Here is a list of all the postings Paul Kemp has made in our forums. Click on a thread name to jump to the thread.
Thread: Minnie traction engine stays help need |
07/01/2020 23:15:35 |
George, I feel your pain! Also tend to agree with fizzy although you may be in with a chance as it is still brand new and never steamed. Best plan if you intend silver soldering a repair would be oxy gear although very little room for manoeuvre inside that firebox! The way to go maybe to mill the existing stays away, top the inner and outer plates and make some close fitting screwed stays, peen the edges over lightly and then caulk with some HT soft solder (Comsol) if you can still get it. Probably time to have a word with your boiler inspector if you intend getting it certificated and see what they would accept / suggest. Sadly there is a lesson here, the guy doing the drilling obviously didn't fully understand what was to be achieved. Always best to make sure there is a clear understanding as to what is to be done. Easy to say with hindsight though! Hope they didn't charge you for wrecking it! Paul. |
Thread: Timesaver lapping compound quandary |
07/01/2020 23:05:39 |
Zan, Sorry I don't have the original packaging, I would say it was a fairly course grade though, was originally purchased by a mate for a job on a full size traction engine and he kindly passed on a small amount loose to me for my job. I can try to find out this coming weekend and if I do will let you know. Paul. |
Thread: Hello from Norfolk |
07/01/2020 23:01:47 |
David, Is it a steel boiler or copper? If it's steel and you have no certification whatsoever (material certs or welder qualification certs) even you may struggle to get it certificated. Copper is not so much of an issue but depending on the testing route you choose it's likely the cladding will have to come off. Paul. |
Thread: Really basic lubrication question? |
06/01/2020 00:34:15 |
There is no simple questions or simple answers when it comes to lubrication, there is a whole science behind it! The base question grease or oil depends on many things, relative speed of the surfaces and load being the first considerations. Many high speed applications can use plain bearings (turbochargers being a case in point where speeds are up to 50krpm) with plain pressure fed oil lubricated bearings. Highly loaded spherical roller bearings such as the SKF SOFN series of blocks do not use grease but oil. The key to successful lubrication is the surfaces remaining separated by the lubricant. You need to be careful with grease in roller bearings, the SKF Cooper split roller bearings will run excessively hot if there is too much grease in the casing, not always a case or more being better! No easy answers! Paul. |
Thread: Timesaver lapping compound quandary |
06/01/2020 00:21:37 |
I have used it but only on a steel shaft into a cast iron bore so far. 1 1/4" diameter, I used the green, no science, was what I had! I need to ease some bronze bushes in the second shaft bearings (bronze bushes, steel shaft) this year and will probably use yellow for that. Seems really good stuff, worked well on the part I did. Paul. |
Thread: Choice between cheap mini milling machines. |
04/01/2020 00:48:29 |
Andrew, I have the equivalent of the Clarke CMD10 as one of my machines. Despite the fact I have done some good work on it I wouldn't recomend you adopt one as a primary means of drilling holes! Anything over about 10mm will mean some extreme frustration, trust me. I certainly wouldn't recommend any intent to replace even a small 1/2" capacity drill press with one of these! As a light mill it is fine in my small shop at home but it's not a serious contender for doing any reasonably large jobs. My advice for general purpose work is look for something bigger and heavier with a bit more grunt if you want to drill 13mm holes, especially in steel! Dont get me wrong, for what it is I am satisfied with it but I do have experience of commercial machines and I bought it with eyes open and a reasonable idea of what to expect having trained as a fitter/turner. My main mill is an Elliot Omnimill and that has both horizontal and vertical facility and that will do 13mm holes in steel as thick as you like for fun but that is a light industrial machine and a whole different ball game! I don't have experience of the larger Sieg machines but they do get a good write up and seem from what has been posted on here to be quite capable. If you don't have much experience of milling I think you would find one of those much more suitable. Have a look at Ron Laden's thread on his and some of Jason's posts for an idea of what they can do. Just my 2penny worth! Paul.
