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Steering box worm shaft and nut help

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
Looking for general ideas/info on how these parts might have been made, and possibly how they could be reproduced on manual machines.

IMG_20191120_114617.jpg IMG_20191120_114655.jpg IMG_20191120_114811.jpg

Im guessing the shaft would have been rough turned, hardened then ground to finish. Not sure on the nut :o

Cheers
D
 

Limy Sami

Diamond
Joined
Jan 7, 2007
Location
Norfolk, UK
The shafts were thread milled then HT and ground - but essentially the same process as turning.

Like you I have no idea about the nut.
 

welderboyjk

Cast Iron
Joined
Nov 22, 2006
Location
south west michigan
I'm curious as to what the box came off of.
I have had hundreds of power boxes and a handful of manual boxes apart. Never saw a sector/piston/nut that small before. Looks like it only has half a loop.
 

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
I'm curious as to what the box came off of.
I have had hundreds of power boxes and a handful of manual boxes apart. Never saw a sector/piston/nut that small before. Looks like it only has half a loop.

Its from a Sunbeam Alpine. I think the steering box was common to quite few other cars from that era tho.
The nut sits atop the worm, a fork sits on top of that and held down by a spring. Only the top half of the nut engages the worm, the bottom half is a tube to recirculate the balls. Ive got most of the box so will post more pics when I get a mo.

Cheers
D
 

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
Oh he is the moderator on the metrology forum.

270499d1574260197-who-moderator-here-now-capture.jpg

giphy.gif
 

welderboyjk

Cast Iron
Joined
Nov 22, 2006
Location
south west michigan
Its from a Sunbeam Alpine. I think the steering box was common to quite few other cars from that era tho.
The nut sits atop the worm, a fork sits on top of that and held down by a spring. Only the top half of the nut engages the worm, the bottom half is a tube to recirculate the balls. Ive got most of the box so will post more pics when I get a mo.

Cheers
D

Having only 1/2 of a loop in contact with the worm looks like there would only be 6 or so balls in contact at any time. Just seems sketchy to me. Although that might have been a way to negate the need for tight tolerancing.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
Burman F type half nut ......Burman also made a F type full nut used in trucks......as we all know ,Burmans also made motor bike gearboxes......S Burman and Sons,Wychall Lane ,Birmingham the factory is still there ,now owned by a laminated glass multinational.
 

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
Having only 1/2 of a loop in contact with the worm looks like there would only be 6 or so balls in contact at any time. Just seems sketchy to me. Although that might have been a way to negate the need for tight tolerancing.

My buddy also mentioned it helps take the shock out of the steering is you hit a pothole etc. Not sure how true that is but makes sense.

Cheers
D
 

thermite

Diamond
That's another computer screen you can clean the tea off :D

Coffee as well..

ISTR what was to become Saginaw Gear Division of General Motors implemented the early patents on recirculating ball systems in mass production, 1930's?

Steering was only one application. As with Getrag (not recirculating ball), same goods are fitted to "many" uses, old 1950's fords and newer 1970's BMW's using much the same Getrag boxes.

Rather than make one, better to just find one off some other application. ELSE order a length of the ready-made screw and the balls & nuts to match.

See also CNC ballscrews..
 

thermite

Diamond
My buddy also mentioned it helps take the shock out of the steering is you hit a pothole etc. Not sure how true that is but makes sense.

Cheers
D

Per an Uncle long deceased, they were HATED by farmers when first applied to tractors. "That g-damned ball-feed contraption" CAN have nearly 100% feedback, so the rough ground was hard on the guy steering, pre-power-steering era.

Ag equipment HAD made use of worm and sector steering for the most part, which can be engineered for NO discernible kick-back or "just enough" for useful feel.
 

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
Coffee as well..

ISTR what was to become Saginaw Gear Division of General Motors implemented the early patents on recirculating ball systems in mass production, 1930's?

Steering was only one application. As with Getrag (not recirculating ball), same goods are fitted to "many" uses, old 1950's fords and newer 1970's BMW's using much the same Getrag boxes.

Rather than make one, better to just find one off some other application. ELSE order a length of the ready-made screw and the balls & nuts to match.

See also CNC ballscrews..

You might have something there Bill. I found this on screw stock to finished item, im guessing the size required wont be off shelf so depends on cost. The Induction heater, I want one! :cloud9:
 

Demon69

Titanium
Joined
Mar 3, 2013
Location
Area 69.
If I was gonna have a go:-

i) How hard does this thing really need to be? Its seems the case hardening breaking down is the problem.
ii) What material? EN24T/19T? EN8? It needs to be welded to a column so would be nice to keep that bit simple.
iii) What questions do I not know to ask, liability aside :D
 
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