How do I mount motors and gearboxes to a PCB? I've seen
one photo of a pcb with mounting hardware drilled directly into it, but I
don't know where to find this type of hardware.
This is my first 'from scratch' robot project and I know NOTHING about how
to construct a frame.
Ideally, I would like an aluminum or other metal frame ~4"x4"; enough to
hold a microcontroller and a few sensors and sturdy enough to last through
many projects. How do you experienced builders handle bases for small
projects like this?
Any help is greatly appreciated.
Under most circumstances, mounting larger hardware items to circuit boards
is not a good practice. For small robots, it can work as long as the mechanical
loads are not enough to flex or stress the board much.
Most mounting devices are as simple as right angle brackets. Many can be
found in hardware stores, usually intended as mounting for shelving or other
devices. Use your imagination with small fasteners. Hobby shops and surplus
stores are excellent places to look for mounting hardware.
For small motors with small loads, you can often use conduit clamps or Adel
clamps. A pair of Adel clamps along the body of a cylinder shaped motor can
provide a nice, firm mount that is easy to adjust.
Well, you will find yourself having to learn a little metal forming to get
what you want cheaply. I often buy flat aluminum stock and use a simple vise
with some angle iron in the jaws to allow me to form and bend the aluminum into
complex shapes. Using the bare vise jaws will "eat" the aluminum. Covering
them with steel angle will create a smooth, non-marring jaw for holding your
aluminum. A hammer and a little patience can allow you to create really nice
right angle brackets, frame pieces, or circuit card mounting devices.
Have a look at my page and you might get a few ideas from looking at some of
the robots I have built. I have to admit that I do machine a lot of pieces on a
mill, but I also create quite a few pieces using nothing more than vise, hammer,
some pounding blocks, and a few of those low-temperature aluminum "welding"
rods. Alumalloy is pretty easy to get and allows you to weld (actually braze)
aluminum together with a propane bottle torch, so with a little practice you can
create some really nice pieces from bare aluminum stock.
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip
I'll second Chip's idea for using a vise and angle iron for metal
forming. By adding a little leverage, you can form fairly thick stock
for very sturdy motor mounts.
Home Depot is your friend -- shelf brackets make very good motor mounts
if your motor has a flat-surfaced gearbox.
As far as a base, at the sizes you're talking about you can use a small
sheet of plexiglass. You can even use wood; some of the stock (meant, I
suppose, for paneling or other finishing work) makes sturdy bases for
smaller robots, is really easy to work with, and at least once side will
take paint quite nicely -- allowing you to hide the fact that your robot
is made of such a low tech material as wood. Pretty adequate for a 4"x4"
You can also get really cheap base chassis and parts from
http://www.budgetrobotics.com (no affiliation, yada yada). I think the
base panels run around 7 bucks or so. They are PVC whic is extremely
easy to drill.
Hope that helps -- taFkaks
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