[leeputman]

OK, the reason I cannot take care of my threading problem is that I do not have the 127 tooth change gear with will allow me to turn this fine of thread. While I do not have the metric gear set the machine can tune 1.0mm pitch with the standard gear set if it was supplied with the Metric yoke which I seem to think I have.

Who knows enough about these to help me positively identify what I need. I am surprised at how little information is contained in these old machine manuals.

I would also like to learn how to positively identify a type of gear so I can order it from a place like Boston Gear and finish the hole myself. I need to do this with a Clausing Colchester 15" lathe also.

Thanks. I can figure out a great deal and even invest time in making gears but I need someone to guild me.

[Kiwi]

The 127 tooth gear is supplied so metric threads can be cut on a lathe with a imperial leadscrew. (127 is the lowest interger. 25.4 X 5 = 127)
When not using a 127 gear, is the 1.0mm pitch correct or just very close?
I suspect the later.
Some gear suppliers have drawings of gears which can be view at their web site. From these details, you may be able to determine the pressure angle, DP etc.

[NC Cams]

Rule of thumb = imported metric machines have module pitch gears, domestic machines used standard diametral pitch (8, 16, 32 etc).

Thus, once you know the type of machine (imported, domestic) you can focuse your attention on simply identifying the tooth count and pitch. Hardinge surely had standard diametral pitch gears.


If you can't figure out the pitch, assuming they are not using stub tooth or some other special, simply measure the OD and count the teeth. By looking in the gear chart, you can find or come darn close in determining the pitch.

Pressure angle, however is something you need to scope out a bit closer. I don't have any "tricks" for that.

[leeputman]

Thank you both for the information. Yes, the lathe was purchased new in 1977 so I will assume that the gears are standard DP. As I understand gears I should be able to measure the OD of the other gears in the train, count teeth and determine the DP thus finding the DP of the gear I need and knowing the tooth count I should be able to determine the OD, right? I'll work on the pressure angle. I think I will contact Boston Grear and arrange to send them one of the extra gears I have. Let them measure it and order the gear I need.

Along the same subject, I am pretty much teaching myself the trade and would like names of any refference material you may know of. While there is not much call to make gears any longer I still want to learn more and do it from time to time. Preserve the skills of the trade. thanks

[NC Cams]

THe "Stock Drive Products" catalog has some neat gear calculation formulae that are REAL helpful.

There is a decent college text entitled "Design of Machine Elements" by M.F. Spotts that provides design insight into a lot of basic machine design principles - bolting and gearing are well presented.

Then there is the absolutely essential and MANDATORY to own "Machinist Handbook".

[leeputman]

Yes, there is no replacement for the Machinist Handbook, I need a little more on the "hoe to's" and not so much definitions. I will look up the other books. My family and friends are always amazed at what I make and they ask, how did you learn this stuff?

I read a book.

Lee

[CNCezee]

Help!!!!

I have just had the bargain of the century I bought a Jones and Shipman 540p surface grinder and colchester student square head 1800 lathe for £400.00.......But somebody has robbed the lathe for spares the two most annoying bits missing are the tail stock, and all of the change gears.

The tail stock i have found but the change gears are proving a problem, i have a record of the numbers of teeth but i need the diameters so i can cut some replacements, is there any one out there who can provide this information

The numbers of teeth should be supplied with each machine on the plate on the gearbox. i can work from the root diameter.
Another annoying pice missing are the main bed saddle gibb strips, can anyone give a clue as to how i can remanufacture a pair, the supporting brackets are there as is the adjusting screws, but sadly no strips.

If anyone can help it would be appreciated

Roger