Re: Feedback on Free stepper calculator

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Fred Smith <imserv@v...>"
<imserv@v...> wrote:

> Did anybody get a chance to check the calculations on the rack and
> pinion and pulley ratio calculations on the free stepper motor
> calculator? At least in inches? Please let me know if there are
> any errors
> data set can be copied to clipboard and printed with notepad.

> Best Regards, Fred Smith- IMService

Fred,
Nice !
I did a quick check of the Screw calculations using my program in the
Group Files area, ~ Or was I checking mine against yours? :)~, and it
all seems kosher.
The Rack and Pinion figures I found confusing, however.

I assumed that the units are: Pinion: [Teeth]; Rack: [T.P.I.] (and
not "pitch", as labelled, although it seems that "(1/T.P.I.)=pitch
[ins]" has been applied).

A quick test:
I set the stepper motor to 200 [steps/rev],
Stepper to 3.33333~ [steps/sec] ( =200 steps/min = 1 r.p.m.),
and the Rack & Pinion values both to "any-same-figure": "N".
The resulting speed seems to be suspiciously involved with "PI",
whereas it should produce a linear speed of 1 inch per minute, based
on my assumption.
Has someone "pied" your calculations when your guard was down ? :),
or have I erroneously assumed the "unit" as: [Pinion-Teeth] instead
of [T.P.I. around pinion's "pitch-circle circumference"]
(a rather odd specification).

"PI" will not come into linear calculations for Rack & Pinion setups,
when [#Teeth] is the Pinion "unit".
(Quick explanation: "It was vanished by the cycloidal gear-cutter.")
[Steps/min]/[Steps/turn]*[Teeth/turn]*[inches/tooth] = [inches/min]
(Pulserate)__(Stepper)_____(Pinion)____(1/Rack TPI)____(Rack speed)
(*"belt-gearing", if applicable)
It would be well worth labelling the "units" to be input for Rack &
Pinion values to avoid confusion.

Have a play with my spreadsheet to check calculations. It is
specifically designed for screw systems, but, by entering an
equivalent value for "Screw-Pitch" (=PI*Pinion-Diameter) ~(it's
back !)~, it will give all the Rack & Pinion output figures you want.
Use "Goal-Seek" to enter outrageous "off-scrollbar-scale" values.

......and you could brighten up that Visual-Basic grey with a splash
of colour ! :))

Cheers, Don