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Thread: Ml7 New Owner. |
02/01/2020 22:11:24 |
Which end of the taper spins? Chuck or the taper in the tailstock? Not unusual for older myfords that have been abused to have damage in the tailstock taper... If it's the chuck on the arbor I had a similar problem from a chuck and arbor from one of the common suppliers, can't remember which. Turned out the arbor was too long and bottoming in the chuck just as it started to grip. Ended up putting the end on the grinder and shortening by about 0.030". Tapped it back on and been fine ever since! Eject the arbor from the tailstock taper on an ML7 with a brass drift. Paul. |
Thread: Any real risks corrosion etc combining aluminium and steel |
28/12/2019 13:41:02 |
Depends on actual material grades, how combined, environment in which they will reside, design stresses and corrosion allowance and your perception of risk. Paul. |
Thread: Replacement inverter advise |
26/12/2019 00:52:00 |
Clive, I ended up with a couple of those inverters. Tried to buy them in early 2018 direct from a Chinese vendor similar to the one you linked for £40 ea. To cut a long story short there were lots of issues getting them where the supplier told porky pies and a mate of mine who has business connections out there intervened and they ended up eventually fulfilling the original order FOC. I ended up using one a week or so ago and as you say, it works fine. Luckily I had a bit of experience setting up another pair of Chinese inverters on my big mill that I bought for the same purpose as these but got fed up waiting for them to arrive so I knew roughly what to play with and the set up took me maybe 10 mins tops. Does exactly what I need it to do. I bought a motor from IDS recently, delivery was great, motor seems good quality, only bug bear is postage and VAT which combined was 50% of the listed price of the motor on top of the advertised price. Fair enough shipping costs and VAT can't be avoided but you do end up paying a fair bit more than the initial advertised price. Seems to be about 50/50 on here for or against this type of foreign import versus named units through UK suppliers. Biggest criticsm seems to be quality of internal components and build quality is low or poor on the imports. That may well be true, I am not qualified to comment. The second issue is after sales and technical support which from overseas suppliers is pretty well non existent but there is plenty of info out there in forums and on YouTube that if you have some common sense the set up is not that onerous. So it comes down to price for me. At the time I bought this pair getting a similar product from a UK supplier (and I tried the usual suspects) with delivery and VAT charges (how they can send these things for £40 including carriage from China and still make a profit beats me!) was going to be three times the price and at the time that wasn't really justifiable, so I took a punt! So far I have no complaints with 2 imports running now nearly 2 years and they have done a lot of work and the latest the same as yours only having run about an hour so far. Certainly the latest one seems quieter electrically than the old variable speed DC drive set up as the workshop DAb radio was knocked out immediately the DC drive was powered up, even before the motor was turning. The latest VFD and motor dont bother it at all! So for my money I am very satisfied so far. Paul.
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Thread: 042 Locomotive plans |
24/12/2019 17:25:21 |
Brad, That looks interesting, I don't recognise the design personally but hopefully someone will. It looks vaguely Hunslet style, certainly narrow gauge prototype I would say. Paul. |
Thread: What Did You Do Today 2019 |
20/12/2019 22:36:50 |
Andrew, Mine needed trimming too, it was a test one I think that Edward kindly threw in with the castings if it was any use to me. I clamped it to a length of wood laid inside after roughing down with the nibbler (I think) and finished with a file. I don't think I posted any pics of that bit, will have a look in my archive when I get chance and see if I have any other pictures not previously posted. I can tell you exactly where I got the rivets, Port of Spain, in Trinidad, big "hardware" store at the top of the main drag from the lighthouse just before the church. I am guessing that won't help much though! I was looking for some csk rivets for the tyre mod I did on the Fowler ploughing engine. I was working out there for a while. I think I had their last box! Don't forget the chimney cap. Mine goes on from the bottom of the taper, thus the top rivet of my seam is too tall to allow it past so has been made as a threaded one with a thin nut inside. Paul. |
Thread: Slight repair required |
19/12/2019 21:40:30 |
Is that ferrous or non ferrous? Thought weight was prime concern in aviation so assumed everything would be alu or variants of? Paul. |
Thread: What Did You Do Today 2019 |
19/12/2019 20:52:05 |
Posted by Andrew Johnston on 19/12/2019 20:17:35:
Posted by JasonB on 19/12/2019 17:09:17:
Would you have more luck with pyramid rolls? I suppose ideally you would need the lower two to move horizontally to form a vee and the top to come down more on the narrower end. Would a wooden former be upto it? There was a video online showing a 4 roll in action; basically a pinch roll but with free rolls in front and behind the pinch pair. But that doesn't help me. I'd considered wood, but I've no idea what to buy or where to get it. I just tried an online shop; for 100mm by 100mm by 500mm long of American Ash I was quoted £13852.
