I'm considering doing something like that for the last episode to discuss the design, what mistakes were made and how I would like to go forward from here.
I have several Nikken versions of this type of indicator stand and had to disassemble and clean them. They use two pins with a wedge between them (per side) to transfer force to internal push rods acting on aluminum cups that bear on the balls. My impression is that the cone and wedge angles are key in tuning the holding force vs. self release.
Yes, that's exactly how this one works as well. I made the push rods from aluminium tubing which turned out to be a mistake. The clamping force I can generate with the M10 bolt is way too much for the push rod and I believe it expanded inside of the mechanism. The contact wedges and cones are hardened steel so no problem there, just the rod in between. In the future I'll see if I can replace it with steel tubing but I would like to avoid the risk of damaging the arm on disassembly.
@@ED_T The push rods in mine were solid, any reason why you want to use tubing? I could see tubing with solid contacts (hardened dial indicator tips?) threaded in, might make tuning the length easier too.
I have ground and polished the wedges as you'll be able to see in a future episode. Having the balls be actual hardened bearing balls also helps. The sticky part is likely due to the inner push rod expanding under the pressure. I opted to make it from aluminum which was probably not the best choice.
Hi ED&T, the pause happens because there are some teeth worn out in a gear inside the apron, this gear (usually is made of brass) is in contact with the lead screw. Take a look!
Hello, thanks for your comment! The feed mechanism in this lathe is driven by a shaft with keyway. I haven’t seen any missing teeth while I was in there when I bought the machine for inspection. It only happens when longitudinal feeding, not when cross feeding. I suspect a key or pin somewhere that’s half broken. Either way I’ll have to open it back up at some point.
Very nice video, im sutting up a shop for my own, but i only have the knux carbide inserts and they are better for roughing and your chips are perfectly broken so i was wandering what carbide Inserts do you use in your roughing tool?
There are a couple of factors that go into making a successful cut happen on the lathe. First of all know what material you are cutting. In my case that was some free cutting steel that I had in stock which makes cutting a lot easier. I'm familiar with the KNUX style tools and you should definitely be able to get similar results to my inserts. Mine are TNMG inserts but with a positive angle chip breaker. I'll take a guess that you're using rolled mild steel to practise on, which is challenging to get a good surface finish on. In my experience more feed rate and more cutting speed helps there. Depending on the corner radius of your insert you are also supposed to have a minimum depth of cut below which the chip breaker cannot do its job. It's a lot but generally the harder you push a carbide insert the better they perform, especially on a small-ish manual lathe
None of the above currently, however I would like to get into providing drawings that at some point. The drawings I made for this project are for my own reference to build the parts. Here and there I had to deviate from some tolerances to make things work so they are not on point yet. I will be showing all the part drawings in upcoming episodes too so if you really want to build it too and figure some stuff out along the way feel free to do so.
I was searching on how to do this for my low fidelity prototype, and I'm just AMAZED by this
I for one would love to hear you explain the design and your processes. I end up listening to UA-cam much more often than watching. Subscribed.
I'm considering doing something like that for the last episode to discuss the design, what mistakes were made and how I would like to go forward from here.
I have several Nikken versions of this type of indicator stand and had to disassemble and clean them. They use two pins with a wedge between them (per side) to transfer force to internal push rods acting on aluminum cups that bear on the balls. My impression is that the cone and wedge angles are key in tuning the holding force vs. self release.
Yes, that's exactly how this one works as well. I made the push rods from aluminium tubing which turned out to be a mistake. The clamping force I can generate with the M10 bolt is way too much for the push rod and I believe it expanded inside of the mechanism. The contact wedges and cones are hardened steel so no problem there, just the rod in between. In the future I'll see if I can replace it with steel tubing but I would like to avoid the risk of damaging the arm on disassembly.
@@ED_T The push rods in mine were solid, any reason why you want to use tubing? I could see tubing with solid contacts (hardened dial indicator tips?) threaded in, might make tuning the length easier too.
Great job sir! I'm looking forward to seeing the rest of the build
lapped surfaces make a huge difference, it's an interesting challenge making these.
I have ground and polished the wedges as you'll be able to see in a future episode. Having the balls be actual hardened bearing balls also helps.
The sticky part is likely due to the inner push rod expanding under the pressure. I opted to make it from aluminum which was probably not the best choice.
Can you build socket & ball joint articulating arm? This arm more flexible
Hi ED&T, the pause happens because there are some teeth worn out in a gear inside the apron, this gear (usually is made of brass) is in contact with the lead screw. Take a look!
Hello, thanks for your comment!
The feed mechanism in this lathe is driven by a shaft with keyway. I haven’t seen any missing teeth while I was in there when I bought the machine for inspection. It only happens when longitudinal feeding, not when cross feeding. I suspect a key or pin somewhere that’s half broken. Either way I’ll have to open it back up at some point.
Careful using your vise as a press, broke our vise doing that, then had to finish project without the vise, wasn't very fun!
Luckily this is a Heuer Front vise made from forged steel, as long as you don’t put a too long pipe on the handle it will be fine 👌
Very nice video, im sutting up a shop for my own, but i only have the knux carbide inserts and they are better for roughing and your chips are perfectly broken so i was wandering what carbide Inserts do you use in your roughing tool?
There are a couple of factors that go into making a successful cut happen on the lathe. First of all know what material you are cutting. In my case that was some free cutting steel that I had in stock which makes cutting a lot easier. I'm familiar with the KNUX style tools and you should definitely be able to get similar results to my inserts. Mine are TNMG inserts but with a positive angle chip breaker. I'll take a guess that you're using rolled mild steel to practise on, which is challenging to get a good surface finish on. In my experience more feed rate and more cutting speed helps there. Depending on the corner radius of your insert you are also supposed to have a minimum depth of cut below which the chip breaker cannot do its job.
It's a lot but generally the harder you push a carbide insert the better they perform, especially on a small-ish manual lathe
@@ED_T thank you man👍 i'll try when i will get to it
Excellent work!! New subscriber!
Nice work, new sub..
Thanks!
Nice work, do you sell the drawings\model, or have patreon
None of the above currently, however I would like to get into providing drawings that at some point. The drawings I made for this project are for my own reference to build the parts. Here and there I had to deviate from some tolerances to make things work so they are not on point yet. I will be showing all the part drawings in upcoming episodes too so if you really want to build it too and figure some stuff out along the way feel free to do so.