Building the Gen 1 Belt Grinder

about two years ago john heiss released his video of building a 2x72 belt grinder and that was the first time i had ever heard of this fairly popular knife making machine that also has a lot of other uses and at that time i really wanted one then a few months later i was in one of my friend's shops and found out that he had built a 2x72 belt grinder and i got to use it at that point i was very sure that i wanted a belt grinder so i spent the last two years working on the design for this machine a couple times i almost started on it but i'm really glad i waited because it wasn't quite ready yet and finally here it is i'm really excited about this it's powered off a one and a half horsepower motor not really enough but i got the motor really cheap that's turning a five inch drive wheel which creates about 5000 feet per minute on the belt and that's driven off of this k back frequency drive the main part of the machine is on a hinge so when i loosen this bolt i can then tilt at 90 degrees and use it as a horizontal belt grinder like many belt grinders this one has a receiver in the frame and you can slide different attachments into it i only have the platen attachment right now but in the future i can build contact wheels and small wheel attachment etc and it will fit just like this one does it works the same way with the table this is just a temporary table but it mounts on a bar that slides in just like that it's nothing too uncommon for a bell grinder to tilt however most of the time the table is mounted to the same thing as the platen so when you tilt it the table tilts as well this one well the table just stays there it's a lot more convenient interesting i can't say i recommend doing this but well you can tilt it with it running the tool arm slots the the table and this attachment mount to give me a lot of flexibility and sort of future proofing anytime i come up with an idea for a new attachment or a new table or any kind of jig so long as i make it have that inch and a half square bar to mount it to the machine it will fit probably notice that all the materials used on this is really heavy and stout i used 3 8 material pretty much everywhere and i could have definitely got by with probably eighth inch it would be strong enough it wouldn't break but thin material like that has more flex which means under load it would probably chatter and vibrate this way it's super rigid and strong it just runs smooth so that's the belt grinder now let's jump back in time about a month to when i started this build so this is the tool arm stock and this is what the table and the what i'm just calling the attachment mounts to that would be the platen or the contact wheel or whatever so this is what needs to slide inside of the frame i already tried to make the frame once and completely failed because of warping one end is still okay for a little ways and then it starts to lock up this is essentially a square tube but the reason i'm making it out of flat bar is because the inside of square tube isn't really precise but it is challenging to try to weld something like this up precisely so i've cut the stock for a second attempt and the way i'm going to try to do this is to tack about every inch and a half and then come back and fill those in and jump around quite a bit so that i don't get a big buildup of heat in one spot because a big buildup of heat in one spot is what causes warpage pop can shims pop cans are normally about four thousandths thick so this is eight thousandths since it's doubled over and i'm going to be putting one on both sides hopefully sixteen thousandths will be enough that even after warpage this will still fit without too much play so you can see how i've tack weld this every couple inches i'm going to try to take this off this is kind of the moment of truth if this shrunk too much during welding i won't be able to get that off and i'll have to just cut the tack welds off this bar weighs about 50 pounds so it's probably about the most effective hammer in the shop and this table is about 700 pounds so it's a pretty good anvil so to try to hammer this piece off usually when i'm doing this kind of thing i always just keep a camera running so i don't miss the shot but i did this time and the last halfways came with one whack it almost dropped the bar off the other side of the table and i dropped this on the floor it was great i'm sorry you had to miss it without the shims in there it slides very easily now so this is perfect which is probably a bad thing because when i go to weld this i'm probably going to make it imperfect to give me the best chance of getting this all welded up straight without warping it i'm going to again just like i did with the tack welds i'm going to jump around kind of the way you do tightening lug nuts i'll weld a little bit here then i'll jump to over here then i'll do some on the other side probably in some kind of pattern the point is you don't want to get a lot of heat build up in one place so you want to go clear the other side and move around as much as you can i think it might look okay after some paint the amazing thing is with only two of these pop can shims per side it works this tube needs to be bolted down to the table so i cut these two plates and drilled holes in them so those can be bolted down this goes on top of there but i need some spacers up from there and i think i'm going to make some little i-beams this doesn't need to be very precise it just needs to look right i think i'll just eyeball most of this oh wait a minute there's actually a hole that needs to be drilled right here before i weld this down [Applause] the purpose of this hole is for a locking knob which will lock the two alarm in place all right now we can weld that down now there's one more thing that gets welded down to this frame and that is the hinges that hold the other frame that's the shapes that i need to cut out this should be within the capacities of this bandsaw for some reason just as it finished the cut it