NIKON COMPARATOR RESTORE

hello everyone.welcome my shop I'm Robin today we're going to be taking a look at the nikon compared to rebuild I've done and this isn't a complete rebuild of every single detail of everything but it covers some of the interesting aspects of what I had to do to rebuild this got this very cheap and it turned in a really really nice comparator and extremely useful and as most things I wonder how I got away without one for so long so let's get to it here's the comparator in its final resting place this is the right-hand door which I never opened to go into the shop and so I can just pop my head out the door from the shop there you see I've got one of these folding a wide folding stool to stand on because this thing was made for Giants my eyes are a little bit low on the screen for viewing this without that stool so everything came out really nice the table will reground you see in place and micrometer head the Vblock degree ground generally really pleased with this thing has a huge 15 degree helix angle adjust which most compared or some compares I didn't have a helix angle adjusted some of them do have a very limited range and the back dovetail there you can see in place and we've seen all the redo of the ways new fasteners new paint on the panels little bodywork on the panels to get them get them all the dents and things knocked out Jorgen is working nicely and then we'll come down here and take a look at the lens drawer and this has nice pockets for the lenses where I can just reach in and grab like this but the ends are protected that the plastics actually snug on the ends 10 20 50 and 100 the 50s right now but this keeps them totally protected they're solid but yet you can just grab and you're not unwrapping them taking them out of a box and I like carrying on so always thinking of ways to make things efficient that you don't hesitate to do them because they take too long this used to be the end of the comparator where the door was and those kind of cabinets are in my mind just a total waste of space you stick a few things in the front you forget what's in the back and that's why we integrated the two drawer units that I found at a home home goods store and you'll see some footage there where I put those in the micrometer head just needed some cosmetic work redid the zebra stripes on this display and it's real happy it's a two inch travel and zero whole inch metric reads one micron in metric 1/10 an inch so a four inch travel digital indicator this sales flyer and I realized that would be perfect for this vertical travel because it's just about like 4.1 inches for stop to stop with this thing so that really worked out nicely and now gives me digital readout on both axes these are pictures of the comparator that I saw from the industrial supplier that had it and in general it looked like it was in fair condition but I could see that the rust was on some of the areas that indicator never showed up so I got a a credit for that there's the cabinet had several overlays in there which was nice you see the lenses on top in general the whole outside was not in too bad of shape main problems were the rusty table and the rusty vertical travel system there you can see it's really bad was was very very rusty so here you'll see coming up the how bad the rust was on the rollers those are the two millimeter rollers and then there's a picture of the whole thing with the rusty right now we're looking at the main reason why everyone but me stayed away from this comparator the plague and that's because the main travel waste system of the main tabletop well it's completely trashed by rust this actually looks immensely better than it did this was all bright orange rust and this rust is fairly deep but I don't care because this is a roller system where it uses four millimeter by 25 millimeter rollers in here and they were completely rusted this was pretty rusty but cleaned up pretty well the cage this holds the rollers in alignment and keeps them perpendicular to the axis as travel so they don't track off and then these are the little cages for the two they're the two sides of this I believe it's maybe 60 degrees I haven't actually measured yet but these go on either side holding two millimeter by seven millimeter rollers so this forms a roller table system so it's very low friction there's two constant force Springs that sit on here that pull the table against the micrometer to maintain position so this is simply a matter of regrinding these surfaces till they clean up on both pieces re-establishing the height of them such that they actually bury evenly because they have to be just right that you get as these sit properly this is parallel so you've got two millimeter gap here four millimeter gap here and until you get those Heights exactly right these rollers are going to hit one end or the other until you get it parallel where they're hitting dead-dead parallel across there and you get full even bearing so that's about the only tricky part about doing this regrind is is maintaining that I can dress that this is the focus axis of the comparator this is the swivel base that sits on the knee and allows helix angle adjusted pivots on that and slides with a circus and then they're using a basically a ball v way type arrangement where they've got four five sixteenths we're eight millimeter ball bearings a hardened rail and then in the actual iron base here they've got spring steel inserts and as you can see here we look at the actual surface where the where the balls right you