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Forum Index : Windmills : Not a happy chappy! Non windmill related.
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| KiwiJohn Guru  Joined: 01/12/2005 Location: New ZealandPosts: 691 |
So my new lathe arrives, it had been in the showroom for 6 years and it came at a good price. However  after one hour of running the motor makes a loud buzzing, harsh sound, like a stalled motor but louder. Now I am waiting on them to send me a new motor. |
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oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Sounds like the start capacitor (he he.. non-polarised electrolytic of course) is in series with the start windings. Failed triac if electronic, or welded contacts if centripetal. Hmmm, I wonder if the electro (long storage) lost its..... never mind 
At least your not isolated... here it means I start rewinding the start fields and/or, and up the centripetal switch or build a new triac starter. 
So it's not so bad really
..........oztules Village idiot...or... just another hack out of his depth |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
I figures the centripetal switch, even went to far as to take the cover off the motor but it is a fairly well sealed machine and I would need to take off an end plate which would mean pulling the pulley, and I only have a little puller..... and it is a holiday week end. I have lived in a few isolated places, spent years at the end of a 75 mile alpine road that could be closed for months and another year or so on an island with a weekly air service and a quarterly ship, so I kind of understand having to make do. The machine has a box of relays (think they are called 'contactors' nowadays?) to handle all the safety interlocks, motor reversing and starting. Nothing 'electronic' though. The motor is a capacitor start, capacitor run, 2HP single phase. |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
. I recently had a Mono pump (cap start/cap run) turn up for repair.... shorted run cap.... I wonder??? In this case I unwound two of the burnt start coils,(the other two were ok), and left it like that. I increased the start caps (back to back dc ones) and it runs as before... oh and replaced the run cap..... yes I'm a butcher..but it worked well. ..........oztules Village idiot...or... just another hack out of his depth |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1461 |
John, If you've gone and spent the money on a lathe go the extra step and strip out all the electrical stuff, grab a 2hp 3 phase motor, wire it in delta and grab a vfd. Not only do have all the features but you'll find the power draw is heaps less. For a small expense the VFD way is the way to go in my opnion, otherwise, I wouldn't have 3 of them and planning on the next one for my surface grinder. Cheers Bryan  |
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| Dinges Senior Member  Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
KiwiJohn, Every cloud has its silver lining... looks like you now have a candidate for a motorconversion. Oztules, what do you reckon was the failure mode of the pump motor: defect cap causing burnt-out windings, or a defect winding damaging the capacitor? Peter. |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Considering I only got this thing home last week I think I will be allowing the vendor to meet his obligations under the relevant consumer protection legislation! 
But I do have a couple or three 3phase motors kicking around here, hmmmmmm! |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Good luck with the problem, hope it gets resolved satisfactorily. But you got me curious now, have you any pictures of your new toy? If its Chinese made, like mine, it would pay to pull it apart before using it. I found swarf stuck in the oil galleries and bearings that were below my standards. Guess I got what I paid for. After fixing all that I have a robust lathe that has been working well and trouble free these last 5 years. Klaus |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Here we are Tinker, nothing terribly fancy, no digitial readouts or CNC, a basic lathe that is big enough for anything I am likely to do, maybe bigger than I was looking for but this one came for the price of a smaller one. 
The only difference between this picture and mine that I can see: All one colour (no yellow or red), the light shade is a different shape, it is not called 'Crusader', mine does not have the nifty socks on the feed screw. 810mm between centres, 310mm maximum swing, 38mm spindle, 2HP(when fixed), 9 speeds (75 - 1810). |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Now I have the attention of some lathe-proficient folks here is a newbie question! The specs say maximum tool size 16mm but when I buy (a bloody expensive) 16mm tool bar with cutting chip it is too high, more than a mm above centre, where did I go wrong? |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Dinges, It's hard to say in hind sight. I tend to get the problems no one else can fix. There were actually two pumps turn up. They previously went to the mob that sold them over here. They can sell pumps but can't fixem by the looks. They had fiddled with both units and changed the caps across and generally floundered around pretending to understand what they were doing.... pronounced then both dead and returned them to the owner. This makes it hard to determine the original cause of failure. From what I can ascertain from the owner, the water table had dropped, and so the pressure differential had increased, and the pump must have been close to it's limits before this. These Mono's although only a rubber jacket over a wobble screw, actually behave as a fixed displacement pump. If the outlet is blocked they stall. If the pressure is too high, they will overload and cook. I suspect that they ran very hot for some time. The plastic flanges were deformed from the heat of the motor body. This probably caused the start caps in one to dry out (which it was), and the run cap to denature the plastic film to puncture the plastic and short the conducting films together. The second one had good windings, but the rubber had stuck to the wobble screw, and so stalled the start. This meant that start up was very high current and the bimetal o/load saved it each time it tried to start. Because they had swapped bits and pieces, I can't be sure, but I assume the run cap failed during running, and cooked the start winding. The run was fine, so this happened while it was still running, where there was enough current to burn the coils, but not enough to blow the o/load fast enough..... until the next start.... then both the run and start would present as a shorted transformer and blow the o/load quickly. The start winding being high resistance (comparatively) would not be enough on it's own to blow the o/load fast enough to protect itself...... and lets face it, a burnt start winding can't blow up a run capacitor anyway.... no matter how short it was. Well that's my best guess. Suffice to say both pumps run well now... even with the butchery and back to back dc caps for the start caps in one, with only half the start windings (at 90 degrees). ............oztules Village idiot...or... just another hack out of his depth |
