Airtool chamfer attachment

[Music] hey welcome back today i want to talk about this contraption this is something i needed for quite some time and robin with his uh miniature air tool chamfermeister kicked me over the edge to build it and i'm working currently on a project where i have to where i need something like this what it is it's a attachment for a die grinder this is the air air powered 55 000 rpm die grinder from bx and this attachment allows me to to cut chamfers on free form contours so you can do not only straight lines but you can also follow a curve or a radius and the way this works for the woodworkers or people in mass production this is an old hat it's a pin router same principle as a router bit with a bearing with a guide bearing that follows the contour of the work and there are small deburring bits for metal with a bearing but the bearing is super fragile and they're crazy expensive i could make one myself i could grind down the end of a chamfer and i'll put on a tiny thrimler with a ball bearing but i think this is a better solution the pin router doesn't use a bearing it removes the bearing and it has concentrical to the spindle of of the router they have a guide pin and that allows to trace either a template or the contour of the part and that's the same what i'm doing here you might be able to see the this is a carbide 90 degree d bit that's what's cutting the chamfer and i have a small carbide pin silver soldered onto this this finger that this is concentrical to the spindle of the die grinder i will pull the dike render out in a second so you can see what's going on don't get too excited this is not a build video i i needed this right now so i didn't have too much time to film it or didn't have any time to film it at all but i took pictures and i will do a slideshow of the build now let's pull the die grinder out it's clamped here with a single m3 screw it's a solid solid piece here and the finger the guide pin is inset this is all turned then machined down to form this clamping arrangement here slit it drill them board to fit the and this is concentrical this is adjustable uh i didn't want to make this a solid one-piece affair with the guide pin solidly soldered into the the base because i want the option to exchange it for different attachment i adjust it just by eyeballing it central over the the tip of the d bit under the microscope and that seems to be good enough so let's look at uh how this works we have by bx style grinder really a nice die grinder runs excellent 55 000 rpm and i have a 90 degree d bit this is just around 90 degree with 20 degree back back relief ground on the d bit grinder you adjust the the chamfer width by moving the die grinder in and out and currently there is no way to to set it to a quantified dimension what i'm going to do is i ordered a shaft collar that i'm going to bore to the diameter of the die grinder and then i'm able to use gauge blocks between the clamping collar and this this fit this rear face of the chamfer unit that gives me a direct direct representation of the chamfer width i could calibrate it so a one millimeter gauge block is a is barely scratching the edge of the material and then just a 1.1 millimeter gauge block would be a 0.1 millimeter a chamfer a 2 millimeter gauge block would be a one millimeter chamfer and so on uh this can do maximum a one millimeter chamfer but i think that's pushing it already uh i i built this for something like a point three point five millimeter chamfer that's what i'm intending i'm i'm debating myself if i'm going to send it out for night riding so it's hard and then i uh lap the base here nice and flat and and smooth i'm most likely going to do that and this finger is just a piece off of cold rolled shaped a little bit of belt sander and silver soldered in a small 1.5 carbide pin okay i have this part here there's a scrap part i i messed this one up so you can use this for test cutting and this is actually the part i made this this d-bar for some of these pockets need a relatively precise and well-defined chamfer i set a chamfer width and the nice thing about this this arrangement is you cannot overcut the chamfer if you if you tilt it in in any direction you will never cut a chamfer that's too deep it will always cut a smaller chamfer but never dig into the material so that's a nice safety factor there if you work on delicate parts and then you just turn it on i blewed up the the surfaces around this edge so we can see the chamfer later this is a solid 0.75 millimeter chamfer here and still it did a nice job it it's controllable uh if you go conventional milling in this case uh on a very light chamfer you you you will be able to do a climb cut works very nicely and that's also the reason why i made this guide finger so narrow so it it's able to to go in into shapes like this and you can you can snake your way through there and follow here like this go into the corner follow the radius go around and trace the contour like this then you have to to change orientation and do the other side we can also do materials like laxan of course [Music] a reasonably nice chamfer a little bit of burr here and earlier i did i did this contour here and this works this works really nice following the radii