control can do this no problem, and is a lot cheaper than an enclosed machining center.

Regarding the chatter in the corners, either slow down your federate on all G02/G03 internal arc commands, or put in a half second dwell command while in the corner, so the cutter doesn't cut on 2 sides at once. This will eliminate your chatter. Make sure you climb mill.

[This message has been edited by cam-a-lot (edited 01-23-2015).]

zkhennings JAN 23, 01:32 PM

quote
Originally posted by cam-a-lot:

Why would you buy a new CNC for hobby jobs? I know of dozens of usable, full 3 axis CNC mills for sale for less than 25k. A good knee mill with 3 axis CNC control can do this no problem, and is a lot cheaper than an enclosed machining center.

Regarding the chatter in the corners, either slow down your federate on all G02/G03 internal arc commands, or put in a half second dwell command while in the corner, so the cutter doesn't cut on 2 sides at once. This will eliminate your chatter. Make sure you climb mill.




I was planning on DIY CNC router type deal for cheap like ~ $1000, the enclosed machine is the HAAS mini mill that I used a lot in college, not what I would be planning on buying. And yea we chose a profile that took out pockets at a time instead of following the wall profile.

And Will, I know you still need camber gain in normal cornering situations, but the additional caster angle would cause additional camber in higher speed turns, just not as much. I was just wondering if that gets taken into your considerations when designing the camber curve of the front suspension.
wftb JAN 24, 03:13 PM
A custom made machined aluminum rear spindle would be something I would buy .Would make it much easier to do this :
You could machine in a fork type mount on both sides for bolting in upper arms .Bolting arms to the strut stub is a bit of a pain .
Will JAN 25, 10:25 AM
Is that your build?
Why not put the pivot outboard of the "strut stub"?
wftb JAN 25, 01:33 PM
I put the pivot where it is so the arm would follow the same basic motion as the strut .I did not want to wrestle with all the calculations to figure the geometry changes so I hope that it will be close to stock geometry .The arms are very simple to build , I am going to see how this setup works and decide if I need to change it or not .I have to drop the cradle to finish the welding so it will be a while before a test run in my backyard .
Bloozberry JAN 25, 02:12 PM
Are you also rigidly mounting the strut to the top of that knuckle with the two large bolts?
Will JAN 25, 03:42 PM

quote
Originally posted by wftb:

I put the pivot where it is so the arm would follow the same basic motion as the strut .I did not want to wrestle with all the calculations to figure the geometry changes so I hope that it will be close to stock geometry .The arms are very simple to build , I am going to see how this setup works and decide if I need to change it or not .I have to drop the cradle to finish the welding so it will be a while before a test run in my backyard .



Well... don't finish the welding just yet...

An arm can't follow the motion of the strut. Ever. The arm moves in an arc and the strut moves in a straight line.
I see only one upper link. Am I missing something?
Do you still have the stock toe link?

[This message has been edited by Will (edited 01-25-2015).]

wftb JAN 25, 03:47 PM
I am going to use a QA1 coilover .The mount for it will go in between the arm mounts and what remains of the strut .Trying to get it as close to the strut mounting stub as I can , I do not want the upper arm to carry the cars weight .The large bolts will just hold the finished arm and coilover mount assembly to the stub , the same as they hold the strut assembly on a stock setup .I will get a pic of the finished mount later today , got a lot of welding and grinding to do to get it ready to paint up .
wftb JAN 25, 03:57 PM
Toe link is there but it will not be used .The arm will not move like a strut , I know that .My reasoning was to mount the arm on the line that you can draw from the strut to the lower ball joint .That way I am hoping the geometry will be close to stock , only now I can use a much better coilover assembly .If it does not work as planned , I can go back to what I had .The shock tower will remain , I will just have to patch it up .