Slowspeed carbide grinder

[Music] hey welcome back I'm glad you're joining me today I want to talk about this contraption here there's a slow-speed carbide grinding and lapping machine very much like a Q finish grinder you can look up those via google they're basically a very slow running grinder bench grinder with an adjustable table and some accessories they are a little bit pricey if you want to buy them you and I was very close about this close to buying one new but in the end I didn't and I cobbled together this thing it has a 24 volt motor gear motor runs about 240 RPM here on the wheel it takes hundred millimeter wheels and the wheels have a quick change mechanism denied side they are held on with magnets for magnets here in this aluminum faceplate and to drive pins which drives the grinding wheel and it just slide the wheel in here and it holds we at a magnet and this has already proven to work excellent it's self-contained it has a 24 volt power supply in the base in here and it's running both directions has an adjustable table here goes from 45 to I think minus 20 degrees and it's a shot especially useful to put the final touch on carbine lathe tooling like this this 45 degree I do D chamfering tool can come in here and put a almost mirror like finish on this this edge and in tungsten carbide without any any edge fractures also you can change the orientation which the motor runs so you're always grinding into the edge you want to grind carbide whenever possible always into the cutting edge otherwise you create micro fractures and you end up with a with a ragged edge that wears way faster of course it's also useful to grind carbide scraper blades like this one this is a like a sandwich scraper blade in certain things and you can just do your usual radius grinding on here your freehand lapping this is not for massive material removal this is only for sharpening lapping and also to to to form tiny corner radii on leaf tooling for example I do not only have this time and wheel but I also have a ceramic disc this is an aluminum oxide alumina ceramic wheel or disc this comes out of the chemical laboratory equipment I bought this on eBay and I cannot recall what it was called who the seller was or whatever this is I hope somebody will put the name for these things in the comments you can also buy a real ceramic lamp for for the Glenda grinders but also she look on eBay and you look for gem cutting or stone grinding equipment you will also find ceramic laps and the idea behind these is you charge them with for example 1 micron diamond then you have a crazy crazy fine diamond wheel and as it's ceramic you can easily grind against the cutting edge and the carbide tool will not dig into it because it's it's very hard a lot of people use try to use cast iron lab for carbide but does not really work so well because the carbide will dig into the into the tungsten core and into the cast iron lap if you run run it against the cutting edge that's what you want so I'm going to take a piece of one millimeter sheet metal or 2 millimeter sheet metal and super glue it to the back of this ceramic disc and previously I will have drilled the holes that I need into the steel disc so I can put this on here too and use it as a ceramic lap so I didn't film a whole lot of machining but I have some footage then I will show you and some some construction details I didn't show making the the base here at all this is this is bad ugly this is just welded together on off out of square tubing and I proxied some some dibond aluminum material this is a 3 millimeter plastic with aluminum on both sides in here as panels and the power supply's down here I will show the power supply later put on this bud ugly color this part here is 3d printed in another but ugly green and yeah that's it okay let's say we have this 90 degree tool for life which was ground out of solid carbide and has a large large relief to the bottom here so it can work on the ID and we want to lap it or put a very nice finish on it that means that we firstly blew up the surfaces so we see what's going on and then we come in here and we get an idea how to orient the tool block and then we lap away and after some a few moments you will see black dust starting to form on on top of the tool that means that we're very close to being ready there we go that's the that's the finish we get off this carbide lap or this time in lap now I go to the other side of the tool and repeat you can use some for example wd-40 which helps to keep the wheel clean but it's not strictly necessary and there we go on the other side quite a nice finish not a mirror fit not a mirror finish that's what the Corbett layer of ceramic lab before but we can put a nice radius on the end of this tool now just by free-handing it we can put very nice nose radius and of course we want to lap the top of this tool - that will reverse the direct transportation [Laughter] and we lap like this this takes of course longer because of the larger contact area but that's what we get okay here is a close-up of the labs tool and you can see here and here are the relief surfaces and they have an excellent finish this is this is almost a mirror finish and you can see the radius in front here which has the same very good finish and the top is not not as good it's still pretty decent and very serviceable but here can see the real advantage of the slow speed grinder it allowed me to form this small corner radius without much trouble and with excellent surface finish another very cool application are molded inserts molded carbide inserts with even-even coated ones I do a lot of very small turning turned parts I have to do about 40 very precise very small stainless parts in near future and for those applications razor sharp carbide tools are really useful and you can take a molded insert and grind the micro bevel like here that's a smaller bevel with a slightly smaller relief angle than than the main relief angle on to the in certain and then it's a short insert and that's really quick too there we go the idea is normally the insert here in the cross section you have your relief angle and then you have an edge radius then you have kind of a land or some something else then there is