digital readouts

[Speedy]

I just read that you can use digital calipers for a Dro on your mill or lathe, the only thing I dont understand is how you guys are getting the display on a laptop or screen.
right now I just checked my digital caliper and on the opposite side of the battery holder is another cover, removing this cover you see the board with 3 or 4 lines is this what your hooking them up to? (what are you hooking up for display?)
and why do the companies make them with that?

(hope you understand, sometimes I can be confusing? :big

 

[Loose nut]

Some people use digital calipers, but it is better to buy digital scales (calipers without the jaws). CDCO is the cheapest but other companies sell the same scales. The port you mentioned is for connecting to a readout, the more expensive digital calipers use a standard connector for this , the cheaper caliper's and scales may use a non-standard connector. The easiest way to hookup a display is to use a digital readout, CDCO, and others, sell a simple 3 axis readout made for these digital scales. They are limited to a 0.001" accuracy and should not be confused with a "proper" DRO outfit but for a home shop they are more than accurate enough, repeatable and relatively cheap. Also DRO's are coming down in price and a set up might be available for not much more money. Connecting yo a computer may require a special interface card to work.

 

[Speedy]

thanks Loose nut.
I noticed the scales on the CDCO site are the exact same ones I buy locally on sale at Canadian tire, there a mastercraft brand (stores)

they are cheaper right now then the CDCO site.

you mentioned that its better to buy the calipers without jaws, is it ideal? I was thinking that it wouldn't make much of a difference and if they were in the way just simply cut them off?

only thing right now that I can see as a problem is the lengths, but couldn't I just add to the rail? or the inner chip may not be programmed for that much more movement.

im just trying to find the cheaper way, since my plan is to cnc eventually (im planning ahead, no machines yet :big

if you belive mine would work with the CDCO readout box I would like to take advantage of my local sale

these are them
http://www.canadiantire.ca/browse/p...4443278728&assortment=primary&fromSearch=true
(dont belive thats the sale price listed.)

 

[Cedge]

Speedy
I used calipers as DRO's foro a while, before making the jump to the scales and readout display. There isn't a whole lot of difference in performance, even using Harbor Freight grade calipers. I ground the tangs off and even lengthened one of them using a piece of scale from another. The reader head doesn't care if the scale is 6 inches or 6 feet. It simply reads until there is no more to read.

It's an inexpensive way to achieve added accuracy, if you don't mind craning the old neck around a bit. I would highly suggest going with the larger number display calipers so you don't wind up with a permanent squint to go along with the strange bend you get in your neck...(grin).

Steve

 

[Speedy]

awsome Cadge, sounds like it would suit me well.
do you know if the ones in my link would be compatible with the CDCO's read out box?

im going to try some other local sources for ones with bigger displays if the CDCO box wont work.
(maybe I can try it withought the box first, then get it if needbe)

 

[lugnut]

Speedy take a look at Grizzly's digital scales Part# H8134 is a 12" scale for $49.95. I think that's a lot less than the CDCO's price. here is a link.
http://www.grizzly.com/products/h8134

Mel

 

[bentprop]

Speedy,here's a fairly cheap way,using an old computer:
http://www.yadro.de/dro/diy.html
This does take up more room than a "proper"readout,but the Monitor's screen size means it should be easy to read.
This is my own caliper readout on my mill-drill:

The scales are still a bit expensive here,I'm waiting for the price to drop before I get some for the X and Y axes
Hans.

 

[firebird]

Hi

If you go to the tools section of this forum, then page 11, then look at my post DRO ON THE MILL it will show how I did it. Below is one photo to give an idea.

cheers

 

[Speedy]

bentprop, yadro is very neat. something to consider now for the future
Firebird looked over the thread, nice build. only thing I dont see is where you got your lcd display?
is it cheap enough to get 3? and just laybel them. x,y,z

 

[Loose nut]

Speedy it's usually cheaper to buy one display with XYZ axis than 3 separate displays.

These scales are probably all the same and should work with the CDCO display, check the plug receptacle and see if it has four small wire connectors, the opening is about 1/4 " square. I bought my scales from one place and the display from CDCO and have no problems getting them to work.

All of these scales or calipers are sensitive to moisture and oil which can make them go squirrelly for a while, a good cleaning and letting them dry out is a common fix. I've mounted guards over the top of the scales to keep oil and such off of them. I'll get a picture tomorrow and post it here to show you.

Using a calipers with the jaws "off" will let you fit it into a smaller space if that a consideration.

I used a caliper on my lathe and after doing all the work getting it mounted it lasted about a week and died, I don't know if it was vibration buggering it up or it's time was just up.

The calipers are probably cheaper in the short (6") size but if you want to go to longer lengths then check the prices on the scales, it will probably be cheaper.

 

[firebird]

Hi speedy

Readouts came from Arc eurotrade at £30.00 each. Have just fitted 2 to my new x3 mill as well. They work very well. Combined readouts start at £120.00+.

Cheers

 

[Loose nut]

Here are some pictures of the scales on my mill,

the first one shows the Y axis scale with the homemade mounting fixture and a shield over the top to protect it from swarf and oil

the next is the X axis also with a shield over it

the third is the display mounted on a movable support, the mounting plate can also be rotated

the Z axis mount , paint still drying, will be bolted to the front of the mill head and has a cover that can be opened or closed to protect the scale

the cable to the Z axis scale with a piece of flex cable spliced in to lengthen it, which also pulls it back out of the way when the head is raise or lowered

all the guards and mountings were painted yellow so they would be highly visible, to keep me from getting fouled up in them and causing expensive damage.

One really important point that may be obvious to most but not all is that the scales or calipers must be mounted parallel and level to the ways of the machine within a few thou.

To show this point, exaggerated obviously, if the scales were mounted on a 45 degree angle and the table moved 1" the scale display would show a move of 1.414" so the closer the scales are mounted the more accurate the reading, a few thou on these scales won't make much difference (0.030" will make less than a 1/2 thou error but closer is better).

This is were the idiot factor shows up. I was setting up the display and i moved the table and compared the distance on it to the dial on the lead screw, I was getting a 0.025" travel on the table before the display even moved. Thinking that something was horribly wrong with the system, I finally realized that I hadn't bolted the scale down and it was moving a long with the table a bit.

DUH!!!!!