You don’t think that people have been able to leave the flat earth without falling into the abyss?
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Do you really think the Soviets would have allowed the U.S. to get away with faking it?
You do realize that there was never any sort of conspiracy theory about this until the movie Capricorn One was released?
There’s a mirror placed on the moon by astronauts you can bounce a laser off of to measure the distance to the moon — that experiment used to not be possible — that it is now, is proof.
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Actually, 12…
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@WillAdams
And that was 50 years ago!! Vacuum tubes (valves) still dominated in consumer and military electronics and computers. Really primitive computers and slide rules instead of calculators. 3-4 black and white television channels if you were lucky. No internet or Wi-Fi. It blows me away!!
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@ispot
"I’m about to order the HDZ for my XXL. I’m looking for a complete water-cooled package as the one mentioned here, but I need it 110Volts, instead of 220Volts. Or, should I be getting 220Volts? and if so, whay? I sincerely appreciate your help, thank you."
You’ll probably need 220V if you want a 2200 Watt spindle like the one shown here. But you should be OK with a 800 Watt spindle like this one.
Yep. 50 years ago.
My dad cut his teeth on the Bell X1, moved on to the Bell Convertaplane, (think 1950’s Osprey). XB70 bomber, Saturn S IVB, on to B1 bomber. Toned it back late in his career to spend a few years at JPL. Rich C may have met him?
Pretty interesting times.
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50% distilled water, 50% automotive coolant, does that sound ok ?
I have found various opinions but no definitive answer on the do’s and don’ts.
The submersible pump is absolutely silent, I’ll have to wire it to the spindle’s input power or I will forget it’s on, guaranteed.
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Nice little trick, wire the pump into the VFD power input. It ensures that when the vfd is on the pump is also on. They incredibly low power.
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Wow… That would even dwarf my 1.5kw spindle!
Turns out I had to go to the hardware store to buy this giant wrench, I did not have any that fit the collet nut size…
It’s going to feel weird tightening a 1/32" endmill into its ER collet using this beast…
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[EDIT: spoiler alert, I was very wrong on the following]
Bad surprise: the ER collets won’t go all the way into the collet nut,
unless I push the (empty) collet such that it shrinks a bit and makes it way through the neck (?) inside the collet nut:
When I looked closer inside the collet nut, I stumbled upon the first evidence of chinese quality control:
The red circle is the thing that goes into the groove (?) of the ER collet:
It’s severely off centered, which explains why the collet does not fit without a little help. Once it is in there though, everything is good (the groove must be deep enough that the off-centered part does not matter anymore), and I verified that I get ~0.01mm (0.0004’’) runout on the endmill shaft.
But then it takes a bit of wiggling the collet to remove it from the collet nut, which I guess it absolutely not normal? I think I will have to file the perimeter of this off-centered section inside the collet, while being careful to not touch anything else (the conical part actually in contact with the collet) 
You could probably get a new/better nut to replace it. Doing this by hand instead of a lathe may create other issues and collets may not sit properly.
Yes this is the first thing I considered, however this collet nut was balanced specifically for this spindle (hence the multiple ugly drill marks on the side), and they must have done a decent job because I don’t feel any weird vibration/sound across the RPM range, it’s humming along nicely at 24.000RPM. If I were to buy a brand new collet nut, I would also have to learn how to balance it, and I have zero clue as to how is done or if this is even doable without specific tooling?
EDIT: well an ER20 collet nut is 4$ on Aliexpress, maybe this would be the opportunity to learn a new trick…
Fair but removing nut material could also affect balance since you will be removing more from one side vs another.
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Indeed…I was hoping I could get away with filing just a teeny tiny part of it, since it must be a matter of a few tenths of mm. I guess for now I’ll just use it as is (not convenient, but usable), order a new collet nut, and learn about balancing in the meantime.
Now wait a second, this ER20 collet nut on Amazon seems to also have the weird off-center section:
And I found these statements:
“The collet nut snaps into the groove so the collet nut can serve as a collet extractor .”
“The groove is to catch on the offset washer in the nut to assist in releasing the collet. Dont forget to put the ER collet in the nut first, it should snap in and be retained by the nut before putting the assembly into the collet holder.”
Now I feel dumb, is this off-center section (“snap ring?”) done on purpose? It seems to be the case.
ER gurus, please educate me !
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No guru but I found this while researching for spindle and accessories.
https://www.precisebits.com/tutorials/er_collet_system.asp
Wealth of information at the Precise Bits site.
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great link, now I’m educated, feel bad for initially blaming G penny, and happy that my collet nut is fine after all !