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Member postings for Phil Whitley

Here is a list of all the postings Phil Whitley has made in our forums. Click on a thread name to jump to the thread.

Thread: Colchester Student Mk1 Won't Start
11/04/2020 11:13:19

Just treat it like a normal motor. plenty of online bearing suppliers, order on ID/ED , Don't buy the cheapest, you will get the lowest quality chinese bearings, and some of them are rubbish, SKF or RHP are good. Just use a normal LM high melting point grease same as you would use for car wheelbearings. You could try cleaning out the bearings you have, but from the noise it was making, I think they are shot! can you post up a pic of the top end of the motor where the flexi conduit goes in? The rotor may just pull out, but there could be a couple of bearing retainer screws inside the terminal box, as it is vertically mounted. The lower (or both) bearingd may be axial thrust types.

Phil.

Edited By Phil Whitley on 11/04/2020 11:19:57

Edited By Phil Whitley on 11/04/2020 11:21:08

Thread: Workshop insulation
10/04/2020 20:10:34

Tar paper is the vapour barrier at the moment, but general opinion and building regs says DPM on the warm side of the insulation, that is between the insulation and the lining. I wouldnt bother removing the tar paper, you only get condensation when warm moist air hits a cold surface, the cold surface will be the outside boarding, and the cavity behind the boarding will be at the same temperature as ambient outside. leave a 1" gap next to the boarding to allow air to circulate, if the joists are 4", use 3" jablite, or cellotex/kingspan if you can afford it! you could use 75mm rockwool batts, but dont use loose glasswool, it just gets damp and slumps. I used visqueen dpm on my brick walls, but put the insulation in contact with the brickwork, and put the dpm over the top, immediately under the lining. With a timber building,which already has a tarpaper dpm, it is debatable whether you really need another DPM. No point in using breathable under tile type, as it has nowhere to breathe too!

Phil

Thread: My week this week! My workshop videos
10/04/2020 19:25:30
Week 3 of lockdown, I have not been to the workshop at all, may go next week, see how it goes. This is a little look round our back garden showing my rustic brickwork and a garden tour narrated by my eldest daughter,Izzy, including a brief glimpse of Catherine, my wife, and Emily, my youngest, brief because they refused to be filmed!. Warning, contains gratuitous pressure washer action! Phil East Yorkshire

Edited By Phil Whitley on 10/04/2020 19:28:20

Thread: Meddings Driltrue blowing fuse?
10/04/2020 11:33:35

This sounds about right Adrian, if the drill is set to one of the higher range of speeds, the inrush current will be quite high, but only for a few seconds, and dry bearings will not help at all. Check the motor and the spindle with the belts off, and lube as required.

Phil

Thread: Colchester Student Mk1 Won't Start
10/04/2020 11:26:45

Don't worry too much about the wear Richard, it is not a "precision" control. Fit a spacer to take up the play, clean out the oil holes into the bushes, and call it done!

Phil

Thread: Inverter Tripping RCD
09/04/2020 12:53:06

Thats interesting Lynne! I wonder what the screw actually does? If not dissconecting the filter entirely, it must perhaps change the way the filter works? The leakage curret to earth is the filter dumping what charges it has filtered out of the supply, and also any harmonics that the vfd emits back to the supply Maybe it is unwise to ponder on anything beyond finding a solution to the immediate problem?

Phil

Thread: Colchester Student Mk1 Won't Start
09/04/2020 11:48:11

Hi Richard,

to remove the apron, you remove the lead screw and feed drive shaft first, they disconnect from the SC box under the sc box top cover. So, with the saddle still on, you disconnect the lead screw and feed shaft from the SC box, remove the support at the tailstock end (you might have to do this first, to get enough clearance to get the leadscrew and feed shaft disconnected), slide the leadscrew and shaft out of the apron, remove the apron, and then remove the saddle retainers front and rear under the saddle, and remove the saddle. You could still do this if you support the apron on some wood blocks, do not let the weight of the apron hang on the leadscrew and feed shaft, they may bend!!

Phil

Edited By Phil Whitley on 09/04/2020 12:04:16

08/04/2020 20:00:47

Hi Richard, checked the manual again, and although it gives the position of the supposed jacking bolts. the details it gives for alignment are for the headstock and tailstock, not for eliminating twist on the bed.. I will be at the workshop in the next couple of days, not sure when, but I will have a look for jacking bolts (or threaded holes) in the positions marked, although I am sure I have looked before, and there are none, if there is, and I missed them, it would make it a lot easier to straighten the bed by twisting the cabinet as the front one is at the left end and the rear one at the right end, so definitely positioned to induce twist, and from the diagram, it looks like they are inside the motor housing,and inside the cupboard|!