stalled the blade but hey that was a lot easier than using hacksaw [Music] so there's these three identical parts that mount to the base frame to make up the hinge and then there's this one which is the same shape as far as the bottom half goes but then it has this curved slot in it for locking the position to cut out the curved slot here i'm just going to drill a series of holes and then i can clean that up and make it a slot so this is just slightly bigger than 3 8. ultimately there's going to be a 3 8 bolt moving through here so i need it a little oversized i don't have any burrs small enough for this thing almost there [Music] these these just make up half of the hinge this is the other half [Applause] so this hinge is the same as the one i just showed you except that it has the piece with the slot on it so it tilts like that and then you could lock that in place of course this isn't the right pull before i can mount the hinges to the base frame i have to make the main frame that's the one that killed this hole has the same purpose as the hole in the other tube which is to lock the tool arm that's inside of it in place now i just need to jig this up with this tube in the right spot and then i can just set the hinges on there and weld them in place i've got everything jigged up now how i want it the only problem is these are not necessarily going to stay in line this way and if they're out of line that's going to make the hinge not work well so instead of putting bolts through them like this i'm going to put this piece of rod so with this hinge in the correct position and this bar perfectly lined up with this bolt that will ensure that this hinge is in the perfect position relative to this one [Music] i was a little bit worried that these would get super tight because of welding them but that works great i want to go ahead and put in the locking bolt but you can see as i rotate this it actually goes behind this piece and i don't want to have to notch this piece out for that that'll weaken it quite a bit so what i'm going to do is tap this hole and then weld the bolt in and the tapping is just to hold the bolt straight while i weld it in i'll just thread that down until it's a little below the surface that way i can grind this side completely flush so it'll fit behind there this definitely makes it a little more fiddly to put it together [Music] so now with a nut and washer on there you can rotate it to any position and lock it up and i'll replace this with a knob or a handle or something later next up is the motor mount the motor is going to sit right here and of course be welded onto the frame that tilts so that starts out by welding this piece right here and then there's these two parts that are going to go behind that to support it like that and like that and then finally there's this plate that actually holds the motor and i still need to drill and tap that it never fails the two nicest looking welds are on the bottom of the machine so i'm making another i-beam this time with inch and a half on both sides and two inch in the middle this is to hold the tracking and tensioning wheel and it goes right here so i need to drill a couple of holes in these sides and round these corners the way i did these hinges now to get this one lined up correctly i can use this same piece of rod now just check this with a square to make sure it's straight up and down i got my i-beam all done this one corner is left sharp to be used as a stop and you'll see that in a little bit i'm ready to weld it in now when it's in its horizontal orientation there are some clearance issues so this has to be just the right spot [Music] this is not the actual motor that i'm going to use but i just want to put it on here as a placeholder to mock it up so obviously the drive wheel goes here and then the tensioning and tracking wheel goes here this needs to be able to move up and down and also tilt side to side for tracking so next i'm going to make a bracket to hold this off of here [Music] the tensioner is going to look like this and you see i left this corner sharp on the post this is the reason for that that's the stop right there i think it would be neat if this would stop with this piece perfectly straight up and down so i'll just get that lined up now i'll just tack this piece in with it right up against here and that way the stop will be in this exact position so this is the tensioner and the wheel is going to mount here you can see how that moves it up and down now i need to make the tracking assembly that's going to turn the wheel this way which means it needs to mount on a hinge whose axis runs this way you do not need a lathe for this project the only reason i'm using it is because i'm using up stock i already have to turn it into dom you can easily just go to the store and buy this size of dom off the shelf it's just three quarter inch outside 3 8 inch inside so this is just eighth inch material as a shim and i'll clamp this into place right there and then i can just set the hinge on top and weld it into place before i weld this up i want to put a sham in here so that this doesn't get too tight this is a fairly typical belt grinder tensioner tracker setup most grinders use the bolt coming from this way to push against here so you thread it in and it pushes against that to adjust the tracking on this machine when you tilt it that would then be on the bottom and extremely inconvenient so instead i cut this little piece and it's going to go right here and then a threaded rod through here so that way a knot on the top of this rod when you thread it down will push down on this piece and therefore push this out so i'm going to tap this hole and weld the rod in and weld this piece onto here again the tapped hole is just to hold the threaded rod straight but i can improve that even more by threading a knot down against the plate i just made a kind of dumb mistake this is now completely captive there's no way to get this off of here i guess that doesn't really matter shouldn't ever need to come