Pull Gear Speed Reducer Part 2 - Thanks to Mr. Pete

great spreads oh here back at the live and welcome back to part two of the Paul gear and that is the reverse engineering of in the last episode I got to the stage where I had finished the bottom casting of the fall gear which included the three-step police with the poly the gurus in them and I made a complete hash of this I tore out huge sections of the casting as I was trying to cut and machine the grooves for the the poly be felt and as I wound up this last episode I said I was going to try and track down a piece of 6061 alloy turn replaced his casting and I tried and failed to find a piece the right size the only piece I could find was selling you had a piece 200 millimetres diameter it was the correct length but I've thought about it and I just thought it's going to be turning all of that metal into swarf it didn't seem right so what I've decided to do is just a machine off these three step pulley sections and replace that with a smaller piece of 6061 so I can get fact I've ordered the piece that will do that job and it's going to mean having to attach this replacement machine section to this large disc here and there's not metal there to be able to put say six socket head screws on the inside to rigidly that mount don't place I'll also use a lock tight just to ensure that nothing here that gets loose on that so so what at work but I didn't fancy re doing the casting and possibly having the same problem happen again so I'm gonna go ahead and machine all this off and we'll make the new part get that fitted and then keep going with making the rest of the parts all righty well that may be a bit sad to have to do that but it's the only solution I can find it's not gonna waste a lot of material one of the next jobs I need to do here is to drill six holes around this circumference to attach the ring gear to the casting for the step pulley and this is the casting and I just machined the back off now I've got this dialed in no four jaw Chuck ready to go on so that after I've drilled my set of six holes here and I have the indexing attachment and the drilling attachment from my load set up I can just swap out the chuck and drill all of the holes exactly the same setting so I'm gonna get my drilling attachment set up and I'll draw the six holes and they're going to be countersunk for socket head screws [Music] well there's the six holes around the ring here these will be later drilled to clearance for the screws that I'll be using and I'll countersink these deeply enough so the head sit just below the surface so what I need to do now is to swap out the face boat for the four jaw Chuck with the casting for the lower pulley section and drill the identical pattern of holes in it and I've locked my cross slide in position so as long as I use the same number of divisions I should get perfectly matching holes at least that's the plan [Music] well here's the assembly now do you want the good news or the bad news well the bad news is that there is no good news firstly I have misaligned one of the drilled holes all of the other five screws went in fine the drilled hole in the casting underneath here does not line up with drilled hole in the ring gear how did that happen I have no idea I can only think that I miscounted when I was indexing around for one that one hole so that in itself means that this casting to me anyway scrapped and I can't use it but the more batterer news was that when I checked the concentricity of the ring gear in reference to the unmeaning casting it was out by nearly 0.8 of a millimeter once again I have no explanation as to why that happened but that means that this part is unusable because I had machined the outer circumference of this exactly the size and the bore on the inside here was also exactly the size so that with that out of alignment with the ring gear it means that it's scrapped so that means that I have to start again now what I've done is I made a new casting for the lower section of the pipe I machined a shoulder here which is the same time it was the inside of the ring gear so I was added with the ring gear over that shoulder and then I spotted through all six holes drilled and tapped so I know that those six holes line up with the ring gear I've also left this outer diameter oversize by about a millimeter and all of the other dimensions on this piping machine casting are also oversized so when I got the ring gear back on I will set that up in the four jaw Chuck and dial in the ring gear and all of the other features are going to be machined from that ring gear reference now it should be obvious that that's what you do from from the get-go but I didn't do it I've also managed to track down a piece of alloy which I can use to make a step pulley section that means I'm going to have to fabricate the entire assembly by once again drilling six holes and bolting this down to this casting from the inside which I can do that's going to work but it's less than ideal it means that you don't have the integrity of a complete casting but given the loads that this thing is going to work under I think it's going to be okay so it's it's just one of those things it's like one step forward two step backwards and I'm angry at myself I should have been more careful I should have thought it through more and like so I got no excuse for what happened there that's a complete train wreck so what do you do well like I say when the going gets tough the losses go