1953 Tray Top 12 1/2 x 30

restore49 · Oct 26, 2017

Hi;
Need to make a 36 tooth gear in the change box - would like to know if 14 1/2 or 20 pressure angle or proprietary and can not be made ??? new cost $1279 per gear. Bob

johnoder · Oct 27, 2017

Might get more response if you clarify SPEED change or feed/thread change

Spindle speed gears HAVE TO BE RIGHT - however much trouble or expense is involved. Not only the "making", but also the heat treat and finishing

If OEM drawings are unavailable to you, in order to make a gear you will need to have the gear in question reverse engineered by a party that knows everything there is to know about making such gears

restore49 · Oct 27, 2017

Yes it is one of the speed change gears - my feed/ thread box is the same as in the photo. Just pulled the gear out of a friends identical machine tonight and need to figure out ---- find someone brighten than I am that would know the pressure angle ( if 141/2 or 20) so one can be made??? Cincinnati will NOT provide any information other than price Bob

johnoder · Oct 27, 2017

Several posts here - like my Post #49 - showing both 14 1/2 and 20 pressure angles on the same tooth count may help you decide which is nearer to what you have

Basically, the 20 has broader base tooth and more "pointy" tooth space than the 14 1/2

http://www.practicalmachinist.com/v...-gear-built-323022/index3.html?highlight=gear

restore49 · Oct 27, 2017

From you post copied one profile on one side of paper the other on back side. Held up to light and can really see the difference . Will check against gear. Bob

restore49 · Nov 7, 2017

A little more information.1953 Cincinnati Tray top - 36 tooth 1.725 OD - change gear. Thinking 22DP 14 1/2 degree. My try at clay. Will order cutter if sure the correct one. Bob

johnoder · Nov 7, 2017

May want to try the info in Post #3 before spending money

http://www.practicalmachinist.com/v...-gears-pa-203860/?highlight=span+measurements

Here are the values for some pressure angles at 1 DP
14 1/2 = 3.04115 (which is why in the linked thread Post #2 he is using .304 for 10DP)
17 1/2 = 2.9962
20 = 2.9521

I'll check the collection and see if any 22 DP of the right number - sorry, none for 36 teeth

restore49 · Dec 24, 2017

Update - made some progress with borrowed parts from another Cincinnati to duplicate. All new oval handles and the curved shift plate plus a new aluminum shifting Yoke. Now to make the 36 tooth gear. A good deal of time repairing a broken shift fork and damaged gear in the Gear Head. Gear only .1925 wide and running against hardened gears. Not running in a shop 24-7 what would be a usable material for the gear - cast iron - delrin - 4140 hardened - 4140 not hardened - aluminum . ??? This gear is easy to change so can check durability after a few uses. Bob

Monarchist · Dec 24, 2017

restore49 said:
running against hardened gears. Not running in a shop 24-7 what would be a usable material for the gear...

If you have access to an experienced HT shop, 8620 might even be close to what was used, OEM, and the case-hardening doesn't need to be very deep to pay-off in running life extension.

If DIY, no HT? Bronze, rather, even where the OEM gear was not.

It marries-up well when run against hardened steel. So long as it's running mate is still smooth-surfaced, even if worn a bit from its original involute shape, Bronze - decently lubed - can extend the life of both players.

In their time-era, traytops were not exactly paragons of virtue in their gear department to begin with, so there is room for improvement if you must go to the effort.

restore49 · Dec 24, 2017

DIY - Bronze - have in stock will give a try. Thanks

Monarchist · Dec 24, 2017

restore49 said:
DIY - Bronze - have in stock will give a try. Thanks

Fair 'nuf but "in stock" rather than purpose-ordered is I hope one of the right ones among the Bronzes.

There are rather a lot of them, some are far better than others for any of many given purposes, and a few aren't really Bronze at all, but Brass, rather. (C200, Tobin/Admiralty...)

restore49 · Dec 24, 2017

Sir:
Since I only need 1 3/4 x 1/2 I can order - lathe will be with me for 20 years if I live that long. What grade Bronze should I order? I do have a large Manganese Bronze Prop I could cut it out of. . Thanks Bob

Monarchist · Dec 24, 2017

restore49 said:
Sir:
Since I only need 1 3/4 x 1/2 I can order - lathe will be with me for 20 years if I live that long. What grade Bronze should I order . Thanks Bob

C86300 AKA SAE 430B Manganese Bronze is serious-good for gears. All you need is a "drop", and a small one at that. See if recycler // ebay seller Moses Glick has any. Otherwise Speedy, Online, or such by the inch.

I harbour several of the Aluminium or Nickel-Aluminium Bronzes, but use them sparingly. Strong, but rather abrasive, those are, and capable of destroying a mating part if shorted on good lube. Stay away from those, even if someone goes on about how strong they are, 'coz they are also a right b***h to machine.

restore49 · Jan 7, 2018

Finally after 46 years of sitting in friends cellar gear is done. DP22 Pa 20 degree.Thanks everyone for the input. Bob

restore49 · Jan 9, 2018

New Cincinnati puzzle - Input shaft to Change gear Box. Noticed gear had a wobble and found this. Turned on Lathe till it feel apart. Still have original welders 3/16 center pin to work with. Shaft is soft gear hard 3/4"shaft was thinking finish taper on both halves set in centers in a jig and Mig weld (do not have tig)? Would appreciate input on procedure. Shaft not available and not trying to build new. Bob

cmike · Jan 11, 2018

Cincinnati in the old days use taper pins a lot. Roll pins too. They use double set screw to lock things in place. Not sure on the lathe side of manfacturing.

restore49 · Jan 11, 2018

Set in centers on jig - rotated and continues weld - got lucky .005 finished machine. Yes Cincinnati loves to use taper pins.

restore49 · Dec 24, 2018

VFD Micro Switches

Removed the Gear for the Drum Switch and made up a bracket to mount switches without having to make any other changes to the 100Lbs. of original (working)controls mounted in the left leg. Nice to have the quick stop for the chuck with the VFD. Before and after pic. Bob

ratbldr427 · Dec 25, 2018

When I have a shaft like yours I would in this case weld a larger od piece to the gear holding half.Simply because alignment would be taken when machining to size and that end is the easiest less complicated to machine.

cmike · Dec 29, 2018

Did that gear have a part number on it ?

1953 Tray Top 12 1/2 x 30

Aluminum

Diamond

Aluminum

Diamond

Aluminum

Aluminum

Diamond

Aluminum

Diamond

Aluminum

Diamond

Aluminum

Diamond

Aluminum

Aluminum

Hot Rolled

Aluminum

Aluminum

Titanium

Hot Rolled

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