How To Repair A Dial Indicator

I tin can add some important information that might save you some headaches that the swain in the video had no way of knowing. If you cease the video right about 3:09 you'll notice the small-scale hand isn't on either side of the zero. This in and of itself isn't terrible merely information technology tells me he didn't pre-wind the mainspring tension before reassembly and his indicator will absolutely not be authentic in i direction.

99% of the time the shock from a dropped indicator will either damage the rack and or pinnion gear (rare) or only pull the master gear (sometimes referred to every bit a pinnion) away from the rack so that the main spring tension is released. When yous repair your indicator it is important to await advisedly at the gear contact points. If you see damage as shown below, supervene upon the damaged office.

Assuming you lot were lucky and there is no damage check the action of the stem to see if it moves freely inside the body. It is almost impossible to curve a stem because they are very difficult, but the plunger tube the stem passes through can become disoriented inside the indicator torso and may need realigned. It's not every bit scientific as information technology sounds.

The indicator shown in the video did not require the hands to be removed earlier getting to the screws nether the confront. I have never been so lucky in all the years I've been repairing gauges. You lot tin can buy a cheap hand puller on Ebay for $5. Of course you lot tin can try to remove them another manner, but don't curve the stem!

Before reassembling the face you lot have to pre-wind the main spring. This is done before you put the face back onto the body by rotating the large hand while you watch the mainspring coil to run across that information technology is getting smaller with each revolution. If it's getting larger in diameter you're turning the incorrect mode. On a test indicator I give it almost 6 revolutions. On a dial indicator it will always be a lot more than. In the video he should have rotated the big mitt to tighten the primary spring until the modest hand was approaching the zero and the big hand was nearly .04" away from zero. (I'm assuming the hands were still timed) You lot want the hands to coincide then that they both are at zero at the same fourth dimension. It'due south easier to do if you took the easily off showtime.

Once y'all have the leap tensioned keep your finger on the large hand to hold the spring in the wound state while y'all reassemble the face to the body and get the rack and pinion meshed. Put some screws in snug and piece of work the stem and listen to the gears. If they are noisy, loosen the screws and move the face slightly until they repose down and then tighten them and reassemble the indicator.

I test my repaired indicators on a special calibration fixture called an "Indi-check" through out the range both forwards and backwards to verify that all the problems were constitute and corrected. Dropped gauges do the darnedest things sometimes.