Q.        What is the difference between the “Motor” and the “Drill” version?
A.        The only difference is the output shaft configuration.  “Motors” have a ¼” Dia. output shaft with
a milled flat that allows use of an attachment set-screw.  “Drills” are supplied with a 1/8" Dia. drill
collet (see picture on the right) and wrenches for tightening the collet.  Both can be ordered in “right
hand” or “reversible” rotation.  Note: when generically referring to either the standard shaft version
or the “drill” version we usually refer to them in general as “motors”.

Q.        Do these air motors have to be lubricated?

A1.       Yes.  Motors need to be automatically lubricated with an inline luber, or manually lubricated
on a regular basis.  See the
Operations and Maintenance page for details of lubrication types and frequency.

A2.       And No.  If your application demands a lube-free model you can order some of the models with the Lube Free (LF) option.  Please see
the motor order page to view the motors that are available in the Lube Free option.  Please also view the
Operations and Maintenance page
for details as there is an increase in maintenance requirements for the Lube Free models.

Q.        Where does the air exhaust from these motors?
("MMR" & "MMDR" models vs. "MMF" & "MMD"  models)

A1.        It depends.  If you buy an MMR or an MMDR then the motor comes with two 1/16 NPT threaded ports as
shown at the right (upper).  Exhaust can then be piped to some other area if desired.  This dual porting also
allows for additional muffling of the exhaust for quieter operation.  The MMR or MMDR version is reversible
but people often select the "R" version, even though they only want a "forward" running motor, because they
want the additional port for routing of the exhaust air or for muffling purposes.   For this reason we
typically advise getting an MMR or MMDR version, if there is any doubt, since you end up with more flexibility.

A2.        If you buy an MMF or MMD there will only be one 1/8 NPT inlet port (lower photo on the right).  The
exhaust air will escape from two small holes on either side of the inlet port as shown in the picture to the
right.  You can NOT easily add additional muffling or re-routing of the exhaust air with these MMF or MMD

Q.        Do these motors come with air fitting and collet wrenches?
A.        Yes, they come with metal version push-to-connect tube fitting(s) sized for 1/4" diameter tubing (not
compression fittings as shown in the photo on the right).  The drill versions (MMD and MMDR) also
come with two wrenches for tightening the drill collet.

Q.        How much output shaft axial end-play should we expect?
A.        Axial end-play on most of these motors is 0.002 – 0.005”.

Q.        What is the  maximum allowable output shaft radial loading?
A.        10 lbs. applied at the center of the shaft flat.

Q.        What is the collet thread size on the drill units?  (I want to screw on my own attachment.)
A.        The drill collet thread is a 12-40 (slightly smaller that a ¼” thread and very fine pitch).

Q.        Can I mount this motor some other way than with the supplied flange?
A.        Yes.  The mounting flange is removable.  The motor has a 5/8 – 32 left-handed (reverse) thread on the shaft end which can then be
used to direct mount the motor to your equipment.  The motor body should not be clamped in such a way as to crush the sides causing
internal binding.

Q.        What is the highest/lowest pressure I can run this motor at?
A.        These motors are rated for pressures up to 150 PSI and are designed for use with compressed air, nitrogen or other inert gases.  The
lowest recommended pressure for smooth operation is 30 PSI (we have seen them run at much lower pressure but to insure proper startup
under load and smooth running over time, 30 PSI is the recommended minimum).

Q.        The part number on the side of my motor says: (S) or NF or LF or X or a combination of these
designations after the main Model number.  What do these mean?

A.        The (S) designation is for the "sealed" option.  This adds a shaft seal at the output end of the motor for applications that are sensitive to
lube in the work area or in wet applications where you want to prevent moisture from entering the shaft end of the motor.  Please contact us
before ordering if you have an "under water" application that requires a "bubble tight" sealed motor.  You may need sealing on both ends.

The NF designation or "X" stand for "No Flange".  Motors are normally supplied with a mounting flange already attached.  Please note that "no
flange" part numbers are normally not stocked and for one or two motors it is much easier to order the standard part number and simply
remove the flange before use (there is negligible price difference unless you are ordering larger quantities of motors).

The LF designation is for the Lube Free option.  See the question above that discusses lubrication.

Q.        Do you offer volume pricing?
A.        Yes we do.    Discounts are listed at the bottom of the Micro Motors shopping page.  Call or email for even larger volumes.

Q.        Do you have CAD drawings for these motors?
A.        Currently we have 3D SolidWorks models and STEP files available for most motors (Click here).

Q.        How noisy are these air motor devices and is there published noise data available?
A.        There is no published data on motor noise.  They do make the characteristic rotary-vane air motor "whine" but there are so many
application-specific variables involved in the noise question that no attempt has been made to formalize that data.  If noise is an issue for
your application, then order the MMDR or MMR version (two ports) which allows you to route the exhaust air to a muffler.  Proper muffling can
result in a very quiet motor.

Q.        I would like to try out one of these motors but I don’t want to have to pay the full motor price in case it
does not work in my application.  Could I get a “loaner”?
A.        No, but we have a solution that may help.  We have a “rental” option that allows you to try out the basic motor models.  For a lot less
than the cost of a new motor you can get one to test for as long as you care to rent it.  This allows you to get a hands-on feel for how it will
work in your application.  Email or call for more details:
Email or (805) 461-3920.

Q.        How much air do these motors use during operation?
A.        It depends on the application.  Maximum air consumption at 90 PSI is 4.8 SCFM.  At low pressure and slower speeds they will use less
than 1 SCFM.  In most typical application the motor uses less than the maximum rated consumption because when the motor is loaded it will
be running at a slower speed than the unloaded (maximum) speed - and often with less pressure needed than the rated 90 PSI.

Q.        Can I get one of these with an all Stainless Steel body?
A.        No, the S.S. body option is no longer offered.

Q.        Can I use these motors underwater?
A.        We do have applications that use these motors underwater.  Please contact us about your specific sealing needs before ordering.

Q.        Are these motors ATEX certified?
A.        No, these motor do not carry ATEX certification.

Q.        Do you make these in a non-magnetic version (MRI "compatible")?
A.        No.  Most of the construction is aluminum and S.S., but they are not available in a strictly non-magnetic version.

Q.        Why the long lead times and minimum order quantities on some models?
A.        On February 26th, 2020, Pro-Dex announced that, effective immediately, they have changed their standard lead
time as well as their minimum order policy to all distributors.

    They increased standard lead time on all units to six weeks minimum.  We try to minimize the effect of that change on standard MMR
    motors by holding greater stock levels so that they will be on hand in most cases. But for many non-MMR motors, and on all special
    orders, please be prepared for at least a 6-week lead time.

    They also increased the minimum order quantity to (5) pieces for any one SKU ordered by their distributors.  This should make little
    difference to your order of most standard MMR motors but will greatly impact special orders like Sealed motors and Lube Free
    motors.  It will also affect most MMF, MMD and MMDR series motors.  This means that in most cases we will NOT be able to take non-
    MMR orders or special orders (S, LF, NF or NL) unless the quantity is 3-4 units or greater.

    If in doubt, please check with us by email.  We apologize for any inconvenience these unexpected changes cause you or your clients.
"Drill" version shown.
(2) 1/16 NPT
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(1) 1/8 NPT
Pro-Dex Micro Motor FAQ
(805) 461-3920