Yah, but I verify using my micrometers...also chinese....
Which is why I bought some under/over reamers. That way, I can select the wrong reamer for the first item I build.
Ain't that the truth.
We don't need no stinkin drawings...
jn
edit: just watched a video the other day on repairing pinions in clocks, the guy had a left handed digital caliper. I never knew they existed.
Last edited:
In other science news (which I can barely get my head around) big Yay for Fermilab
Muons: '''Strong''' evidence found for a new force of nature - BBC News
The expensive Muon wiggler is up to 4.1 Sigma on a 5th force having been found. I am sure theoretical physicists are prepping grant applications all over the world and the Muon wranglers are hoping for funds for a bigger machine
.
Seriously Always gives me hope with this cutting edge stuff. Shame audiophile proof doesn't need 5 sigma
Muons: '''Strong''' evidence found for a new force of nature - BBC News
The expensive Muon wiggler is up to 4.1 Sigma on a 5th force having been found. I am sure theoretical physicists are prepping grant applications all over the world and the Muon wranglers are hoping for funds for a bigger machine
. Seriously Always gives me hope with this cutting edge stuff. Shame audiophile proof doesn't need 5 sigma
The magnet for that was built here, it ran for years. A while ago it was shipped to Fermilab to be used for their research.
It was on a tractor trailer, weighed 700 tons, they had to cut trees down near the road as it was 50 feet in diameter, they had to close the main highway, police escorts down to the atlantic ocean, loaded on a barge, around florida up the mississippi river, eventually on land to Fermiab.
Since it was completely covered in the white plastic they use to seal up boats for the winter, there was no end of UFO conspiracy people running around claiming that "SEE, there was a UFO that fell in lake Ronkonkoma and hidden at that lab!!!
I will admit, it certainly did look like a UFO...
jn
It was on a tractor trailer, weighed 700 tons, they had to cut trees down near the road as it was 50 feet in diameter, they had to close the main highway, police escorts down to the atlantic ocean, loaded on a barge, around florida up the mississippi river, eventually on land to Fermiab.
Since it was completely covered in the white plastic they use to seal up boats for the winter, there was no end of UFO conspiracy people running around claiming that "SEE, there was a UFO that fell in lake Ronkonkoma and hidden at that lab!!!
I will admit, it certainly did look like a UFO...
jn
First rate science with a second hand magnet! Ingenuity (and budget restrictions) at their best.
I'd love to have been in that meeting where the boss walks in and told you that he'd sold it. (Assuming these things are generally designed to be build ONCE in situ then only moved when scrapped). Risk analysis on that must have run to a few pages?
Biggest load I am aware of being moved in UK was a paltry 600 ton transformer Didcot power station transformer moved - BBC News But our roads are narrower.
I'd love to have been in that meeting where the boss walks in and told you that he'd sold it. (Assuming these things are generally designed to be build ONCE in situ then only moved when scrapped). Risk analysis on that must have run to a few pages?
Biggest load I am aware of being moved in UK was a paltry 600 ton transformer Didcot power station transformer moved - BBC News But our roads are narrower.
50yr. ago we had to take down a Fairchild printing press and the handle on the main cylinder was screwed on with a left handed screw (obvious after realizing the rotation had to tighten rather than loosen). I went to the MIT shop and asked for a left handed easy out and they said no problem, what size.
Scott,
Not as rare as you think. I keep left handed drill bits for normal screw extraction. I also have sets of both left and right handed EZ outs. They also come in straight for folks who want to go both ways.
There is a good reason to keep the left handed EZ outs. All too many folks who encounter particularly small machine screws, try to unscrew it the wrong way and keep increasing the force until it shears off.
My shop practice is to paint all reverse threaded parts yellow! Did have one very temporary help idiot who twice tried the wrong direction on a battery drill. (Very strong back...)
Not as rare as you think. I keep left handed drill bits for normal screw extraction. I also have sets of both left and right handed EZ outs. They also come in straight for folks who want to go both ways.
There is a good reason to keep the left handed EZ outs. All too many folks who encounter particularly small machine screws, try to unscrew it the wrong way and keep increasing the force until it shears off.
My shop practice is to paint all reverse threaded parts yellow! Did have one very temporary help idiot who twice tried the wrong direction on a battery drill. (Very strong back...)
