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Member postings for WALLACE

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

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Thread: How to drill a square hole?
10/08/2010 20:04:35

 
Don't know about a square hole but I find it all too easy to put a triangular one into thin metal  when I want it to be round . . 
 
 
w.
Thread: What price frustration?
04/08/2010 00:25:56

Outr of curiosity, has anyone ever had a 'qualty' issue with a new Myford ? (such as sand in bearings, things not being square etc etc) ?
 
 
 
Nuff said.  
Thread: New lathe advice
29/07/2010 22:24:58
Hello Mark
 
I have a L5a and can confirm it will do a flywheel - did one for a lancia engine some years ago. A lathe is definetly the way to go as the steel to make it was about £25 pound - so if you don't include the time / initial cost of the lathe, it's very cost effective !
 
As to other lathes, I wouldn't really want to comment - certainly it's done everything I've thrown at it  - but sometimes you do get the feeling that the castings are a little lightweight - a colchester from what I've seen of them look a bit ' beefier'. not that I'd notice the difference in the turning I do  .  .
 
One good point is the clutch - it's in a very easy place to get at if things go wrong - I've linked mine up to the inverter drive so it all comes on and off together.
 
Why did I get a L5a ? The garage it lives in is very tight for space - and the one I brought has its motor in the base unlike everyother Harrison I've seen which has it hanging over the back. This means it's about a foot shallower   - so I can squeeze the car in..
 
One thing you will need if doing a flywheel is a lathe with power cross feed. Something the lathes your looking at should have as they're big, but make sure !!    
 
And I wouldn't go for a single phase - they buzz ! The Harrisons are a bit more limited in gear (speed) ranges than the Colchesters, but an inverter plus a 3 phase motor sorts that one out !  Imperial leadscrew not a problem - just buy a 127 tooth translation cog.
 
W. 
  
Thread: Lathe Drive Motors, 1ph or 3ph?
13/07/2010 22:34:34
Hello Paul.
 
It's a while since I converted a motor from 440 to 220 - so I don't take it as gospel ! I was going to write something for MEW a few years ago when I acquired a  motor for a tool and cutter grinder - but it was wired up for both so I didn't have to do it !
 
Anyhow - I've only done this trick on the old Brook-Crompton motors. It's fairly straightforward to strip them down - the only tricky bit is to identify the sleave where the bottom of all 3 windings come together.  The windings are segmented so there are other joins. If you look carefully, then go away and look again (!) you should see the only one where three wires go in.   Carefully peel this one away - the wires are very brittle and everything's stuck together with varnish so take it easy.
 
When the fabric sleave is removed, you should see the 3 ends of the windings soldered and twisted together. These will need to be seperated and  joined individually to 3 insulated multicore wires ('tails') to take up to the junction box.   Ideally these should be yellow, blue and red - but it doesn't really matter as the 3 windings are easy to identify afterwards. The thickness should be good enough to take 10 amps or so - use the existing ones as a guide.. The joins should obviously be soldered and then covered with several layers of heat shrink sleaving.Be very careful at this point - it's easy to break the coil windings.
 
The joins and tails need to be tied down with string  - as the other windings are. Then  cover everything with varnish - I used some that I had in a tin in the garage giving it several coats over a week.  Obviously the centre of the motor needs to be kept clear  - the new tails should be tucked out of harms way so tno rotating parts rub against them when it's all put back together.  
 
Right - so hopefully you now have a motor with 3 sets of windings that need to be brought out to seperate connections at the terminal block. You might be lucky and find that the paxolin plate can take another 3 studs - if not, you'll need to get hold of some to make up a new one ! M4 or 4BA bolts are fine to make up the connection studs - make sure they're as far appart as possible from each other AND any metalwork ! The studs should be in two rows of three columns. I used solder tags to keep everything apart and neat - plus spring washers and loctite on the studs to make sure everything stays tight.
 
The wiring from the tails should be as
 
 
And that's pretty much it.   !
 
If in doubt, get the motor checked by someone who knows what they're doing !
 
 MAKE SURE THE CASE IS EARTHED PROPERLY BEFORE YOU TRY IT OUT FOR REAL !!!!!
 
I used a insulation tester to make sure everything was ok - but it was a high voltage one (generally called a 'megga'). This puts about 500 volts across everything which is a way of making sure the motor  will take mains voltages - if you test the insulation resistance with a bog standard multimeter it only puts about 9 volts across the insulation - which may be fine - but not so good at 220 ! 
 
