Believe me he has your own best interests at heart. You're obvoiusly savvy with regards to engineering. Do the math. If your spindle is a few mm across amd the imbalance is only 10mg @ 200,000g the force is 2kg across it. Ultras tend to run for extended periods and when they break either the whole instrument flings itself through the nearest brick wall, or the rotor disintegrates shedding pieces at omegasquaredr. Without containment these will act like a high velocity rifle bullet. Hence the commemt with regards to armour plate, a mild steel containment chamber will spall shards off the outside even if it contains the initial Ti fragments.
No-one is saying don't do it. Just don't anywhere near anyone else.
Zeb
Sent from Samsung Mobile
Sent from Samsung Mobile
-------- Original message --------
Subject: Re: [DIYbio] Re: ultracentrifuge
From: John Griessen <john@industromatic.com>
To: diybio@googlegroups.com
CC:
On 03/01/2012 12:06 PM, Cathal Garvey wrote:
> Because an ultracentrifuge can kill you and is highly prone to explosion if used without training?
Isn't this list about training? I see it going on all the time. We have someone
researching ultracentrifugation and why not evolve a design? Not me saying
"Do it this way and you'll be guaranteed safe.", but what guarantees are there
with anything DIY?
So, we've had comments about concrete for mitigating centrifuge risk, and that's
good. Concrete is good. Steel plate is good. They go together well.
Concrete is easy to form around any plastic as a mold that releases easily.
So, a containment well with tapering narrower as it goes up top can easily be made
for the motor/rotor to fit in with a 1/2 in steel lid over it. All the kinetic energy
of the ultra rotor is angular and won't change easily, so forces are sideways and gravity
keeps it down. Precession can change the angle a little, so sloping inward sides
are good to keep it down, not let it climb even if it starts precessing around the
containment well interior. Lining the cast concrete interior with smooth plastic
such as HDPE would be great for keeping the concrete surface from crumbling by an
attacking loose rotor -- how would you hot spray coat that plastic?
Let's talk about it, OK?
Make your ultra rotor 6 cm across of Ti metal on an air bearing, driven by
an air turbine. Let it hold vials with a cone bottom that are 2 cm deep and 1 cm across
holding maybe 1.2 ml at the full mark. What turbine parts are out there that can be re-purposed?
What bearings does the Portescap motor company recommend for their 70,000 RPM motors?
Why not talk about it?
--
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To post to this group, send email to diybio@googlegroups.com.
To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/diybio?hl=en.
> Because an ultracentrifuge can kill you and is highly prone to explosion if used without training?
Isn't this list about training? I see it going on all the time. We have someone
researching ultracentrifugation and why not evolve a design? Not me saying
"Do it this way and you'll be guaranteed safe.", but what guarantees are there
with anything DIY?
So, we've had comments about concrete for mitigating centrifuge risk, and that's
good. Concrete is good. Steel plate is good. They go together well.
Concrete is easy to form around any plastic as a mold that releases easily.
So, a containment well with tapering narrower as it goes up top can easily be made
for the motor/rotor to fit in with a 1/2 in steel lid over it. All the kinetic energy
of the ultra rotor is angular and won't change easily, so forces are sideways and gravity
keeps it down. Precession can change the angle a little, so sloping inward sides
are good to keep it down, not let it climb even if it starts precessing around the
containment well interior. Lining the cast concrete interior with smooth plastic
such as HDPE would be great for keeping the concrete surface from crumbling by an
attacking loose rotor -- how would you hot spray coat that plastic?
Let's talk about it, OK?
Make your ultra rotor 6 cm across of Ti metal on an air bearing, driven by
an air turbine. Let it hold vials with a cone bottom that are 2 cm deep and 1 cm across
holding maybe 1.2 ml at the full mark. What turbine parts are out there that can be re-purposed?
What bearings does the Portescap motor company recommend for their 70,000 RPM motors?
Why not talk about it?
--
You received this message because you are subscribed to the Google Groups "DIYbio" group.
To post to this group, send email to diybio@googlegroups.com.
To unsubscribe from this group, send email to diybio+unsubscribe@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/diybio?hl=en.
0 comments:
Post a Comment