What drives a BS-0 drive dog?

[benmychree]

Back to my jaw question, would a vee in the jaws be a help or a bad idea? Once I'm set up to do a vee, might as well do a bunch of them...

A vee in the jaws would defeat the purpose of the jaws, which is to allow a bit of axial movement between the jaws.
My wife thinks that Christiansburg might be near Radford where her sister went to college --- ?

 

[WobblyHand]

@benmychree, I don't understand the expression axial movement between the jaws. Axial movement of which element? the dog pin, the bolt through the H, the mandrel, or the bolts for the jaws? There's quite a few axes in the picture. I was thinking of a vee that was along the dog pin axis. Would that vee restrict axial movement? The vee would restrict radial movement.

Christiansburg is SSW of Roanoke, off I81, not too far from Radford. Your wife has a good memory.

 

[benmychree]

What I am talking about is the need not to restrict the motion of the dog tail in a direction either in or out of the slot towards or away from the headstock.
My wife has been in Ca. since about 1962, but has been back in Va. many times since then, and I have been back there a number of times as well; her folks brought her out here back then, as he was offered a job and living accomodations by an aunt whose husband was a partner in a boiler shop in San Francisco, but lived in Napa, where she and I attended high school. eventually he retired and they moved back to Bristol where my wife's sister and family lived, that being after my wife and I were married in '72. They left Va. because of a downturn in coal mining, her father being a foreman in the Derby mine.

 

[dewbane]

Was hoping you'd show me how it's done! No problem. I could cut some gears with the 3J as well, just to work out some of the basics. I do need to figure out this mandrel stuff to make real gears though.

I don't know if the setup I put together will be good enough or not. I turned a rod with center divots on either end that unscrews, with a couple of hexes machined so it can be tightened. It takes a gear blank with a reamed 1/4" hole, and holds the blank through a combination of the center hole fit and compression. I made this on the 3-jaw on the lathe, flipping it end for end, so it's not perfect. Is it good enough in practice? I think it probably is for my purposes. I'm sure if I indicate the runout on any of the gears I've made, it will be very measurable, but will that actually impede their function? Maybe I'm too cavalier, but I think this setup will probably be fine.

My shop is currently at 13℉. We had a ton of ice the other day. Basically everywhere in 200 miles in every direction has thawed out, but lucky me, I still have substantial ice on all my trees. Spring seems a distant daydream at this point.

Anyway, sorry I haven't worked through things far enough to have the between centers deal worked out. It's on the someday list. Someday after I get the shop moved. I really wish I didn't have to move the shop. I like the setup a lot, and I have so many problems to solve in moving it.

 

[dewbane]

My wife thinks that Christiansburg might be near Radford where her sister went to college --- ?

That's the place, yes. I went to college in Radford as well.

 

[WobblyHand]

I don't know if the setup I put together will be good enough or not. I turned a rod with center divots on either end that unscrews, with a couple of hexes machined so it can be tightened. It takes a gear blank with a reamed 1/4" hole, and holds the blank through a combination of the center hole fit and compression. I made this on the 3-jaw on the lathe, flipping it end for end, so it's not perfect. Is it good enough in practice? I think it probably is for my purposes. I'm sure if I indicate the runout on any of the gears I've made, it will be very measurable, but will that actually impede their function? Maybe I'm too cavalier, but I think this setup will probably be fine.

My shop is currently at 13℉. We had a ton of ice the other day. Basically everywhere in 200 miles in every direction has thawed out, but lucky me, I still have substantial ice on all my trees. Spring seems a distant daydream at this point.

Anyway, sorry I haven't worked through things far enough to have the between centers deal worked out. It's on the someday list. Someday after I get the shop moved. I really wish I didn't have to move the shop. I like the setup a lot, and I have so many problems to solve in moving it.

No need to apologize! Life happens. I was only kidding, but it didn't come through very well. My fault.

Your shop is like my unheated garage. In the winter, basically I can't do much work there. I had a 220V heater which helped, but everything I was working on was stone cold, tools, metals, everything that I had to touch. It was really had to work there. My fluorescents lights ran dim due to the cold. I've fixed some of that, but it's just too cold to work in and not be miserable. Here in S.NH we have a foot of snow on the ground. I don't remember when I last saw the ground. Fortunately - so far we haven't had much ice. I sympathize with you, as ice is awful. It causes a lot of destruction and is difficult to get around in. A few years back we had a bad ice storm and lost power for a week. It was really hard to keep the house from freezing the pipes. (Believe me, you never want to experience that. A freeze over causes an unbelievable amount of destruction in a home.) I had to work round the clock to feed a small coal stove to get some heat in the house. It was very warm near the stove, but pretty darned cold at the ends of the house. Not good times at all.

My shop is in an unimproved basement, dug in 1851. It's primitive, and has air leaks. I've been trying to patch the cracks in the stone walls with lime mortar as time permits, but I've got a lot more to go. There's a draft there that I haven't found yet near the ground. So at 4ft the thermometer reads 55F, at 1ft it's like 35F. Even though I have a rubber pad by my machines, the drafty cold seeps into my feet. Today I'll measure out the run for 220V and figure out how much romex to buy. It's messy work in an old basement, but it needs to be done to make the workspace a little more habitable. Once it's more temperate down there, I plan to re-organize the space, as it's far from optimal.

I understand the someday list all too well. Have far too many items on that list. There are times when you just have to grab an item off that someday list and stick it in today's list. Otherwise, that event won't ever happen. So I'm picking one thing and trying to get it done. My one thing is 220V.

Spring will come. It's not that far away. By April it will be a lot nicer, especially in VA. That's only 5-1/2 weeks

 

[benmychree]

I don't know if the setup I put together will be good enough or not. I turned a rod with center divots on either end that unscrews, with a couple of hexes machined so it can be tightened. It takes a gear blank with a reamed 1/4" hole, and holds the blank through a combination of the center hole fit and compression. I made this on the 3-jaw on the lathe, flipping it end for end, so it's not perfect. Is it good enough in practice? I think it probably is for my purposes. I'm sure if I indicate the runout on any of the gears I've made, it will be very measurable, but will that actually impede their function? Maybe I'm too cavalier, but I think this setup will probably be fine.

My shop is currently at 13℉. We had a ton of ice the other day. Basically everywhere in 200 miles in every direction has thawed out, but lucky me, I still have substantial ice on all my trees. Spring seems a distant daydream at this point.

Anyway, sorry I haven't worked through things far enough to have the between centers deal worked out. It's on the someday list. Someday after I get the shop moved. I really wish I didn't have to move the shop. I like the setup a lot, and I have so many problems to solve in moving it.

For gears that are going to be used, they should be concentric with the bore, the finer the pitch, even more so. Your arbors should be quite concentric with the center holes, at least, the portion that the gear blank seats on, to that end, they should be turned between centers to ensure concentricity.

 

[dewbane]

For gears that are going to be used, they should be concentric with the bore, the finer the pitch, even more so. Your arbors should be quite concentric with the center holes, at least, the portion that the gear blank seats on, to that end, they should be turned between centers to ensure concentricity.

Oh, I get that they should be, but I have yet to successfully drive anything between centers, so I improvised. I think it might work well enough for my purposes. I should mount the gears I've already made on some rigid test stand and measure how big the error actually is.