Mike Macartney Posted August 10, 2019 Author Share Posted August 10, 2019 17 hours ago, mike6024 said: I took just one material science class back in college, don't remember much, Neither do I - I did OND and half of an HND in Mechanical Engineering, back in the 1960's, it was a long time ago. I seem to remember something about martensite and austenite steel. Since then, I have never had the need to use the information and have forgotten anything I may have learnt about the subject. I have just searched the words and came up with this: “Martensite” most commonly refers to a very hard constituent of steel (the alloy of iron and carbon) important in some tool steels. The martensite is formed by rapid cooling (quenching) of austenite which traps carbon atoms that do not have time to diffuse out of the crystal structure. I'm none the wiser! It's all rocket science to me. Thanks very much for your posts on the carbon steels. 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 10, 2019 Share Posted August 10, 2019 I've never seen a spiral roll pin like that... it looks alike a good idea. 3 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 11, 2019 Author Share Posted August 11, 2019 22 hours ago, JV Puleo said: I've never seen a spiral roll pin like that... it looks alike a good idea. That's what I thought. I have just ordered 10 off x 3mm diameter on eBay. Later this morning, when I measured the diameter of the hole, I found this:- It looks as if I need a larger diameter pin, not only because the hole is a larger diameter but of this: I dare not drill out to the diameter of the wide diameter of the oval as is will not leave enough 'meat' around the hole. I might get away with using a 4mm diameter spiral roll pin if I can find them. The wear and the split pin must have worn the hole oval. I have been having fun machining the shafts, to go through the big ends and small ends, for checking the straightness of the conrods! All the suitable material I have is second hand bits of metal that I have no idea of the type of the make up of the steel. This bar that I was machining for fitting into the large big end bush on the conrod seemed extremely hard. I tried using HSS tool and nothing happened. I used a carbide tool and that cut OK, but the metal turned off in nice dark blue spirals! The tool appeared, to me, as if it was going blunt halfway towards the headstock. When I measured the diameter at the headstock end, it was 12 thou lager diameter, than the diameter at the tailstock end! I packed up for the day to have a think. Overnight I thought about the problem and realised that the tailstock was not lined up with the headstock. I had checked it before, by putting a centre in the chuck and a centre in the tailstock. Pushing the tailstock up to the one in the headstock, they seemed to look in line, so I didn't adjust anything. I suppose trying to visually see the small difference between the two points is impossible. When I worked out how to adjust the tailstock and check it., the bar then turned down fine. I had managed to adjust the tailstock so that there was only 2 thou difference between the diameter at the headstock end and tailstock end and that was over 10" between my two diameter measurments. With taking a few more cuts off the bar. . . . . . . . the conrod slid onto the bar nicely with no slack or wobble. I was pleased with myself. I then started on the shaft to go through the small big end on the large conrod. Making these shafts has taken a lot longer than I thought it would, but I have learnt a bit more about the lathe and machining in the process. 4 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 11, 2019 Author Share Posted August 11, 2019 On 8/10/2019 at 2:54 PM, Mike Macartney said: I'd suggest buy one of these, they're cheap Mike, I have checked the diameter I need and found that I need a pin that is just over 13mm (13.1mm). I have searched on the internet and ACCU have them at 14mm diameter which would be OK, but they only have then in hardened steel which I will not be able to drill for the locating pin. Are there any shoulder bolts that would be suitable, for this 'small' big end pin, for sale in the USA? Link to comment Share on other sites More sharing options...
JV Puleo Posted August 11, 2019 Share Posted August 11, 2019 Have you looked for 14mm drill rod? It's high carbon steel, suitable for hardening but probably isn't needed in this case. jp 1 Link to comment Share on other sites More sharing options...