off but i don't like it as you'll see toward the end of this video i actually did have to take this off so i'm really glad i did the right thing and fixed it much better to mount the wheel right here it's going to be mounted on a bolt like this so i need to tap this hole i may be crazy crazy but i like to buy us-made products whenever i can support u.s manufacturers and so far every single part of this machine was made in usa i wanted to buy the wheels online they're very cheap like about 35 dollars per wheel which there is absolutely no way you can make them for that but all of the wheels i can find even the ones that say made in usa on the wheel are still using chinese bearings and i actually contacted one of the sellers and asked him what he would charge to put us bearings in for me and he says double like that is just outrageous okay anyways i bought all of the stock to make them myself i also bought us bearings as it comes right down to it i don't really have what it takes to make these i have a lathe but i would need about another thousand dollars in steric instruments to be able to do this and i don't want to spend that much right now on this project although it would be a good excuse anyways my brother has all of the tools he needs so i'm just going to take all this stock and bearings to him and let him do it they will be us-made at least all of the cutting and grinding is done on this now so while my brother machines the wheels i'll take it apart and paint it you probably noticed that i'm using pretty long bolts here that's because i don't want any threads inside the hinge so this is long enough the shoulder of the bolt goes all the way through the hinge i've been storing the motor and frequency drive for the grinder on the drill press which has been really cool but now i need a spring to apply upward pressure on this to tension the belt so one option would have been to extend this piece this way and put a spring that pulls down but it's kind of hard to put it there especially with the belt coming right here so another thing that might seem like an option is to put a compression spring underneath here but nope i personally really like torsion springs i think they're just kind of cool and they make a really clean look so i want to put a torsion spring around this bolt problem is i don't have any idea how much tension that spring would need so i got to looking around and you've probably been noticing there's a swather parked in the background of this video those fingers seem a little bit stiff but it gave me an idea the pickup fingers on a hay baler still a torsion spring but they're a slightly smaller wire and have a few more rounds on the torsion part so i found a new one of these and i'm gonna put that on and try it if it's too strong or too weak then i know where i need to go next i'm just gonna have to cut this in half a little bit off center about here that should work i'm not sure if that's the right tension or not i'll have to put the belt on it and see seems about right though so you can see how the tensioner is going to work there and then up front i'm going to go ahead and build the platen right now so that just needs to have two wheels like so and a flat piece of metal between for it to rub against and i'm not really showing how i'm making these parts anymore because it's all just more the same it gets repetitive just bandsaw grinder and you know the drill so the wheels will mount here and here now these two plates need to be very precisely positioned and clamped down to the table because if they warp at all that's going to put the wheels out of alignment so pretty important then on top of that we'll go this little piece then this goes 15 16 inch off the table and then this goes here i'll just clamp all of that in place and weld it all together making sure it doesn't work that's very important for this long part i notched this corner and then i also cut this off and then the little piece that i cut off from here i'm going to weld on the opposite side to make it look like it just kind of comes and bends a little bit i left the clamps on and went and ate dinner while this cooled so now i can take them off and see if they spring up at all there's just an ever so slight little spot of light you can see through there since the platen is going to mount on a piece of this inch and a half square bar i need to make another tube and that's just because i really can't weld to this stuff with the little welder that i have i won't get this hot enough to get good penetration so i actually want this to fit quite tightly in one direction and very loosely in the other direction so i'm just going to use 8 000 shim this way and then in the other direction i'm going to use a whole eighth inch that doesn't fit and then in the other direction i'm going to use a whole eighth inch that still doesn't fit i'm going to use a whole eighth inch the tube fits on there then this just gets welded on just like that except i want to put an end cap on here i think that'll add to the strength a little bit just in case this wasn't already strong enough i think i'm going to add this little scrap right here just because i can so this fits very loosely and now i'm going to bolt that on and then i can lock that in place with the bolts with it perfectly square to the frame if you can't make it perfect at least make it adjustable remember that let's talk a little bit about the design for this platinum attachment so you'll notice that the frame is jogged both this way and this way it would have been much easier to just make a straight frame like that but that would have gotten in the way see the belt is going to go right here kind of like that so if that had been straight for one thing i could have never used this as a slack belt attachment see now i can push back into this belt and i've got about an extra inch here also the frame would have been coming beside the belt instead of behind it so this is just tucked back around behind the belt really nicely it's out of the way this is the