Nope, though I certainly wish we had. I convinced my boss aka the money guy to let me spend $500 on an ultrafuge because it came with an Edwards E2M8 that’s worth more than we paid for the whole thing and it came with two rotors. That’s about as far as I got in the bargain because he won’t let me have the time to play with it. Shit, he won’t even let me use the nice oil in it lol.
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Don’t you just love weighing out all the bottles? centrifuge life homie!
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I have a bunch of botched winterization filtrate with a bunch of water in them. I don’t want to distill the water out because it’s a waste of time on a rotovap but I know I precipitated a bunch of goodies because of all the water. Fucking score for the centrifuge, right? Well 7 times trying to get the rotor to balance later and I’m about to kill a mofo. They weigh the same but the density within the 250ml tubes must be different and it won’t balance out. Shoulda just thrown the goop in the still I guess
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weight is weight, should be fine. I would weigh the bucket, tube, and sample all at once make sure the entire rotating mass is within manufacture spec tolerance and weight. Rotovap would probably been done by now, but hey I love the adventure of the chase!
btw, are you able to vacuum the air out of your centrifuge?
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Yep it actually has a diffusion pump, pulls down to a few micron.
The tubes are as close to exactly the same weight as I can weigh lol. Like .01g dead nuts the same. But it’s an angled rotor and the center of mass might be different between the tubes. That or I’m just fucking cursed because it runs fine with the rotor empty lol
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Helping out the farmers bro
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you might have a curse! 
…or electrical demons
is the rotor overweight?
how fast can you get to going before it alarms out?
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I don’t believe so. The centrifuge is a Beckman L8-70 and the rotor is a type 19. I’ve run it a dozen times up to full speed for that rotor with homogeneous liquids (crude) without any trouble. It is a big rotor but I’m pretty sure the tubes are under the published max weight. Every time I get to 3-4k rpm and then trip the balance alert. I ran it up to 3k in “zonal” with the door open and it looks fine but I imagine the spindle is a little more discerning than my eyeballs.
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How are you distributing tubes in the rotor? It is pretty standard practice to offset the weight of a sample with a tube filled with the same weight in h20. After all which weighs more a lb of feathers or bricks?
this may be your issue:
Always balance rotor tubes to the nearest 1/100 on a balance or scale.
Double check the weight of the samples on a more accurate scale, If I had to guess that is why she wont choch.
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That’s awesome man. Keep it up!
I started with all 6 tubes, then dropped to 3, then 2. Still no love. I don’t have a balance that has mg precision and can take 300g on site but that doesn’t mean it isn’t my issue, I’ll take another shot at it.
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It could also be the distribution of the tubes in the rotor, perhaps they are not directly across from one another?
I don’t think it’s that, definitely loaded them symmetrically. Unless it was the hallucinations again lol
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optical delusion
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