Re: [CAD_CAM_EDM_DRO] Re: Stepper cnc retrofit ? For Tape-O-Matic

>>
>> The Tape-O-Matic was primarly designed for drilling but is capable of
>> light duty milling.
>>
>> You want to use a Tape-O-Matic for drilling with peck and some 2D
>> milling.
>>
>> 1) Machine has zero backlash ballscrews on X and Y axis.
>>
>> 2) The steppers are 400 in. oz. 5 wire unipolar steppers mounted
>> with a 1-1 belt ratio.
>>
>> 4) Machine originally had a speed of 10 in./min. max. But you would
>> like to see 30" to 60"/min.
>>

The tape-0-matic of that era used a rapid motor-I think it was an 1800 rpm
1/4 hp and a stepper motor for slow positioning which was driven at two
speeds. I set one up to mill by making the oscillator which drove the
stepper motors variable. It worked fine. The rapid motor drove it through
a belt at over 100 IPM. the 50 slot - 400 count (4 count logic) encoder
disk was fastened to one end of the ball screw , the stepper motor was on
the other end. The end with the stepper motor had a sprocket for the
toothed belt to the rapid motor. This is from long dormant memory.

There isn't much required to restore it to operate the way it was
originally designed. Milling works fine.

The head, as used on the tape-o-matic A was provided by another drill press
manufacturer. The heads on the B and C models were made by Pratt. They
were reasonably rigid. They needed to be kept in balance. I don't know if
Pratt will provide parts at a reasonable price. They were never fun to do
business with.

They were the first machine tool manufacturer to sell their products like
encyclopedias. Smokestack door-to-door. Kids with liberal arts degrees
who had never been in a machine shop did most of the selling. It worked
quite well, as they delt in quantity at a low price. It sure introduced nc
to the machine shop much better than the far better machines sold on the
old knowledge based marketing models.

An important aid to conversion is the junction box at the bottom of the
back of the column. Almost every wire that goes between sub assemblies is
routed through that j-box. Don't tear it out. Uou can gut the control
panel if you wish, but tab each wire, so you can wire in a control panel to
suit you. There are plenty of extra wires between the j=box and control
panel because the technology of that era required many wires rather than
some simple logic and a single wire for a given function. The same holds
true for the wires to the electronics box. You can replace it with a much
smaller box, but tab the wires as you disconnect them.

You may decide to replace the spindle drive mechanism with a variable speed
direct drive, but the spindle and quill are quite rugged.

Ted Robbins