Indicator Basics - Using a Test Indicator - Haas Automation, Inc.

[Music] an indicator is a basic tool in machining building machines and fixing machines you use it to make extremely fine measurements to ensure that things are made or assembled correctly now an indicator doesn't actually provide absolute measurements like length or width you use a caliper a micrometer or even a scale for that an indicator measures the difference between a desired position and the actual feature how tall is this part you need a scale for that how tall is this part compared to this one that's when you use an indicator before we use an indicator however let's talk a little bit about machinist math this is important because we all need to speak the same language and machinist math can take a little getting used to the basic measurement is one thousandth of an inch called a thousandth or a thou this is how it's expressed on paper and this is ten thousands so what would you call this that's a hundred thousands because we're counting up or down from the third decimal place going the other way a tenth or ten thousandth looks like this test indicators are commonly available with either five tenths or one tenth graduations the dial of a one-tenth indicator is broken up into units of a ten thousandth of an inch or point zero zero zero one as the needle moves each tick measures less than a hair's worth of travel it's that precision that makes these tools so valuable here at the haas factory we use two types of indicators test indicators and drop indicators the test indicator often called a dial indicator uses this lever style arm called a stylus to convert very small lateral movements into a rotary reading on the dial the spindle of the drop indicator also called a travel or plunge indicator is usually set to drop straight down on the part being measured they're great for measuring movement in the range of an inch or more the distance being measured here is pretty large you can see the number of revolutions the needle makes on the drop indicator the stylus on the test indicator can't even reach most of the distance here the distance is particularly small now the test indicator measures it accurately but the precise distance isn't quite visible on the drop indicator as you can imagine these instruments are amazingly sensitive so you'll want to make sure your indicator is firmly mounted to something like a magnetic base secure the base firmly against a clean flat surface like the face of a spindle keep the indicator as close to the primary shaft of the base as possible as it gets farther and farther from the mag base it gets more susceptible to vibrations deflections and droop in the different arm connections this can lead to inaccurate readings so you've got your indicator attached to the mag base now if you're using an interrupt indicator like we use here in the haas factory you'll need to align the stylus so that it rests at a 12 degree angle to the surface you're indicating 12 degrees is where these are most accurate to see the importance of setting this angle correctly let's measure the same surface at different stylus angles first we'll set our indicator to 12 degrees set it to zero our reference position on this accurate 0.15 inch gauge block now we'll move the indicator to this .149 inch gauge block as you can see the dial moved by one mark or a thou as we know the height of the two blocks we know that this is an accurate measurement next let's change the angle from 12 to 30 degrees we'll set the indicator stylus on the 0.15 block and set the indicator to zero when we move to the 0.149 block now we get a reading of one thousand two tenths that's twenty percent off which doesn't seem like much but imagine one of your shoes being 20 percent tighter than the other so let's try the stylus at 45 degrees now the indicator reads one thousand five tenths that's an error of 50 percent in the world of accurate machining and machine tool building an error of this size can result in parts getting scrapped or a machine getting built out of spec finally let's go to the ridiculous extreme of putting the stylus at 90 degrees obviously that's just silly because the stylus wasn't even designed to move in that axis so always set an inner rapid indicator at 12 degrees from the surface to be measured if you're using an indicator made by a different manufacturer be sure to know the angle at which you should set the stylus now with the drop indicator the spindle reads linear movement as it moves into the indicator body this instrument should always be mounted perpendicular or at 90 degrees to the surface being measured you can get the stylus to move if you amounted say 85 degrees but the measurement will not be correct remember this type should always be mounted square to the surface being indicated at hofs we routinely calibrate the company's supplied indicators it's a best practice that keeps our indicators accurate you'll find the next recalibration date printed on the indicator's case now if you drop or shock an indicator you definitely need to get it recalibrated immediately and you should also get it recalibrated anytime the readings don't seem to be quite right while they're designed to be used in an industrial environment it's important to take care of these sensitive instruments put them back in their protective cases when you're done with them don't subject them to coolant or any other liquid if you do get liquid on your indicator wipe it off immediately take care not to bang them around and definitely do not drop them if you give an indicator a hard knock get it recalibrated before you use it again and now you have an introduction on how to use a basic but critical tool in the machine building and machining businesses

Channel: Haas Automation, Inc.

Views: 15,166

Rating: 4.9157896 out of 5

Keywords: CNC machine tools, CNC machining, Gene Haas, Haas Automation, Haas CNC, CNC, Haas, haascnc, machining, manufacturing, cnc machines, cnc mill, milling machine, cnc machine, cnc milling machine, machine tools, lathes, cnc machining, rotary table, cnc machinery, cnc machine tool, boring bar, cnc machining center, cnc cutting machine, haas automation indicator basics, haas test indicator basics, setting up a test indicator, haas training test indicator setup

Id: Iucf8DW5XMs

Length: 5min 18sec (318 seconds)

Published: Wed May 05 2021