Think I'll stick to steel! Andrew
Andrew, chimney for my 6" was supplied vaguely round and coned but the wrong diameter / taper. I managed to persuade that into shape over a length of 50mm steel supported on a pair of axle stands while pulling it in to diameter with a couple of heavy jubilee clips! If you have a rough shape you may be able to do similar. I also put a joggled edge on mine so the rivetted seam gave a flush fit in the chimney base and cap rather than a step of an ordinary lap joint. I used one of those air powered car body edge setters - was right on its limits! Riveted using flat head rivets put in from inside and a formed round head outside, again supported on the 50mm bar. I think I put a bit of info and pictures on TT, was a while back now though! Paul. |
Thread: Micro Mill |
15/12/2019 13:07:50 |
Ron, Well the moment of truth approaches! I have just mounted the box on the wall and about to try it on the webs for the valve rod support bracket for the engine! Not particularly challenging for it, just milling down the edge of some 1/4" steel plate but will give me an idea how it compares. Original was input power and calculations done by my mate suggest the new one will give more at the spindle. As to the engine itself, I was moving it forward quite well at the beginning of the year and the plan was to be in steam for August just gone! Then foolishly I agreed to help out a company based in London, part time working mainly from home for a fixed 3 month term - that has ended up pretty well full time recently so progress has suffered badly! However hopefully in the new year a balance will be struck and progress will improve. I have machined all the large castings now, cylinder is finished with the liner in, trunk guide I am just finishing now so lots of studs to make in the new year to start joining everything together so need to get my Coventry die box up and running! Seasons greetings! Paul. |
14/12/2019 21:08:34 |
I decided to go for it, motor came from Inverter drive supermarket or something like that, bit miffed when I ordered it that their quoted prices don't include VAT so it was £9 carriage plus £9 VAT so final price was closer to £50 than £35, hey ho, it came in 24hrs, well packed and allegedly made in Portugal. First mechanical job was to transfer and drill new holes for the mounting bolts, motor was a universal mount so used 2 of the cap screws that held one of the feet on as I didn't need the feet! The other two bolts had to be turned down hex heads to get the clearance on the mating gear. Then had to set up the nylon drive gear which was as slack as a yak on the old 8mm motor spindle to open it out to 9mm. Easy enough then had to open out the keyway deeper. Then needed a couple of spacers with keyways to clear the key and get the gear in the right position relative to the input gear on the two speed shaft, had a bar end of free cutting stainless on the bench the right OD so used that for the spacers and a new clamp washer. Reassembled and connected the VFD (currently laying on bench) programmed it up for. 4 pole motor max 75hz so I can if I want match the old top speed (never really used that much though), switched on expecting the lights to go out and she burst into life! All works as it should, about as noisy as it was before and the advantage the VFD allows an instant reverse of direction which will be handy for power tapping. Despite following the terminals faithfully I had to swap 2 phases to get it to run forward when the VFD indication said fwd! Not cut any metal yet as the battery drill was flat and I have to screw the box on the wall, tomorrow for that, so far so good!
6 wall plugs and a couple of cable clips and we are away! One improvement is the old DC drive knocked out Planet Rock on the dab workshop radio as soon as it was switched on, no problem now! Sorry about the last two sideways pictures! Paul. |
Thread: my first lathe. |
12/12/2019 |
Posted by Michael Gilligan on 11/12/2019 23:41:12:
Sorry, Rod ... I didn’t ask the question clearly I realise how one tool is clamped, but I’m struggling to see the benefit of having multiple ‘stations’ when the tool-post is just a static plate. MichaelG.
