Cycle thread taps & dies

[olderdan]

My main activity is restoring vintage motorcycles so having some clean up taps and dies is very useful. I have to prioritise on spending to afford some of the things I can’t make as it it is not a cheap hobby, the answer for me was to make them.
So far I have 5/16 and 3/8 BSCY in 26 TPI made of oil hardening tool steel and they have even been used to make new items sometimes in stainless as the thread depth is only .0205. the dies are made with the taps, anything larger can be screwcut, and I have chasers for that.
I know some will view this thread system as archaic but the motorcycle I am working on is 97 years old and apart from an engine has more in common with a bicycle (you can’t change history).
Having said that some of these threads were still in use into the sixties until UNF became more common and then of course Metric.
The main reason for posting is to show it is fairly easy to make them especially if you encounter an oddball size.

[thirdbike]

"The main reason for posting is to show it is fairly easy to make them especially if you encounter an oddball size."
Very interesting and thank you for sharing the info. If you do have a minute I would be very interested in how you go about making them.

[ncollar]

"The main reason for posting is to show it is fairly easy to make them especially if you encounter an oddball size."
Very interesting and thank you for sharing the info. If you do have a minute I would be very interested in how you go about making them.

not just odd ball sizes but custom bolts and nuts. I have always thought South Bend did a crappy job of tail stock hold down bolt. If they would have decreased the pitch the nut would tighten faster and like wise loosen faster.

[NortonDommi]

Olderdan,
Did you make RH and LH? My oldest motorcycle was a 1926? Royal Enfield that was the first motorcycle to have foot gear-change, it still had the hand-change as well. Hand oil pump, spark advance/retard and externally adjustable main jet on a thing called a carburetor. I really, really regret selling it now to buy a new 1980 Yamaha TT500.
A lot of motorcycles from around the world were still using RH and LH threads into the early 1960's, not so dumb either as the total harmonics were considered and everything tightened itself up and as long as you knew never a problem.
The above 'bike I bought age 15 and rebuilt including a Gold plated carb as Dad had a polishing business,(it was Brass).
I wonder how a millennium would cope?

[Frank S]

I've had several bikes over the years some were lots of fun more were lots of work all were unique in in their own right one way or another. a Powell that was supposed to be a mini bike but had a 10 hp Kohler a stupid and I mean that in the literal sense Honda 50 with a real tube frame not the stamped pressed factory thing. BSA 1 lung 500
ankle buster. Harley 45, chopped & raked 750 Kawasaki half a dozen 350 & 450 Honda's a 48 Harley Pan head a 74 Electraglide Triumph 650 a 1921 Ner-a-car but the 1 bike that if I still had it today that would melt a millennial's brain was my 73 850 commando that would pull the front wheel of the ground in 3rd gear if you sat back on the seat and really gassed on it would eat a Kawa 1300 or a GS 1100 Suzuki as long as you weren't going more than a 1/4 mile at a time. it would hit top about half way between the 1/8 & the 1/4 mark all you had to do was aly down on the tank and hold on .and let those 32 mm Mukuni s feed it the stock Amal 28's were better run around carb's but just couldn't feed it as well as the Mukuni's when you wanted to get there NOW! the only thing was when you wanted to start it you had better want to start it or it would toss you over the bars.

[NortonDommi]

Well I take it the Commando wasn't an Interstate then? No way you would lift the front with a full tank of gas aye? I have some very funny stories to tell about adventures with Norton's. That Isolastic suspension was a revelation at the time but I would have laid money that a 750 was quicker over a short run. I had in order all of the 'H' series Kawaka's and if they could have connected the two wheels together with something other than rubber bands they would have been great bikes, the one that held the steering head on was a real problem plus they were crap on gravel. I remember what an impact Mikuni's had, A lot to do with the fact that they were new and if going from a clapped out single carb on a duel manifold to individual carbs was like supercharging.
I don't know if you can tell but I do like Norton's. Sacrilegious heresy to think that I consider the 1979 Triumph Bonneville probably the most beautiful motorcycle ever built, just a crying shame it couldn't go around corners properly.
Still to this day I always look at threads to check their hand regardless of what it is I am doing. Learnt young and looking first is good, just wish I could follow my own advice.

[NortonDommi]

Forgot to ask, the Ner-a-car, by Osbourn Engineering Company?? Center-hub steering? A concept that just has to be fully embraced one day. Might have the builder confused. Can see the pictures in my head. I know that O.E.C. patented his Parallelogram steering concept and I built a trike with it. Solved a lot of the weight transfer problems with two wheels at the back not at the front where they should be.

[Frank S]

The ner-a-car had the center hub steering designed by Carl Neracher made in both England and Syracuse NY. mine had an asthmatic 121 cc Sheffield engine the the 350cc Blackburne 4 cycle was popular in England transmission if you could call it that was a friction disk drive 3 settings 1 disk slid across the other 1 having a leather tire someone even put a 4 cylinder in one
Like I said about pulling the front wheel on the commando you had to sit all the way back to get it to do it plenty of power just too much weight up front. the nice thing about the engine mounting was the vibrations were not transmitted to the bars but really weak when an extra disk was added to the clutch I felt the transmission was undersized as I separated the internals and split the case on 2 of them and broke the primary a few times before I figured out I had too much clutch with the 5 pack Barnett

[olderdan]

Hi ncollar
I agree with your comment on South Bend tailstock clamping, a bit of a blind spot on what is otherwise an excellent lathe.
With only a 2 inch travel on the tailstock barrel it is a real pain to have to clamp and realise when drilling deep holes. Before converting to a lever clamp I had tried different thread types on the bolt with no improvement. You may want to look at my post on the conversion which has transformed its use.

http://www.homemadetools.net/forum/l...1762#post94654

[olderdan]

"The main reason for posting is to show it is fairly easy to make them especially if you encounter an oddball size."
Very interesting and thank you for sharing the info. If you do have a minute I would be very interested in how you go about making them.

I can't help much on making these as they were made some years ago before joining HMT, but there are some video's on Youtube on making taps etc.