Terry Harper Posted August 12, 2019 Share Posted August 12, 2019 Hi Mike, You might want to use a test bar to adjust the tail stock with more precision. I have to do this with my old South Bend due to wear on ways. Like many old lathes there is a bit of drop as the apron moves towards the head stock. I am not sure if your familiar with this method or not and there are a number of different ways to align the tail stock but this works for me. You could use straight stock but a dumbbell shape works best since you don't need to cut the full length just at each end. What I do is setup the stock running on a dead center (you can use a live center but dead works best) I take a light cut at both ends then measure to find the difference. If the measurement at the tail stock is larger than using a dial indicator I move the tail stock towards the tool for half the difference. and away if its smaller. Make another cut and try again until you get it spot on. This helps compensate for any wear on the ways or re-align the tail stock if it got thumped or you had it setup to do a tapper. 2 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 12, 2019 Author Share Posted August 12, 2019 15 hours ago, JV Puleo said: Have you looked for 14mm drill rod? Yesterday afternoon I started looking for different material and looked at 'silver steel' the UK name for drill rod. This morning I have ordered a length of 14mm. Thanks for the tip. 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 12, 2019 Author Share Posted August 12, 2019 7 hours ago, Terry Harper said: Like many old lathes there is a bit of drop as the apron moves towards the head stock Hi Terry, That is more or less what I did. I used the shaft I was making and made cuts each end and measured the diameters. I will check again later, using a dead centre and put the tailstock nearer the headstock, to see if there is any drop on the apron nearer the headstock. Thanks for the information. 2 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 13, 2019 Author Share Posted August 13, 2019 Checking the conrods for straightness and starting to make new nuts for the big end pin. To check for any bending of the conrod, I made up four shafts to go through the big and small end bushes, on the conrods. I hoped that these would highlight any problems by magnifying any distortion. Two shafts made for the big ends, now I need machine a couple for the small ends. With the tailstock now set to machine the same diameter at both ends of the shaft, life was a lot easier! Having no suitable stock bar in steel I had to use aluminium for the shafts for the small end bushes. Making these shafts maybe a complete waste of time, but at least it is giving me some practise on this big lathe. Even before measuring, I could see that the two shafts in the small ends weren't parallel. I tried rotating small conrod by 180 degrees, it looked better, but it still didn't look quite parallel. It was time to get out my glass surface plate, I bought it a few years ago, because it was cheap on eBay, I have not used yet. The problem is it's in the bottom shed, it's heavy, I'll pack up now and bring it up with me tomorrow morning when I'm feeling more lively. I found some blocks that were the same height by using a dial gauge. The two in the photo at the big end of the conrods weren't the same height although they looked the same. With the large shaft in the big end bush and a matched pair of blocks under the shaft on each side of the conrod, the shaft heights on each side, were exactly the same, when measured with the dial indicator. So far so good. At the other end (the small end shaft), with the shaft on a pair of matching height blocks. This side touched the block. (you can see I still have not got the hang of the focus of this replacement camera!) At the other end there was an air gap between the block and the shaft. I need to have a think about whether or not I try and bend the rod straight, or leave it as it is? Perhaps I will leave it be for the time being. I can't measure the distances between the big end shaft and the small end shaft as my Vernier caliper is too short. I have ordered a longer one, that should arrive later this week. I'll get on with another job instead - making the male threaded jig for the nuts for each side of the big end pin. I found an odd bit of hexagon bar which I turned down to 3/4" on the end. The next job was to cut the 18 tpi thread on it. This will be the first time I have cut a thread using this big lathe. It should be easier than cutting threads on my Myford? Before I tried the screw cutting, I turned down the area by the hexagonal to the thread depth so that I knew when I was getting near to completing the thread to the correct depth. I then moved the compound slide over to 22.5 degrees, half of the 55 degree thread angle. Set the compound slide on zero and moved the tool towards the round part of the metal until it just touched. I then set the cross slide dial also to zero. I wound the carriage away from work piece and put on a 5 thou cut with the compound slide. Making sure the cross slide was set back on zero. I also checked that the screw cutting gearbox was set on 18 tpi and set the thread cutting in motion by engaging the lead screw. It worked - the thread started cutting. I stopped the cut with the clutch lever wound the cross slide out a bit and changed the direction of the lead screw which wound the cutter back towards the tailstock. I kept repeating the above process until the lathe tool was down to the thread depth. I then tried the nut and if fitted! It was a bit tight, but it fitted. Tomorrow, I will try lapping the threads to make it a bit easier to screw the nut on. 4 Link to comment Share on other sites More sharing options...
