diy crankshaft balancer 2

[racear]

Want to build a crankshaft balancer. Been reading up on dual plane dynamic balancing. Looks like I will need to use piezo accelerometers or ?. What kind of software will be needed. What kind of dac card? I know(too many questions not enough answers). Any help and all help would be appreciated.

 

[racear]

jclough
I can't deal with autocad at home but I can carry to work and do. Yes I am familar with using autocad.
reed

 

[Tmoose]

Balance machine dangers -
"End drives" are a real pain in the neck because of UNAVOIDABLE centering variations and tight u-joints. Beautifully balanced adapters do NOTHING to compensate for that. and Do not be complacent Just because the readings go down in response to balance corrections. Balance machines adhere blindly to the rule that IX force/motion phenomena are caused by unbalance. A suspicious nature, CAreful work with dial indicators, and proving runs re-indexing the components are the only protection against the devious pranks that balance machines enjoy pulling on their human operators.

Be sure and run the belt drive perpendicular to the direction of measurement. Otherwise the once-per-rev variation in belt tension due to small drive journal eccentricities will talk the balance electonics into convincing you to drill holes that should not really be there. Ditto for any stops or end thrust device. Balance machines adhere blindly to the rule that IX force/motion phenomena are caused by unbalance. ( I repeated that on purpose.) Please also run thru the math once or twice comparing ballpark unbalance resulting physical runout to unbalance before becoming too smug about the attainable and attained residual unbalance results.

 

[racear]

Still need help on how to get the load cell mounted perpendicular to drive. I thought I was ready to start, now 2nd guessing mounting of load cell. Any help?
thanks
reed

 

[jclough]

Anyone know how to post an AutoCad dwg here?

 

[derekwhite]

Just some ideas and observations. How about floating the vees or roller blocks on air (most workshops have a compressor.) Both underneath and end float can be air. The machine I worked with some years ago locked down the bearing blocks until the machine was up to speed (to save the sensors from the hammering of startup and in case the shaft was very out of balance.) Before you start drilling, turn the shaft around and check if you get the same results. How about an adjustable strobe light triggered by the load cells to check the out of balance plane? This could be very simple electronics and no encoder or computer needed.
Let me know how it ends up as I want to make one too! Thanks, derekrwhite@yahoo.com

 

[racear]

jclough
send dwg by email if need to.
thanks
reed.grant@att.net