and have a beer and drown their sorrows [Music] [Applause] [Music] right let's go and operate some heavy machinery well leave me on our back on the lathe and I must say after that last setback I felt a bit tired and emotional but I've reset and got new assembly dialed in on the four jaw Chuck so this is the ring here at the back here and I've set that to be running as accurate as I can get it I've also machine this flat face of the casting to be it's correct intention and I machine the outer diameter of the casting to be almost the correct dimension I didn't worry about bringing it down exactly the same size of the ring here it is no need I also bought out the bearing recess close to finish size and I machined secondary recess here which is going to allow me to locate this piece of stock so this is all oversized at the moment and once I drill through my six screw holes I can Sheena's to a finished spigot dimension fitted inside that recess transfer through the holes and drill and tap everything and I'm going to talk that down with six envious screws and I'll also Loctite it as well just to be as sure as I can that nothing is going to move later when all of that is done I can finish machine the step calling section so let's go ahead and get these six holes drilled [Music] [Music] [Music] [Music] okay let's park and come out now and I'm going to work on getting this Prix by machining this edge down to fit that recess and then we can marry the two parts together [Music] well that's good enough for me so I'm going to spot these holes through now and tap the threaded holes in our section the new stock and when that's all bolted down hard I can go ahead and finish off the lower section there's still some work to be done in here too there needs to be a recess cut and we need to bore out precisely for the bearing and the shaft but you know what things are looking up it's not such a disaster after all so as you can see here I've talked down these cap head screws and they're locking that piece of alloy stopped at the back of the base casting and because all of this is oversized I can go ahead now and grip this in the four jaw Chuck and dial in the ring gear and make sure that's running accurately I've got some copper shim around the jaws of the four jaw so I don't damage the teeth on the inside of the ring gear so let's go ahead and get this all mouth and running through and we'll just have a quick look at some of that machining if you can see that that this edge of the Ring year is not actually truly circular which is surprising it's sort of running oddly it seems to have two high spots two low spots I sort of dial it in get the average that I can like a certain speed awkward because it's not consistently running out anyway I've got it set at an average so that's about the best I can do it anyway we're gonna go ahead and get this all machined up here now [Music] [Music] I'm going to use this as a temporary Center so that when I start machining the outside of this billet I can keep some tailstock pressure on this part and the bearing looks like it's the right sort of fit I won't press it in just in case I can't get it out again but I'm happy with that so it's got another board to finish off inside here and then we can start shaping the outside alrighty that's step 2 so I got one to go and in the grooves okay what I got here is a high speed steel tool its ground much like a threading tool except the included angle here is 40 degrees which matches the polyb belt and what I need to go do is to cut three groups in each one of these diameters and the last time I just plunged the tool straight in and of course that led to disaster what I've done is I've set my compound slide round to 1/2 the flank ankle that's 20 degrees off 90 degrees cross lathe I have set my tools so it's parallel to this face here and I have offset the tool from this corner of the stop this corner of the pulley face and all I could do there was just a bullet so I've used a steel rule placed so against the shoulder what the tool back until I thought the corner was against the edge of the steel rule now I did watch a video by Joe paczynski who showed how to offset angular tools from edges and face and so on and it was brilliant but I forgot it all and in any case it doesn't really matter what's important is that the three grooves are equally spaced the offset from this edge is less important the belt is not as wide as that face even if I get it slightly wrong it doesn't matter now I've also brought a tool in until it's just touching the stock and I've used a my finest feeler gauge stop to locate that and I've set my compound slide collar to zero and according to my CAD drawings I need to be able to advance that tool in along that flank for 129th out now I usually work in metric but my compound slide is an imperial so I have to work with that and I've assigned either the biggest one first if if it all goes really badly wrong I guess I could machine it off and do something different I'm not sure but it just seemed to make sense to work with the one closest to the Chuck face just in case something digs in so I got a towel stock type I'm going to run it at fairly low speed and use plenty of coolant and we'll see how the first one goes the potential things to go wrong here is extraordinarily high so let's just see [Applause] we're at about 45 deep seems to be going okay but I'm just I'm noticing that one edge is saying to call up a little bit which worries me if it gets