mike6024 Posted August 13, 2019 Share Posted August 13, 2019 (edited) So the original pin would have been 1/2 inch but things were loose so we considered 13mm to tighten things up. But the holes are at 13.1mm. Are you thinking of turning down a 14mm tool steel bar? or opening up the holes to 14mm? Here's something : 13.1mm = 33/64 inch almost exactly. Is that interesting? That is 1/2 inch plus 1/64 = 33/64. There are drills size 33/64, and this tool steel bar 33/64. 33/64 Inch Diameter Tool Steel, O-1 Oil Hardening Drill Rod, US $11.94 You could buy this. http://www.ebay.com/itm/Value-Collection-33-64-Inch-Diameter-Tool-Steel-O-1-Oil-Hardening-Drill-Rod/283301115908? Edited August 13, 2019 by mike6024 (see edit history) Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 14, 2019 Author Share Posted August 14, 2019 19 hours ago, mike6024 said: Are you thinking of turning down a 14mm tool steel bar? or opening up the holes to 14mm? Thanks for your input regarding the 33/64" drill rod. You got me thinking that this maybe the answer. This morning I turned down a length of bar to 33/64" to see how the fit was in the smaller of the two big ends. It fitted perfectly into the small end for the piston wrist pins which are the same size as the small big end. But when I tried the 33/64" bar, in the small end bronze bush, of the smaller conrod, the fit was very slack. On inspecting the bronze bush I could see that the bronze bush has worn oval. I ordered the 14mm drill rod yesterday so I think I will use this and bore out the bronze bush and holes in the big conrod to fit the 14mm diameter drill rod. Thanks again for your continued interest, ideas and assistance in the project. I put some fine grinding paste to the 'big end pin nut' and after a couple of tightening and loosening's it the nut fitted perfectly. I also checked that the old nuts still fitted the large big end pin. Which they did, perfectly with no 'wobble'. As least my machining is getting better, even though my camera operation is getting worse! (Camera focus problems again. Sorry!) 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 14, 2019 Share Posted August 14, 2019 (edited) That technique works really well, doesn't it? I might be a good idea to get a 14mm reamer slightly undersize...I don't know how that works in metric but if it were imperial I'd say half a thousandth under. Then you can lap the pin into the bush but it will be tight in the rods. Look up "barrel laps" if you don't already have some. You might be standing too close with the camera. That is a problem I have with my "point & shoot" shop camera. It isn't designed for close work so it doesn't focus. I have to take big photos and then crop them. Edited August 14, 2019 by JV Puleo (see edit history) 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 15, 2019 Author Share Posted August 15, 2019 14 hours ago, JV Puleo said: That technique works really well, doesn't it? So far so good! Next job, this morning, is making the nuts. At least I am enjoying the process. 14 hours ago, JV Puleo said: Look up "barrel laps" if you don't already have some. Another new one on me - I'll look them up. I have sent my old camera for repair. I think the problem with this big camera of Fay's is that it is too big and complicated, it's more of an operator problem, rather than the camera itself! Just looked up "barrel laps" they only seem to be available on American sites. Is there another name for them? Link to comment Share on other sites More sharing options...
JV Puleo Posted August 15, 2019 Share Posted August 15, 2019 I don't know...Acro is the company that makes them but they may not be available in the UK. 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 15, 2019 Author Share Posted August 15, 2019 Thanks for that Joe. I have just sent Acro an email to ask if they have any agents in the UK. Link to comment Share on other sites More sharing options...
JV Puleo Posted August 15, 2019 Share Posted August 15, 2019 If not, they aren't very big or heavy. You could order one from the US and the shipping wouldn't be outrageous. I find them extremely useful when you want a close fit. You might also look into a abrasive called "Time Saver"... it degrades in use so if any particles are left they won't damage anything. I think it might be a British invention. something in the back of my mind says it was developed for the Royal Navy to make repairs to engines while at sea...or maybe I'm mixing it up with plastigage which I know is a British invention. 1 Link to comment Share on other sites More sharing options...