can see that well number one this has had rust but also that line contact is you know isn't the best for the focus axis you know it doesn't really matter that much but you want to be consistent so I just happen to have some six millimeter crossed roller packs now these are about seven eighths of an inch shorter than what I need but I can cut it in half put a 7/8 spacer between these and this line contact cylinder on plane as opposed to ball on plane will have much much better load capacity and everybody will be much happier as but here's the dovetail where the rust was on the dovetail section and here's after I stone with precision grab flat stones and wd-40 so I'm walking through the home goods store with my wife and I say these cabinets they had casters on the bottoms and all the handles were on there alright had the wife strip them down two of them they're sitting there one's got a dent in the top and I look at it and I say well what $29 I'm just I haven't even got the comparator yet it was it was I bought it but it had not arrived yet and I said you know what I think those little darn-near fit two of those in sideways in that comparator base and then I'd have tons of actual usable space you know drawers for lenses Jory you know whatever inserts any kind of relatively light these these don't have fancy drawer slides or literally just sheet metal slides but they work reasonably well so that's what I'm working on I'm going to actually insert these two in there they using Lee roll install to split this square plate into two corner pieces for the casters really a nice big cut because it was cut long ways a lot easier on the on the blade teeth also never got all my corner plates stacked how to caster on their located with some clearance for the silicon bronze rod billets that will be holding this to the sheet metal I've gotten my upper right corner set a zero and I'm gonna drill and tap through all of that right in that location and then others crank off the actual bolt or the slot spacing of the caster there we go all four holes tapped now we just have to make sure we put them on the right direction flip them the right way so we have the casters are in the correct location on the base there's the frames from the two drawer units tacked together tacked into the hole I cut it in the wall of the old cabinet it's all bronze things braised and now I'm going to drop the bottom in that I've already pre done with the quarter inch thick reinforced corners already drilled and tapped flattened and that's ready to go so that's nice and flat and just gonna sit down sit on the bottom of the units so that actually will support the bottom those that's going to sit flush on there and then I'll get spot welded and take braced into the base there's the bottom before I get ready to prime it put the casters on take praised the support pieces in and severe bondo job I'm making this look like a million dollars compared to that original well d so yeah I'm gonna put the cancers on it flip it over and put some paint on it here's the base I have all the sides filled in body putty but the top is a really wobbly mess so I'm just put a painting taste dam around the outside I've got and I'm pouring in some potting a compound that I had left over from a jobs and that's just going to level out this top it's probably got undulation maybe as high as an eighth of an inch so I'm just going to pour this into a better grip this stuff's very fluid and we'll be self levelling and should have a mirror finished top when this is done but it's going to get painted over this epoxy flows very slowly so this is sped up a lot you can see how it just wets out and just flows and you'll see my reflection there there's the cabinet with all the bodywork done and a fresh coat of paint here I have my Renzetti 30-60-90 blocks aligned and indicated in on the grinder getting ready to do the dovetail grind here's the traverse across there basically just a jiggle of the needle one of 50 millions indicator and I've accomplished that by putting a shim in the bottom here and adjusting its position so that I can tweak the the setting there I thought this was a 60-degree dovetail because I had these angled blocks that were sitting on her exactly 30 60 but it's not so I have to shim to get that angle correct a bar and toolmaker clamp that you see there in the middle is where I'm pulling a slight bow out of that dovetail so that it's actually straight on the flat mounting surface if I didn't do that the they would end up being not uniform across pin measurement on the dovetail when it gets bolted to the mainframe so you'll see me tweaking things here just watching how it's grinding and gently adjusting this till I get the response that I'm looking for grinding wise yeah this you can mess things up easily doing this so be careful if you're replicating this I'm used to tapping these things around you know how tight I have it so I can get away with just nudging this and seeing what the what the grinding wheels doing then once I've got this happy and I Traverse and do a full traverse grind across there to grind that face so it cleans up and there it is finished ground here I have the part clamped to a two four six block so that I can measure over pins to see how parallel the grind was from end to end [Music] [Applause] and make sure it's not twisted in this knot it's nice and flat she's reminding us in on a point sisters actually 60 degrees lot quicker to just consume 30 60 90 blocks on to use indicate in we on this and moves you can see how at that