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Member postings for mgnbuk

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

Thread: Soft start
10/05/2018 20:13:12

Plenty of cheap thyristor speed controllesr / dimmers on Ebay :

2Kw rated 192410752118 £1.23 delivered

4Kw rtaed 192410975598 £2.85 delivered

5Kw rated 192441295326 £4.69 delivered

I have used the 2Kw type to reduce the speed of pistol drills - put the module in a small diecast box wth a 13A plug on one end & a trailing socket on the other, so it could be put in circuit as required. Worked fine for my intended use, though for yours you would have to manually ramp up the speed with the pot.

Nigel B

Thread: Imperial acme threaded rod
03/05/2018 16:09:36

If Abssac can't supply, this company **LINK**

were recommended by John Stevenson when this topic was discussed some time ago on this forum. If you go the download page, the standatrd screw products .pdf lists 1/2" 10 tpi LH and RH as stock products.

Nigel B.

Edited By mgnbuk on 03/05/2018 16:09:56

03/05/2018 11:47:18

Abbsac still list this as a "legacy product" **LINK**

Might be worth a call ?

Nigel B

Thread: The Workshop Progress thread 2018
03/05/2018 07:52:04

I'm not sure if a lathe boring bar will work as they tend to set the tip at an angle

Can't see why it should make a difference ? If I use the boring bar in the lathe (set correctly on centre) to machine a bore larger than the minimum specified for the tool in a rotating workpiece, or rotate the same bar set on centre in a boring head to generate the same diameter bore in a stationary workpiece, the tip is presented in the same way to the bore regardless ?

I have used larger diameter lathe boring bars in larger than ME size boring heads at work (admittedly into graphite components, not metal) & they have worked fine without rubbing, and have also mounted lathe internal screwcutting tools in milling chucks & using them as fly cutters for thread milling on CNC milling machines.

I have the bars I linked to & intend to try them in my 2" boring head - just require the 1/2" to whatever reducing sleeves making to be able to try them out. I'll report back after doing so, though these projects do seem to take longer than initially anticipated !

Nigel B

02/05/2018 18:35:53

Rod,

How about one of these Ebay 352259180098 & turn it down from 10mm to 3/8" ?

Also available in 6, 7 & 8mm diameter taking the same CCMT0602** inserts to sleeve up. Searching "SCLCR" brings up most of them.

Nigel B

Thread: Warco WM250 Lathe and Warco WM18 Milling machine (Advice please)
01/05/2018 21:22:34

We get a lot of raw material & finished parts from China at work & very rarely do the containers turn up "on time", due to many factors. The source factory can be late shipping, ships get delayed by weather (we have had containers delivered to Rotterdam instead of Felixstowe due to weather, then lost 3 or 4 weeks getting it back from Rotterdam to Felixstowe again). Even when your container does get into the UK, some get impounded at random by C&E for X-ray checking, which can take over a week (for which you are charged storage by the day !). And rarely can the shipping agents give any kind of delivery update until the day the container is actually released to them at the port.

It is not good for the blood pressure when you have "late" parts that have to get to customers to keep production lines running & you don't know if they will get to you on time. 4-6 weeks "late" from intial estimates given 3 or more months previously is not unusual & no amount of huffing and puffing on our part will get "late" shipments to us any quicker - it arrives when it get here & not before !

I enquired about a WM18 with an MT3 spindle recently (not currently shown on Warco's website - they seem to have standardised on R8) & was told that one could be special ordered no problem & delivery would be the normal 5 months - it is a long supply chain ! So it is quite likely than Warco got an estimated delivery date at the time they placed their order several months back & genuinely don't know when the container will actually turn up if it is "late".

And Warco are not alone in this - SPG are OOS of their equivalent milling machine at the moment - the answer to my restock query being that delivery "should be next month". It must be just as frustrating for suppliers not to have stock to sell & not knowing when it will appear (due to circumstances beyound their control) as it is for you as a customer - you could try cutting them a bit of slack.

Nigel B

Thread: Mobile Networks
01/05/2018 07:59:25

Does anybody still do a real Pay As You Go?

Yes - I use Virgin for both landline, internet, TV & mobile. As a landline user, they have a lower rate for PAYG (8p/min & 8p texts, with free Virgin - Virgin calls & texts). I top up £20 every 18-24 months (no time limits).

