Thread: custom made trailing arm

Originally Posted by Bush65

X-ray will be out of the question (not possible) for welds on a trailing arm. Because of the hollow arm, there is no way to get the x-ray plate on the other side (inside hollow bar) of weld.

Ultrasonic would be the best method of NDT (non destructive testing), then mag partical. Failing those use dye penetrant.

Thanks John, hadn't thought of that.

The only things I've had x-rayed/scanned in the last few years are my shoulders and multiple horse legs/joints

We didn't bother with the head, that'd be a waste of time.....

I planned on having my TA dye tested then destructive tested against oem item
Engineer was happy with just a welding process
Mine don't have welding at the chassis end
I have pieces made up threaded both ends (4140)
One end copies oem specs through the TA bush
The other end threads into 40 mm hollow bar
That's a mofo to cut that thread
Dc

Dave, what dia did you bore and thread the Hollow bar to? Did you do the thread on the lathe (cut) or use a tap?

A lot of aircraft control rod and actuator end fittings are locked by tab washers that engage a small lengthwise keyway in the thread of the end fitting, and also have a protrusion on the face of the washer that engages into a notch in the end of the rod/tube itself. Held in place by a lock nut, but the locking is done by the tabs not the friction of the thread.
Nuts are generally lockwired to the tab to prevent the nut from coming undone.

All have published specs eg NAS513 and the nuts and washers should be easily available through parts suppliers.

Examples here: Locking Devices, Keys & Keyways by New Hampshire Ball Bearing

Steve

Thanks steve,

maybe getting a bit over complicated for my needs.....I may be already

The tap and paperwork are out of reach
Tapped using lathe about 16 mm I think
Could do by hand but I have electricians chicken arms
All parts are in a mates workshop
I have to pick them up next week so ill have to learn how to do photos
40mm x 10 mm hollow bar is overkill but I specced it to handle cranking
Dc

Ive been looking through my Sutton industrial catalogue, most normal taps are only good for 1-1.5xdia for depth of tapping.

Dave, are you using RR pin end?

Deefer pin end or the larger courser one
The tap has been 'extended to tap/bore deeper
This part is not my specialty
I can bumble my way around a lathe but I leave screw cutting and
Large tapping to the experts that owe me favors



Or pay to have it done
Dc