room to clear the in grinding we are here directions to clear the wall and get into the 60 I'll be able to flip it and be a hundred knees look and viewers top which gives it better for this edge moves the second operation you see we have clearance but in each case I this back surface has been indicated in so it's dead nut so that's 0 0 orange one that 60 degree surface in on both of my angle plates back here so that's already been tram din toolmaker and I'm fortunate to be able to is grab relief I'm actually using the V way for that was for the focus travel and that's what that's what we're clamping with so that we don't distort and we have a good grip without being in the grind zone so grinding on this face at 60 degrees I have to adjust in this axis to get that face of the original dovetail to line up the backs of line but you got to get that lined taking one thousandth off this face actually off both faces one thousandth off each face will require mm removed from that surface it's just the trigonometric relationship of those two surfaces so I'm going to remove a thousandth off the bottom there and then there's the finish ground surface and we'll move over the other side I've just flipped the part and we are indicating it in again and we've indicated on the back surface back here and make sure that that's aligned in that direction and now we're going to remove one thousandth off of this surface and you can see we're clearing wheel there and we had to adjust the twist in this angle to get that to line up properly and then we go ahead and remove a thousands from that face and there's the final grind of the female V now we've moved on to the table and we're doing the male V on the table and we've indicated that in and we're grinding one thousandth off that face [Music] this indication edgewise when you're doing something on an angle plates like this is very important you need to make sure that angle plates are indicated but in this direction you have to pick a reference you're going to use to align especially when you're flipping apart so I'll use that exact same edge when I flip it to make sure I've got these acts 8:1 because that definitely influences where you're grinding here the actual alignment of that group so even though the setup looks like it's wicked dirty but you have to really impede things in very well in all directions here was indicated on the actual tabletop zero-zero meeting there so with the edge up here and this space run both running through though we have the axis of this burning tree so when we grind this actual way surface here if you're ever wondering why I think these modified play scripts are so cool this is a fine example I lost you here and yet still have proved to get off over the port under the edge like that these things just really coming in so now we're going to take a look at the indicator try to do this or not as I indicated sitting right there and now I'm going to reverse my my marks here other mark state places that I market before on the up and that is the opposite direction you can see what i'm doing here i'm making sure I've got the exact same tram so the access that I grind this base of this way is going to be parallel to everything else there's the last perfect ground they put up we're going to grind the flat nail where the purple Sharpie is and you'll see how we align that we're grinding the flat way and we've removed mm from it and that gives us the relationship of the mm so on the flat to the one-thousandth on each side of the 60-degree v just in case you think mr. Puzder never shows up in our shop this is where the thought and the real sucked it through push the wheel off center on the hub and then took a swipe on here fortunately because this is a roller set up here it's not gonna cause any issues functionally and it's out of sight so at the end of the world that's not happy about it so now we have the saddle mounted on the tape on the grinder table and the comparator table that's been finished ground sitting on top and I'm grinding the flat of the saddle to the right height so that as we Traverse we will get parallelism like once we get a ground to the right height and since the two to one relationship of the 60-degree V and the antutu one relationship of the rollers that were being used allows these to sit metal to metal and as you can see we get a nice parallel Traverse there when it's ground to the exact right height so changed my mind and I'm going to make the actual bearing Strip thicker to make up for the difference from the eight millimeter ball to the six and a half millimeter cross rollers so looking around the shop for something I want to do it now I want to get done today looking around for some heat treated material that I already have so I have to get caliper bodies I know you guys are gonna cry but I have lots of these laying around from stealing the heads off them before we started buying the heads separately as a repair item for digital readouts that make for special grinding equipment so I'm going to whack these off here and here and grind them down to a seventy-five thick which will split them in half and then I'll grind down to my three sixteenths wide and those will be my bearing strips [Music] more sacrilege here where's what the grid pattern looks like on the on the calipers underneath decoding pretty neat stuff these are filled off back so now I've got my two places where I'm going to be able to get my 75 by 3/16 wide strips 150 millimeters long out of some reasonably hard material I ran a cut-off this we've