DRO for milling machine

Hey guys looking for a DRO for my Bridgeport. I don't need a real complicated setup. I would like the ability to set up holes in a perfect circle. PCD function I think its called? What's the better glass scales, magnetic? pros-cons.

I have seen $150 kits and $1500+ kits I just want something decent and easy to use. Remember I am the weakest link in the operation. Was looking at some thing like this.


Thanks for your help
https://machinetoolproducts.com/ditron-d80-3-axis-mill-dro-kit-w-glass-scales

I got some $30.00 ones from amazon. Set three of them up on my mill.
Simple and cheap.

Newall with the magnet ball tube scales are very easy to install and hold up well against dirt/oil/grime I think DP500 is the lower function model. About $700. User interface is easy. I have DP700's on 6 mills in the machine shop. All hold thousandths easily.

I never use PCD for bolt circles only because I've memorized the trig values for 3/6/12 and 4/8 patterns. Just zero on the center and don't worry about whether I keyed in something wrong.

3/6 is (X=.866*radius, Y=.500*radius) & holes at (X=0, Y=radius)

4 @90 deg straight is (X=radius, Y=0) & (X=0, Y=radius); 4@ 45 deg is (X=.707*radius, Y=.707*radius)

thanks gtermini, I will look in to them

I put one of these on my Bridgeport a year ago and so far no issues.
https://www.ebay.com/itm/2-Axis-Dig...871423?hash=item2f2e65923f:g:ISAAAOSwYENcof7z

What did you end up choosing?

The lcd units from dropros look very nice.

I discovered my Bridgeport is predrilled for a Acurite set up so I am thinking of using them. haven't ordered it yet.