Stator Tube Question - Is it possible to make one out of tubing?

[blueskies]

Just figured out why the trafficator turns and why the oil runs out of the steering box on the BN4 - no stator tube. And neither of the two spare steering columns have the stator tube. Where do all the stator tubes go???

Anyway, if I knew the dimensions of the tube, it might be possible to make one out of thin wall steel brake line or fuel line. I'm guessing 5/16" inside diameter and about six inches shorter than the steering column length. Then a slot cut in one end to mesh with the trafficator. But those dimensions are just a guess.

Does anyone have a one piece stator tube, old or new, not presently installed in a car of course, that they can measure - inside and outside diameter, overall length, and the length of the slot? Or is this a dumb idea? If so, it will have to wait until the next parts order from a supplier.

 

[Keoke]

It is not Dumb , But getting a factory fabricated replacement is probably the most rewarding proposition.

 

[Bob_Spidell]

Just figured out why the trafficator turns and why the oil runs out of the steering box on the BN4 - no stator tube. ...

That's really strange. The main problem with stator tubes is the slots at the top are cut straight--i.e. the corners of the slot aren't radiused--so they develop stress cracks. This also means your wiring has been bathed in steering box oil and will likely deteriorate faster and, it's conceivable they could foul your steering mechanism (haven't been in a steering box in a while, but it seems possible).

How did your DPO (Dreaded Previous Owner) seal the end of the box (where the wiring comes out)?

 

[blueskies]

Ordering a new one certainly would be my preferred choice, Keoke. Unfortunately, most parts for these cars are thousands of miles away. My last parts order of large things (bumpers, etc) is on the way with UPS; wish I had thought of ordering a stator tube a few days ago before the order shipped. To ship a long part like a stator tube, alone, is not easy or cheap. That's why I am looking for the specs to make one.

 

[John Turney]

If no one gives you the dimensions, measure the OD and the width of the raised bumps of the trafficator tube. You also need the ID of the olive that seals the bottom of the stator tube. The OD and ID you measure will determine the tubing size. The tubing is a sliding fit with no slop. The width of the bumps will determine the slot size. I recall that the tubing is thicker walled and more rigid than brake or fuel line. Brake and fuel line is meant to be bent, but not the stator tube.

 

[johnea]

I made up a new stator tube as the original tube was cracked at the end of the slot. I've kept the old tube. The dimensions are 6/16" outside diameter. The inside diameter is probably 5/16" (difficult to take exact measurements with vernier calipers). Length of the slot 4"and 3/16". Overall length 60" and 3/4". Width of the slot 1/8" Try to make the corners of the slot in a radius like Bob_Spidell suggested.

 

[Healey Nut]

Go buy a 6ft length of 3/8th OD rigid brake or fuel line line , cut of the flares and tube nuts . Now the task is to cut a straight slot in it to engage in the steering head tube . A small cut off wheel would be my choice . The length of the slot and length of the tube are not critical as long as it inserts to the steering head far enough to engage and protrudes far enough out of the steering box by an 1/2" or so then just cut it off there as its a compression fitting . The wiring is about 1/4" so should fit easily inside the brake line . The hardest part will be cutting the slot straight .

 

[blueskies]

Thanks for the info and suggestions. In the meantime, I found a short piece of 3/8" (.375") brake or fuel line and tried to feed the wires through. They fit! I also looked at the BJ7 stator tube that projects an inch or two out of the steering box; that also is .375. I agree that cutting the slot likely is the most exacting job. As suggested by Healey Nut, a thin cutting wheel on a grinder should do the job.

The wiring on the trafficator should be fine. It is a "new" trafficator that came with a parts car - another Longbridge 100-6 - and most of the oil had already run out of the box before I fed the wires down the steering column. Once everything is in place, I will refill the steering box.

Learning about these cars by trial and error does help keep the mind active!

 

[HealeyRick]

The hardest part will be cutting the slot straight .

How about chucking the Dremel horizontally into a vice with the cutoff wheel protruding vertically the proper distance so that when the tube is run along the side of the jaws the wheel will make the cut at the correct distance? Might also be able to rig some pieces of wood to limit the vertical depth in the tube as well.
Or maybe something like this made out of wood with a cutoff wheel instead of the grinder?

 

[HealeyRick]

So what I'm thinking is if you made a stand like in the video then added an "L" shaped channel of the right dimensions to the end where the cutting wheel is, you could just feed the tube through the channel and get a straight cut of the right depth.

 

[blueskies]

Thanks for the suggestion, Rick. I also have a few stationary saws. A radial arm saw with an abrasive metal cutting blade may also be a good way to make the cut; the tube would be stable in a groove on the table, and the saw would be pulled straight outwards.

 

[Randy Forbes]

Drill a hole at the end of the cut__whatever distance you need the slot length to be from the end of the tube. The "cut" the slot to the leading edge of the hole, thereby leaving the corners radiused.

This minimizes the chance of stress risers leading the tube to crack at the corners of the slot, as Bob alludes to.

Personally, I would use 3/8" O.D. stainless steel instrumentation tubing; it's quite rigid, even though it is intended to be bent, and you know it'll last darn near forever.

 

[drambuie]

I agree with Randy's idea, what ever grade you decide to use, Austenitic stainless steel in 304 grade would be fine.. Many times you need a business number to order material from a steel distributor in your area. The tubing usually comes in standard lengths 6 meters or more, however many steel/tubing companies custom cut your order to length if requested. If you find it difficult to order your material without a business number, simply visit one of your local small machine shops and they can order your tubing and why not ask them to machine the small hole and slot for you!

 

[John Turney]

You will also need to clamp something to the tube as you feed it past the cutter to keep the tube from rotating.

 

[blueskies]

The new stator tube is now installed in the car; it fit as if it belonged there. If it helps anyone else, the length of the tube is 60 inches, and the slot cut measures 4.25 inches x .125 inches with (as suggested) a radius drilled at the end of the cut. An abrasive blade in the small radial arm, with the tube placed in the well-worn groove in the table and held down by a strip of wood and a couple of screws, allowed for a stable and precise cut. Stainless steel sounded good, but this coated steel line was more easily available; it should last. Thanks for the discussion and ideas!

 

[HealeyRick]

Nicely done. Don't know if your front wheels are in the straight ahead position in the last photo, but if so, the steering wheel is on upside down. The center spoke should be at the top. That way the spokes won't block the view of the instruments when you're driving.

 

[blueskies]

Nicely done. Don't know if your front wheels are in the straight ahead position in the last photo, but if so, the steering wheel is on upside down. The center spoke should be at the top. That way the spokes won't block the view of the instruments when you're driving.

Aah, I wondered about that; I should have checked. Fortunately, it won't take long to fix that.