got a pretty that's right grooves in the calipers discrediting half ocean and then take it down to the 316 squad first they'll take a done deal 75 we shift look like when your class small koala material yeah they are got down to 3/16 thick we call the hair among hairy fibres I feel about that would be the thickest hey Eric down down to 75 pick both sides parallel here I'm grinding a little notch in the rails that is clearance for where there's an m3 screw that holds these rails tight into the V groove in the cast iron so I have to put that on all these as one of the cross well in this case going to be cross roll or rail and I've just dusted this face and I just used my v block I have the outside surfaces of the rail stone nicely take this out clean everything put this back in Brian the other side did the same with the other so these are exactly centered and they because they are same depth to the back which really doesn't matter but that's how we clean this rails up it only took a few thousandths to get rid of the rust and get a really nice grind finish on there for those new roller packs to ride on some of these large headed screws that are used to hold the panels on the comparator were damaged that we actually smashed shut and some of them have Drive you know swell from it the bit not being engaged properly and in my mind when you're sort of restoring something and what the appearance to look kind of new there's nothing like a a nice new fasteners to brighten things up and I'm not a fan of Phillips screws if I can avoid them so I got these flanged head butting heads to get the diameter to be big enough to be a corollary to the to the ones I'm replacing and it's only like 6 bucks for 25 of these and I think I needed a little bit more about 2 packages of them so trivial but at the bottom of the comparator they have these which were special screws these are bakelite phenolic resin whatever you want to call it and obviously these didn't survive as well some of the some have got stuck in the threads and this is M 16 by 2 thread so how do I replace these and you know of course I've got lay then a CNC and all that and your first thoughts are oh I could machine these and do the metric thread and turn the heads and but I'm trying to get this thing rebuilt and not make a project out of it so then comes to mind hey why don't you get the same style screw as these I would look really nice it's around the same face and put that on there well that works and obviously this diameter here needs to be at least as big as this one because it has a pretty big hole in it I think these large GRU holes were done for tooling purposes of machining the casting so that's the only good reason I can think of that they would do something like that there's two of them on each side of the panel or of the frame so I get this is the largest that I can get from McMaster and it has appropriate head size but it's not the right thread size so just a lot of people would know this trick but I buy a piece of all thread or a bolt or whatever you you can get that has the right threads aren't this this is just piece of stud sixteen by two stud and I'm just going to throw a tap at the m10 thread here part off a piece such that this becomes an m-16 screw like that with this head on it so not rocket science but not something some people might think about you can take your pick between lock tiding this into the frame and having this screw go in and out or locked hiding the threaded portion on this and letting it stay with the screw really doesn't matter just that one or the other works because if you don't do one or the other you'll end up where this will end up driving through the the threaded portion will end up driving through the frame and not engaging so you need to tie it down one way or the other so you ever have those moments where you go like I was real bright after I get that machine these I say myself oh I bet you'd mcmaster-carr has a threaded insert for this and they're not hopefully to justify me making them I was thinking yeah but they're not going to have the right thread combination of n 10 by 1.5 inside and 16 by 2 on the outside guess what that's standard I could have got five of them for thirteen dollars and 62 cents from mcmaster-carr so if I thought a little further through that I would have bought them instead so just a note to keep in your metal arsenal well the protractor ring on the comparator is out of round I think this thing sat out in the rain for a long time and it worked this I believe this is a casting and has been machined so I'm using the knee of the Bridgeport as a press to gently press this and I've got indicators zeroed here and the difference in diameter reading is of good 20 30 thousandths so I'm going to gently press on this a little bit using the dial on the knee as an indication of how far up like go and until I get a reading of where it responds and actually takes a set and then I'll start comparing the heights of you know as I are in different locations around there to make sure I'm getting as round as possible so what you see here is a broken comparator screen where I popped up the comparator and left it and it fell over and cracked the screen so I bought a disc from the local glass place they cut a nice round disc and I'm going to show you how I engrave the lines in it and frost it so I'm using the calipers here to measure the diameter of the glass and this isn't super critical but it's what I'm doing is to use this to cut the halfway between this whatever this family is I'm going to go in the middle of that measurement for the distance from here to the edge of the glass so that's why I'm measuring that but now that I have that measurement cut them too I've actually moved that the bar until I've got that dimension mm 2 and 1/2 thousands or whatever that the in theory I should account for the thickness of that blade but there's more than enough room for that and not to mention the fact that things probably not even anywhere near that round it's just cut by the glass company but they did a super nice job and there's running down before that maybe on that list and you can see here we've removed all the bevel this is a beam a thousand snick now I'm gonna drive this down to about 4,000 green have four four you can see I've just touched off here on me get my whip that I want I don't want you to do why because so here's our groove lap to cut the groove in the glass this is for four and a half thousand stick where I ground it down here you can see I put these radius scallops in here and that's to give room for the diamond slurry to get in between and actually feed and lap in each of these positions I just left it straight basically the center section would get starved you just have what could climb it at the ends even on the ends I have a bevel there so that the diamond is encouraged to get down under and roll down through there just have a piece of bamboo that I lapped flat on the on a piece of sandpaper on the plate too glued to this to be a backer to hold this firmly and straight against the reference real yeah right here I've just super glued some washers on to have the lap stop at the about 3/8 of an inch from the edge tearing that groove all the way out to the edge is just inviting that plate to snap in half remember we're creating a stress riser in this and we have to be very careful there's no guarantee that I won't get half way through this and have the thing crack through the groove that I put in here so just pray for the best okay we're going for here hold this in place snug a little tough on the outside take an actual travel here and try to get a little slurry lined up on the edge there now I'll use both hands to gently press down and in I'm using the multi and will Mike - Mike over the actual lap to determine how deep the groove is so I put the measurement take the measurement while the lap is down in the groove and then I move the lap up off the out of the groove put a little spacer behind it so it sits on the glass surface compare those two measurements to determine how deep the groove is don't need much just need enough for the epoxy to have a place to embed in the group okay one of the things that I pondered about how to get these crosshairs even though they don't need to be exactly centered they do need to be exactly perpendicular within reason so thought about a lot of different ways of doing it wanted to keep it simple so what I'm doing is I've had this on you've seen me do the first groove first grooves in there it's roughly three three and a half thousands deep now I need to place this bar exactly 90 degrees exactly the centerline of the of the diameter so what I'm doing is I'm putting this block alone I have tape pads under here to contact on the glass I have a clamp ready and a lot of this was strategic planning on exactly where I'm going to be able to put clamps as I move so I have this long clamp realized that okay I'm going to go from here to here with my with this bar I still need it to be able to clamp two places here so I did all that planning beforehand to make sure that when I got to moving to the next position that I would actually be able to do it so I'm going to set this up now with the calipers to have this be the midline dimension clamp this down release the bar here clean it off slide it up tight against this in this direction clamp it down remove the block and they're not the second groove gonna let you know a little secret this is actually the speed I work at all the time and all the rest of the videos is actually slowed down so I just wanted to let you in on that okay I think we're done it clamps off hope nothing pops here in the process of getting the clamps off it's all without cracking the glass I think we're home free oh yeah so see what's going on here let's just take a peek at this there's the lines right there put a scale in here just for reference rule actually rule in here for a reference you can see this lines are finer than a finer than a rule division yeah just a little bit finer than a rule division so now I need to fill this in with black so I'll use some JB plastic weld very very good high-strength epoxy this is like 3500 psi so very very strong epoxy and relatively quick setting blend this up first before I put carbon black in it to blacken it up we're gonna add carbon black to the epoxy to darken it up you have to make sure you add sufficient amount of carbon black the lines in this are only about four or five thousands wide and about 3,000 s deep if you don't have enough carbon black in there it can look dark until you spread it thin and then it will just be kind of grayish so you need to have a really good load of carbon black in there stuff on there so now I'm going to go over and put this on the actually on the glass at an angle here that works without blowing out the camera over your on different angle you well this epoxy is curing it in the gooey state I come along here with the razor blade and just scrape off the excess leaving a strip there that we can just wet stand down until we get to the glass and then we will frost the entire glass with Diamond these are lines after sanding off the epoxy the lines are six thousandths thick red with a little pocket microscope so this is where experience comes in in feel of what's going on knowing what tumbling abrasion feels like as compared to you know a charge lap even though this lap has what looks like a charge that's just where it's been rolling so I think I think this is good where we are here I might put some more diamonds on for this other part then we're just going to start going around the whole thing I switched to water for my vehicle vehicles the trade term for the carrier of your slurry zombies and water here the alcohol evaporates too quick and all we're after something to somewhat lubricate help the help the abrasion process go to town so yeah i switched to water here for that for that purpose and I'm just keeping it wet so that we don't have any sludge sludge going up we don't want to cut with sludge we want to cut with free rolling diamond particles one thing it's difficult is with it being wet it's hard to assess its level of crossing because when wet the frost kind of here [Music] I think I didn't mention is this is a silicon cooking mat and the beauty of the silicon is number one it gets a death grip on this glass so it can't move it also keeps relative motion from happening with any slurry or grit or get that gets underneath and if this is shifting around this would end up frosting the back of the plate and we don't want that to happen we only want frosting on the front front face here where the engraving is there's a section I just cleaned off with alcohol and we've got a pretty nice uniform frost there yeah one thing I want you to see is see all the black that is the aluminum being abraded and that is actually ideal because we know that the aluminum is not charging the aluminum is being abraded by the tumbling action with the glass so that's perfect if I charge the aluminum lap completely washed it off and started cutting this glass you'd see no aluminum residue because the aluminum would have a grip on the particles and there wouldn't be anything to actually cut the aluminum other than the glass fragments the glass swarf would act somewhat as an abrasive so that dark that you see there is actually a good sign that this aluminum and glass is a good combination this is one of those things where experience and thinking about them graphically thinking about the mechanics of what's going on with these particles is important when I did glass on glass you would think well they're equal so everything should tumble but there's the aspect of it that the glass has almost zero ductility and therefore the particles don't want to embed and get a bite to initiate a roll whereas the aluminum being ductile as these various particle Peaks are sticking up they actually poke in the aluminum get enough traction that that aluminum is rolling that particle so that's I'm not saying that's exactly what's going on but that's the way my mind is processing what's going on to make decisions on which way to go the iron was okay which is a little more ductile but the aluminum they performed nicely and initially I thought the glass would be perfect because they'd be equally matched but then I realized after I felt its action and and saw that it was just not getting a good bite that made me rethink it and say okay what's going on ah probably just not enough ductile enough well not ductile at all therefore not getting a grip on the particle to initiate a roll clean this off completely just to see what's going on I can see that there are some stray scratches that are not the perfect uniform frosting here so the outer edges need to get hit hard but I think we're going to need to clean off at the very end and do a very gentle pass on here to get a nice uniform frost the frost looks good it's really nice but one of the things I wanted to mention was very important even though this is silicone even though this isn't moving technically it's got a good grip as slurry and abrasive particles get underneath here if I left this go for too long I could get to wear some relative motion could cause scratches on the back so just as a precaution tip everything off wiped off the back of the glass wiped off the silicone put it down clean again and we'll start over I found a good section here to show you the difference between frosted enough and not like come over here you see that all reflection is gone I come over here on the edge and you can see I'm getting a reflection off the original surface of the glass that's just barely been scratched up you can see the little bit of hazy scratches there and then as we move into the fully frosted that reflection just totally disappears and the light as you can tell the light normally that light would follow as it would go across here so it's not like some magic where the the lights going out it's it's it's gone so I need to hit the outer edge a little more so there it is completely frosted with the epoxy lines in and it's ready to go into the comparator there you seeing my camera through the frosting on the glass and there it is all complete ready to go you can see an image lip there on the screen the projection and gonna be a very useful piece of equipment in the shop

Channel: ROBRENZ

Views: 40,191

Rating: 4.951952 out of 5

Keywords: Optical comparator, profile projector, Shadowgraph, nikon, rebuilding, etching glass, engraving glass

Id: gPo1QBZj1Hg

Length: 45min 1sec (2701 seconds)

Published: Wed Jul 18 2018