Spinneyhill Posted August 15, 2019 Share Posted August 15, 2019 I searched for "barrel lap site: .uk". One response was "helilap bore finishing tools". Any good? https://www.kemet.co.uk/products/toolroom/helilap-bore-finishing-tools Link to comment Share on other sites More sharing options...
mike6024 Posted August 16, 2019 Share Posted August 16, 2019 I'm watching a movie now that features not one, but two V-twins. Very good movie. Not sure if it would be of any help on this project, but maybe. 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 16, 2019 Author Share Posted August 16, 2019 Mike, Your post of the film Easy Rider took me back to 1969 when I last watched the film at the cinema. I hadn't been long married, Jane and I went to see the film at the local cinema. It is the only movie that has made me nearly cry. I came out of the picture house feeling very sad. I have not watched the movie since. Perhaps, 50 years on, it is time to watch it again. Mike 1 Link to comment Share on other sites More sharing options...
mike6024 Posted August 17, 2019 Share Posted August 17, 2019 (edited) Ironically Peter Fonda just died today. I'll watch the second half of the movie tonight. Didn't really even get halfway through it last night. It will be more poignant seeing it now. That's a heck of a chopper; the front end is so far out in front and such a lower angle when the front wheel it turned the wheel gets laid sideways. And the sissy bar. High handlebars. Edited August 17, 2019 by mike6024 (see edit history) Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 17, 2019 Author Share Posted August 17, 2019 BARREL LAPS On 8/15/2019 at 12:30 PM, JV Puleo said: Acro is the company that makes them but they may not be available in the UK. They emailed me more or less straight back and said sending them to the UK would be no problem. They attached an Excel spreadsheet of the sizes and prices. All I have to do is pick the sizes I want and they will give me a quote. Acro were very helpful. My dilemma now is what sizes to order? I need to have a good think as to what sizes would be useful to me now and in the future. I don't want to waste money on tools that I am never going to use, but as I am buying from the USA, I don't want to later think why didn't I buy more sizes! On 8/15/2019 at 8:54 PM, Spinneyhill said: I searched for "barrel lap site: .uk". One response was "helilap bore finishing tools". Any good? Thanks for posting the link. I have not contacted them as Acro responded so quickly to my email. I looked at the site and there were no prices. Their lap's looked expensive and more for use with professional production work, if you know what I mean. Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 17, 2019 Author Share Posted August 17, 2019 MAKING THE NUTS FOR THE BIG END PIN On 8/15/2019 at 8:41 AM, Mike Macartney said: So far so good! Next job, this morning, is making the nuts. At least I am enjoying the process. Well, I was enjoying myself until I started on the nuts! I found it very stressful. Maybe because there was a lot to think about, I was cutting into a blind hole, and it was the first time I had tried it on this big lathe. I managed it, tried the jig, that Joe had suggested to make first. That fitted OK, but seemed a bit loose. Perhaps I had machined off a 'tad' too much metal? I then tried the big end pin and that fitted the same, a bit 'wobblily'. I used the donkey saw to cut the internal threaded part of the hexagon bar. I worry about using a parting tool as I seem to break parting tools when I use them. I will have to look at a U-tube video to see if I am doing it the wrong way! I then split the threaded part into two using an angle grinder fitted in a 'cut off' stand. Being disappointed with my nut making I had another go. This time I cut off a section of the hex bar so I was not cutting a thread into a blind hole. Yet again I ended up with a wobblily nut! This is a photo of the thread I cut. It looks OK. I finished the day feeling rather dejected with my workmanship. Overnight I thought about it and decided that the nuts would really need to be good as they need tightening up very tight to stop the flywheels moving. In the morning I rang Tracy tools and asked them if they happened to have a 3/4" x 18 tpi tap in stock. They did, it was high speed steel, hence was a lot more expensive than a carbon steel tap. After a bit of moaning about the price the guy on the other end of the phone said I could have it at a good discount as it was 'old stock'. It should arrive on Saturday. The next morning I thought I would do something different and try and get my head around measuring the conrods. I had a clear up before I started, I saw the big end pin and thought I would try the original nuts on it. Guess what, they had a wobble as well! That made me feel a lot better. When the tap arrives I can try that and see if that gives less wobble than my efforts. 