actual platen this is what the belt is going to run against eventually i want to replace this with a glass platen that is going to go right there and the position of the jug how much i jogged it over is based on the width of this platen the idea is that i can mount a piece of flat bar centered on the back of the platen like that and that will be just the right position to bolt flat against this side now speaking of bolting that on i want this platen to be removable for a couple reasons one is just so i can take it off and use this as a slack belt a slack belt is the best way to kind of just smooth edges and things and i see a lot of people do that on the top up here which is fine but i think it'd be more convenient to do it on the front also i want the platen to be interchangeable you can rip these belts in half down their length and make narrower belts out of them so i want to be able to make narrower platens to use with narrower belts so i can make this a half by 72 grinder however if they're just simply bolted on i'm going to be kind of scared to take them off because i'm going to lose the position i'll never get it back on in the right spot so the way to remedy that is to have some alignment pegs and i think the best way to do that is to drill a couple of holes through the frame and use bolts with a fairly long shoulder so that this part of the bolt the shoulder part can be used like a dowel for alignment and obviously since it's a bolt you can just thread a nut on it to hold the platen in place so that's what i'll do next so these bolts need to be cut off otherwise all this excess out here is going to get in the way i just used this long bolts only so that i get a long enough smooth portion here to use for alignment i only need 3 8 inch threads i left tapping this until the very last so that i'm not going to be doing any more welding i'm not going to be warping this after tapping these i have this set up with this piece sitting perfectly level on the table now i can take and tap that and i made this little jig to confirm that i'm square so well they look straight anyways i epoxied a nut into the bottom of this wooden knob so that'll be my tracking knob and this handle is just so that i can easily release the tension just like that i might shorten this yet see if it turns the right way nope that's wrong it should turn the right way now time to assemble the wheels so the wheels all mount on a half inch bolt instead of just using half inch bearings since those are kind of not all that common we want a 17 millimeter bore and then these bushings have this 17 millimeter portion on both ends that this fits on and then of course this middle step portion is just so that i can tighten the bolt against the inner races of both bearings without putting any axial load on them also the distance between the end of this and the step is slightly less than the width of the bearing so that way i can tighten the bolt down on here and it won't be bottoming out on the bushing instead it'll be bottoming out on the inner race of the bearing so it'll be clamping directly on that to make sure that these inner races don't spin on the bushing there's some rust on this shaft so i'm going to have to take that off before i can put the drive bushing on in case you're not familiar with these tapered drive bushings uh typically in this case you would just have a set screw on the outside instead of this bushing i chose to go with a bushing because it's a lot more balanced with a set screw you have to drill a hole all the way from the outside and you've got all that removed material this way pretty much everything about this entire wheel is completely symmetrical or concentric i could say and if that still doesn't make sense just google something like tapered drive bushing you should be able to find some information in this case i'm just trying to get it positioned side to side so that the center line of the belt should be just in line with the center of this bolt that looks good enough and then these little bolts pull the wheel onto that taper so that causes this split bushing to pinch down around the shaft that is smooth wow that runs perfect if i was deaf and blind i would hardly be able to tell this was running from vibration it is super super smooth i'm going to have to adjust the number of washers in here to move the wheel in or out to make sure it's centered on the frame the platen wheels just get one washer per side and assuming that i didn't warp the frame too bad that should put them in exactly the right spot this is the moment i've been waiting for for about two and a half years since i first started designing this belt grinder putting the belt on and turning it on on the first attempt it wasn't tracking quite right i never even turned it on just ran it by hand and it quite quickly tracked off the side so i took out the bracket that holds the tracking wheel and i bent it just very slightly it seemed like this wheel was skewed to the side just a little bit so i'll give that another try now i bent a little bit too much the tracking issues seem to be solved so let's see what happens with some high speed grinding it works so this machine is not really done yet i still have ideas for new attachments for the front and more tables and jigs and all sorts of stuff but that'll all come in future videos i think this one's long enough thanks for watching and i just have to do this [Music] you

Channel: Jer Schmidt

Views: 1,956,645

Keywords: belt grinder, 2x72, belt sander, grinder, knife grinder, homemade, vertical, horizontal, combination, tilting, 90 degree, hinge, variable speed, vfd, frequency drive, belt tracking, tracking wheel, belt tensioner, tensioning, belt, grinding belt, steel, iron, metal, welding, welded, heavy duty, platen, contact wheel, small wheel, attachment, table, platen wheels, diy, metalworking, machine, build, make, jeremy schmidt, jer's woodshop, jers, workshop, tools, homemade tools, how to

Id: a_RlL1O-bK4

Length: 35min 51sec (2151 seconds)

Published: Wed Apr 12 2017