to chip break of geometry whichever the manufacturer does there this is cross sectional relief angle each radius and chip breaker this is what what the manufacturer does especially the edge radius here this is what makes the carbide insert last in a production environment that sharp edge does just not last as long but I have different needs on an insert than somebody who does high production on a CNC machine so what I basically do is i lap away all the material up to here and I end up basically with relief angle land chip breaker so I have a dead sharp edge here this what allows me to turn with very very small depth of cuts and still get a very good finish I usually did this with very fine diamond tuile on deep it grinder but on the slow speed grinder here it's it's faster and easier to do because it can just freehand it so in my in my junk pile I found this motor this looks like a window wiper motor that's the same I used on my power feed of the milling machine but before your concern this is rated for a hundred percent duty cycle so it can wrap around continuous these are out of a piece of industrial equipment that's used in PCB manufacturing so these run all the time and do not fail so I'm going to use this this rounds of 24 volts and it runs about I think 200 rpm it's full speed I I already machined off-camera this flange here which bolts to the face of this motor and has bearing pressed into it and this is to stabilize the output shaft of this motor because it does not have a ball bearing in here it's running in a sintered bronze bearing in here and the nature of load we are going to put on this wheel is a lot of pressure on the outside here and I'm pretty sure that a ball bearing will hold up better for this I also your just saw this this is a chunk of aluminium 7075 high-strength aluminum turn into a disc board to ten millimeters goes over the shaft of the motor this is our actual grinding plate this will accept these hundred millimeter sheet metal wheels that are direct bound diamond wheels there is actual diamond on these this is a thousand grit they are a will bow up to 3000 grit and also have a solution for ceramic lapping well Josh will show you later the way we are going to mount these on here is with magnets I want them to be easily exchangeable so we're going to put three magnets on here and these plates are steel so they will think hold up nicely and we will add two pins to transfer the torque and a central hub to Center it so it's as easy as that so next step will be to drill and tap this plate here for the magnets and the drive pins also we have to drill this motor on the on the in the end of the shaft for an m5 screw so we can bolt this whole mess together I have my aux tools inspired set up lock your device which is tapped for threads up here and I can hang the motor over the edge of this block like this with the flange mounted and use a strap clamp here and a piece of aluminum brass shim stock to bolt it down back here yeah I could take off the wife's and build something elaborate with with a lot of blocks and parallels and stuff like that but this is a quick and dirty set up here I could also take the shaft out of the motor and put it on the leaf and do it there but I have no idea how this gear box goes apart so in my mind this is the easiest and fastest solution and I'm pretty sure this is already rigid enough to do the drilling so I'm not going to do any supporting on this outboard end here let's get the rough position just using the drill chuck there we go rough positioned so i centered the motor shaft which is a little bit tricky because it has a d' shape means a large flat on here oh I'm stupid take bronze bushing on here which is a very close fit I have a full round surface that I can use to indicate it just a cure to me already yeah that's way better that's way easier let's hope this doesn't fly apart [Music] yeah even as this is a warm drive it still wants to move let's add a tool makers clamp as a drive dog just rests against the clamp here we go went in sixteen millimeters deeper and tap it run it at slow speed throughout the Dro and we're going 1300 meters deep there we go I put the faceplate for the grinder on the mill and I drilled the hole pattern for to draft in drive pins three metal pins and four pockets for these magnets which I also happen to have in my scrap bin which will be epoxy or super glued into these pockets now we'll cut to two small notches in the from the outside so I can use a screwdriver to get the grinding wheels off doesn't mean much 0.75 mourners depth or is probably enough yeah and while we here it's also easy to drill the one grinding disk that I have just put this on here and use two clamps to hold it in place and then would drill through it that's easy because we already have centered on the aluminum disk and this will make it easy for now I only have this one grinding wheel that I definitely going to order more of these you will find them on ebay if you search for diamond wheel or diamond thousand grit or a dime and hundred millimeters over time and for inch or whatever you will find them I'm not going to put a link to this wheel into this description because the the people who sell these change each week anyway so it's probably completely useless to put the link in there because it will be available for a few minutes notice that the diamond does not go all the way up to to the center of the plate so it's easy to drill here we could grow through the dilating - because drill well bite through but in this case we don't have to there we go - Holt off camera and the magnets into the aluminium plate so I super glued the magnets in here and I used a strip of plastic Delrin with a clamp to hold the magnets flush or slightly below flush with a clamp the Delrin has the nice effect that quickly doesn't stick - it's a can just pulled off afterwards and I glued in two dowel pins they are slightly proud of the surface about 1.5 millimeters and here is the diamond plated disc that's drilled for for the to drive pins and this snaps nicely into place and it's really firm on there it's really it's really holding on very nicely this big aluminum just before you asked has an m5 shred on the side to lock it against the