Fair point, I have used the front pair for boring bars, the side pair for normal tools and occasionally the rear pair when turning a large diameter, never used the pair on the tailstock side myself - but supplied with the lathe as std is an angle plate which mounts to the cross slide onto which the top slide bolts to give you a vertical slide for milling. Also provided was a small machine vice for work holding on the top slide in the vertical position. I suppose you could leave the tool post in position as another way of clamping the workpiece in which case the screws on the tailstock side may be used? Before I got the micro mill I did a fair bit of milling using the supplied vice but I have never used the tool post to hold milling jobs, never occurred to me before! Agreed the standard tool post is a bit unconventional as well but it has served me well and I think they are great little machines, the only real limitation is the slow speed is not slow enough for coarse thread screw cutting unless you are quick and brave! This was addressed by Essel Engineering who produced an additional set of pulleys, I don't have this though. Paul. |
09/12/2019 23:25:53 |
Jamie, Thanks for the bigger picture. Never seen a tool post like that before! Can't imagine what advantage it gives, disadvantage I would say is the large negative top rake, not really what you want for steel. I think you will get better results with the conventional round tool post that came as standard, that will give you a zero or positive rake depending how the tool is ground. I get a decent consistent finish without locking slides on mine. Paul. |
Thread: Micro Mill |
09/12/2019 22:05:28 |
Thanks gents, Replies in turn; Ron, I had a mate who knows a lot more about these things than I do some calculations and he reckons the three phase due to the difference input / output ratings will give me slightly more power than the original. Unfortunately the next motor up has a 60mm spigot and as the end plate is recessed inside there isn't enough meat to turn it down to 50mm. I could open up the hole in the existing plate but there will be little room left for the motor holding bolts so given the info above I am going to give it a go, little to lose! Michael, I have not had the gear selector rattle but I have broken it twice! Second time I realised what was happening with the poor fitting short radiused end of the key which was effectively jacking the gears apart first time I bought a new one but second time I welded it back together and since sorting the key issue have had no more problems. The motor gear gets loose on the shaft, I assume that is a combination of heat through the spindle and load. With the new motor the spindle is 1mm larger so I can bore out the gear to a good fit and cut a new keyway, the 3ph should run cooler as it has a fan so that may improve too. Ian, Wow, some radical surgery there! Interesting, not sure I want to go that far but food for thought in the future if am looking for a project. Having the bigger industrial grade mill I do only tend to do smaller jobs on this one now, it's handy for quick jobs that I don't want to travel to the big machine (would love a larger shed at home in response to the other suggestion re extending but we are completely out of space! Need to move!). Good to see / hear what others have done though, where there is a will..... Will update when I get the motor and get it running again. Paul. |
08/12/2019 22:50:15 |
Emgee, i can't find a higher power 3ph motor with a 50mm spigot. The drive train is a weakness anyway. Yes I definitely ask too much of it but my big mill is in my mates shed about 20mins drive away so having the small one at home is handy. The DC motor is 150w in and the 3ph is 120w out so power at the spindle won't be a lot different. I have never stalled a cutter on the old motor the rest of the machine is not up to heavy enough cuts for that! As the new 3ph motor is only just over £30 and a new DC is £100 and a new board I think was around £50 economically it's a better bet, inverter is free cos I have it already. Paul. |
08/12/2019 22:05:03 |
Well it's happened again! My long suffering micro mill has stopped going round! Last time I used it I had a problem but poking around in the controller seemed to set it off again. Today, no chance. Plug in, all good, switch to fwd, green light comes on as it should, turn the pot on to make it revolve, orange light comes on (as it would if the overload had tripped), no motion! Same in reverse. Quick prod about inside with a meter reveals no volts to the motor under any condition. Yes the fuse is good. Given the limited space in my workshop at home it's a handy little machine but on the limit of things I do! Generally though it puts up with it although I have had my share of broken gear selectors and split gears and on a marathon session with no regard to the temperature of the motor burnt it out. A new motor was £100! i have checked the motor and the resistance seems good, brushes are good so this time I think it's something on the control board, there is nothing obviously fried though. i have a spare inverter (well 2 actually) and looking around I can get a 3ph 240v motor rated at 0.12kw at 2700 50hz but continuously rated between 5 and 75hz 200 to 4050 rpm for £35! Original set up is 240v AC in, 230v DC out to a 4000rpm 150w motor. Anyone think I will notice the difference? Paul. |
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