Announcement

Collapse
No announcement yet.

On the subject of DTIs ...

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • On the subject of DTIs ...

    Any recomendations for brands, types etc?

    Right now I'm looking at one of these two:

    http://www.use-enco.com/CGI/INSRIT?P...PMAKA=606-4752

    http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32

    I like the top one better, I think. Its more like the B&S BestTest ones we use at the shop. It says, "No clutch structure for automatic measuring. Clockwise movement only", but I don't know what that means...

    I'm rather silly about brands. I like my tools to follow a certain "theme" when it comes to brands. For instance, all of my sockets are Craftsman. My layout tools, i.e. scribe, combination square and various sheet metal gauges like center gauges are B&S. I know its ridiculous. Anyway, I've got that Mitutoyo dial caliper and I thought a Mitutoyo DTI would be a nice compliment for it.

    This will be the first precision measuring tool that I actually buy, instead of recieving via hand-me-down or etc. I don't want to screw up!

    Thanks guys!

  • #2
    I have my favorites too according to tool type.I like Mitu on calipers and master height gauges,Starrett for mics and Teclock for indicators.

    http://www.use-enco.com/CGI/INSRIT?P...&PMPXNO=951932

    It's also nice to have a 1 or 2" throw AGD2 indicator around.I catch these onsale at KBC for less than $30 regular.

    http://www.use-enco.com/CGI/INPDFF?PMPAGE=335&PMCTLG=00

    Plus the back attachments from Teclock are cheaper-
    I just need one more tool,just one!

    Comment


    • #3
      "Clockwise only" means it only goes that direction regardless of needle deflection. Not sure on "no clutch".

      For DTI, it's personal preference. I find I prefer my B&S most of the time. I've got an Interrapid, but it drives me bonkers because it's "backwards" to everything else, so I find I avoid it most of the time. I've got a fully jeweled large face Swiss Tesa that I really like to use when I really care, probably my current favorite, though the jeweled B&S are really just as nice. You already know about the difference with Jeweled, and I would suggest jeweled in any that you want to really take care of. I've also got a non-jeweled Mitutoyo that sets out all the time for quick access. Just for slapping on and dialing a 4 jaw, or a 3 jaw rechuck, whatever. Works well enough and is an 0.0005 so not too twitchy, but just doesn't "feel" as nice, so I don't mind risking it setting out on the shelf behind the lathe. You won't find my fine jeweled Tesa, Interrapid, or good B&S setting out. And of course I have them in 0.001, 0.0005, 0.0001 (and smaller, though useless).

      But my least favorite by FAR are the Starrett DTIs. I've got/had a few of the "Last Word" and universally hated them. However, because of the switching mechanism they make great embedded tools, and I've got some permanently mounted to shop made jigs that I like quite well. Federal is very nice, IFF it IS very nice when you get it. If there is a problem, they are largely impossible to fix or work on, and parts are insane. I've got a pair of 0.00005 with a 0.010(?) range that seem to have never been used and work well, like I need such a thing. I've also got even finer resolution "Harris" sets (leather cases with neat attachments) and a jeweled large face "Geneva" that is really sweet, but more a museum piece.

      Hello, my name is Russ, and I have a problem... <grin>
      Last edited by BadDog; 08-20-2008, 02:48 AM.
      Russ
      Master Floor Sweeper

      Comment


      • #4
        Oh, and I also prefer the triple dovetail variety as well. The pin-n-tail Interrapid isn't too bad, but I really dislike the barrel variety (ala "Last Word"). No big deal, I have adapters and mounts to mount any of them on any of my holders, but the dovetails are (IMO) just more convenient in so many ways.
        Russ
        Master Floor Sweeper

        Comment


        • #5
          Do you really need a .0001 reading indicator? .0005 is much more useful. .0001 is just too sensitive for most work.

          Comment


          • #6
            I counted and I'm up to a even dozen indicators, all brand name, and the one that has risen to the top of the pile, that gets used for almost everything is my tenths larg(ish) dial Verdict. Don't know if they make them anymore, but it is imo the nicest.