flat of the shaft and the axial screw that pulls it up against the face and against the bearing so this is reasonably rigid and has basically no axial play because it's running up against the bearing so that's okay [Music] [Music] [Music] okay I cut these two parts out here and see Sarada of streamit millimeter sheet metal and these are the site Ron Ian's that go on the tilting table of the of the slow speed grinder the parts were held on a sacrificial block of French shape which is a poly gray urethane foam I like to use this stuff as a sacrificial block because you can cut into it and does harm that the cutter at all can be superglued it takes wood screws takes metal screws and it's reasonably cheap and it's easy to surface if it's worn down and the way I hope these parts on here is with blue scotch tape on both sides and super glue between the so calls but to super glue technique john saunders showed that numerous times in bunch of videos the only problem is to get it off sometimes you can sneak in a screwdriver just pry it off like this and really the the benefit compared to using double sided double sticky tape it doesn't leave as much residue or at all and it doesn't tend to gum up the end mill I tried the powder take the powder coating tape that John recommends but I'm not too happy with it I prefer I prefer the blue masking tape let's see if we can get these parts off here without damaging them too much sneak in a razor blade and use a screwdriver to pry it off dunk a reasonably nice wall finish here used to three millimeters refuse carbide end mill and I spiral spiral down the contour into solid and then to get finishing pass at full height all the way around go slide a razor blade in get a screwdriver you could Jam the screwdriver between the part and the polar roofing foam too but that tends to leave a mark on the part there we go that's two for two here is the base which is a frame out of 20 by millimeter square tubing it has the two trunnions which are out of three millimeter sheet metal welded to it and had they have a reamed it millimeter hole when I welded the trunnions should a base I had a millimeter shaft in here and I checked for for warpage so it did still spun freely in there and I machine those two moving trunnions on the CNC router and I took a piece of angle iron i machined the inside here so I could weld those two brackets in there here and here and I took a piece of three millimeter sheet metal round at the edges and tich brace that to this angle I went for take brazing because I didn't want to put a lot of heat into this displayed and work worked it like potato chip and it stayed reasonably flat so that's the table and it goes on here and take your shaft and it goes through there chef collar will go on both ends off the shafts it's locked it's at the end captive then we have these arc shaped holes those screws that go along here I will get some adjustable hip handles don't have m4 in stock and that's my angle adjustment it's as easy as that then we have our drive unit with the flange machined with the two and six holes that bolt in here there is our slow speed car by grinder with an adjustable angle table goes from - not sure how much that is - down to 45 I think it's - 20 or something like that way more than you need normally you need - 5 to get to shorten your your scraper blades and yes it would be wise to put the pivot point exactly on the face in line with the face after grinding wheel because then the distance between the table and the grinding wheel will never change but for various reasons I opted to go this route for 1 I need this large gap here so I can yank the grinding wheel out there yes those magnets are strong and I recommend using a screwdriver there and also have different thicknesses of grinding wheels and also it was easier to do the alignment with those shafts through there and the motor in place I have gates blocks in here to align everything and that it was just easier and the the changing gap size here is not really a big deal for the work I do and if I really need zero clearance against the grinding wheel I can - always take a piece of sheet metal and then just clamp temporarily to the table and move it all the way up to the grinding wheel if I have to lap something really tiny so apart from that quite happy heart came out strictly stuff that I had lying around except for the grinding wheel I kind of bought that for something else but it fit it here quite well this motor doesn't have any cover back here so I designed one in CAD and 3d printed it in green PLA I printed it with 100% infill testing is crazy sturdy took 5 hours though the problem mister smother has no way to mount a cover back here I'm not sure how this was designed but it has this plastic dovetail shape here probably that's what used to to mount some way of a cover or a large connector or something like that onto the motor so I designed this piece here which intersects with the shape and has a captive m6 nut back here because I dislike threading into purely and this slides very tightly onto this contour and gives me a good heart point to mount down and discover here when you when you wind up all the wiring in here goes up right here and has a central m6 group which goes into this camp if not in this black piece here the wiring is very simple I have a two pole to throw switch so it has neutral left-right and it's wired so I can run the motor in both directions cable comes out here this is 24 volts input there's 24 volt power supply which will be housed and the base of the grinder so let's let's coil out all these wires up and get them in here put put a screw in and because people will ask what I use I use a Lieber design expert as a CAD I use pressure slicer as the slicing software and I have an ender 2 3d printer so I hope you enjoyed this this discussion of the slow speed grinder thank you all for watching and see you next time you

Channel: Stefan Gotteswinter

Views: 85,314

Rating: 4.9612765 out of 5

Keywords: accufinish, slowspeed grinder, toolgrinding, werkzeugschleifen, läppmaschine, lapping, lap, ceramic lap, diamond grinding, diamond, werkzeugschleifmaschine

Id: GOBtH4m2TYo

Length: 32min 31sec (1951 seconds)

Published: Sun Nov 10 2019