Progressing From The Dark Ages.

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

Moderators: GlennW, Harold_V

armscor 1
Posts: 311
Joined: Sun Jun 12, 2016 3:12 am
Location: Philippines

Progressing From The Dark Ages.

Post by armscor 1 »

Hi Guys, bit the bullet and ordered a DRO for my Mill, sick of counting turns of the handles, compensating for backlash and reading the dials.
The kit comes with 2 glass scales, but the "X" is too long, anyone shortened scales, is there an easy method?
And yes I know Harold it takes some of the skills away from the operator :)
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Progressing From The Dark Ages.

Post by Harold_V »

Chuckle!

Well, just don't forget that using a DRO can lead to backlash problems, so remember to set it in the right direction when it matters.

Congrats! If a guy can afford a DRO and doesn't have need for other things, there's certainly nothing wrong with having one.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
ERIE S-1 BERKSHIRES
Posts: 105
Joined: Sun Jan 25, 2009 12:43 pm
Location: Barberton Ohio

Re: Progressing From The Dark Ages.

Post by ERIE S-1 BERKSHIRES »

There's a couple of videos on YouTube
KellyJones
Posts: 189
Joined: Mon Nov 29, 2010 10:10 pm
Location: Snohomish, WA

Re: Progressing From The Dark Ages.

Post by KellyJones »

I put a DRO on my mill about 5 years ago. Best tool I ever bought. My eyes simply couldn't read the dials anymore.

Despite Harold's warning, I seem to have no problems with backlash. Perhaps I got lucky in the set up, but the DRO seems repeatable and accurate (within my needs, anyway).

I wasn't aware you could change the length of the scales. I would be interested in what you find out.
Kelly Jones, PE
A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing.
George Bernard Shaw
(1856-1950)
armscor 1
Posts: 311
Joined: Sun Jun 12, 2016 3:12 am
Location: Philippines

Re: Progressing From The Dark Ages.

Post by armscor 1 »

Thanks, watched some people on youtube shortening scales, have to be gentle cutting the glass scale but it is doable, let you know how I get on.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Progressing From The Dark Ages.

Post by Harold_V »

KellyJones wrote: Wed Jul 15, 2020 12:07 pm Despite Harold's warning, I seem to have no problems with backlash. Perhaps I got lucky in the set up, but the DRO seems repeatable and accurate (within my needs, anyway).
The backlash issue rears its head when you set location with the screw unloaded. For light cuts, it generally makes little difference, but if you take heavy cuts, cutting pressure will cause movement of the given axis against which the cut is taken. The problem is real, even if the machine has no DRO. It's just a lot easier to forget backlash with a DRO, which is the reason for my note of caution.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Progressing From The Dark Ages.

Post by NP317 »

I always lock the axis on my mill during cutting. Then the DRO reading remains true as the table does not move.
I seldom make heavy cuts, which also helps.
RussN
RSG
Posts: 1541
Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: Progressing From The Dark Ages.

Post by RSG »

Congrats! I absolutely could not do what I do without one! With the number of duplicate parts/cuts and complexity I'd make a mistake in short order without one.
Vision is not seeing things as they are, but as they will be.
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Progressing From The Dark Ages.

Post by NP317 »

I just spent the past several days machining the main body bronze casting for a Coles Power Models Worthington Duplex Pump, and the DRO on my mill greatly increased my machining speed. With so many mirror-image ports and passages to machine, the DRO easily kept references valid and let me move for side to side without making mistakes in positioning.

Yes, I could have done the work with just the mill dials, but it would have been far slower and my chances of making mistakes would have been higher.
That's how my brain works.
RussN
KellyJones
Posts: 189
Joined: Mon Nov 29, 2010 10:10 pm
Location: Snohomish, WA

Re: Progressing From The Dark Ages.

Post by KellyJones »

I see what Harold is talking about now. I had considered that "deflection", but I can see how it can also be properly referred to as "backlash". That's exactly why I, like RussN, always set the locks on the axis when milling. In fact, I lock the axis on all but the "active" axis (the direction of the cut).

When I was just starting out, I experienced some rather exciting moments on my mill. I had never used a mill before, and did not realize that when shipped, new mills are not locked in every direction. After about 10 minutes of operation, the milling head "jumped" about 2 inches and the end mill shattered into pieces and flew about the shop. (Maybe I shouldn't be telling on myself...).

Anyway, I learned that lesson well...all adjustments and axes must be firmly locked with only the direction of travel free.
Kelly Jones, PE
A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing.
George Bernard Shaw
(1856-1950)
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Progressing From The Dark Ages.

Post by Harold_V »

KellyJones wrote: Mon Jul 20, 2020 5:27 pm I see what Harold is talking about now. I had considered that "deflection", but I can see how it can also be properly referred to as "backlash".
What it is is movement caused by cutting pressure, the result of backlash being in the wrong direction. If the screw isn't loaded by the movement of the slide (when you move to the location where you intend to cut), that's what you can expect. For very light machining, or small hole drilling, it usually makes no difference, but if you take heavy cuts, you can be pretty much assured that the cut will move the slide. By having backlash set in the proper direction, that can't happen. And, as I said previously, it's not something related to DRO use. If a guy doesn't understand the concept of backlash, it's going to bite him on the butt with dials, too. In fact, dials are worse in that they don't reflect true location if backlash isn't set properly. A DRO reports location, not dial setting, thus you can find the proper location in either direction. One will hold it there, while the other won't.

Using locks is always a good idea. However, if you're doing ultra precision work, using the lock in and of itself often results in improper location. That may not be true when running a jig borer, but it usually is with a mill. As a result, I often don't use the locks, or I may use them slightly snugged, and never release them while working on the project. That, of course, is for close tolerance work.

Put an indicator on the slide in question, then lock the slide. Mills generally will shift a few tenths. Really shows up when you're trying to dial in a hole.

These comments are not intended to harass or annoy anyone. What they are is information that can save you from making scrap when it really matters. Be mindful that these conditions exist--that they are commonplace, and you must learn to deal with them.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
KellyJones
Posts: 189
Joined: Mon Nov 29, 2010 10:10 pm
Location: Snohomish, WA

Re: Progressing From The Dark Ages.

Post by KellyJones »

Got it. Thanks Harold.
Kelly Jones, PE
A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing.
George Bernard Shaw
(1856-1950)
Post Reply