and due to the shape of this tool you can hold it really this this sits nicely in the hand you can rest your thumb on this this clamping collar and kinda can control its orientation to follow to follower shape you can also use it semi-stationary holding it in hand [Music] [Music] [Music] does really a nice job in brass keep in mind due to the fact that you're using a guide pin the surface finish off the wall copies directly to the quality of the chamfer so if if there are tons of chatter marks in the side wall of the part you're chamfering you will get a ton of chatter in the in the chamfer too there's no way around it using a guide pin or a guide bearing and this tool is relatively safe [Music] i wouldn't say it's it's uh it's it's idiot proof but it's close to if you if you make an idiot proof tool they will just invent a better idiot uh the cutter only extends like one one millimeter out here and when i press my finger up up against here it's almost impossible if if i came in here with my thumb i could touch it but yeah that's the case of a better idiot so yeah that's the tool and yeah i'm i really i'm really happy that i finally built it let's look at the cad model for this contraption the green thing here is the diagram where it's sticking in this large body here this is the actual chamfering device and we have this here this is the guide finger with the pin this small round thing here is a 1.5 millimeter carbide pin and this is exactly in the center of rotation of the d bit below it the later design of this finger is different from what you see here this was too wide from here to here to fit the particular application that i made it for so i'm i made it way narrower this design here with the clamping arrangement back here this is heavily inspired or almost copied from robin from robin's dot co chamfermeister and i really liked the way it looked so i i blatantly copied it it almost looks like it's out of one piece so it's it's really cool so let's look at the section view you can see that the uh this this in front here this is all die grinder geometry with the collet this is modeled as one piece the d bit sticking out and meeting up with the guide pin in the center there is really not much to this thing [Music] let's look at the at this thing alone and how it it evolved let's go back in the model tree i modeled it like like it's machined it starts as a lathe part and some holes are drilled [Music] then we cut away all this material to form this clamping arrangement cut the slot [Music] drill counter bore [Music] drill and tap that's it that's the whole part in reality um i added a shallow slot here for the for the guide finger but that's a minor in progress modification do a quick rundown of the machining of the main body of this chamfer device here you can see a piece of low carbon mild steel c45 in the lathe and i used the parting tool to hog out most of the material and i always left about the width of the parting tool between my cuts then i came back and removed the material between those cuts um removing material that way is safer than stepping over just the the width of the parting blade because parting blade does not deflect it's always cutting into solid material that way then i took the the same parting tool it has an insert for for plunging and turning so you can move sideways and i cleaned up the the very wide slot that i just machined then i drilled out the center and use a boring bar with a very sharp re-sharpened insert to bore it to the final diameter you can see the tiny tiny chips this re-ground boring bar produces and the bike style grinder fits very nicely so that's after bandsawing it off here i'm set up to machine the clamping band and remove all the excess material i'm cutting two tangent lines 40 degree offset to each using a 40 degree angled block after i cut the first one to to offset the second one and that leaves me with this shape here then i just roll the part on the on the parallels and do repeating cuts to remove all the material in a faceted manner and this is the result i get and then it's just a little bit of filing work to blend those facets into the cylindrical part next to it drilling and tapping kind of boring for the clamping screw then i slid it with a slitting saw drilled two tapped holes and cut a pocket for the guide finger here is the guide finger in in the making drill two holes counter boarded the smaller hole is where a later solder the carbide guide pin this is after some shaping most of it was removed on the mill and then finished on the belt sander silver soldering in the carbide pin it's a 1.5 millimeter carbide pin and silver soldered it in with a tiny amount of solder here you can see it after cleanup so you can use this handheld you could use it stationary you could build this for for your small handheld die grinder you can use your woodworking router with a small with a larger bit in fact i used my woodworking router mostly in plastic and in plastic and aluminium so hope you enjoyed thank you all for watching and see you next time you

Channel: Stefan Gotteswinter

Views: 23,734

Rating: 4.9708848 out of 5

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Id: vtBDId-2AT8

Length: 16min 15sec (975 seconds)

Published: Fri Aug 28 2020