 
Final point about inverters. Usually if you switch them into reverse, they'll ramp down, stop, then go backwards over a few seconds depending on how they're programmed (talking inverters here). I would NEVER just flip one of the windings round to do a reverse when it's rotating - the only thing that would be instantaneous would be the blowing up of the IGBT's in the inverter !
 
W.
 

Edited By WALLACE on 13/07/2010 22:36:35

Thread: Need for recomandations on cut off or parting tool
13/07/2010 13:11:18
I can't fit a rear tool post on my L5A - but as it has a L00 spindle I could mount the tool upside down and run the lathe in reverse  as the chuck can't unscrew.. .
 
Is it worth trying ? !
 
 
W.
 
Thread: Lathe Drive Motors, 1ph or 3ph?
02/06/2010 20:35:26

Possibly final point (!). If you're short of the readies or just too mean like me, it's not too difficult to convert a delta 440 volt motor to a star 220. I've done several old Brook Crompton types and they work just fine.
 
A long hard look at the windings on the opposite end of the armature to where the tails come out  should  show you where all windings are joined together - then it's just a matter of very carefully stripping back the insulation / cloth sleaving to get to the wire.
 
These can then be soldered onto new tails and brought out to the connection plate. It's important to do this properly - I always use several layers of heat shrink sleaving to cover the joins and tie everything up with string to match the original. Then I'll spend a few days liberally coating everything with varnish.
 
I used M4 brass bolts as studs on the paxolin connection plate with solder tags on the tails.  
 
Just to make sure everything was ok, I checked everything out with a megga - might be worth getting someone to do this for you if you don't have one as it puts 400-500 volts across everything so it really gives the insulation a good test - a multimeter  powered by a  9 volt battery doesn't !    
 
WALLACE.
 
  
Thread: Tool Post Grinder
25/05/2010 16:00:28

Hello everyone - any hints or tips on using a toolpost grinder ? I brought and refurbished one a few years ago but never really got to grips with it.
 
A source of wheels with a 3/8 bore would be great as well - and any recomendations to grade etc.
 
 
thanks.
 
 
WALLACE.
 
 
Thread: Marking out fluid
03/05/2010 19:17:34
Cromwell Tools do it - I think it's in 1 litre containers - that amount should last a lifetime but very careful NOT to spill it on the caprpet - I suggest putting it into much smaller bottles . . . 
 
w. 
Thread: Lathe Drive Motors, 1ph or 3ph?
30/04/2010 16:14:35
Don't touch a modern single phase with a bargepole. One I brought from a major supplier litterally buzzed itself around the workshop floor when first wired up to test  - the noise when actually bolted into a Harrison lathe was undescribable !
 
The older Brook -Crompton ones are a lot better - but a 3 phase one is so much quieter with less vibration - and that's not even mentioning the varying speed advanatages, quicker overload cutout (useful for the odd dig in) etc etc .  . 
 
Also - though probably due to the way I butcher cutting tools on the grinder - is the fact that you can vary the speed during actual cutting if it all starts to ring due to chatter. Wouldn't care to say what this does to the finnish though .  .!
 
W.
 
  

Edited By WALLACE on 30/04/2010 16:15:15

Thread: Cover for a milling machine table
24/02/2010 20:35:50
Perhaps a smidge off topic but I found that when I first started using suds on a Harrison L5 ( applied with a 1 litre garden centre squirty bottle ), I'd often get staining under the felt wipers on the saddle.
 
The cure was to remove the little metal covers so the felt was bare - persumably, this  allowed the suds to evaporate more quickly and reduce the time it was in contact with the bed 
 
So perhaps likewise for a mill table, don't leave any cover on where suds can sit for long periods !   
 
W.
Thread: Blown X1 Mill speed control
17/02/2010 14:04:12
Don't know if it's possible, but maybe loosing the belt a smidge so it slips under too heavy a load  might extend tje life of the IGBT's !
 
As an aside, I built a 3 phase converter some years ago based on a design in Elektor magazine that was rated 750 watts  - but upped it by fitting bigger reservoir capacitors and a lot heaftyier IGBT's.  As theyr'e voltage driven, fitting ones with bigger current capacity worked in practice - I chose to ignore (i.e. didn't know enough to make a judgement  !)  variations in input capacitance, switching speed etc. 
 
I have blown up the odd one since   -  usually a complete phase goes down and the inverter won't work at all as the current limiter comes in and kills the drive to all the IGBT's.
 