3 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 18, 2019 Author Share Posted August 18, 2019 Still playing with my nuts! They are for the crankshaft big end pin. The 3/4" x 18 tpi tap I ordered, arrived, I peeled off the protective coating and tried it in one of the original nuts. It only went in this far without forcing it. It was a taper tap so I expected it to go in a lot further than this before becoming a tight fit. I did not force it, as I did not want to enlarge the original thread. Buying this tap was a waste of money! Never mind, I will put it down to experience. I decided to go back to threading my own nuts! Well, the ones I had made previously, or make new ones if I had to. I decided to start again and make a new threaded jig first. As I still have doubts over my machining capabilities, I decided to make the nut deep enough to cover the exposed thread that was not covered by the nut, when it was tightened up, thinking that this may help the strength of the fixing. As you can see the original nut does not cover the whole of the threaded portion of the male thread. I measured the depth needed. Turned the new jig down to 3/4" diameter and threaded it. This time after studying Joe's posts I followed his method more closely. Made the nut and lapped it in on the threaded jig. I tightened it up and marked where it got to on the threaded jig with blue chalk marks. I could then see that, when I tightened up and loosened, whether the grinding paste was doing anything, it did. With grinding paste on the thread I kept undoing and tightening the nut until it tightened up to the shoulder of the jig. Faced the nut on the jig. . . . . and chamfered the top edges of the nut. The old 'brutalised' nut and my new nut. Mines of the left if your not sure! The new nut, fitted 'loosely', to one side of the big end pin. Both nuts are now made, fit and Mikes a 'Happy Bunny'! 5 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 18, 2019 Share Posted August 18, 2019 (edited) Nice job Mike. Internal threading does take a little practice. When I am working to a close fit I often make several "spring cuts"... i.e. run the tool through the nut a second or third time without setting it to take anything off. You.d be surprised at how much it can take off on the 2nd or even the 3rd pass but this is opening the hole in smaller increments than you could with the dial on the lathe. The last step in a case like this would be lapping...I'd stop with the nut going on tight and lap until it goes on smoothly. All this is much more easily demonstrated than it is to explain and there really is not way to get good at it without doing it a few times but it looks as if you've figured it all out. Using the wrench was a very good idea. Oh... the difference between the tap and the threaded hole in the original nut is an artifact of the period. Manufacturing tolerances were not as precise as they became during WWII and, of course all the parts were likely made in the Humber factory and all matched there. Chances are their toolmakers made their taps and reamers but I'd guess that nuts were made on screw machines. If everything wasn't set up to industry wide standard gages (I don't think there were any in 1914) there will be minor variations. Because of problems like this, at the beginning of WWI, the War Office assigned auto makers to specific services to minimize the effect on the mechanics who had to fix the vehicles. Vauxhall got the Royal Flying Corp. The British Red Cross got Buick. The Royal Navy Armored Car Service got Rolls Royce and Lanchester (the only two chassis suitable for making armoured cars). I forget where Humber went but it may have been the Army Service Corp. Edited August 18, 2019 by JV Puleo (see edit history) 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 19, 2019 Author Share Posted August 19, 2019 14 hours ago, JV Puleo said: Internal threading does take a little practice. When I am working to a close fit I often make several "spring cuts". Thanks Joe. I found out about the "spring cuts" by accident. I stopped machining and went back to the house for a break and a cup of tea. When I got back to the lathe I was not sure whether I had made the cut that the cross slide was set on, or not, and started the cut as it was and could see the tool taking off very small bits of material. I then used this method, that I found by accident, when the nut nearly fitted the thread. Strange as it may seem. The nuts for the crankshaft main shaft ends are the same size but full nuts. Just out of interest, I tried the big end pin nuts on the cranks shaft ends and they did not fit. Thanks again for all your help. I am really enjoying "Uncle Joe's" long distance machining apprenticeship scheme. Next, it is time to figure out whether, or not, I attempt to remove the slight twist in the large conrod and how to bore out the 14mm hole. If you don't mind I'll pass my ideas by you before I start attacking the conrod. 