Post By Wanna-Be
Post By rockcampbell
Post By rockcampbell
Brown & Sharpe Mod 4-36" gear cutting machine
I found this old machine gathering dust and grime in a machine shop in Aberdeen WA. It had previously been in one other shop all it's life and with the same operator (so I'm told). When he retired, no one else used it.
Since it can only cut spur gears there hasn't been much demand or need. I couldn't pass it up and brought it into my shop (museum) of old machines. If I need anything for these old machines, it is spur gears for the missing, broken or worn out gears. Most I could make on a milling machine but the idea of having a automatic machine got my imagination working. Without any manual or mentor, I was intially over whelmed. I did have a faded old wall chart of the gear change combinations for the indexer. After sorting and inventorying the drive, feed and indexer gears I found I was only missing one of the approx. 35 gear required to index gear teeth counts from 12 to 400 teeth (less the couple that are not possible). I have no idea of what I might be missing in the drive and feed gear sets but I'm confident I can make what ever is missing with what I have on hand. (An old machine-repairing and old machine. Self perpetuatiing hobby!)
After a year or so of research and playing around with it, it seems to be about 98% complete, only missing that one index gear and a most of the oiler caps. The cutting oil return gutter is broken in one area that will need to be repaired. Otherwise, I feel fortunate that is has survived this long, to serve again.
So far I have found this machine illustrated in a couple old books and someone sent me an illustration and spec. sheet for this machine.
I have uploaded a few pictures with my comments on each at Pictures by SteveWlf - Photobucket
I will find a way to post the illustration and spec and add that link later.
If anyone has any further history or experience on this machine, I would be interested. Without an operators manual or mentor it will be trial and perhaps error.
Once you have a first post, you can "attach" pix to it. Or do a (now) 2nd reply and add the pix to that one.
Something about a thread has to exist before you can upload pix and attach to it.
Here is a video of my Cincinnati running. These are similar machines and will cut ratchets as well as spur gears.
Not real hard to set up. Just make sure you have your cutter on center and a speed and feed that will not destroy your cutter. I put a micro switch on mine to shut it off after a complete revolution.
I do not use it alot. 4 pitch is as big as it will cut on 36" diameter. I wish it would cut 3 pitch.
The job shop I started out in had 2 of them this size and one that would cut up to about 60 inch. I also had a heavy version for cutting pinions in my shop for a while but let it go due to lack of use. They were really good at cutting spur gears or sprockets one tooth at a time. The work arbors were long enough to set up several blanks at once if they were thin. In your photo bucket photos you have one of the old illustration of the machine. On the lower right hand side of the photo the cutter centering gage is shown, it makes it a whole lot easier to adjust the cutter on center if you got it too. Watch out for the handle on the end when it rapids the carriage back cause it can get stuck engaged and do some serious whipping on you. Also make sure you set the dog position for the carriage return well back initially to allow time for the blank to index and lock before the cutter advances into again. Once you get the hang of setting it up and how it works you will be letting it run while you do other things. We used to run a separate time card for gear cutter running time after the setup was made because they ran by themselves. Also when you set the cutter depth touch the cutter to the blank od, put an indicator on the work slide and set to "0", get the cutter clear and let the work slide down past correct depth of cut and then raise it back to the correct cut depth. This way the depth screw is contacting the bottom of the work slide nut and the backlash is at the top. If you have any specific issues let me know and I will try to help. Its been 25 years since I ran one but I had plenty of time on them.
Thanks for the video clip. That cincinnati is very similar to my B&S.
I don't know what the pitch limitations might be but I'm thinking, maybe the No. 4 model number might be the indicator since both our machines have that designation. If you have any other way to advise me on this I would appreciate that.
Still learning and these post responses have been very encouraging and helpful.
Again, I am pleased with what I am able to learn from others about this old machine. When I purchased it from the second owner, he told me that the old operator retired when they sold the machine to him, about 15 year previous. He and run it all of it's life and wasn't even interested training a new operator. However, his son did come to work at the shop I found it in. He was also a a general machinist of some skill and told me his father only told him a few features and wasn't interest in training him or anyone else. The shop owner, was lacking gear cutting knowledge and eventually offered it to sale to me. He kept refering to it as a "gear hobbing machine" and that it could cut helical gears. By the time I had made up my mind to purchase it I had convince myself and the seller that it was limited to spur gears, splines and perhaps ratchets. Due to these limitation and the fact that it had a 440 3ph motor (not duel voltage) I got the price down. In this haggling process, he with drew his collection of gear cutters. (not a big issue for me since I recently inherited a very large collection of cutters)
One thing that I was lead to believe from the son of the old operator and others have taken exception to, this machine process is capable of cutting each tooth in a single pass. After considering this and the comments of others, looking through old books on gear cutting and now, watch the YouTube video of the Cincinnati machine, I'd have to say I should start by roughing it out before reaching final tooth depth. You mention the above procedure and yet I still have to ask if "single pass" is what your are describing??
