Ham Radio Gear Repair

all right here's our problem for tonight so what we got here is we have a realistic on the x-302 digital receiver this is from a friend of mine at work and he asked if I could help out it's got a mechanical problem that's why I'm involved he does a electronic stuff at work so he can handle all the electronics in here but he asked for a little bit of mechanical help and I'll show you what's the matter with it and the second has to do with the kind of the main frequency tuner here but he claims this is some kind of interesting you know ham radio piece and and what it is is it was marketed by candy which is Radio Shack for all you folks that's when Radio Shack really you know sold some cool stuff and instead of just batteries and cell phones right and this is a it has a wide range is what he was telling me is interesting about this one and it goes from 10 kilohertz to 30 megahertz so that's it's kind of its range that it can operate in and it's pretty cool actually it's kind of a mechanical Marvel insight we're gonna pop the cover off and get a look at it and I'll show you what the problem is with the main tuner that we're gonna fix so so we're actually gonna make some make a gear form it's what we're gonna do so let's check it out alright here's our sick gear right here so this is a there's a speed reduction through this knob and this outer knob through to a potentiometer that's behind here and it's actually kind of cool I was you know I took the gear off and this gear was originally molded to this shaft and we're not gonna be able to do that again so we're gonna make a metal gear to replace this one and then we have to come up with a way to attach it to the shaft securely but what's interesting is they have these their ball bearing what I would call coaxial gear speed reducers so when I turn this knob it has a a gear reduction to the potentiometer which is kind of neat and there's several examples on it there's one over here there's one here and there's one on the backside of this and I I was trying to get this shaft out originally and in you know to make it easier to mount the gear to it but there's some magic going on behind it that I don't know I really don't want to disturb its yet you have to dig pretty deep so I think I can do the repair on the front side and do a good job but we made it we'll take a closer look at this these little speed reducers and again actually this is probably good one to look at here I'll zoom in on this one we get a look at this and you'll get a idea of how that works and it's it's actually very clever so let's check that out alright so hopefully you guys can you guys can see this and and get a sense of this thing here so you can just barely see him here see that that's a it's a ball bearing and there's three of them inside this assembly here so it has a center assembly and then it has the main actuator here so what I want you to do is a way to watch this part here in relation to me turning this and you'll see that there's a fairly significant speed reduction between this and this okay so let's see if we can we can demo that and you get a you get a sense of it okay so you're watching the rate that I'm turning here but watch this rate don't watch this but watch that shaft okay maybe it's a maybe I should put a little put a little dot on there and then it'll help you guys track it okay so there's a little dot there you see that so the way that works is they're using the ball bearings is is kind of gear elements right so it has a little a small shaft they go through the contacts the idea the bearings okay and then it's the bearings are captured in a cage that's part of this this element here and then the outer race is the ID of this part here so that keeps the whole mess together right but if you think about it we're turning a small shaft against the ball and then the ball is turning in rotating so we actually get effectively a gear reduction it's really clever and it's super compact and I think he can get some pretty high reduction ratios there so anyway this thing's loaded with these things it's got one two three four that I've found in here and I was like what's going on there and then I looked at it I was like well that's pretty clever so so anything that's kind of neat and this whole assembly here is is a bunch of molded gears too you know this I don't even know what this is right it's I guess this is the frequency ranges or whatever presets or something like that so anyway let's look at let's look at our sick gear and see what we need to do to make a new gear all right here's our gear and I made a little chicken sketch here so that we can make the blank and get everything correct so I did a little measuring on this so that all the gears that are in that thing after checking them they're all there metric they're module gears okay so and the module system is interconnected with the the diametral pitch system but there's a there's this differences in the way they're measured so but anyway I've identified this as a point for module gear it's 36 teeth and so what I did was measured OD and and and then looked at the teeth and then determined the proper wire size here to to measure the pitch diameter okay which is I'm just kind of giving you a visual demo here Mike Dover that okay and then you match up with the number of teeth and the and the the module the pitch module and you come up with a pitch diameter and it agrees pretty closely okay within a couple of tenths which is in the I would say the margins of error for a gear that's split in half and you know etc okay so anyway here's here's some information on that particular gear right so point for module 36 teeth pitch diameter fourteen point four millimeters OD fifteen point two which it's there it's right on