[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [TCML] Rotary Gap Balancing, other plane advcse



Hi Folks,

I'm not sure I understand this technique. I balanced my 11" rotor by buying
two fresh roller bearing (US) and a 3" long bolt with a ~1/2' untapped
shank, that fit the bearings and the rotor hole snugly the bearings were
secured on either side of the rotor with centered washers and a nut on the
thread. Now the rotor turns very freely and will turn quickly to the heavy
spot. The bolt threads can be held in a vise or clamped somehow.

I then drilled partial holes (in the flat of the G10 as to not weaken the
edge near the edge and away from the electrodes). Balance was achieved I
believe accurately and simply.

This is good for the plane of centrifugal spinning! However, what is the
best way to balance the rotor flat plane like a car wheel and a bubble
balance? Ideas? This will probably require going back and forth to a happy
medium.

Thanks,
Jim Mora

My next rotor will be 18"x 5/8" g10 for a 16" or 17" flying electrode circle
(it's at the machinist waiting for $$). The electrodes are 3/8" x2"
Tungsten. This will be spun by 1.5 HP 3p motor under control of a VFD which
can make 3P from single phase so balance in both planes will be a serious
issue. Advice welcomed.


-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of Quarkster
Sent: Wednesday, December 03, 2008 8:05 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] Rotary Gap Balancing

Christopher -
 
Sorry, pretty much a failed hope. In most home-made RSG disks, the greatest
source of imbalance in dues to slight mismatch in the radial positions of
the electrodes, and differences in the mass of the electrode assemblies.
 
The easiest and most accurate approach is probably to disassemble the motor,
secure the RSG disk to the rotor shaft, and balance the RSG disk and the
motor rotor as an assembly. The RSG disk must be keyed to the motor shaft,
or marked so the angular relationship between motor shaft and RSG can be
preserved after reassembly. 
 
Actually, supporting the assembly on parallel knife edges is a simple and
effective method of balancing. Cheap knife edges can be made by using thin
stainless-steel rulers from a graphic-arts supplier. These are very thin
stainless steel, usually with a cork composition backing. Simply attach two
small "C" clamps to each ruler to hold them upright, and adjust the clamp
positions to get the top edges of the rulers parallel and at the same
height. Use plywood spacers under the rulers to get enought height to
provide clearance for the RSG disk above the worksurface.
 
Make sure that the rotor shaft is absolutely clean, place the rotor on the
knife edges, and give it a little nudge. If it is grossly out of balance, it
will immediately rotate until the heavy part is lowest. When it comes to a
stop, mark the lowest point with a felt pen, and remove a little material
from the edge of the RSG disk with a file. Alternately, to get some idea of
the amount of material that must be removed, add a small piece of modeling
clay to the top of the rotor, and nudge it again. If you've added too much
material, the "lump" will now rotate and be at the bottom. Remove part of
the lump, and try again. When the rotor assembly stops at random locations,
it is balanced (at least statically). Remove the lump of clay, and remove a
similar volume of material from the OPPOSITE location on the periphery of
the disk.
 
Go slowly, and check balance frequently.
 
Its an iterative process, and takes some time, but can give very good
results.
 
Regards,
Herr Zapp

--- On Wed, 12/3/08, Christopher Karr <chriskarr4@xxxxxxxxxxx> wrote:

From: Christopher Karr <chriskarr4@xxxxxxxxxxx>
Subject: [TCML] Rotary Gap Balancing
To: "Tesla Pupman List" <tesla@xxxxxxxxxx>
Date: Wednesday, December 3, 2008, 2:34 PM

Hello, I was wondering if there was any good method of balancing a rotary
spark
gap disk. I don't know of any extremely simple methods, but I was thinking
of taking an electric sander, while it's rotating at high speed, and sanding
down the imperfections in the wheel from the side. This would allow it to
balance the wheel by mainly sanding down the imperfections, due to
vibrations.
 
Am I right in guessing this, or is this just a failed hope?
 
         - Christopher
_________________________________________________________________
Send e-mail faster without improving your typing skills.
http://windowslive.com/Explore/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_speed_1
22008_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla