Control rods. Riveted U.C.

[shaun]

Lynn, Thats all very handy info mate. the engine tie rods do have a long length of thread because you have to be able to wind the nuts a long way on the bars. This is so you are able to jiggle them through the hull and then through the block, does that make sence to you ?
TTFN
Shaun

[RichardT10829]

no hurry at all Lynn..... and as always your efforts here are greatly appreciated.

[Lynn Eades]

Richard, the short rods are there, but as stated need someone to check the details, as my sample, I made, and may not be accurate.
Thanks Shaun for the explanation. I havent got that far yet, so didnt know.

[RichardT10829]

Sorry to resurrect the thread Lynn... The lengths quoted, is that minus the clevis pieces, ie it's the length of the actual rod rather than the assembly ?

Just getting ready to make up the front to rear brake rods, thinking about material, I cut the remains of one with ease using a blunt hacksaw today, my thoughts are if the brake works by being pulled on by the rod rather than pushed, then mild steel might be ok to use as it should be ok in tension.... Different gravy if they are pushed on though.

[Ben]

I made some using these dimensions and they were for the rod only, no clevis.

I ordered slightly higher grade steel. Mild steel today is generally crap. It wasn't much more money but seems to be better. For the life of me I can't find the invoice with the material name and number. If you ring a wholesaler and ask for some advise it would pay off. You'll be slightly limited in that you want 7/16 but the one I got has a little chromium in it as it's used it the petrochemical industry.

Ben

[Andrew Rowe]

Probably was 4140 -medium tensile , you can also get '' free cutting '' steels which cuts and forms threads better than mild steel grades.

[Lynn Eades]

I was only ever talking about the finished length of the rod, including the threads and nothing extra. I'm sure I have already covered this. (see line 5 first post)

The rod is a medium tensile, which is what you would require. You have to be able to put a thread on it, but you want it strong.
Free cutting mild steel has a lower tensile strength than mild steel (mild steel doesn't have a spec) It is higher in lead content to make the thread cutting easier. It is not suitable for this job.

On the thread cutting;
It is easy to screw it up! (start it crooked)
When you buy your steel for your long rods, and you have cut them to length, you have only one shot at it.
The best way to do it (unless you have access to special thread rolling gear) is to put the rod in a lathe (chuck) and your die holder against the spindle of the tail stock.
This helps you to keep it all square for the thread cutting
You can then "feed' the die with the tail stock, while turning the chuck by hand (maybe easier swinging it with the chuck key)
It the case of the long rods, careful planning to support the rod is required (maybe put it in a pipe that fits in the hole through the headstock and supporting the other end with a stand or timber frame or what have you) Make sure the lathe is isolated (switched off at the main) or serious damage is likely.