Re: Help with Bridgeport retrofit parts and plans

> At the moment we are running at 80,000 steps per second, 2,000

steps per rev and 5 tpi so that's 10,000 steps per inch.

> 10,000 into 80,000 = 8 inches per second or 480 in /min.
> We can't run any faster as the machine isn't bolted down <g>
>

I am trying to figure out if you are pulling my leg.

What are you using for a motor drive.

What are you using to get step and direction for the drive.

> > 2 What is maximum IPM you can take a good cut with.
>
> How long is a piece of string? depends on tooling, depth of cut,

speed, material and horsepower available.

> In steel we normally run a 20mm inserted 2 bit cutter at 2,800 rpm

and a depth of cut of 5mm at about 400mm/min

> In english 3/4" cutter, 3/16" deep at 16in/min.

Have you ever tried to take a heavy cut in aluminum at 40 IPM or use
a flycutter at 80 IPM.

Wally




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "John Stevenson" <john@s...>
wrote:

>
>
> > For my reasoning on steppers and Bridgeport's read my post #80854.
> >
> > I can understand why your Beaver is direct drive. With all the
> > torque on a stepper in the 300 rpm and lower range it would have

no

> > speed with a belt reduction.
> >
> > I also think many people would consider the step of a direct drive
> > motor to coarse.
> > Assuming .2" lead screw each full step would be .001". Even half
> > step is a little rough.
> >
> > I would like to hear some real world specs on the beaver.
> >
> > 1 What are the rapids.
>
> What do you want them to be <g>
> At the moment we are running at 80,000 steps per second, 2,000

steps per rev and 5 tpi so that's 10,000 steps per inch.

> 10,000 into 80,000 = 8 inches per second or 480 in /min.
> We can't run any faster as the machine isn't bolted down <g>
>
> > 2 What is maximum IPM you can take a good cut with.
>
> How long is a piece of string? depends on tooling, depth of cut,

speed, material and horsepower available.

> In steel we normally run a 20mm inserted 2 bit cutter at 2,800 rpm

and a depth of cut of 5mm at about 400mm/min

> In english 3/4" cutter, 3/16" deep at 16in/min.
>
> > 3 If you cut a circle, what does the finish look like.
>
> As 2 above, decent material and tooling = good finish.
>
> > 4 What is the lead on the ballscrew.
>
> 0.200" or 5tpi.
>
> >
> >
> > Wally
> >
>
>
>
>
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