Barnes Change Gear Question
I am nearing the point where I can start using my #13. I have a question about the change gear that goes on the screw? Is it held on by virtue of being captured by another gear? Seems like some combinations might not hold it on. There does not appear to be enough room for a bolt. I have not looked to see if the end of the lead screw is even tapped.
Thanks for any help!!
You are using your gears in "compound" mode. It should be possible to do a "direct" mode.
Likely in direct, the large gear becomes the intermediate. And the smaller one next to it (whatever it is) goes on the outside and is held by the keyed bushing that rotates on the stud (and held by its own nut on a Barnes No. 5 and by a pin on yours?)
The small gear on the lead screw should be able to be changed. It also should be held somehow so it doesn't walk off the lead screw and end up broken on the floor. This attachment method, screw or nut, COULD be not used for compound gearing since the large gear kind of gets in the way.
You certainly can get an idea of what changes are done even if you don't have all the gears by looking at the gear chart (I think I see the edge of it in one of the pix.) The Barnes No. 5 uses a double width 16 gear at the spindle, either of two gears (small or large) as the intermediate/compound on the stud, and the rest of the 13 gears on the screw. The largest gear was typically located on the lead screw for "ordinary turning" and otherwise was used as one of the intermediate.
Watch you don't get your fingers into those pretty gears. Get in the habit of operating the lathe "one handed" with your left hand kept in your pocket. It makes you slow down and THINK about what you're doing, and then take your time about doing it. 19th century machinery was NOT user friendly.
Good luck with this. Looking REAL fine.
Joe in NH
There should be a bolt similar to the stud bolt shown in your photos. The screw bolt differs slightly from the stud bolt in that it has a slight recess on its face to securely hold the screw gear on the screw shaft. The stud bolt has a straight face to allow the stud sleeve to be compressed and allow the stud gears to turn freely. When a selected thread requires a large diameter gear for the stud, put it on the screw instead and rearrange the other gears accordingly. On my #5, I had the same issue. The thread chart shows the 104 tooth gear going on the stud and for some gear combinations it would interfere with the screw stud. I just order the gears so that doesn't happen.
You will run into a similar issue with a stud gear not being able to be meshed with a spindle gear in some combinations.
Here is a photo of my #5 showing the two bolts.
That gear is bigger ...
The big gear looks to be about 120 tooth, (I attempted to count the teeth) which 104 tooth was the largest standard gear Barnes offered. On the Change Gear Chart the 104t and 52t were compounded for threading 14-32 tpi
You can swap the smaller compounded gear and the lead screw shaft gear for a slower feed. The big gear keeps the lead screw gear secure, they may rub slightly, which is acceptable.
However, if I recall correctly the #13 Barnes uses the keyway in the lead screw of the feed rod, thus the half nut is not used except for threading. And the rate of feed is adjustable at the apron.
Just FWIW, I fairly recently sold my Barnes 13. A package deal came up for a SB heavy 10, a Sheldon horizontal mill. and a SB 7" shaper, so the Barnes got sold For the money and more important, the space in the garage. But it was a deal that I couldn't turn down and the "new" stuff was only 350' away! ! ! Making the logistics of moving it all not a concearn.
My 13 seemed to be "low mileage" as all of the ways had little to no wear. (I am somewhat having sellers remorse, but I needed the space). My 13 was retrofitted with a QC toolpost, a modern 3-jaw reversable chuck, and a rather large framed electric motor. I was always impressed at the quality of work that it would do for something that old and primative. It would cut very straight with minimal taper. I had no problems with tougher metals like 4130 and the like. But I never had all of the necessary change gears to chase threads with it. (that was one of the reasons for letting it go) Once you get it up and going, I think you'll have a lot of fun with it!
As far as anchoring the gear onto the leadscrew, mine was missing the screw as well, allowing the gears to clang together rather loudly. It hd a tapped center hole in the leadscrew allready, so I made a bolt with a stepped head that recessed itself into the end of the gear almost flush with the face of the gear to hold the gear on tightly. Short, sweet and simple. (I'm a firm believer in the K.I.S.S. rule)
Thanks to all for the feedback. Sounds like I need to play with the combonations a bit to see what will work best. I only have the one stud cap to hold the gears on, Thanks to Irby for that, but I can make a copy. I believe that the large one is actually a 104 but I'll have to double check. I had a guy lose a finger in a set of change gears a few years back in one of the plants I worked in. Just another reminder to respect all the machines. I am almost done wiht this machine and plan to start using it. I need to find a small mill of the same vintage to restore next. Something small and lineshaft driven. I bought the Copes book but there are so many and I have no idea what is likely to be found especially around here. A bit off topic but I am open to suggestions!
That was another contributing factor in the selling off of my 13. I destroyed too many jackets and shirts by them getting sucked into the gears. Luckily, I never damaged any body parts when it happened. I was always able to hit the switch with my right hand as the sleeve tore off of my jacket.................
The Advantage ....
of keeping them foot powered
One would hope they could stop pedaling when they were caught up in the gears.