the right on the money and then I actually I found one online I bought a molded one just for fun and actually there's some of my so I was thinking it might be a sixty-four DP but it turns out that it's a point for module and those are like really close so anyway in this anyway it's the same okay so that meshes nicely and it seems to be good alright so now there's more to this story actually because this is an involute gear forum right and so at first I was like well me all this hand grind a tool and I'm like I don't feel like doing that and you know to get the tooth form correct I mean technically you can hand grind a little fly cutter bit and go to town right and I said well let me hey let me check on eBay right and see what's on eBay and what might be available right and guess what it the amazing world of the Internet so I found a point for DP involute gear cutter happened to be in China of all places and it was brand new anyway so the funny part of the story is I went ahead and and ordered the gear and it showed up obviously so the cutter plus shipping free shipping actually 15 bucks to get this and I'm like I don't even want to pull a blank tool steel blank out to grind anything for that kind of money so anyway we went ahead and ordered it and showed up on a little little envelope here right and it came from Xing Zhu Yao yang and in off such as such village on ba-bang Road in Shandong China right and this is the best part here and if you guys can see that but it says this is the customs form here it says line number one quantity one gadget and its value is two US dollars right and so anyway I just I just kind of got a kick out of that but you know the Internet is this is wonderful thing right so this guy lives in this in this village on Bob Wang Road and he got my order and he put my name on the thing and put it in an envelope and guess what we got a gear cutter so pretty cool so what do you say we go do some machining instead of yappin and let's make we're gonna make this out of brass and I got a chunk of brass rod and let's go over to the lathe then let's make the blank for this little monkey all right so we got some brass rod here this is just 360 brass run-of-the-mill plain D and brass nothing too radical about it turns real nice see I meant the indexer I'm gonna stick it out a little bit so okay let's do that you know I got an email from somebody the other day and they're asking about dr.oz right and I'll so I'll explain what I'm doing here so I took a little skim cut there and I haven't I haven't touched the the cross slide the x-axis here right so what I've done is I backed off of that and now what I'm going to do is I'm going to take a good measurement of that turn section and I'm going to calibrate the Dro is what I'm gonna do and they were they had a different idea of what I was doing I think and so I'm just trying to explain it so I'm getting the measurement here there's my measurement okay point six one seven five okay so I'm going to enter that I'm gonna enter that in the Dro now so point six one seven five so now my dro is kind of calibrated the tour the tool is calibrated to that diameter okay and now I can just watch the Dro and look for my number that that I want this OD to be which in our case is 0.5 984 to 0.5 974 so we got about a basically I can there the Finnish Pass so I'm going to turn it back a little ways because when you when you cut a gear like this it's it's basically free to go a little bit further and you know so we could make so we screw one up later on we got a we got some blanks to work with and then I want a nicely turned diameter that's concentric with the gear so that I can indicate on that later on too turn an inch or so fine I'm just gonna so my dro says 0.599 six let's see where we are see how close we are to that all right so we're pretty close to that all right [Music] [Music] all right now we're gonna do the same thing with a boring bar [Music] a little bit and we'll go in a little ways [Music] touching anything we're gonna use our little starett small hole gauge go in there and open it up give a nice nice feel these are they're they're kind of polished tool steels so you get a you get a pretty good feel on okay I'm gonna Mike over that all right so we're actually pretty close huh well sometimes you get lucky I probably should have drill a little smaller but looks like we got a little bit left to 401 for I'm gonna double-check that shaft diameter and then we'll pour that hole this turns out the actually I decided to show some of this measuring that diameter reasonably accurately turns out to kind of be a pain in the neck mainly because this is in the way and it overhangs this is next to it these little stub shafts are sticking out here so you you know just to get a quick thing you can get a sense of it here right but it's not a very confidence that's it's inspiring measurement so you know normal normal my kilometer here you know the bulk of the of the frame and whatnot doesn't really lend itself actually no so there's too much meat around this thing to to get a meaningful measurement right so what do you do right so yeah what do you do well that's the way you buy tools all the time because then you might have something really cute like this little thing so this actually does kind of get in here and it doesn't have a lot of extra real estate our overhead I should say so around the around the top of it okay so a little over 245 and a couple of tents 245 one and then so that's one way that's a 0 to 1/2 inch micrometer and that's a cute little Lufkin and I don't use this very often but it's small up here so every once in a while it comes in really handy when you got a tight little space to work with and then the other way you can do this too is with a disk micrometer too