I did have a data only contract tablet with EE. It worked reliably enough in the UK, but was useless abroad. Getting EE to cancel the contract at the end of the signed-up period was made especially difficult by EE & I would not choose to use them again. Currently have a pre-paid 3 data only Sim for the tablet - £27 (IIRC) for 24Gb over 2 years & works equally well home or abroad.

Nigel B

Thread: Glass-scales-ZX45-RF45 clone
01/05/2018 07:46:49

Y-axis scale mounted at the rear of the table leaving the front clear

In normal industrial parlance, that is the X axis (table left-right movement) - the Y axis is the table front-back movement.

Nice installation, with the table scale in the "optimum" position nearest the fixed dovetail (opposite side to the gib strip) . I am currently looking at a 3 axis DRO for my FB2 clone & it oden't look like I have enough room to put the scale at the back of the table without restricting an already short (140mm) Y axis travel.

Nigel B

Thread: Aldi 3 drawer steel toolchest
27/04/2018 13:23:33

Bought one of these **LINK**

along with the shopping this morning.

27042018885.jpg

While not super high quality, it seems reasonably well made. It was well packaged & undamaged when unpacked. The outer chassis & lid are approx. 0.8mm steel, with the drawers being approx 0.7mm. All drawers & the top area have liners, with the first drawer being segemented for small parts or tool storage,

27042018884.jpg

A drop-in bar secures the drawers when the lid is closed (the bar is in it's "parking" position on the left of the picture - it locks the drawers when inserted in the slot at the back) & two keys are supplied for the lock. Not sure why there is a "mousehole" in the back wall on the right - any ideas ? Finish is satin red & appears well applied. According to the Aldi link, black units were also available, though my local store only had red.

27042018883.jpg

Another step towards organising the garage / workshop & reasonable value for £40. At the time of writing, these are still available to mail order from the Aldi website if you don't have a local store or they are OOS.

Nigel B

Thread: Aircraft General Discussion
25/04/2018 08:33:08

Or, given Sam's location, possibly CAC Wirraways.

**LINK**

Thread: Warco WM250 Lathe and Warco WM18 Milling machine (Advice please)
24/04/2018 14:42:45

To check if the quill is perpendicular to the table, proceed as follows :

Fully extend the quill and clamp it.
Mount your magnetic base on the table & set up a dial gauge to bear on the front of the quill as close as possible to where it exits the head casting. (You may need to use a finger clock to get close to the top of the quill & so be able to check over the longest distance.)
Clamp the head to the column.
Using the X axis (table moving left - right) "wipe" the dial gauge across the quill and adjust so that the needle reads zero on the high point. (Note that you may get a different reading depending on the direction of movement - just remember which way you were moving to get the zero when you take the next reading.)
Unclamp & raise the head such that the dial gauge reads close to the bottom of the quill (don't touch the dial gauge !). Reclamp the head.
"Wipe" the dial gauge across the quill again & the error is the highest (or lowest) reading on the gauge at the high point on the quill when moving in the direction that you set the initial zero.

Then repeat the process, but with the dial gauge set on the side of the quill & "wipe" it with the Y axis (table moving front - back) rather than the X.

The readings "should" be pretty well the same top & bottom from both setups - my guess is that the side value will be close & the front value will be out.


If the column is perpendicular to the table in both directions (as you suggested earlier) & the quill isn't, that suggests that the quill bore isn't parallel to the rotating joint face at the rear of the head casting. This could well be the source of your front to back tramming error.

HTH

Nigel B

Thread: Where to get a running bearing for Ajax AJ8 mill
18/04/2018 12:41:13

**LINK**

1 1/2" Od x 1 1/4" Id x just over an inch long hardened & ground inner bearing ring.

Press or glue 2 onto a 1" bore x 1 1/4" Od sleeve & away you go.

Quite a range of Imperial bearing inner rings readily available - precision ground hardend parts at reasonable prices

Nigel B

18/04/2018 09:01:57

What about using needle roller bearing inner ring(s) ?

**LINK**

May need to use more than one is series, but I don't think that would cause problems.

