hi folks the infamous heimer 0d taster most of us just call it the himer what makes these so magical is not only are they incredibly accurate but they have the ability to measure both your Z offset as well as X&Y; unfortunately we did something really bad we hit psycho start and spun it up to 0,0 rpms I assure you it was not for the purpose of making this video but it does give us the chance to tear one of these apart take a look at how it works and let's see if we can fix it disassembling what five thousand rpms didn't disassemble for us we'll start by removing the TTS Arbor and we'll remove the eight socket head cap screws at the top of the himer unit so why are there eight screws all the way around the periphery of this ring is it typical German over engineering or is there a real reason well there's actually a real reason the way you indicate in a heimer tip as you induce stress with the four set screws that are perpendicular to the shaft that mates into your TTS collar and your spindle and thus you are skewing or canting the whole body of the himer to align that probe tip this is a process you must do when you install a new heimer tip and you should do periodically even with an existing installed tip those eight screws around the periphery of that ring and sure that the stress that you're imparting with those four set screws pushes directly into that stud instead of causing that ring itself to flex after those eight screws are removed you do need to be careful as you're pulling this top bracket plate off of the heimer unit it's held in with some tension and when you do pull it out there'll be a spring right behind it next up removing the four set screws that hold the face or the dial in these screws are very small so I recommend packing about just enough to remove the dial indicator face with the dial face removed you can use a screwdriver to remove the aluminum insert part and after that the black plastic sleeve and the ball bearings will fall out again just be careful here I recommend doing this over something like a red shower bin or a plastic box just in case you drop anything you don't have any parts for ball bearings rolling across the floor so with the unit disassembled the first thing I wanted to do is just see how the dial indicator mechanism felt did it seem like it itself was damaged in this process and if so was that something that we were going to be able to repair fortunately the dial indicator does not appear damaged it was a very free moving feel and it did not stick at either end of travel or anywhere throughout I was perplexed though because the 0,0 rpms was a very efficient way to remove the face I wasn't exactly sure how to get it back on and fall I still don't exactly know how it came off I have realized it to get it back on we are gonna have to remove the snap ring that's holding the clear bezel onto this frame that let me take apart this stack of parts that was the clear bezel the ring as well as the printed piece of metal or paper that has the markings on it there are three Springs I would call them like a leaf style spring that are used to hold that bezel in place they were bent which I'm guessing had something to do again with the face being removed at 0,0 rpms we did have to bend those back into place carefully lifting up the high Murs sort of second hand or the longer thinner hand with a pair of tweezers to slide the marking ring back into place luckily it was able to be flexed without permanently deforming so I don't think again we did any risk for damage here where I did really struggle was if you look at that stack of parts on the piece of paper above me there's a ring a tapered plastic bezel the clear bezel and then the lock ring it was very difficult to get all of those parts to nest into place and I don't know if that's my lack of skill and experience or whether it's because of some other damage that we did to this unit the o-ring is an important feature to the protection of the internal mechanism against dust debris and coolant but it's probably not critical to assembling this unit back together just to confirm if we've even kind of working heimer left since we couldn't seem to get it in we left it out for now the other problem we have is we sheared or snapped off the threaded stud that holds the replaceable himer tip into the heimer body this is an incredibly critical because having the heimer tip mate squarely against that face is key to its repeatability and its accuracy but we're trying though is using some jb weld and trying to put that screw back into place using a brand new himer tip to hold it in the correct location once that glue cures that threaded stud should be back in the right location the right place and should have enough holding power for a normal use of a high mer meaning when you don't turn it at 0,0 rpms the biggest pucker factor here is making sure we didn't get glue on the portion of the threads that we needed to use the trick I like to do as well on any glue project especially a critical one is I leave some of the extra glue on a piece of paper that way I can confirm when I think it's dry that it did to get a good mix and a good cure testing out that fit making sure again that those two phases seat next to each other the stud is securely held in place I think we were okay however spoiler alert we were able to fix this heimer on the z-axis I'm struggling with its ability to handle X and I think that the damage that we did to that piece there may be a cause of that issue so exactly how do these Hummers work the Z motion directly up and down was quite simple and really no different than a traditional dial indicator but how is it magically able to also accurately measure X and this piece is the key we'll call it the slider and I've got it crudely modeled up here in fusion 0 our himer tip would connect to this face right here and this hemispherical section here mates into the body of the himer allowing it to pivot and in the traditional Z motion the slider will travel directly up and down so how does that same slider also give us the X Y well the key is how it interfaces with what I call the cage the cage is actually two separate pieces the outside sleeve has the ball bearings and it's this internal plastic piece where the magic happens and like so many amazing things in life beauty is in the simplicity any idiot can design something complicated all it takes is a hemispherical shape inside the top of this cage as you can see here outline in blue or in fusion if we do a quick section analysis like so so when the heimer tip is deflected in the x axis and push this way top ball on the slider actually against the inside hemispherical shape of the cage and pushes it up and the spring resting at the top pushes it back to center when the tip is not contacting something the center ring of the cage also plays an important role in providing some amount of resistance or a default state to keeping the tip of perpendicular that way when you're measuring and Z you're moving the himer directly up and down and the tip will not deviate in an X or Y starting reassembly the tricky part here is number one make sure you put the aluminum piece in the correct orientation and then number two that's a really small screw so getting that screw started in that hole and then lightly screwing it in to secure that aluminum machined part into its housing cage we now use those four screws we showed in the beginning of the video to adjust the run out on the high mur tip very similar to a four jaw Chuck pro tip get two two millimeter hex wrenches that allows you to tighten one side as you loosen the opposite and be careful these have a very limited range of motion and they tend to get sticky so it's easy to kind of cause one to pop and you don't want to over tighten these so this takes a little bit of play and I try to start with them all kind of in the out position or lightly snug that way I don't end up in a situation where I've tightened one too far and I'm out of adjustment range I like to use a tints indicator find the high spot and put that high spot facing you that means you need to tighten that screw as you loosen the other one and I just out half the distance and then rotate again and then rinse and repeat when you've got the total indicated reading or run out down to a number you're happy with you can check all four screws to make sure they are slightly snug basically not loose but nothing needs to be quote unquote tight here or really torqued down and in terms of what is good enough so the question is how accurate is the work that you're doing I like to stack the deck in my favor and get that pretty low and if you practice this it really shouldn't take long to get it down to 0/ maybe even 0/ anything tighter than that I think is probably of marginal benefit if you are trying to encode some really tight tolerances there's a number of other things you need to be aware of or think about including checking the run out of your spindle and clocking the himer within the spindle so that you insert it at the same orientation each time the next thing that we need to do is we'll recalibrate the high Murs zero every himer that we've owned has had a compressed gauge length of four point seven six eight so using our height gage will compress the himer tip to four point seven six eight and then use the four screws along the periphery of the dial indicator face to ensure that when you're at that height baheim a reads 0 RZ repeats as one would expect quite accurate quite repeatable was very happy with that unfortunately I can't get the X or the Y to work work consistently thousandths of an inch off we tested that on both sides of the one two three by repeating that measurement putting up another one two three block so that our X moves were all positive which would take out any backlash or lost in the machine of movement and it's clear that it's just not right I suspect that problem ties back to one of the internal mechanisms possibly the great piece that has the hemispherical bowl on it and the next step would be to send these off to himer you can't send them in for repair my understanding is it is a fairly expensive and lengthy process so my advice would be don't run in at 0,0 rpms hope you the folks learn something hope you enjoy take care see you soon
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