Chuck backstop

so I come back to a shop everybody that has leaf for a certain time and thus work with it most problem you have a thin disc shaped object and you want to clamped up in the Chuck like this and you want it to run true and in many cases you want to check it on on a very small amount of material and there are a number number of different ways you can do this the most common ways to use set of parallels there is slightly lower than your truck Charles dropped apart on top of it press it down clamp it and pull out the parallels don't forget to pull out parallels the impact that parallels a new chip pan is one it's quite noticeable and everybody will notice it also if one of these hits you in the forehead yeah so that's one way normally I do it that way but the parallels are especially when you use the reversed jaws when you have large disc-shaped object this doesn't work very well other people use a ball a ball bearing mounted again on a stick clamp up in the tool post to push against the part to make it run true but I don't like that very much that's not my style and then there are Chuck spiders they look like yeah it's a disc that's milled out to fit over the jaws and provide support for the part and Posey stop is a very non brand for those Tom let me showed how to make one yourself but yeah I also don't like that stuff cause it's very material it takes a lot of material to make them and then I saw Robert Robin run SETI's videos on the caliper modifications where he showed this this guy here this is just a screenshot printed out in my notebook for future reference and what he has is this stop here is gets clamped against the Czech body with this clamping piece here and this can slide in and out to accommodate different diameters of parts and the height can adjust it with these screws they have hex heads we can manipulate them with a small ranch in the body of this backstop is slit and has clamping screw so you can lock this screw in place at least that's how I interpret this 10 that thing and he shows the setup in his in the video I mentioned I will also put the link down in the description this seems to work very well problem is ah my life uses a hundred twenty five millimeter Chuck what's that six inch 6 inch Chuck and the jaws are pretty pretty small and there is not much space to make adjuster a backstop like this with the height adjustment built-in well I'm going to build this something similar but um I make screw in height adjusters with fixed length I will make them so you're just screw them in full length and then they have a fixed distance from the top of your jaw they will be surface ground also the same height so precision is not a problem and the remaining design is the same I will the sliding body and the clamp screw to you chuck and a row of holes so I can accommodate every possible Andrew when we go over here there are some design iterations I started to sketch out my Chuck jaw and the block next to it some some more iterations and this is the final the sign that I came up with what you see here is practically a view from that direction on to the Chuck Chow this is the cross-section of the Chuck Chow next to it we have this plaque with a slot cut into it and top off the of this block screws in we standoff which gives our support for a park and next to there is this block with just a clamp that engages into the slot and gets screwed down with 2 m4 screws and holds this whole mess together that's what we're going to build I already picked out a piece of tool steel out of my bin tool steel precision ground precision ground to steel or ground tool steel is quite expensive and I really keep every small drop of it that when I buy a piece and I have some leftovers I just drop it in here and this is always a good source or some cereal phones because I don't like to use mild steel for most things because soft and the tool steels machine generally quite well if you don't use 123 79 which is d2 to steel I think and that's quite a mess to work with but this one 2767 machines quite nice and it's stupid easy to harm well that's what we're going to use this piece off 10 by 10 with some grinding alarms so I think I will keep the parts soft in a soft state so we're going to grind this piece down to ten by ten and that machine parts out of it so I have the piece of tool steel all squared up and to size the actual dimensions not really important but I ground it to ten roughly ten millimeters so at least caliper precision next step before we cut it into the three single standoffs is to machine the slot into it so I don't I don't have to cut three slots okay I have to clamp the part directly onto the table of the mill because my Weiss is not wide enough to support the whole piece I tucked down the part of two clamps already I will add two more on the other side after I indicated it in and I have this clamp here tightened down very lightly just just so nothing flies away and this one is only that down with fingers so I can move the part with my small copper knocker and have my dial indicator back here give it some preload move it to a convenient number like zero and let the table Traverse with power feet that you can see we're dropping so the part needs to go that direction and you just knock it until you hit your zero again you you might have to adjust it slightly when you get to the end there we go zero here that's plus one you might have to do this two times because due to the rotation the dimension change but we go back to zero over here that means we have one hundredth of a millimeter bow in the part which doesn't matter at all for this purpose so now we can tighten down the locking screws completely and we just moved the part as it seems double-check it I'll go back at zero slightly slight bow and apart that's perfect and that's how fast you can indicate parts on the milling machine it don't have to knock it around on to it when you start to knock parts around on two sides while measuring you will never get it straight at least not in a reasonable time that's also the reason why I don't have keys or alignment pins or stuff like that in my Weiss or my rotary table I like to indicate every piece every time I use it that way I have two advantages first of all I get always the precision I want second I get pretty fast at indicating you saw this didn't took two minutes now I know my slot will be in line with part so indicate not a line so using the edge finder to find the scent on the workpiece touched up on both side then I'm using the half button to Center I just have to crank back to zero now and my tool is exactly in the center of the workpiece I'm using a four millimeter - flute carbide end mill cut this slot dry without lubricant this works just fine it took a few cuts to get to go to full depth and then actually met the size here I'm using a six to cover down milk to clean up the ends of the workpiece just take a skim cup I do this before I saw the pieces part I used two caliper and a pen to mark out my cup lines for to cut it apart on the bandsaw and finally I got round to make a table for my band saws I can use it as vertical bands so as you can see I'm just using a piece of particle board as a table right now the sheet metal has not arrived yet the song pieces get back on the mill against the stop and cut to final length using roughing and you know the casters and it was quite a lot of material left on I'm using a spotting drill there's one of my shop ground spotting drills to get the positions of those radicals for the standoffs and tap drill three point three millimeters using some water soluble oil and then power tapping for millimetre thread running at I think 100 rpm for such low quantities a tapping head with the total overkill by tapping with the quill and reverse of the motor they're just fine tempering the edges of the hole getting a nice counter bore so the threat doesn't get cooled out over the surface and using my tempering machine to deburr and chamfer all the edges of all the pieces I made so far just a very small point five four point 75 millimeter chamfer okay that's slowly coming all together I finished the sliding part which have the back stop screw right now it's just a normal machine screw in there and these will go next to the jobs them off-camera I already made this clamping profile which has the step milled out and goes next to the sliding part here and will of course be shorter and it will be screwed down with two screws and it will lock the sliding piece in place and as you can see they interlock like this and the clamping part is relieved down here and there is only a step back here contacting the chuck so there are some some clearance for clamping and as I said these screws are just a placeholder so next step will be to cut them apart into individual pieces I will do that on the bandsaw again since I have the the bandsaw table cutting up such small pieces gotten way easier it's easier than trying to check it up in the giant Y softer the bandsaw in horizontal mode it's easier just pushing through the saw blade okay cleaning out the whites with compressed air and now I'm machining the clamping pieces to length as I cut them before on the bandsaw again run your six fluid car ride a mule and now this is set up to drill the screw holes to mount pieces against the Czech body always make sure everything is clean you don't have chips on any clamping surface or you will embed the chip in your part and lose precision of course I took out the parallels because I don't like to drill into them it's pop drilling clearance hole four four millimeter screw and counter boring with six-millimeter and mill normally a counter bore for a four millimeter screw would be bigger but this parts a bit small and I don't have space for a full-sized countable so I have to turn down the heads of screws slightly okay I turned down a set of screws so I can mount these blocks to the chuck like this and now we have to take the Chuck apart and drill tap it down we should better not mess this up a proton tap in the chuck body would not beat a true first I have to figure out where the holes go because I want to I want to have full range of adjustment here let's take this guy apart first you have to get the back plate off okay that's how normally every chuck looks when take it apart or take the back plate after is always third in it and in here we have the truck body I think I'm going to throw all these into in the ultrasonic cleaner to get most of the dirt out I to grease them to a certain level okay we're over the milling machine and I want to set the check body up on the rotary table so it can drill the holes and our rotary table is obviously too small to clamp down from the sides with studs strap clamps so the next obvious thing would be to to run a stud through the center and have a big Walker or strap across the hole to clamp down a single bolt will be good enough so doesn't move on when we drill it but the rotary table head of course knows Fred and wholeness centered has only a more steeper to socket so what's what what should I do the easiest solution is to take a strap clamp that has a threaded hole in the end normally that's for the jackscrew to level it out but you can also use these to place a to move a thread out from your camping position so when we screw down this strap length here on the rotary table now we have a threaded hole in the center of the rotary table I can droppin a piece of threaded rod take two parallels and I don't know if this is if everybody does this but for me it got totally to be a habit every time I pick up a parallel or some other set up gear I run it through my fingers first I will remove any minor pieces of dust or grime dust or debris or chips and I will also feel if there's burr so I don't have to stone my parallels all the time and we can take our Chuck also wipe it down and drop it over the threaded rod now can't camp it down very very easy from the center like this water and a six millimeter flange nut and as we're clamping on machined surfaces piece of brass shim stock can't hurt just tighten it down very lightly we still have to align it to center of the rotary table indicating the Chuck body on the rotary table looking for the high spot and going half the after indicator sweep in the other direction that's a pretty fast way to get part centered I have to Center the spindle of the machine over the part and I'm sweeping the outer diameter of the Chuck a mirror is always helpful if you do that I don't like the coax indicators very much I prefer that I'll test Nicator now I'm aligning a one of the jaws slots with the travel of the axis and I drill my tap holes for the m4 sweats maxing just with the dial through next pair of holes and of course I'm using the depth stuff because I don't want to break through into the housing of the truck because that way a lot of dirt would get overtime into the Chuck and then power tapping and for threat against the stop quill stopping metas this is operation you have to be very careful okay um you saw me just threading the holes for the clamping pieces here and I already put it back together at least partially of course there is still all the internals of the track missing but just to give you an idea how this works you use crew D you mount these backstop onto the truck body and you can adjust it wherever you need it like this and then you clamp it with these two formal meter screws I'm going to tighten this down only a bit you have no chance that these parts will move okay I'm machining three of the first fixed height standoffs and they're just turned from six millimeter drill rod four millimeters thread on one side thread relief and a hard shoulder here the shoulder is very carefully faced then I parted them off to be a bit longer than I need them and I didn't bother to clean up the other end because I'm going to harden them and then this side will get surface ground so they all are perfectly the same height anyway so no need to do any more work than needed after doing right now machine a five millimeter hex on the on the end of the standoff so we can screw it in with with a socket or a small wrench and I'm just doing this by manually indexing on the rotary table and to get them to the same height I'm using a parallel here on the Chuck body and I will part rest on the parallel with the shoulder that I machined like this holding down the parallel with one finger pressing down on the part with the other finger and tightening down the street-- chart check with the other hand just snug it up remove the parallel and cut the hex I'm just indexing every 60 degree by I okay I have to spruce finished and I hardened in this torch just winch them in water and then yoke them back to be not as hard I took one of the sliding pieces off the backstop out of them Chuck and we've all used that to grind these three standoffs to exactly the same height as this block is surface ground to be precisely parallel when I was crew all three of these standoffs in I rest this on the magnetic chucking surface ground over the top all three will come come out perfectly same height just snug them down okay now can go to a surface grinder in different take a cut over the top okay setting up the part on a surface grinder I'm using a big parallel behind my part and I use a small Y script to clamp the parts together because the stop piece itself has boot has a very little surf face and I want to be on the safe side I'm also putting a parallel behind it as a stop or in line with it as a stop then it's just a matter of plunging down with the grinding wheel until we hit the right height lunging down and then traversing over the part to clean up the surface a quick check on the height of the standoffs with the calper this dimension is not critical at all they only have to be the same height now I'm at the life and I screw all the standoffs into the truck using a five millimeter socket don't over tighten them and now I'm checking with the dial test indicator against the face of the standoffs if there are all the same position when mounted on the lathe first one is zero second one zero and the last one zero and that's as good as it gets okay and with these back stops you can allow clamp parts very act very accurately in the Chow in the truck without any run out in the axial direction because they are all the same height and I can make them to any length I need for any purpose so I'm very flexible that way I like the setup this is really this seems to work quite nice and tons will show how it fares and practical use so okay there are a few pictures this is with the internal step just holding a large piece and here I'm using the back step already to machine a big washer I did code blue all the steel parts and I made a few more of these standoffs in different heights and that's the complete set right now with the allen wrench and a screwdriver to use it and when the stop is not mounted I'm closing these threaded holes with some set screws hope this was interesting for you thank you all for watching and see you next time

Channel: Stefan Gotteswinter

Views: 83,474

Rating: 4.9466019 out of 5

Keywords: chuck, posistop, backstop, anschlag, drehbank, lathe, surface grinder, optimum mb4, rf45

Id: 8czgFc5Avcs

Length: 31min 54sec (1914 seconds)

Published: Sun Oct 30 2016