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| Dinges Senior Member Joined: 04/01/2008 Location: AlbaniaPosts: 510 |
Thanks Oztules. |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
It means you can just fit a 16mm tool in the post , you have to either machine of the bottom of the tool , or do what I did , carefully work out exact centre , mark the tool then take a 5" grinder and remove most of the material and finnish by draw file, micrometer and bearing blue on a surface plate . You will then have a strong tool that slips straight in at centre and no stuffing arround with shims.. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
KiwiJohn, your late looks like a later version of mine, some parts are identical, as are the specs. I have an earlier version with V-belt speed change under the top box (6 speed + back gear) and the old fashioned 'poke the lever into the appropriate hole' feed speed change box. That safety cover over the chuck is going to be a nuisance, I removed mine. There were also other electrical 'safety interlocks', no doubt required to pass the CE certification but a nuisance when it came to use the machine. Do check it out thoroughly before tackling precision work. You should be able to spin the chuck easily by hand with the carriage set on auto feed, if you can't something is set too tight with the gear train. Re the tool post, I can't fit 16mm either. Bought a cheap set of 12mm insert tools with the lathe but they were crap and had non standard (not available)inserts. Have since made my own tool holders that accept the 1/4" square HSS bits and one for 3/8" square, these I use most of the time. The tool is easy to sharpen or grind into a different pattern. Bought some boring bars with the triangular inserts, a good investment. Have fun Klaus Klaus |
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GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi kiwijohn, This is very similar to the lathe I had, with a similar problem. I measured the offset error of the tool holder. I then set the tool holder up in the 4 jaw chuck, with the bottom surface facing out. You may need to put a spacer on the chuck side. I then machined off the bottom of the tool holder the required amount. This keeps all the surfaces straight. Gordon. become more energy aware |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Thanks everyone for the advice re the tool holder. Yes, I would rather like the no shims situation if I can get it so this expensive bit of Norwegian steel is going to feel the bite. Fortunately I have a friend with a mill who might take it down for me, I just have to accurately measure centre height which should not be too hard even for someone like me.
Klaus, yes, the safety interlocks could get a bit tiring, I will leave them as is until I have had it a while though. The shop gave me a sett of 10mm tools to get started with, Chinese painted nice blue, they do seem to work even on a fairly hard piece of an old forged Isuzu drive shaft but I got a bit greedy with feeding the tool and one bent like a pretzel, I think I know who to blame for that one.
Gordon, I would probably try that today, if I had a motor on the lathe! |
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| grub Senior Member Joined: 27/11/2007 Location: AustraliaPosts: 169 |
Here is a working idea for a boring bar holder. Take a length of round blank bar that is of larger diameter than your boring bar and weld to it's side a length of square bar. Weld the two together so that the round bar centre is about the centre height for the boring bar on the lathe. Put this jointed piece into the tool post as if to use it to bore a hole (nice and parallel to lathe centre). Putinto your chuck a centre drill and centre drill your blank at its near centre. Next place a drill into your chuck and drill out your blank to the diameter of your boring bar (neat fit is best and in your case a new 16mm drill bit will do the trick). Remove the boring bar holder from the tool post and drill and tap along the top of the holder so clamping screws can be used. Now you have a quick and accurate boring bar holder that is easy to fit and remove. Make one for each size boring bar that you have. It should not take more that an hour for each one. I have made heaps of these things and they work a treat. |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Kiwijohn, When you get it going, you will be in possession of a X-axis Z-axis milling machine. You can then (by being an animal really), build a quick change toolpost and a few holders... easier than it looks with a bit of interesting fabrication
Then you will have full control of your heights. The more holders you make, the easier life is. I have built 5. Mine takes up to 16-32mm tools... overkill. Fun begins as soon as the new motor is installed. I can't imagine using shims. If you don't wish to go that route, I would remachine the tool holder to larger slots (drop the bottom of the slot 3-6mm so you can shim up at least. ..............oztules ps I have noticed that the bimetal holesaws make good milling tools for facing in slots, and make a fly cutter for other facing jobs. Second hand quick change tungsten carbide tips are good to braze onto anything you can find to make all sorts of useful tools. Village idiot...or... just another hack out of his depth |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Oh I am sure there is plenty of scope for all sorts of 'mods' that can be done to avoid shims. Heck, I was even thinking that by putting a shim under the tool post itself I could avoid shims for each tool, only problem is I would need a 'negative shim'! 
I do have a few other motors around here and I really should have one mounted already and in full play mode until the new motor arrives, but I am being a bit slack and instead taking trailer loads of 'stuff' to the tip! You wouldnt happen to have a need for two steel cabinets (with nice smokey plastic fronts) for your workshop? They are old telecom rack cabinets and are actually too good to throw away so I am taking them to the recycle shop. |
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| Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1461 |
Hiya John, Heres a simple tip to ensure you get the centre height perfect everytime. Machine say a 60 degree point in some scrap steel, get some pre-machined flatbar then measure the height to the centre. Then make a steel rising plate so the underside of the top is exactly on centre. Once thats done when ever you set a tool up just use that guage and you'll be on centre every time. Steel packing tape makes for good shims under tools, aswell as shim steel for the fine tweaking. Oztules has given you a great idea turning the lathe into a mill and I do have all the info here aswell as castings. Now John are you off the grid ??? If so that suggestion of mine on the VFD means anyone based full time on R.E. can run upto a 3hp 3 phase motor off a decent inverter, have forward/reverse via a switch, variable speed via a pot and for the pic micro crowd RS 485 MODBUS control. Now if you need any help just sing out mate and I'll be glad to helpout. Cheers Bryan |
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