Nigel B

Thread: Anyone fancy a larger UK made milling machine?
11/04/2018 16:12:02

Seriously, do they normally machine steel dry,

Yes. IIRC one of the reasons being that the inserts need to be kept at a fairly constant temperature, so coolant needs to be a very strong flood. This is not always possible & is difficult to both guard & collect. Intermittent application of coolant to hot inserts can lead to failure due to thermal shock. Again IIRC, the idea is that most of the heat goes into the swarf, but I have regularly come across operators keeping a pair of welding gloves to hand to change tools, as the tool bodies can get hot enough to burn you. Insert drills, though, need high pressure through-tool coolant to blow the chips out of the hole - that really does go everywhere !.

the Mandelli factory in Piacenza in the late 1980s, they were capable of such work rates that it was refrigerated before re-use.

That may have been to keep the workpiece cool to maintain tolerances. I have seen some machines that use temperature controlled coolant circulated through the machine to keep the machine structure cool for that reason - including through hollow ballscrews via rotating unions. As Mandelli were manufacturers of quality boring machines, I would expect that they took dimensional accuracy of parts seriously.

Nigel B

11/04/2018 13:39:24

I'm not sure that the "UK made" bit is true anymore - pretty certain they announced in the trade press that they were not going to be building their own machines here anymore & were going to be concentrating on the agencies a couple of years ago.

Nigel B

Thread: Faceplate or Independent Chuck?
24/10/2017 07:35:34

If you accept the 'minimum two threads engaged' rule

I work to the " jaws fully engaged in the body with no overhang" rule wherever possible - "two threads engaged" is a new one on me & way outside my comfort zone.

How would your capacity calculations work out for full jaw engagement, Neil ?

Nigel B

Thread: John Stevenson
23/10/2017 20:30:20

Sorry to hear of John's passing.

My condolences to his wife & family.

Nigel B

Thread: Faceplate or Independent Chuck?
23/10/2017 20:27:09

Surely the 4.5 kg mass of the 6" chuck, especially if compounded by an off-centre workpiece adding to the centrifugal forces, be more than the headstock bearings and motor power are designed for and would put great strain on these items. The C3 mini-lathe is probably not designed to take anything bigger than the 100mm (4" chucks.

A standard mini lathe appears to use 6206 deep groove ball bearings fpr the spindle. If you have a look at the ratings for a 6206 bearing, you will see that you will not have an issue with overloading them. A heavier, larger diameter chuck will be advantageous when doing interrupted cuts - it is a large flywheel & will help both the gearbox & the (relatively weak at low revs) motor under such conditions - mini lathe owners on other forums have fitted 5kg 5" 3 jaw chucks without problems & report better finishes using these..The heavier chuck does take longer to accelerate & decelerate, though. But if you feel happier with the smaller chuck, go with your feelings (just watch your digits if you run it with the jaws protruding !).

Not sure what MG means with regard to MB's picture - as the jaws are inboard of the 6" chuck body OD, the jaws are not running in the gap - a Myford will swing 7" over the bed after all. The jaws are running over the gap area, but not in gap.. That configuration would run without fouling on a C3, which also swings 7" over the bed.

Is that a tumbler, MB ?

Nigel B

22/10/2017 16:13:28

the jaws are still going to hold the same size whether they are overhanging a 4" chuck or in a 6" chuck that isn't overhanging.

But the job held in the 4" chuck will not be as secure, due to less of the jaws being supported by the body and less screw engagement. Also, the overhanging jaws will not be visible when the chuck is rotating - potential for an inadvertent operator / moving jaw interface - the operator always comes off worse in such situations. Certain lessons drummed in at Apprentice Training School 40 years ago still resonate !

I think 6" is too big for Colin's lathe.

A C3 mini lathe swings 180mm, according to the Arc website, which is 7.08" - or about the same as my S7. A 6" direct mount fits a S7 fine, so should also fit a C3 fine, though the body will be closer to the bed due to the lack of a gap.

Nigel B

22/10/2017 15:18:50

You aren't going to be able to open the jaws of a 6" chuck very far on a 3 1/2" centre height lathe...

But you can open them to the edge of the chuck body - extending jaws beyond the extents of the chuck body is generally regarded as bad practice *. And opening the jaws to the OD of a 6" chuck will allow larger pieces to be held that doing the same on a 4" version.

Nigel B.

* and yes, I know we all do this at some point and to some extent, but that doesn't make it any less bad practice !

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