            I'm so used to it, i pretty much can't use a .001 indicator. I'm not saying that everything i do is to tenths, obviously it isn't (whether i was deluded into thinking so or not). However when are you using an indicator when aren't you trying to be within a thou? Even if you are only trying to keep things to a thou, the extra resolution of a .0001 indicator makes the job easier, not harder imo.

            now the following is strictly a notion of my own contrivance......i think a tenths indicator encourages better work. Whether you get something to a few tenths or a few thou has more to do with the feedback than the difficulty in adjusting. Once you get onto it, it is no harder to get the same amount of angular movement of the needle from a tenths or a thou DTI when say setting something in the four jaw.....and at same angular movement of the needle obviously things are set more concentric with the tenths indicator. same with tramming the mill or setting the mill vise - it may not always matter but habitually setting things up that much more accurately leads to better work and takes no more time (at least once you're used to it)

            don't tell my wife where her compact went.

            Last edited by Mcgyver; 08-20-2008, 12:04 PM.
            .

            Comment


            • #7
              Hmmm, Verdict, that's one I don't have. But it looks a lot like the Federal Test Masters (I think that's right?) I have.

              And I agree with Mcgyver. I started with a single Fowler 0.0005 for everything (it's all I had). Then I switched to my first Starrett 0.001, went back to the Fowler after trying to get myself to like that Starrett and failing. Got a B&S 0.0001 and found I preferred it for most everything. The rest just sort of spontaneously populated my box over time, but I still tend to prefer 0.0001 for most of what I do.

              I just don't find it difficult at all. Perhaps just personal preference? But in any case, it surely does make it easy to see surface displacements at a glance, no watching carefully for any little wiggle, so hitting within 0.001 is relatively easy. The only exception is dealing with rough surface. For that, I take one of two options (often both). Go to a bigger tip and/or lower res...

              I have often heard/read that if you want a given accuracy, you need resolution (with accuracy) at least 10 times the desired accuracy. Now, accuracy doesn't exactly apply in the normal way when talking about DTI, but the point does seem to apply. Either way, I use 0.0001 quite a lot and don't find it to be a problem...
              Russ
              Master Floor Sweeper

              Comment


              • #8
                Mcgyver, that's a great indicator! As I get older, I love the bigger dials. I will keep a lookout for one. Your granite parallel is also a nice way to smooth the indicator motion.

                Currently, I have 3 Interapid DTI's that I like well. The consensus over on the PM board when I first bought a DTI was to get an Interapid. I have no basis for comparison but that.

                I have a 0.0005" and 2 0.0001". I prefer the tenths indicators. If I'm doing something where that is too twitchy, it is typically a job that likes a plunger type indicator better anyway. I just keep one Interapid and one plunger in a magnetic base and that's my general purpose indicators. I have a tenths Interapid in a Accu-col or whatever the mill spindle mounts are called. The other one is loose so I can plug it into various special situations. For example I have a quick way to slap it into a QCTP holder.

                Having the two mag bases available all the time has been extremely handy.

                One thought on finding a tenths too sensitive. I use mine differently for tramming on the mill. To tram the head to table, I essentially use it as a "feeler" as you would with a height gage (another use for my floating indicator). I touch down until I get a slight read and then use the quill DRO to tell where I am. I zero it, move to the other side, and then touch down. Then I tram out half the measurement on the quill DRO and try again. I'm usually done after the second try to a couple tenths this way. Not how I came up with that, but it's how I do it.

                To tram a vise, I use a long (36") straight edge. I put that in the vise and line the edge up visually with the table or a slot. This gets you within a couple thou, surprisingly. Then I replace the big straightedge with a parallel and sweep the parallel with a tenths indicator to finish tramming the vise. Like the head tram, I start on the left with that bolt tightended. I move out 1/3 of the parallel, tram that to zero, move another third, tram, and then do the last third. I then tighten the right bolt, traverse all the way back left and double check. It's almost always on within a fwe tenths and needs no further adjustment.

                These two method mean I am seldom out very far when I start using my tenths indicator nor do I sweep it over a rough or interrupted surface.