Originally Posted by rockcampbell
Also, I have no speed or feed charts for this machine and I'm sure I don't have a complete set of gears. I could probably find the feed speed in some books but I really need something that tells me what gear combination will produce the desired feed rate. Making the missing gears would be a good learning project. As I mentioned, I'm only missing the 100 tooth gear in the indexer set and that blank is on the machine now. Just have to finish the install of the replacement 220 volt motor.
First, thanks for sharing, second, lordy I'm jealous and finally, the catalog page you posted with the pic's states that a #4 has a 48" max diameter and 10" max face width. Were there "shorter swing" versions of the #4, as you listed yours as 36" max.
As I recall on mine, There simply is not clearance for a 3 pitch cutter in the space allotted on the machine where the cutter arbor sets. A 4 pitch is fine, but a 3 is too big in diameter. I may try to look up the diameters again in the Ash catalog.
Whether or not you can cut a particular gear in 1 pass or if you need to rough and finish is going to depend on a few factors. If the material is 6150ht and its a 4 pitch you will be better off with two passes, about a 80%/20% ratio on rough /finish. Smaller teeth on easier materials 1 cut will do it. Work arbor size and bore length to gear od ratio comes into play as well. If you have a solid 8 inch diameter pinion gear with a 2 inch keyed bore 6 inches long on a 2 inch keyed work arbor it will take a lot more cutting force than a 22 inch diameter x 1.5 thick blank with spoke arms cast in it or plasma cut outs to lighten the blank weight. Vibration and chatter get to be issues as the gear diameter gets bigger.
You will also need a good assortment of bushings, donuts, plate washers, etc. to back up and support various gear blanks. The 60 inch machine we used also had an adjustable support that bolted on the vertical ways below the work slide and it could be extended to the blank face just above the cutter path kind of like a steady rest arm to dampen vibration.
Another issue related to cutter forces was blank rotation. Sometimes on a poorly sharpened or older cutter or one that was slightly off center on the blank rotational forces would be introduced. If that arbor nut was not tightened really tight on an unkeyed blank it could rotate a few thousandths on each tooth and it would end up in scrap.
Gear blank quality is a big issue too, especially when cutting multiple blanks at once. Usually you will have one face machined in the same setup as the bore in the lathe and then you will flip it over and face off the other side. The best results will come from marking the true to bore face and blanchard grinding or surface grinding the back face from it so that you have parallel blank faces. Any error in parallel on the blank faces will potentially bend the work arbor and this will magnify run out on the od's the more blanks you have on the arbor and make it harder to get the blanks running true before cutting. Don't just assume the blank od will be running true because you clamp it to the work arbor, always check it. Your blank od and id will be concentric and in the end you want your pitch line to be concentric with the id or else the gear will be noisy when it runs due to thick and thin teeth. Your check for this will be to take the indexing worm out of mesh on the back so you can spin the work arbor by hand using those big holes in the worm wheel to grab on to and indicate the blank concentricity right before you cut.
Also make sure you have lots of oil flow on the cutter to keep it cool.
Someone was asking if I had the device that is intended to assist in centering the cutter tool. (I can't find that in the thread) I once saw it in a photo in an old book. Kinda looked like a "wish-bone" thingy. I did remember seeing something like that when I was sorting out the gear sets and couldn't see how it was part of this machine. I kept hoping I hadn't tossed it in the scrap bin. Well yesterday, while inventorying my cutter collection (stored in the indexer column base), I found it and it is complete. It will truly come in handy. Fits on the ways, just in front of the carriage, then then there is a fine adjusting nut on the spindle quill. Very neat feature.
Thanks to all for the good advice and encouraging comments.
]Here is another book I came across scrolling though a list on archive.org
Gear-cutting machinery, comprising a complete review of contemporary American and European practice, together with a logical classification and explanation of the principles involved : Flanders, Ralph Edward, 1880- : Free Download & Streaming : Inter
A Brown & Sharpe machine is shown here if the link works ,otherwise choose to read on line , the one page view and scroll down to page 34
Gear-cutting machinery, comprising a complete review of contemporary American and European practice, together with a logical classification and explanation of the principles involved
otherwise choose to read on line , the one page view and scroll down to page 34
I've tried attaching the page incsaase the lin's don't always work.
Tags for this Thread