really bad I'll lower the speed even more [Applause] okay that's 55 now I just heard it starting to dig in there no theory it's really only cutting on the square end and a left-hand flank however it presents a very wide cutting face to the stock so the load on the tool tip goes up quite high as you start to cut across a broad area and given that this lathe is old and not super rigid the potential n is for the tool tip to dig in and deflect downwards now in theory if it deflects downwards the lie on the tool tip clears and it'll spring back up again but you tend to get this sort of oscillating effect and that's when you get chatter and that sort of thing so just I'm just gonna whoa am I at the end a little bit more [Applause] [Applause] [Applause] right 85 now and I can hear it digging in and releasing and I'm taking this very very slowly funny thing is I did this on the original police when I draw pretty years ago and I don't remember having this sort of issue and maybe I was younger and more reckless I don't know but this is really worrying the decoying was push ahead that's 95 bit more [Applause] that's a hundred down so what do we got we got so what they do you got well let's just the next day and after I finished up yesterday I tried cutting that second groove and nearly ruined the whole thing the tool bit was digging in constantly and I was at a complete loss I had no idea why this was happening I had everything locked down everything was tight I had the tool honed and sharp and I check the center hide but it was grabbing and digging in and I was terrified was gonna snap off or disrupt the part so I packed up and slept on it and today what I have done is I've cut all of the group positions with a parting tool first so I've already done these three here with the devii tool these three are the last three to be done so with the parting tool I've got an inverted parting tool holder and I ground the blade that was very finished just over a millimeter thick I index the correct position off this shoulder here and cut each of those three grooves to the correct depth and what that does is that it sort of provides or less removes the bulk of the material so then the V tool only has to form the shoulders of the V groove and I also have a pretty dodgy sort of Chinese electromagnetic coolant pump underneath my lathe here and I also reasoned that if I was able to get a constant supply of coolant it would not only keep the blade from expanding and jamming in the cut but it just provides that lubricant as well so you know what there's no problem you can't solve with a bit of lubricant so I'm about to do these three here and if I get that done without a mishap I'm sort of feeling a lot better about this but as I've yesterday I was just ready to chuck this whole thing in the bin and not counting further with it the only problem was I've already uploaded part one of the video so it would have seen a bit strange I didn't follow it through incidentally I know that said mr. Pete finally got his Paul gear at path and he's uploaded a video showing the interior of the full gear and as I suspected I don't know how he's getting a seven to one ratio with a set of gears he has I like to pause the video and do a tooth count that I'm pretty sure it's not going to be seven to one there was a version that came out with a seven to one ratio and from the information I can find it had a double reduction in the planet gears the one that he has doesn't have that so hopefully mr. Pete's going to shed some more light on that soon so let's go ahead and get these three groups finished and uh we're looking sweet here we go [Applause] alright that one okay so i just keep indexing across now the distance between each v-groove and we'll go from there [Applause] [Applause] what should be able to see now I said the three beads on the back of that polyb belt fit into those three gurus and you get a quite a large surface areas that wraps around those three indentations and because the belt is very thin in section and wraps around really wellis around that smaller diameter so you do get a very positive Drive runs very quiet and very cool and it doesn't it's very efficient you don't get a lot of friction to SAP energy from the drive so what I need to do now is take this out flip it around and start machining out the inside while this casting section and that's where the idler gears are going to fit so I'm very glad to have that finish that was a bit of a nightmare and I can see that I was very close to snatching defeat from the jaws of victory there okay progress report as I close out this video I think I've served done enough to fill up 35 minutes what I got done today was on machine there's eight millimeter wide slot in the top of the cap casting this allows for a latch to be dropped into that slot and that locks the center spindle to the top cap that effectively gives you a one-to-one Drive with the poor gear if you want to engage the low speed drive you need to lift that latch out and rotate it through 90 degrees and then it holes in a position above the top cap that allows the center spindle to rotate independently of the step pulley section now when you want to engage the low speed drive what you need to do is to lock this top cap in a position so it cannot rotate to do that there's a 3/8 diameter drill hole in the edge of this casting and a steel rod will be inserted in that and that steel rod is locked to the body of the drill press so there's a two