08/04/2020 18:52:15

Hi Richard, You dont have to cover all the wire, only where it is exposeed, it is fine when it is inside an enclosure, like inside the switch or the control panel, but it must be protected when it is in the open, or where it goes through any holes in metalwork to prevent vibration wearing away the sheath and exposing bare copper. the metal or plastic flexible conduit fulfills this purpose.

I dont like the idea of feet on a lathe, although many people do use them. If you check the manual, my manual says it has levelling screws ( mine hasnt, or any threaded holes) and it does detail using them to get the bed straight. See what your manual says. There is little point in putting feet on the colchester, it is the bed of the lathe that needs to be level, or more accurately, straight (without twist) and leveling the cabinet will not neccasarily achieve this. If you look at my video of the rebuild on my lathe, you will see a slide of the refitting of the bed to the cabinet, and you will notice that it is only fitted to the cabinet with three bolts, which have sealing washers on them to stop coolant leaking in to the base. I think it would be a lot easier to level (straighten) the bed at this point, instead of applying twist to the cabinet, and hoping that this twists the bed in the right manner. However, it may be that given the small amount of twist required, doing the adjustment between the bed and the cabinet will result in too much bed movement, I don't know, because I am not going to do mine untill I have fitted the new bearings.

What I would do for now is to get the lathe sitting flat on the floor, with the cabinet well supported all round, you can use sheet metal shims to stop any rock if the floor has any low spots, , and then do a test cut to see if there is taper, and which direction it needs twisting in. There are loads of good videos on youtube showing you how to do this. Using a level, you need to level across the bed at each end using a precision engineers level, and the difference in the readings is the amount of twist you have. All things considered, it is more important to see how much taper the lathe turns in use, and correct as much as you can, without becomnig too obsessed with ultimate accuracy. "Rollies dads method" looks good to me, but bear in mind that I have never done this to my Colchester at all (although I fully intend to in the fullnes of time)l, and it has always made the parts I wanted, to an accuracy that was easily sufficient for what I was building or modifying. Have a look at "home made lathe machine" on you tube to see what this guy makes with his home built machine tools.

That coolant pump is very noisy, sounds like bad bearings, but easy to strip and replace them, cheap too compared to what a new one costs!

Phil

Edited By Phil Whitley on 08/04/2020 18:58:52

Thread: Inverter Tripping RCD
08/04/2020 14:05:27

I am taking on board what is being said here, but a VFD without an EMI filter would not last long before a mains spike would take out its electronics. they are there to protect the VFD from the mains, and the mains from any EMI The VFD priduces. EMI filters are capacitive, and therefore BLOCK DC current An RCD is tripped by current flow imbalance, and therefore "you would think" that the AC/DC thing should make no difference, as it is current imbalamce between line and neutral which causes the trip, unless there is some part of the RCD circuitry that reads a DC component in the line as more current than it actually is? If this is the manufacturers explanation, and it works, then the only thing we can argue about is the price, which does seem to be an awful lot for what you actually get. I am lucky, I have "real" three phase, and only have RCD protection on the single phase installation.

Phil

Thread: Colchester Student Mk1 Won't Start
08/04/2020 13:37:33

Hi Richard,

It is not certain that a phase to earth would damage the phase convertor, but having a "leg down" would put a large unequal load on it, and it is not worth the risk! all exposed wiring should have a primary insulation to keep the electric pixies seperate and inside the wires, and a secondary insulation to protect the primary insulation from mechanical damage. Flexible conduit, and bushings where cables pass through metal fulfills this essential safety requirement. Do you remember the wiring on my Rapidor machine hacksaw? Well, Don't do it like that!!

The not starting sometimes, mine does that as well, I put it down to dirty contacts in the C&D switch, OR moving the handle down too quickly, and bypassing the intermediate position of the C&D switch before the contactor has pulled in fully, and closed the holding in contacts. try moving it a bit more slowly and I think the problem will dissapear.

the reason you do not hear a massive clunk like you do with mine is that the modern contactors are virtially silent, and will probably last 10 to 20 years, whereas the one on mine is big, numb, and has a large surface area of armature and contacts, which slams metal to metal in a very noisy fashion, and will last, with a bit of maintenance, forever!

