Have you tried running your air bearing with large molecular gasses? I am thinking that butane or one of its ilk might have a higher effective viscosity (not really sure of the right terminology here) that would damp out vibrations better.
Eric marsh has done some research on this and found there can be some benefits but it’s down at the single digit nanometer level. Ive got bigger issues to address first :)
Nice precision optical mechanical machining setup and callout to Layton Hale. He noted ~4 years ago that for best placement in self-seating condition of Kinematic interface that there is a minimum CoF typically less than 0.3 @~55°. 60° can cause a locked interface. Also @3:35 maybe worth noting and Rx Ry Rz, 6 faces 6 DoF.
@@adammontgomery7980 I never use fusion for cad. Onshape exclusively for that purpose. What I use fusion for is CAM, for which it is totally awesome. I just hate it for CAD.
I would love to see a 10,000 foot overview on building this lathe I hope to oneday build a much bigger version (24x144) Also how reasonable is it to make your own granite parallels? The three plate method is easy enough and I expect it to take me a few weeks to get it that smooth.
China has 1m long parallells for like 150 dollars w shipping. Lapping will work but it is probably worth it to go all in on diamond grit. It is a couple times faster than carbide grit theoretically. Buy grit powder not pre made oil mixes. You will save a lot of money. You need like 20% grit and rest water, oil, isopropanol or whatever you want to use. Also you should not underestimate how long and boring it can become to do lapping. You will probably save time doing small parts first to learn to do it right, at a certain grit you want a certain finish before moving on to the next. Good luck if you try it out.
Did I ask you before if you were interested in spinning out a flat (to 100 microns or so) blank? A reasonably robust, optically pretty-good first surface mirror is relevant to my interests.
@@cylosgarage 4 inch diameter maybe? I do mean microns; I'm sure even modest effort would get you a lot closer but I don't need anything deliberately that flat. My use case is common photography and that is pretty forgiving.
Always a good day when you release a new video!
Thanks Jan!
That's just crazy and very very cool.
What stops the pull from the bolt from bowing the mirror?
The groove in between the coupling teeth and the rest of the mirror, visible around 1:07. This helps isolate the clamping stresses and distortion.
Watching this, does turbulence from the air blast introduce any unwanted cutting tool movement/noise?
no doubt, but it's not the limiting factor here. The vibrations from the z axis air bearings are the main thing limiting surface finish right now.
This series is so awesome. Thanks Cylo!
Have you tried running your air bearing with large molecular gasses? I am thinking that butane or one of its ilk might have a higher effective viscosity (not really sure of the right terminology here) that would damp out vibrations better.
Eric marsh has done some research on this and found there can be some benefits but it’s down at the single digit nanometer level. Ive got bigger issues to address first :)
That aperture and focal length 😂
Not on purpose though.
Bravo sir. Bravo.
Nice precision optical mechanical machining setup and callout to Layton Hale. He noted ~4 years ago that for best placement in self-seating condition of Kinematic interface that there is a minimum CoF typically less than 0.3 @~55°. 60° can cause a locked interface. Also @3:35 maybe worth noting and Rx Ry Rz, 6 faces 6 DoF.
Do you prefer Onshape to Fusion? I noticed that you have both, and I just started using Onshape because I don't want to use Windows anymore.
@@adammontgomery7980 I never use fusion for cad. Onshape exclusively for that purpose. What I use fusion for is CAM, for which it is totally awesome. I just hate it for CAD.
Wow! This is so cool.
Looking forwards to the measurements!
Congrats on the 69mm aperture with 420mm focal length :D
I would love to see a 10,000 foot overview on building this lathe I hope to oneday build a much bigger version (24x144)
Also how reasonable is it to make your own granite parallels? The three plate method is easy enough and I expect it to take me a few weeks to get it that smooth.
China has 1m long parallells for like 150 dollars w shipping. Lapping will work but it is probably worth it to go all in on diamond grit. It is a couple times faster than carbide grit theoretically. Buy grit powder not pre made oil mixes. You will save a lot of money. You need like 20% grit and rest water, oil, isopropanol or whatever you want to use. Also you should not underestimate how long and boring it can become to do lapping. You will probably save time doing small parts first to learn to do it right, at a certain grit you want a certain finish before moving on to the next. Good luck if you try it out.
It's like a cute little fixed Stewart platform
Nice!
Super cool!! 👍👍
I thought telescopic mirrors were hand ground...
not this one
What grade of aluminum are you using for the mirror?
6061-T6
@cylosgarage we've made them from 1100 but it's rare in anything but sheet.
You looking for a job with a big Aerospace company?
Did I ask you before if you were interested in spinning out a flat (to 100 microns or so) blank? A reasonably robust, optically pretty-good first surface mirror is relevant to my interests.
What diameter? And do you mean nanometers?
@@cylosgarage 4 inch diameter maybe? I do mean microns; I'm sure even modest effort would get you a lot closer but I don't need anything deliberately that flat. My use case is common photography and that is pretty forgiving.
what material is that? aluminum?
Yes 6061
Very nice. patent # ?
US6065898A
Very shiny
yet, not shiny enough...