step process to engage the low-speed you need to lift the latch out and insert that steel rod to lock the captain position so the cap is more or less finished the bearing recess where the top of spindle is done the one remaining job to be done here said drill four holes in the underside of this cap for the spindles which going to hold the idle gears in place so these Spindler spindles have been machined from stainless steel it was probably a poor choice because it was extremely hard to machine and cut the threads and lots of stuff it was just very tough Seamus and I thought long and hard about how it's going to fit these spindles into this cap and I thought about press freedom and using lock tight and in the end I decided the cut very fine thread that's 5/16 by 40 TPI model engineer thread it's under cut at shoulder so it will screw down all the way to the shoulder the length of the stud is 0.1 of a millimeter more than the thickness of the gear so the when that's screwed down hard the gear will just sort of rotate just clear the cap and I also thought about how is going to get some torque on this to actually hold that in place as well and in the end I decided to drill a cross hole and I can use a steel rod or a pin punch or something yeah we are so I can put a pin punch through there and use that to get some torque on that stud and hold it in place now it also meant that I could have a through-hole which connects up with that cross hole and I had one of those sort of moments of clarity I suppose you could say when I thought well you know I could use this to lubricate the bronze bushes the centered bronze bushes in the center of gears so the idea is going to be that when I have drilled through and threaded for each one of those studs I'll continue to drill hole all the way through to the other side of the cap and I'm going to fit some of those little brass ball boilers in the cap so there before them one for each stud and they'll be because they're spring-loaded ball ends on them I can inject oil through the studs and they'll close up and stop dust and debris from getting into the bushes so I thought no that's cool that's something that the original manufacturers didn't think of they actually fitted to bronze or to brass Oilers in there but I think they just sort of splashed oil on the gears so this is going to be one of those really cool features that will stop those little scented bronze bushes from running dry if you remember toilet so each one of those little studs is done there's a bronze washer on the top and it's going to just prevent the gear from coming off the start when it's inverted so remember all this is sort of upside down when it's in operation now the location for each one of those holes I'm going to take from the CAD drawing I've drawn this out so I've got point one millimetre clearance or backlash for each of the gear sets and I intend to drill this on the CNC mill now it's a high risk strategy so I'm not going to do it in this part until I've tried it out on a piece of scrap material and if I'm happy with that I'll go ahead and drill each one of those holes so yet the caps done except for those four holes and fitting the oilers which I've ordered and they're on the way now this was the the part that gave me the most grief and I think I've got away with this time so here's my step two pulley it's now held in place with six m5 countersunk screws and I've locked tired of this as well so that it's essentially one component now barring recess has cut the clearance for the main spindle has been cut and that's all going to assemble in there like that later on with the bearings press home second bearing at the top in this recess here which is still to being machined and the gear the drive gear will fit in place like so so that's sort of like 80% done as well the spindle has a on the inside now this part is going to be protruding from the top of the spindle and there'll be an 8 millimeter wide steel latch assembled onto that and that's what's going to lock or unlock the drive so that's just a bit of mild steel and a just a bit of a screen that I have lying around so that's looking good so is it going to work don't know I sort of have ambitions that are a bit beyond my skill level sometimes I'm keen to see how it winds up I know and I do really need some sort of reduction drive on my drill press it's just doesn't have the power that I need to run a large time to drill bits so we'll see how we go so I'll leave this here now I think my explanations of it long-winded sometimes but hey if you want to be entertained go and watch this whole time so for now we'll wind up here the next episode you see hopefully we get this sort of at a stage where we can tell whether it's going to run or not thank you to the people of left comments does give me some encouragement to move forward with this I've noticed that mr. pip has been watching my videos which is cool I really really like it as somebody well known is actually looking at what I'm doing or maybe is just checking up on me because I mentioned his name and the title who knows but yeah exciting times so for now thanks for watching

Channel: Mark Presling

Views: 12,268

Rating: 4.9568343 out of 5

Keywords: Pull Gear, Speed Reducer, gear drive, epicyclic gear drive, DIY, Drill Press, Poly V belt drive, metal casting, metal maching, Mr. Pete, Drill Press speed reducer, Home shop machining

Id: r62nuOBIEc0

Length: 35min 47sec (2147 seconds)

Published: Fri Jul 06 2018