Here is a list of all the postings Ajohnw has made in our forums. Click on a thread name to jump to the thread.
Thread: Newbie with an old Boley lathe |
19/10/2015 20:48:34 |
Anyone know what the spindle size is on this lathe. Morse 1, 2 , 3 etc. If it's up to Schaublin plain bearings size most people seem to use grade 32 hydraulic fluid in them. There may be people about on the yahoo Schaublin group that familiar with this lathe. It looks like it use adjustable taper bearings in the headstock and maybe a tapered gib strip on the saddle. The lathe co uk photo's don't show enough of the rest but the compound and cross slide look conventional. John - |
19/10/2015 17:29:53 |
Chatter on a lathe like that is more likely to be down to loose slides or head stock bearing M4 is big enough providing they are high tensile which they usually are. If not the ends bell out often making them difficult to remove. John - Edited By John W1 on 19/10/2015 17:45:36 |
Thread: Clarkson Autolock vs ER collets |
19/10/2015 17:22:30 |
Posted by John Stevenson on 19/10/2015 15:45:44:
David is correct, they are all 20 tpi across the imperial and metric ranges. Which caused a number of people problems who wanted to make a collet or tool and use a tap or die to do it. Personally I feel they have had their day now.
John - Edited By John W1 on 19/10/2015 17:23:25 |
Thread: ER25 collet chucks that fit a myford spindle nose |
19/10/2015 17:02:18 |
I've been taking chucks of my Boxford and putting them back on along with a light interference fit for a number if years now. JS make a good point. The DW seems to be made a just over a thou over size but I really need to check the cal of the mic to be sure of that.
John - |
19/10/2015 14:50:37 |
if there is a problem with them I thought the best option would be to re machine the register and add a sleeve. That could be done while the collet end is holding a piece of turned bar so should work well providing the collet is ok. The Chinese do seem to work to this sort of tolerance on some parts such a chuck to spindle plate fitting. John -
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19/10/2015 13:55:03 |
It's to go one a Dore Westbury for a milling chuck so back plates wont fit in well. I could always treat one I buy as a casting kit but wondered if any had been made properly. John - |
Thread: Clarkson Autolock vs ER collets |
19/10/2015 13:49:11 |
I haven't always used them like that - simple reason. I didn't want to cut my fingers on the flutes on the cutter. Most of the ones I have used have been resharpened and they were like razors. If there is enough shank sticking out fine. John - |
Thread: ER25 collet chucks that fit a myford spindle nose |
19/10/2015 13:37:48 |
I'm thinking of buying one of these to save making one. There are several suppliers and I wonder if any offer one with a light interference fit on the spindles register rather than being a clearance fit? John - |
Thread: How to machine a back plate on a WM 250 lathe |
19/10/2015 13:28:32 |
Before messing around removing things make sure that the rack is long enough for the saddle to move further along. It might not be. Did you try extending the compound slide as far as it will go and angling the tool post with a V shaped tool in it? Looks like that wont reach either. If not the boring bar is the best option or grind some HSS to suite. Moan.The wonderful Wabeco 4000 could do it apart from the fact that the saddle hits the motor cover. However it will probably reach with the compound slide fully out and the tool post angled. John - |
Thread: ARC - PayPal and Credit Cards |
19/10/2015 12:53:16 |
Paypal does allow people to register more than one address. It caused me a problem. A supplier had shipped to my second one and didn't bother checking the address on the order as the other one was on his system. Result parcel went awol so he sent me another. To the correct address in this case. I only use the other one if I know I will be there. John - |
Thread: 125mm HBM Chuck too heavy for Myford ML7??? |
19/10/2015 12:48:59 |
The weight of the chuck would help compensate for the upward pull of the belt drive which will and does cause bearing wear. Cutting forces push up and back too - hence the popularity of under drive and it's variants. John - |
Thread: Clarkson Autolock vs ER collets |
19/10/2015 12:39:36 |
Posted by Martin Kyte on 19/10/2015 11:59:52:
The way I see it working, the cutting forces tend to rotate the cutter on the centre which draws the COLLET further into the chuck not the CUTTER. If anything Clarksons are easier to undo because only get as tight at they need to. Also if I could quote what is possibly the most accurate statement on Wikipedia "The tightening sequence of Autolock collets is widely misunderstood." ;0) note the old fashioned emoticon
It pushed the nose of the collet more firmly into the mating part of the nut so self tightens if the cutter slips at all. They aren't designed to accept a loose spinning tool bit and totally self tighen - just to limit slippage to a very small fraction of a turn of the cutter. Some of the problems mentioned here are a bit weird. It was one of the most used methods of holding a cutter. Clearly people were mad continuing to use them. They have one weakness as far as I am concerned. The actual collet is driven as well. They have a pair of ears on them. This means that if too much screw thread is allowed to stick out of the back of the collet the engagement distance is reduced, might even be zero . I have seen collets that have been broken due to that - usually far east ones. I've also seen 3 & 4 morse ones that have been bent to. I'd guess on large machines that have been fitted with an adapter rather than buying the correct chuck. John
Edited By John W1 on 19/10/2015 13:05:41 |
Thread: working out screwcutting gears. |
19/10/2015 12:24:28 |
The parts diagrams only show a dog clutch - no high low feed lever. It does mention that there is a 50T gear on the spindle but zero else. There are lots of variations on this one about but no luck finding another make's manual. I found one that did 4 - 120 tpi, others 8 to ??. Some have gearboxes, some have the milling head with and without a separate motor. Some even have power cross feed.