                Cheers,

                BW
                Last edited by BobWarfield; 08-20-2008, 03:00 PM.
                ---------------------------------------------------

                http://www.cnccookbook.com/index.htm
                Try G-Wizard Machinist's Calculator for free:
                http://www.cnccookbook.com/CCGWizard.html

                Comment


                • #9
                  While we're on the subject

                  How many of you folks have played with or used some of those cheapie import DTI's? Don't shoot me, but I'm thinking of buying one (and I used to run a metrology lab, sheesh ). The reason I'm considering doing so, is very simple. As I get older and more decrepit, I find I'm harder on my instruments because I'm not quite as aware where I just set something or my grasp is just not what it used to be. I knock crap off the lathe bench on a consistant basis. I'd much rather send a $30 DTi to the concrete than a $150 DTI. I don't yet own a 3 jaw, I'm 4 jaw, so everything is indicated in. For that purpose I really don't care what the accuracy is, I'm not making an imperial measurement, I really just need some decent repeatability as I indicate the stock. I'm thinking something like the units that Enco currently has in their sale cat for around $30. So what's the scoop, how do you feel about those for that?
                  OK, let 'er rip.
                  Strider

                  Comment


                  • #10
                    The mill tram device is generically called an "Indicol" (like Kleenex I think).

                    Speaking of QCTP mounts, I found a use for the (mostly) useless knurling block from my PII Aloris clone kit. I took a cheapy import short arm mag mount (with mag base so weak as to be useless anyway) and permanently mounted it on the tool block. So I took 2 largely useless things, and made something I use all the time. My Mitutoyo DTI pretty much lives on that QC tool block, and the Tesa or one of my B&S mount on the Noga or Indicol as needed. Of course I also have a variety of plunger DIs as well. That includes a beautiful plunger back Starrett that I need to get a new crystal for...
                    Russ
                    Master Floor Sweeper

                    Comment


                    • #11
                      Strider, look at the Fowler DTI at Enco. That was my first and it worked really well. Seems like it was only about $30, but a HUGE cut above comparably priced no-name Chinese imports. I prefer it to Starrett LastWord, and frankly, it was pretty comparable to low end B&S (IMO). If someone stole all my nice DTIs tomorrow, I would order another Fowler from Enco on the same day. In fact, that junk mag base I robbed my QC tool block arm off of was in that Fowler "kit" they had in the sale flyer "way back then".
                      Russ
                      Master Floor Sweeper

                      Comment


                      • #12
                        Verdict is still around, not sure if its the same incarnation though.....was doing some googling on it and mine says "A CAPP & SONS" whereas there is nothing about A Capp on the current verdict page, looks like old boy Capp sold out to the current owners....don't know how old mine is but would interested in the pedigree if anyone knows. I'd also forgotten the pear shaped tip thing - supposedly compensates for the cosine error so that it accurate regardless of tip position...doesn't matter much to me as using it to compare rather than absolute measurement



                        also Long Island Indicator has a good list of manufacturers and their opinion of them
                        Last edited by Mcgyver; 08-20-2008, 09:28 PM.
                        .

                        Comment


                        • #13
                          I'll second the TESA VERDICT indicators. Very good - Swiss I think.

                          Comment


                          • #14
                            Fasttrack I am not at this time going to read all the answers. But I will say this .As a profesional machinist -Tool maker I have and have used all brands.

                            1. Buy the best one you can afford.
                            2. The best is a Interapid very costley.
                            3. I have 4 Brown & Sharp Best test From experience they are the nexk best . I have seen them fly across the shop hit a brick wall pick them up and still work.
                            You can buy a cheap one if you want to .But you will be able to past the Best Test on to your grand kids. That I know for a fact.
                            Every Mans Work Is A Portrait of Him Self
                            http://sites.google.com/site/machinistsite/TWO-BUDDIES
                            http://s178.photobucket.com/user/lan...?sort=3&page=1

                            Comment


                            • #15
                              Originally posted by lane
                              2. The best is a Interapid very costley.
                              3. I have 4 Brown & Sharp Best test From experience they are the nexk best . I have seen them fly across the shop hit a brick wall pick them up and still work.
                              Lane, is InterRapid better than Tesa? I've heard both mentioned in hallowed terms.

                              I have several of the black face Brown & Sharpe (BestTest) -- I love them!
                              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

                              Comment

                              Working...
                              X