Phil.

Edited By Phil Whitley on 08/04/2020 13:38:45

Thread: Inverter Tripping RCD
08/04/2020 12:35:18

Ouch, that sounds like a lot, are you looking at a 3 or 4 pole RCD when all you need is a 2 pole one? A brief reading of the backstory on this thread seems to show that the understanding of what the filter does in the VFD is incomplete, it prevents EMI and voltage spikes in both directions, in order to protect the VFD from voltage spikes incoming from the mains supply, which would damage the VFD. It does this using a capacitance bridge type circuit which dumps any spike to earth, and depending on the value of the charge that is dumped, plus any residial leakage from other equipment, you arrive at the above mentioned cumulative leakage to earth, and if the leakage current exceeds the tripping current of the RCD, then it will trip, but it may be that the tripping only occurs when other equipment, lighting etc is in use as well, and the cumulative current is greater than the RCD rating, hence a situation where tripping is intermittent. The easy way to solve this is have a non RCD circuit (MCB protected) for the VFD only, or to protect that circuit with its own 60ma RCD (about £35). The other way, and I would recomend this anyway, is to have all the equipment including the VFD circiuts and equipment, checked (including lighting) for residual leakage. Always make sure that all the metalwork of the machine is earthed to the earth point provided by the supply authority. If an RCD trips, it is either sensing a leakage current beyond its tripping threshold, or it is faulty, there is no arcane magic! What often happens to confuse the unwary is that either a spike is discharged as a pulse large enough to cause tripping, but once discharged, does not reappear for some time, or that other equipment on the same RCD has small amounts of leakage, and the small amount of normal current leakage from the filter in the VFD( in other words, the filter doing what it is designed to do) causes the tripping, and the VFD is blamed for the tripping, whereas the tripping is actually caused by the addition of lots of small leakages from other equipment, and switching on the VFD was the "last straw". Leaving the VFD unprotected from spikes by removing or otherwise disabling the filter means that the first mains spike will destroy it, simply doesnt make sense.

Hope this makes sense, and helps with the problem!

Phil.

Edited By Phil Whitley on 08/04/2020 12:36:03

Edited By Phil Whitley on 08/04/2020 12:38:19

Thread: Colchester Student Mk1 Won't Start
07/04/2020 20:28:59

Looking at your well made spacer, I see three red wires emerging from an unbushed hole with no flexible conduit in sight! Get it sorted before there is a bang and a flash, and the phase convertor goes up the pictures! devil

Phil

07/04/2020 20:18:07

flickering lights is just a bit of volt drop, my workshop lights flicker when the compressor starts. Nothing to worry about.! As long as the earth wire is firmly arrached to the isolator box, which is in turn bloted to the lathe, it should be fine. If it was a lathe where the weight of the motor tensioned the belts, and the motor was on a pivot, or the motor moved to change speeds via belts, I would recommend a seperate earth to the motor case, but the motor is bolted solid to the frame of the lathe so that should suffice.

 

Phil

Edited By Phil Whitley on 07/04/2020 20:21:58

07/04/2020 19:21:00

Just watched the videos, Excellent stuff Richard, I am well pleased for you! Knew we would get there in the end, now the fun part, shaking out the fine details, and making stuff! I am trusting that you have earthed it all properly!!?

Phil.

 

Edited By Phil Whitley on 07/04/2020 19:23:41

07/04/2020 19:11:51

Phew! good to hear my wiring was correct! success! Well done Richard. I hate parting off too, make sure that the tool is square to the work, minimal overhang, lock off the saddle, cutting oil! Rigidity in the setup os where its at!.

Phil

06/04/2020 20:32:59

Yup, that gland is fine Richard, just remember that when you try it out, the motor will not be earthed!! put a seperate earth to the motor when testing!

Phil.

06/04/2020 13:13:59

NONE! all my 3 phase machines runs on 16A sockets

 

Edited By Phil Whitley on 06/04/2020 13:14:50

06/04/2020 12:59:43

Make sure you wire an earth from the incoming supply earth in the phase convertor to the output socket earth pin! It does not appear to be earthed at the moment!

06/04/2020 12:53:38

I would get a 16a 3pole +earth 4 pin socket, no need at all for a 32A, the only 32a socket I have is for the welders! if you add the FLA on the motor and the pump, I doubt it will come to 10a! 16 anp is smaller than the 32a.

Phil

 

Edited By Phil Whitley on 06/04/2020 12:55:40

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