You might not need to mill a flat. If you can see the impeller and it's shiny
enough you might be able to get a usable signal with something like one of
these.
http://www.amazon.com/CyberTech-Digital-Photo-Tachometer-Contact/dp/B001N4QY66
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On
Behalf Of Monroe L. King Jr.
Sent: Saturday, December 05, 2015 5:51 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Turbopump prime mover
Thanks for the reply Robert I believe I could do that if I drilled down to the
shaft threw the casing and milled a small round flat on the shaft to reflect
the laser.
The turbine it's self is a Inconel alloy and the pump impeller is SS so that
rules out magnetism on those parts.
Other ideas? Criticism welcome as well.
-------- Original Message --------
Subject: [AR] Re: Turbopump prime mover
From: Robert Steinke <robert.steinke@xxxxxxxxx>
Date: Sat, December 05, 2015 2:50 pm
To: arocket@xxxxxxxxxxxxx
Could you use a laser non-contact tachometer? It shines a laser on
your rotating part and counts the number of times a piece of
reflective tape goes by. I can't visualize your setup so maybe this
isn't useful because the problem is you can't see the rotating part,
but if you can see it, but not touch it this would be a solution.
On Sat, Dec 5, 2015 at 5:36 AM, Monroe L. King Jr. <
monroe@xxxxxxxxxxxxxxxxxx> wrote:
Ok I have a cart for the test engine, now I have to visit the local
junkyard for a useful engine I can rebuild. I believe we can make a
setup similar to this https://www.youtube.com/watch?v=vIzAfwPl3a0 to
make changing turbines/pumps out easier I think we will only need 3
different turbochargers S,M,L so we wont need more than 3 adapters.
Once I get the test engine ready I'll take the cart to a muffler
shop and get the exhaust tubing bent for the test stand.
That flow bench is neeto but it wont supply enough air for load testing.
The only problem now is I have to come up with a new way to get
turbine RPM readings. With cold flow I could get the reading of the
turbine side but now that's not going to be possible and the pump
will be on the cold side. Normally they take the readings off the
cold side put our pump will be in the way.
Any ideas on how to get the RPM readings?
To me this looks like the easiest way to get RPM and HP we need to
test pumps.
Comments?
-------- Original Message --------
Subject: [AR] Re: Turbopump prime mover
From: Ed LeBouthillier <codemonky@xxxxxxxxxxxxx>
Date: Thu, December 03, 2015 1:50 pm
To: arocket@xxxxxxxxxxxxx
over
The main reason I don't want to use a combustion/turbine such as
the ones made from turbochargers.
If your using the compressor/turbine you have to go turboshaft
and I've played with one of these combustion/turbines and they
are far from reliable.
Well to get upwards of 30 HP, you're going to need to come up with
something original.
There was a fella by the name of Nye I corresponded with while he
was developing one of the first of these (back in the 90's) and
they just don't run very well nor are they reliable enough.
Probably true.