Re: Re: Help with Bridgeport retrofit parts and plans

> 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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