[mowbot] Motor Shaft Attachment

KEN_REED nospam at hp-boise-om2.om.hp.com
Sat, 8 Mar 97 09:52:16 -0700


> Ken, there seems to be some problem with your mailer. Your reply came
> back with my remarks unquoted, but your new remarks quoted ???

Yes, I know about the mailer, its Lotus CC:Mail for our PC Network here
at HP. It does no actual quoting, I was adding the ">>>" manually. Sorry about
the problems this may cause, but I haven't many options.

Since some of you all may be trying to attach disks to motor shafts, or motor
shafts to wheels let me describe the method that I used more clearly. Again, I
say this is an experimental method, or slow speed attachement only, since it
vibrates.

Go to an electrical supply place, or local hardware store and ask to see
their "lug connectors for ground wire". They are made of brass and come
in all sizes. Here's the ascii art, total length is about 3/4" to 1".

side view
+===============+
| |
wire goes | |
in here==> | |
| |
| |
+=========================================+
| lug end |
+=========================================+

top view
+===============+========================\
| | |
| /===\ | |
wire goes | / set \ | /==\ |
in here==> | | screw | | lug end| | |
| \ / | \==/ |
| \===/ | |
| | |
+===============+========================/

The motor shaft goes into the end where the wire would normally go, and the
set screw is tightened down onto the motor shaft. Now if one bends the tab
or lug end over 90 degrees and drills another hole in the lug end, the motor
shaft can be attached to nearly anything. I've been using this method for
slow speed things and experiments since my youth, far too long ago.

tighten set screw | |
| | |
v | |
+===============+ | | <== disk
| | | |
Motor shaft | | | |
in here==> | side view | | |
| | | |
| | | |
+=================\ | |
| || |
+=============\ || |
| || |
| || | <== bolt here
| || |
| || |
| || |
| || |
| || | <== bolt here
| || |
+===+| |
| |
| |

Another method that I prefer over this one, and that can be used in
high speed and permanent situations, not just experiments is as follow:

Use a pulley, fan blade, drive gear, about anything that already has a set
screw and that fits the motor shaft you have. Then drill the pulley with
3 or four holes, and bolt it to the wheel, disk, or whatever you are trying to
hook the motor too. I use "Erector set" pulleys, old bathroom-fan blades,
and just about anything with a hole and setscrew. There are a few more
electrical connection items that have setscrews in them and that can be
used to hook to a motor shaft, so browse there too.

(: Personal note: It helps to be a year round parts scrounge. Browse several
locations on a regular basis and be on the lookout for new surplus material
places. Whenever I find an old dc gear motor, pulley, fan blade, drive gear, or
whatever with 3/8" shaft hole or less, I take it home. That way when a project
is started, some things are already on hand. Additionally, it helps to keep a
full folder of Surplus Electrical and Mechanical Catalogues. Watch for places
to scrounge and catalogues all year long, not just when starting a project. For
my LawnBot, I already had the drive wheels, dc gear motors that drive the
wheels, the casters for the non-driven wheels, and lots more items on hand, when
I started.

Another thing that works great, it to design in modules. That is, re-use as
much of the design and therefore the parts sources from the last projects you
have done in the new one. You have already debugged them, and have experience
with their performance, strengths, weaknesses, current draw, etc. LawnBot is a
collection of design pieces I've used before, except for the grass cutting part
and some of the control algorithms of course. That way you have kind of a
Robotic Erector set at your disposal, when you start a project. --Okay off the
soap box-- :)

Hope this helps someone out there, the grass in growing as we work.

| / \ |
bye for now | / \ |
ken reed | \ |
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|/ | | |==+ \|
------------------------+ /| | | | +-----
/ | BotKen | / |
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