Subject: Air = "Aerotyke" / Electric = "Electrotyke"

From: [email-masked]
Date: Fri, 19 Jan 1996 11:20:47 -0500

From:	[email-masked] (Steve Smith)
To:	[email-masked]
CC:	[email-masked]

Dear Chris,

This is starting to sound interesting. A couple of ideas:

  A motor crankshaft might be a good way to generate the eccentric
motion (at least if you spend as much time in junkyards as I).

  You could go all the way to a helve hammer or drop hammer--just use
the motor to raise the weight to the top, foot pedal drops the weight
(free fall). This would make changing the amount of impact very easy.
Either change the weight, or the drop height.

I don't think I know what you meant by 'similar to a sewing machine
with adjustable foot'. My comment about holddowns came from my
misunderstanding. Could you elaborate?

Steve:   I think that I was unclear about what an electric hammer is intended
for so let me back up a bit.  To move metal in a serious way, an air hammer
is the better approach and that is a parallel issue which is currently being
discussed on the list.  No, where air might not be the ideal source of power,
is for very light work especially for incised applications.  Have you ever
seen George Dixon use the treadle hammer for his hand held chisels and
chasers to work on sheet metal?  If not, try to get to one of his demos at
some of the conferences or workshops.  When you hold your workpiece in one
hand and a small chisel with or without a handle in the other, you can have
wonderful control in doing this kind of work.  When you think about it, how
many thousands of light blows (yes, thousands), are you applying by hand with
a hammer to work over a surface?  It's quite a bit of work and of course you
need one hand to hold the chisel, one for the hammer and a means to secure
the workpiece (onto pitch or lead sometimes).  Now think about how a
seamstress works with cloth on a sewing machine.  She holds her material
usually with both hands, (in our case, one hand), and can meticulously guide
the workpiece with a great deal of precision, (embroidering?), while at the
same time, by using a foot pedal, she can  regulate the speed of the machine
needle at a very low speed, almost to a gliding stop.  I envy such a device
that could do something with that kind of control, for certain kinds of work.
 Is this any clearer?  Does it make any sense?  Your suggestions indicate
that once we come together on purpose and principle, we can work something
out together and perhaps with others on the list as well.  You seem to know
something about stepper motors, which I'm totally unfamiliar with, and  we
should be able to work out a viable transmission system to activate the ram
head with a degree of precision.  This machine is for a rather specialized
purpose and may not be of much interest to a lot of the folks, but if
designed properly, could be very useful.  I still haven't given up on
development of the little air device I mentioned in an earlier post.  If a
way can be found to modulate the reciprocation, so that the force of each
blow is determined by a foot control, then that is the easiest and most
economical way to go.  Also because of the simplicity of an air driven
device, I think anyone could make a machine for himself.  The electric device
is going to require some machining skills, though it needn't be on an
advanced level.  Tolerances +/- 2 thousands, or so would be fine on this type
of machine.  Well, let's keep thinking about both or either of these ideas
and see where it leads us.  By the way, to keep both approaches to a small
incising type hammer clear, let's give each project a name so either one can
be identified specifically when we exchange ideas.  Sooner or later one or
the other approach will be abandoned and the prevailing concept can be
pursued with full concentration.  I actually think the air approach will
eventually win out.  Let's call the air project "Aerotyke" and the electric
project "Electrotyke".  Stupid names perhaps, but at least it's an identity.
regards
Chris

---

From: [email-masked] (David Hoopes)
Date: Sat, 20 Jan 1996 11:17:43 -0600

>From:	[email-masked] (Steve Smith)
[snip]
>misunderstanding. Could you elaborate?
[snip]
I really like this idea, but my wife is going to hate you when I 
take apart her sewing machine.

How big of a hammer are you talking about?  25lbs or less?  

------------------------------------------------------------------------
David Hoopes
[email-masked]
Lenexa, Kansas (Near Kansas City, Mo)