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 19, 2019 Author Share Posted August 19, 2019 14 hours ago, mike6024 said: I was interested in when you said if the pin slips in the flywheel hole, the flywheels go out of alignment. So the nut needs to go on tight. It is the taper at each end that does the majority of the 'holding' of the big end pin in place - like a Morse taper. As compression ratios, power outputs raised, and machining accuracy got better Harley Davidson must have decided to 'improve' the bottom end of the engines. To date I have not had any problems with this 'nuts and taper' big ends coming out of align on any of the motorcycles that I have owned. They have all been pre second world war motorcycles with not a lot of power. My 1910 Favourite, that's the make, it's Australian, I would call it a 500cc moped, as it only has one gear and is belt drive. 2 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 19, 2019 Author Share Posted August 19, 2019 I am in need of help again! I decided to at last take of the 3-jaw chuck to see what I need for fitting collets and/or fit the 4-jaw chuck. How do I remove the chuck? I put some wood and some wedges under the chuck to support the weight. I then put the C-spanner that came with the lathe on the bit behind the chuck and tried tapping the bar with a copper hide. I then put the C-spanner the other way up and put a bar between the jaws and tried tapping that in an anticlockwise direction. I then went and had a look at the back of the 4-jaw chuck to see what was on that. It's threaded. Here is a close up showing it's right hand thread. It looked as if the part on the lathe that takes the C-spanner is part of the lathe and the chuck would unscrew by turning anti clockwise. Am I correct? Before I start bashing away, I thought it best to ask first. 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 19, 2019 Share Posted August 19, 2019 (edited) Chances are it's just stuck...an ongoing problem with chucks that have been on the machine a long time. Take a look at the threads on the 4-jaw - that will tell you what direction the spanner has to turn in. I would put a piece of wood in the jaws of the chuck so that it hits the bed, thus keeping the chuck from turning and then put a pipe on the end of the spanner to get more leverage turning it the correct way (whichever that is). Do not put it in back gears to lock the chuck up - you'd run the risk of breaking a gear. I've never had a lathe that new so I'm almost as much in the dark as you are regarding taking it off but I have read multiple threads on the PM site regarding the removal of stuck chucks. jp I have one of those backing plates down stairs so I'll check myself when I get back to the shop. oops... I checked and I don't have one. I did at one time but I gave it to someone who had a lathe they could use it on. Edited August 19, 2019 by JV Puleo (see edit history) 2 Link to comment Share on other sites More sharing options...
Terry Harper Posted August 19, 2019 Share Posted August 19, 2019 Mike, With my South Bend you engage the back gear (so things don't turn) than stick the chuck tool in as if your going to close or open the jaws and give it a rap and it un-threads. 1 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 19, 2019 Share Posted August 19, 2019 I do the same with my Sidney but I worry about using the back gears when the chuck is really stuck. I had a lathe once that had a couple of teeth broken off the back gear and I skuspect that was why. At least everyone says not to yse the back gears that way though I'll bet practically everyone does! 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 20, 2019 Share Posted August 20, 2019 10 hours ago, Mike Macartney said: Here is a close up showing it's right hand thread. It looked as if the part on the lathe that takes the C-spanner is part of the lathe and the chuck would unscrew by turning anti clockwise. Am I correct? Yes. If a RH thread you turn it anti-clockwise to loosen it. It looks to me as if you are one the right track. Chucks that have been on too long can be a bear to remove. I've even heard of guys removing the chuck from the backing plate and turning them off. You won't have to do that but it isn't surprising that it's a chore to get it off. The saving grace is that once it is off and cleaned up it's unlikely to be a problem in the future. 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 20, 2019 Author Share Posted August 20, 2019 Thanks for your help. After I posted my plea yesterday. I suddenly thought - 'why not google it'. I'm of that age that 'googling it' doesn't come naturally! As it turned out, it was no surprise that lots of people have problems with stuck chucks. After watching a few U-tube videos on the subject, all on smaller lathes than mine, and thinking about the problem overnight my opus operandi is:- As the thread on the chuck is defiantly a right hand thread after looking at the 4-jaw chuck. 1. Find a large hexagon bar and tighten it up in the 3-jaw chuck that I want to remove. Hold the part on the headstock part with the C-spanner against the lathe casting. Use the 1/2" drive compressed air impact wrench on the hexagon bar with an impact socket. If that doesn't work. 2. Try the same again after soaking overnight with penetrating oil. If that doesn't work. 3. Get out my 3/4" drive socket set and use that with a length of scaffold bar on the end. If that doesn't work. 4. Try again after heating up the part that the C-spanner fits on with - a heat gun - if no joy - a propane torch - if no joy - heat up the C-spanner part and spray some 'Ice Shock' from an aerosol up the inside of the chuck and have another go at undoing the chuck. If none of those work I will have to think again! 