Actually I had an early one - put me off Chinese lathes for ever but maybe they are better now. They had just updated it by chopping off the tailstock nose to gain an extra 2" between centres. Fine but it needed a morse extension socket to work up to a centre which reduced the centre distance to less than it was before. Head stock out of alignment but could have been shimmed - I think. Tail stock the killer. Hand scraped, it had been but probably 1/2 mm to go and not anything like aligned anyway. John - |
19/10/2015 09:49:02 |
The best option is probably a photo of the dial on the handle on the end of the main lead screw showing the zero in the middle and the numbers each side of it. Extreme but I found that was the only way of finding out if some one was selling a metric or imperial lathe. Naughty might be able to tell or maybe not. There are distinct differences. On the other hand the markings might be approx - not exactly unknown but in the past it's been 2.5mm = 0.100 which it doesn't. Or maybe Clark will reply to the email he sent. John - |
Thread: ARC - PayPal and Credit Cards |
19/10/2015 09:33:02 |
Posted by blowlamp on 19/10/2015 01:11:27:
Posted by Ketan Swali on 18/10/2015 18:31:05:
Yesterday on a shopping channel (don't ask), they showed a person marketing a USB stick which you put into your computer, to hide your IP location. It marketed the concept of security. Really?...sure it was nothing to do with the person not wanting to show who he is incase he is seeing a site which he shouldn't or doing something he shouldn't, or committing fraud of some description? Such devices issue 'virtual I.P' addresses.Combine that with 'virtual cards' to place an order on ARCs site, and it returns a 'high risk' score, because it is difficult to figure out who the payer is and/or if the person is legitimate. What does such a user hope to gain? Ketan at ARC.
Why assume that a person is up to no good, just because he wishes to maintain his privacy?
Martin. You need to figure out how a usb stick would achieve this when your isp provides you ip address. All it can do is pass what ever you are doing through a proxy. There is no way of knowing what is going on on that. John - |
Thread: working out screwcutting gears. |
18/10/2015 23:11:28 |
There should be a graduated handle on the end of the lead screw. The numbers each side of the zero might offer a clue. Trouble is that it could be anything with an unusual drive like that even 13 tpi but I'd guess it's metric. One thing for sure 8.5 tpi is too far out anyway. John - |
18/10/2015 19:44:34 |
The 24 and 52 are effectively a compound train that's always there. The make the lead screw run 24/52 slower than the pitch actually is = finer by that factor. To save me doing one perhaps Rod will add that factor in to his spread sheet. John - |
Thread: ARC - PayPal and Credit Cards |
18/10/2015 18:54:10 |
I generally do use a debit card to pay on line. What I generally don't do In a few cases such as BT details are with them but not the security number - EVER on any of them. It shouldn't be. Not all that much protection really but better than nothing. I have had my debit card hacked and copied but not from online use, simply buying petrol in a garage. I had a phone call at work one day. Bank asking me if I had bought any petrol the day before. Odd thing to recall instantly so they followed it up with the comment buy petrol 3 times, several full shopping baskets from different super markets and lastly a holiday in Spain along with a book to read on the way. Several £1000 in total. The biggest inconvenience to me was that the card was frozen. It took them a few days to sort out. That was bad as I couldn't withdraw any money. We were going on holiday before that happened so had to take £1000 out of the BS and stuff it in the car's glove box. Petrol easily sorted out as I always fill to a £1. Groceries and holiday not me so no problem. Actually they made a note about filling to the nearest £ and noticed that I had changed to nearest 50p suggesting I had bought a VW. I had. Any time I make an online debit card transaction it's vetted through the bank. If feel that things are a lot better in this area these days but I don't generally leave details with retailers due to an experience some friends had - odd transactions rather a long time after they had used the card with a particular retailer. I am not keen on giving the detail out over the phone either for that very same reason. If paypal is offered I do use it providing there is no surcharge but often wonder why the hell I often have to type my address out again. Irritating and it might allow some one to send stuff some where else. I do like the only to paypal registered addresses aspects. There is one problem with using debit cards - protection for the buyer. Credit cards offer more. With distance selling regs in the uk that might not be so much of a problem as it used to be. However if any doubt I use the credit card. John - |
Thread: Cutting Metric thread on an Imperial lathe |
18/10/2015 17:54:46 |
Posted by Bazyle on 12/10/2015 21:08:07:
Useful info there from John for Boxford about the 44 option. It can also get you 0.7 (M4) using 80 on the gearbox (0.6985mm) The challenge is to get the rest of the common threads by only swapping the mandrel gear as on the Myford table. Best I've managed is 3 more gears, 45,24,26 but mostly people may not need the .75mm (18DP if anyone is thinking of making them). gear, gearbox, thread(mm) I did get side tracked. These are for module and dp screw cutting. I suspect the 2 prime gears are essential. Some mod pitches match imperial threads to couple of thou which would be an easier option than trying to work out simple trains.. Module And DP I started on this some time ago so spent an hour finishing it. Haven't cross checked yet but should be ok.
John - Edited By John W1 on 18/10/2015 17:55:51 |
Thread: working out screwcutting gears. |
18/10/2015 17:40:22 |
It looks like you have a setting for 16 tpi A,B,C & D are 60,48,50,27 so if you change the 48 to a 24 you will get 8 tpi. Or some approximation as I think this one has always been metric. Looking at the manual the gear behind A isn't the same size as the one on the end of the spindle. Makes thing tough to work out. If you post a photo of the screw cutting chart that came with the lathe, add any other gears that come with it and count the teeth on gear on the end of the spindle and the one that meshes with it behind A it should be possible to work out what to put in the screw cutting calculations. A photo showing the gear set up that meshes with the spindle might help too in case it's very different to the manual. The problem might be that on what I call real lathes the tooth count on the spindle is usually the same as the one that meshes with it, often via tumbler reverse that is running as an idler. If it's arranged as shown in the manual the lead screw pitch needs to be multiplied by a factor otherwise the sums wont work out. John - |
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