WALLACE.  
Thread: Burnerd Multisize Collet Chuck . .
15/12/2009 14:00:02
Thanks for the reply !
 
I was going to email - but thought I'd have a bit more of a play around first. . . 
 
I turned a scrap piece of  1 1/4" bar paralell and put the chuck onto this ' back to front' if that makes sense - and measured the run out of the LOO taper end. And it was about 1/3 of a thou - so now I'm starting to think the spindle on the lathe isn't true.
 
Yet that appears to be the same - or possibly less. (Slightly diificult to measure around the full 360 degrees due to the locating key ).
 
Finally, I started to wonder about the accuracy of the taper on the chuck - when 'blued' up, it only appears to make contact with the broadest part of the taper - there's virtually none on the front part.
 
All interesting (frustrating ? !) stuff !
 
Out of curiosity - and something to aim for - does anyone know what should be the run out of say a 1" precision ground bar held in the chuck ?   
 
W.
  
30/11/2009 11:18:40
Hello all.
 
I've got a Burnerd Multisize collet chuck which has either been dropped from a very great height or wasn't ground correctly in the frist place as the run out on the end of the collet taper is a couple of thou.
 
So the question is - how or where can I get is reground  ? (and not for totally silly money . . ).
 
I should add that the spindle end is a L00 taper.
 
thanks.
 
WALLACE 
 
Thread: Visiting UK
08/09/2009 13:02:17
Two be honest  - I wouldn't rate The Science Museum in London - seems to me they've taken away a lot of the good bits and put expenive tea bars in there place !
 
Would seriously recomend the pumping engines at Kew. They're in steam at weekends  and are very impresive !
 
 
If  you're heading up the East side of the country, try 
 
http://www.lincsaviation.co.uk/ - every other day or so (check the website for times), the pull their Lancaster bomber out of its hanger and fire up the 4 Merlins  - the noise makes your hair stand on end all over !! It's near to Lincoln which is worth a visit for the cathedral although I think Ely's better - you can go up to onto the roof and see how the it was built 650 years ago .  .
 
W. 
 
 
 
Thread: Geared Head Oil
10/08/2009 21:38:01
I had some fully synthetic car gearbox oil left over from a car project - so I drained and filled the headstock on my Harrison L5 with that ! Definetly quieter than the bog standard gear oil used in there previously - and the main bearing runs cooler if ut's running at high speed for a few hours.. (yes, I know it shouldn't and I do have a new set of bearings - but not the spare time to change them  . .).
 
I would recomend 'adding' a magnet somewhere as it's very effective at removing metal particles from the oil . .  .
 
WALLACE 
10/08/2009 21:37:50
I had some fully synthetic car gearbox oil left over from a car project - so I drained and filled the headstock on my Harrison L5 with that ! Definetly quieter than the bog standard gear oil used in there previously - and the main bearing runs cooler if ut's running at high speed for a few hours.. (yes, I know it shouldn't and I do have a new set of bearings - but not the spare time to change them  . .).
 
I would recomend 'adding' a magnet somewhere as it's very effective at removing metal particles from the oil . .  .
 
WALLACE 
Thread: Variable Speed Controllers for Lathes
31/07/2009 11:50:23
One thing I've never seen mentioned is using a single to three phase inverter to power more than one machine (not at the same time !).
 
I bult one a few years ago from an Elektor design  - although I up-spec'd a few components   so it would deliver a bit more power. It's on a '3 phase ring main' around the workshop with each machine having a big relay to isolate it when not in use. There's a seperate control box on each as well with the direction and speed controls - this is linked back to the ocnverter on what I suppose you could call a 'control ring main'.
 
Each control box has a phono socket on it - to take control, I just plug in a coresponding plug. There's only one which means I can't have more than one running at a time !
 
Works a treat.
 
WALLACE 
Thread: MEW Just gets better
29/07/2009 18:42:12
I just wonder - as one does - what would be the impact of dropping the words 'model' from the magazine title   ?
 
Seems to me that there would be quite an interest in a magazine that catered for a larger variety of workshop hobbies - not those perhaps orientated towards 'model' engineering.
 
Just a thought . . . .... . .  
Thread: Marking out
15/07/2009 12:36:48
Thanks for the tip. I'll start saving mine up from now on !
W. 
14/07/2009 17:18:21
Cromwell tools do marking out blue in 500ml bottles which appeared to be most cost effective. I would recomend decanting some into a smaller bottle (plastic !) as it will make an awfull mess if knocked over .  .  
 
WALLACE
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