Last edited:
What I find amazing is the level of accuracy needed for making some of the mechanics I need. I'm making a zero backlash worm gear 60:1 reducer to drive my EDM linear stage, and near misses of .0005 inches in shaft diameter are failure. It takes trying to build this stuff to appreciate the level of skill needed by a good machinist.
I'm using a 200 count stepper to drive a 4mm pitch ball screw with a 60:1 worm and 32 microsteps, for an effective step resolution of 333 nanometers, and microstep resolution of 10 nanometers. Without an encoder on the motor, I would not expect an accuracy better than about 100 nanometers.
That should be good enough for an EDM process however.
Jn
I'm using a 200 count stepper to drive a 4mm pitch ball screw with a 60:1 worm and 32 microsteps, for an effective step resolution of 333 nanometers, and microstep resolution of 10 nanometers. Without an encoder on the motor, I would not expect an accuracy better than about 100 nanometers.
That should be good enough for an EDM process however.
Jn
J
If you aren't using a grinder for precise work the alternative method is slow. You machine with a cutter until you are just oversize. A safe limit is a mill or two. You then polish to final dimension. Of course with your low cost measurement gear you might want to wear insulated gloves while holding bits. That will reduce thermal effects.
Of course for greater precision you use spiral gears to increase contact area.
Next we could talk about preloading to reduce backlash/hysteresis. Ever look at how a lathe tool slide is geared?
Time to look at adjustable tapers or slotted thread followers.
What alloys are you using? Thermal expansion rates?
If you aren't using a grinder for precise work the alternative method is slow. You machine with a cutter until you are just oversize. A safe limit is a mill or two. You then polish to final dimension. Of course with your low cost measurement gear you might want to wear insulated gloves while holding bits. That will reduce thermal effects.
Of course for greater precision you use spiral gears to increase contact area.
Next we could talk about preloading to reduce backlash/hysteresis. Ever look at how a lathe tool slide is geared?
Time to look at adjustable tapers or slotted thread followers.
What alloys are you using? Thermal expansion rates?
Neither of you have any idea the level of accuracy I am capable of, including the calculation and compensation of TCE for all materials I work with...
Of course, neither do I.. I am winging it...
When I am close to diameter with the lathe, I do four passes without changing the cross setting. It varies from a mil to roughly 1/4 mil as I make the passes.
My friend the mech tech had a word for this, due to the flexure of all the parts. I just can't remember what it was.. hey, it's been at least a day...give me a break..
Hey, it's a learning curve, and I'm faceplanting on it... but having fun.
It is very weird (I guess)... at home, trying to get into the .5 mil range, while at work doing the 1 and 2 nanometer accuracy stuff. I have no idea how to integrate all these things.
So I wont...
I will just do more projects so that I can buy more tools...
jn
Well, excuuuuuuuuuse me...
Of course, neither do I.. I am winging it...
When I am close to diameter with the lathe, I do four passes without changing the cross setting. It varies from a mil to roughly 1/4 mil as I make the passes.
My friend the mech tech had a word for this, due to the flexure of all the parts. I just can't remember what it was.. hey, it's been at least a day...give me a break..
Hey, it's a learning curve, and I'm faceplanting on it... but having fun.
It is very weird (I guess)... at home, trying to get into the .5 mil range, while at work doing the 1 and 2 nanometer accuracy stuff. I have no idea how to integrate all these things.
So I wont...
I will just do more projects so that I can buy more tools...
jn
Well, excuuuuuuuuuse me...
Last edited:
I do not know yet. Once I have the stuff together, I can measure it.
The problem is, I only have calipers that are .5 mil accurate, so that would be the best I can do with the mechanics. Maybe 1/4 mil once the EDM is cutting things.
To get down below 10 to 20 nanometer measurements, I would need the tools at work, the machine shop guys. To use their services, I would probably have to give them the IP I develop, assuming I do..not a problem actually, as if I do get the EDM beyond SOTA, I'd just write a paper to detail how to do it.
If I fail in this endeavor, so what....I have more tools..
If I succeed, others benefit.
jn
Last edited:
No, not too heartbroken (everyone's okay, it's just stuff, no one got hurt). Theft right now is rampant (here? everywhere?) and thieves are brazen enough to wave at cameras/etc. I went with making the garage inconvenient to break into instead. I'll stop there to avoid getting political.
In all cases, I'm back to a point where I feel like getting back out into my mini shop, replace what was lost, and build stuff again.
John -- curious where you end up going with your EDM. Pretty specialized tool but capable of some crazy cuts.