because you don't have a bunch of fuzz on your hand these project out from the spindle a little bit and which allows you to to get up in there a little bit better too and now this you got to be careful because the disks are pretty thin so yeah okay and that pretty much agrees with the other one within well that one this one doesn't read the tents probably for good reason but it looks like 245 and a half so we agree within a three to four tenths or three tenths okay so anyway that's a couple of ways you can do something like that if you got a kind of a tight space right so the more this work you do the more tools that you collect that they kind of help you get reliable measurements I guess is the point so buy tools [Music] back drag down the bore [Music] oh boy that's right where I want it it's like two tents under so I think we're just gonna leave that we're just gonna leave that so we're ready to go over to the mill now and cut our 0.4 module teeth in that all right so we got our our old school LS dividing head here and basically what this is it's a dividing engine so it's got a 40 what 40 to 1 gear reduction through a worm gear to the output here okay and and then we have various index plates that we can put on it okay and depending on the number of divisions that you want you select different numbers numbered circles here so each each one of these circles has a different number of holes in it and so the smallest one here is 21 and the and this looks like it goes up to 33 there I want to set outer one oh that's interesting let's see where the other ones mark because it's not it's not 20 well maybe this 28 gets the spacings farther apart so it looks like 28 yeah okay I get it in our case we're going to be using this 27 whole row here okay yeah this is a little index card here probably won't be able to read that but there's 36 27:27 whole plate and one turn of the crank one turning the crank plus three holes okay and I'll show you what that means in a second so this remember that for 30 60 27 mm hole plate one turn in three holes okay this is actually a fairly simple indexing job okay but what we got to do first is we have to align our get our blank kind of squared away okay and so let's take a look at that so we're just gonna kind of roughly put this in there and come on put it in there and so you know we got some choices about how far in and out we go right well I don't want to put it up to there right because my the radius of my cutter is going to interfere here so I want to stick it out a little bit and but I'll get the I'll get the cutter here and we'll take a look at that in a sec okay so here's our here's our cutter right so we don't want to interfere with the Chuck jaws here so the end of it actually that's actually positioned pretty well I could probably sneak in just a little bit so I'm just gonna go ahead and snug that up okay and then what we want to do is we need to put this very accurately on the center of rotation of this okay now right now you know sure I could sit there and sorry guys I could sit there and crank this around right but there's an easier way or in this case I can disconnect the worm which is what I'm gonna do here like that and you see how that folded out of the way there so now I can kind of freewheel that thing okay so let's indicate that so we're gonna get this up there so we'll do the rotation first okay like that bump it over alright let's see what we got here okay so it's out a little bit so now this is a this Chuck is adjustable here so let's see make sure I know which way this is going so that's high alright clockwise is high alright make sure you want to do our lows alright yeah this is back this is backwards from the normal for job right that's as close as I can get it here it's better than half a thousand in one direction now we have to look at tilt so we'll take a quick look at tilt we're looking at where we are come across the top just touch off all right there no okay and then what I care about it is what's it doing down here right because I don't want to cut anything weird okay so it looks like that's got to go down okay so this thing has the ability to tilt there's some screws on the back side over here that we're going to loosen up and then put some English on it and get that nice and straight and then we'll be pretty much ready to go crack those I don't want to be super loose here you loose enough to move it but not loose enough to to lose it right that makes sense all right so I'll see you a couple now persuade over here I'm gonna kind of split their points here and then see what we got here okay that end didn't change much so bring this one we got here plus one in the corner what but okay so I'm gonna snug a little bit here see if I can do this without moving anything the cutting forces in this case are pretty low so I'm not super worried about things moving while I'm cutting it all right we engage the worm and now what we want to do is we want to set our sectors and you'll see why we wait how we use these in a minute here these help block off and keep us from making a mistake as we're indexing around so we're gonna get in starting position here which we're gonna index in one direction only right okay so what we do is we put the zero up against we're gonna go clockwise so we're gonna go up against the left side of the pin and then so remember I said that we were gonna do one Rev in three holes right so what that means is so one Rev puts us back in that same hole right and then we want three holes so what we want to do is only show three holes like that okay all right and then what we do is we're gonna walk that down and studly or screwdriver there okay so what we do and this is just a quick demo here so what a one index in this case here so one turn okay plus