1 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 20, 2019 Share Posted August 20, 2019 (edited) modus operandi... method of operation. Opus is a written work... as in opus magnus, great work. sorry...I just couldn't resist making use of my limited Latin - the only subject I ever failed. There is a huge Portuguese mortar on the Horse Guards Parade in London that was given to the George IV by the King of Portugal after the Napoleonic Wars. The British cast an extremely fanciful iron carriage for it and on the plinth is a plaque with an inscription from the King to George. It's in Latin on one side and English on the other side. Years ago I was walking across the Parade with my friend Stuart who stopped to read the inscription. He had the same Latin teacher I had and he was struggling with the wording while I corrected him (I was on the other side reading the English)... we turned and walked away and he remarked "I had no idea you were that good at Latin." It was 20 years before I told him the truth. Edited August 20, 2019 by JV Puleo (see edit history) 1 1 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 20, 2019 Author Share Posted August 20, 2019 6 minutes ago, JV Puleo said: It was 20 years before I told him the truth. At least for twenty years Stuart thought you were very clever! I blaim the spill cekin on the compuutor four the misstook inn me spilling of 'Modus Operandi'. Sorry, I should have read through the text before I posted it! Anyway, back to the Chuck removal. I went and helped Robert this morning with cutting up more of that sweet chestnut tree, this time just for firewood. When I got back I used the 3/4" drive socket set with a scaffold pole for extra leverage and the chuck undid OK. It is a similar type of fitting to the Colchester lathe. I'll post a photo tomorrow. I think the lathe is possibly younger than I thought it was. It may even be younger than me! 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 20, 2019 Share Posted August 20, 2019 Good. Clean the threads up really good before you put it back and maybe give it a coating of light oil... that said, it was probably over tightened to begin with or it was used for a job that put a lot of pressure on it. Ideally, if the chuck is turning anti-clockwise the pressure is clockwise which tightens is. You only run into problems when you have to run the lathe backwards - which isn't very often in my experience. I think I've only had to do it twice and one of those times was a stupid mistake. 2 Link to comment Share on other sites More sharing options...
alsfarms Posted August 20, 2019 Share Posted August 20, 2019 Hello Mike, It appears that you have your chuck loose and ready to move along. Little things like a stuck chuck can sure be a bugga boo. When I go from my three jaw to the four jaw chuck on my Southbend lathe, I do not knock it down with a striking wrench. The most common and natural rotation of the head stock keeps it snug. If I am on a "tedious" threading job and want to remove as many possible problems, I will take a cut, stop roll out the tool, shift to reverse, back the apron back, stop, reset the threading tool to the predetermined cutting depth, change gears to forward and make another cut. I have never had an issue with the chuck coming loose, even under this circumstance. Keep up the good work Mike. Joe, interesting Latin lesson!!!! Al 2 Link to comment Share on other sites More sharing options...
John S. Posted August 20, 2019 Share Posted August 20, 2019 Mike, I love the work you are putting in the Humberette. It is truly a fantastic restoration. Thanks, John 2 Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 21, 2019 Author Share Posted August 21, 2019 Thank you John for your kind comments. Link to comment Share on other sites More sharing options...
Mike Macartney Posted August 21, 2019 Author Share Posted August 21, 2019 Here is a photo of the headstock of my lathe with the chuck removed. I wasn't expecting to find a taper and a keyway. The threaded ring locks the chuck onto the taper. I think this maybe the same sort of chuck fitting on Colchester lathes? Finding a collet chuck for this may be a problem? The bore, from looking up it, looks parallel all the way through it. Thanks Al, Joe and Terry for your helpful posts regarding the lathe chuck. 2 Link to comment Share on other sites More sharing options...
JV Puleo Posted August 21, 2019 Share Posted August 21, 2019 I very much doubt it's a straight bore. I've never heard of one on any machine made in the 20th century. It may be a #5 Morse Taper... 1 Link to comment Share on other sites More sharing options...
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