Triggered Strobe

To prove if this system would work I rigged up a simulator using my boring head to simulate the in balance by driving a bearing inside a tube that is mounted on a spring, the speed of the mill is fully adjustable so spin up problems do not occur.

strobe3.JPG

Findings

Yes it flashes and produces a strobe effect on the rotating part but the lines are not readable and the holes in the head show up as oval's
After testing at various speeds between 500 and 2000 rpm . I came to the following conclusions

The flash has to be as short as possible and under separate control, any dwell in the flash produces the blurring and distortion of the image
due to the part moving while the light is on.
Backing off the sensing contact as fine as possible starts to improve the image, but contact is lost before it becomes anywhere near readable.
However I have relearnt things I had forgotten, so not all is lost,
Back to the drawing board. First thing required is to be able to control the time of a single flash. then how to trigger it.

Brian.
 
Perhaps a an old automotive timing light could work, the ones used to tune engines with pre electronic distributer ignitions?
 
Hi Stuart
Will the system you are using produce timed flashes of a controlled length if so it may well be a starting point. The movement May still require a pizio sensor
to get the required sensitivity.

Brian.
 
Hi Eddy
Yes the working end of a ignition strobe will probably work. Getting the trigger sensor sorted will be the problem.
most of the old strobes had a inductive pick up on the HT lead. But it sounds possible. Thanks .
Brian.
 
Electronics is definitely not my area of expertise, but how about incorporating an automotive distributor stator and pickup? Mike
 
Brian -- Am I assuming correctly that the voltage you wish to use needs to be fairly low? Although the timing light is feasible the trigger sensor problem could be beyond reach. Mike has a good idea but again it may have its drawbacks due to required voltage. Wow this has become a real problem for you. Lots of ways to accomplish it means lots of ideas to weed out. What-ever you come up with please share it with the members as a build. It would be greatly appreciated I'm sure.

"Billy G"
 
You just need to couple a narrow low-voltage pulse to the pickup leads (after removing the pickup). You could cut into the leads, hook up a scope to them, hook the timing light up to a running engine, and see what sort of pulse is needed, or you could just wire up a 555 pulse generator, couple the output to the timing light pickup leads with a capacitor or pulse transformer, and experiment. That's what I'd do (in fact, I may do it. I have several timing lights and I only need one for the tractors).
 
Hi Billy
The voltage of both the timing light and the LED solution are low I prefer low volts from the safety point of view.
Mikes idea has draw backs in that the time on for the light is to long and the probe /contact is not sensitive enough, but it was well worth trying.
The inductive pickup on a automotive timing light will be a lot lower voltage than the HT pulse so it may be possible to trigger it ? I have more Googleing to do.
Time is not important as I have only just ordered the first materials for this project, I do not expect to need this strobe for almost two years but I would rather have it on the shelf when I need it.
I see this as a useful tool in the shop of any engine builder, and I know more uses will be found by others.
What ever happens I will post it good or bad you learn both ways.
Brian
 
Brian -- in my time in building Radial Engines (5 now with the 18 cyl. still in the works) I have always dynamically balanced the crank, 0 being at 90 degrees on the balancer. The 18 is no different as the journals are 180 degrees apart. I use a standard Model Airplane Propeller Balancer. When the lobes stay 90 degrees to the Vertical plane without dropping it's done. Either way Strobe or Dynamic, balancing is a necessary PITA. Good Luck in your endeavor, you have chosen quite q feat.

"Billy G"
 
HI John
Our posts seem to have crossed while I was slowly typing my answer to Bill.
Yes that seems the way to go if the strength of the pulse can be determined then a way can be found to trigger the strobe.
I think the sensitivity of the transducer will have to be controllable,
Brian.
 
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