one two three holes and we drop in there right okay and then what we do before we forget is we slide this up to here and then our next index is one turn plus one to three holes then we go like that only slide up one turn three holes slide up and so on so on rinse and repeat all the way around okay so that's kind of how that that whole deal works there for dividing dividing heads and this is a dividing head this is not it does do direct indexing but this is a proper dividing head which is great for doing gears and things that have weird numbers of spacings on them like our thirty-six tooth gear here okay so let's get started doing a little milling so first step here is we got to get our we're gonna cut on the side here I'm just touching off here so that's about I'm a zero there okay now this is a little bit of a tricky part here because I got a touch off on the side of that thing but I don't want to touch off too hard let's put it in neutral here get a little rub mark on there yeah okay so here's what I'm looking at it there's a teeny little little rub mark there you know when you're touching off on the top of round things they're the contact point is actually very very small and so and the at the tip of the gear tooth here I can't really get a good measurement because it's a curve right so I have to go with half of the cutter thickness here which is 150 5 divided by 2 that's o 78 so let's take let's take that out of the equation right now so I'm dialing down the the quilt Dro a 78 okay so now what that does is that puts my my cutting edge right on the rune on the center and it looks right here again just eyeballing it I'm just looking for you know super bozo mistakes and then I want half of this half of my existing diameter which I forgot so the optimal positioning here I forgot what this number is okay I'll using my calculator to make no bozo mistakes all right too [Music] so now we got to get a good good diameter touch offs here they do is just run it up this is this to get me in the neighborhoods I don't look like it's already touch it know what we're doing we're just looking for a little graze and that and then die come okay there it is well I got this the tiniest little scratch there okay and that's actually a pretty sensitive test before I blows over here okay and then we're gonna go to the full depth we're gonna do this in one pass so let's get set up to cut all right you guys ready to cut some teeth the dial in the full depth which from Machinery's handbook is 34 thousands go ahead and lock like the saddle [Applause] like I said I'm gonna cut all way down that way instead of zero all right [Applause] [Applause] [Applause] [Applause] magic pixie dust here so yeah what I wanted just to make sure that I'm 180 degrees apart so what I'm going to do is that yeah I get a good line I'm gonna put the wires that measuring wires in there okay yeah gingerly stick them in there Oh ring just to hold them so I have to do a balancing act there okay you know and then we're gonna measure over the wires and we're gonna compare it to right here or 0.6 0 0 to 7 8 over the over the wires for the original gear so you do all this measuring before you get all excited and pull this thing out to see if it fits right none of us have done that before right none of us have done that before okay six zero zero two you know I'm gonna call it pfg okay okay so from a pitch diameter standpoint I think we're pretty good these are the same two pins I used to measure the so it's just just for fun okay all right so let's check out the next step back over on the lathe and we are going to lop the piece off here it's 160 I'm just gonna go right to size so make an interesting sound [Music] the bronze brush and this kind of D burn it a little bit [Music] [Music] okay so I went looked in my set-screw inventory and I had some some zero eighty set screws and there's one on the end of this Oh 28 allen wrench here so they're pretty small so proportionally to the tooth that's it's pretty small so I'm just gonna go straight in it's just gonna make my life considerably easier than trying to come in at an angle and and do all that so we're gonna count or a spot drill it will counter drill it for a little over the body size of the the set screw then we'll drill and tap it then we'll put it all together and hopefully it's it's good to go [Music] [Music] [Music] okay all that stuff is so so lightweight if you hit it with the air it was a adios muchacho there and it looks workable [Applause] oh look at look at the Allen wrenches that it's spinning on the thing can't win alright let's give this a try that's what gets doing the business here I don't know okay it's in full mesh so I'm just gonna leave it there and leave a little space behind it run the set screw down okay all right mr. chip there's mr. year cool all right don't Sookie well that's about it for tonight we finished our little gear project and I hope you guys like that so if you would do me a favor hit that subscribe button we're not also heads up for all those folks that have been waiting for me to fire up another teespring t-shirt campaign I went ahead and did that I fired one up so there's a link in the description down below so this follow that link and you can go right to a support ox tools t-shirt and it goes to helping out the shop and buying machines and keep the things going around here and you get something back in your hand it's not just a handout to me so if you like it great thank you very much and I'll catch you next time

Channel: oxtoolco

Views: 38,579

Rating: 4.9700885 out of 5

Keywords: Involute, Gear Cutting, Toolmaking, Ham Radio, Radio receiver, Realistic radio, Radio Shack, Spur gear, Dividing head

Id: WhXRlrfhuOg

Length: 43min 42sec (2622 seconds)

Published: Sat Nov 03 2018