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Member postings for John Baron

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

Thread: Milling Vice clamps
25/03/2021 19:47:04

Hi Guys,

Just for the nay sayers, I can remove and replace my vise without all the hassle of setting it up square again ! Which of course also means that I can move the vise anywhere on the mill table and not have to get the gauges out to set it up square. These vises do not have any grooves or slots for alignment keys.

It also prevents the screw from digging into the table when the vise moving jaw isn't quite far enough back !

So thanks for your comments, this system works for me, and that is all that matters.

Thread: LG TV ... updated webOS
25/03/2021 11:51:30

Hi Guys,

Isn't this what Google have done with "Android" ?

A platform designed to collect your data, phone numbers, location etc, whether you like it or not ! Yes there are warnings but if you decline them you can't run the application...

Thread: What's the general consensus please?
24/03/2021 16:59:02

Hi Guys,

JMTPW: I have both a mill and two drills ! I must confess that I could not do without either. The 1/2" Fobco is indespensble and the 5 mm high speed drill gets less use, but it can handle jobs that the other machines can't, Like 1 mm or smaller in PCB's.

Thread: Milling Vice clamps
24/03/2021 16:45:18

Hi Chris, Guys,

There are five pictures, I've put them in an album, so they don't get lost on my computer.

24-03-2021_011.jpg

I've very recently spent some time fitting a DRO and doing some maintenance on the mill. The wooden way covers and the aluminium ones at the back are just a couple of new items.

24-03-2021_010.jpg

The long hold down studs are M8 with 8 mm thick clamp plates. The other new item is the stop on the vise at the left. The one on the right is just a piece of 4 mm plate that I had kicking about.

24-03-2021_012.jpg

24-03-2021_013.jpg

24-03-2021_014.jpg

These are just close up pictures of the clamps. You can see the 12 mm precision ground plate.

Hope these pictures help.

Best Regards:

BaronJ:

24/03/2021 13:44:25
Posted by Chris V on 24/03/2021 09:19:53:

Well as expected some great advice thank you all.

John Baron, what sort of register did you use for your sub base, a couple of pins screwed into the base?
Or milled slot with a length of bar set (screwed)into it?
Also why such a thick base, perhaps you have a big heavy duty mill?

Chris.

Hi Chris,

No my mill is a Chinese copy of the Optimum, similar to the WM16 and others.

I used a shallow slot milled across the bottom of the plate and a length of bar screwed in, it is milled to be just wide enough to drop into the table slots anywhere I choose. The base thickness was simply because I had a piece of precision ground plate of suitable size, and it is a lot harder to distort than thinner plate. It also has the advantage that I can slide the vise to one side and place the rotary table on the mill as well, so I have use of both if I need to.

The vise hold downs are machined from square bar and use M6 cap screws in counterbores to secure them. The plate is held down in the usual way with "T" nuts, studs and plates, the plates supported on alloy pillars sitting in the table slots.

I can take a picture if you want !

 

 

Edited By John Baron on 24/03/2021 13:47:25

23/03/2021 14:35:50

Hi Guys,

I also bought one of the type ll vises as sold by ARC. These have slots along the length of the vise and can accommodate more clamps if felt necessary.

I mounted mine on a ground flat 12 mm thick plate with four hold downs for the vise and four "T" nuts and studs to hold the plate. I put a register on the bottom so that the vise can be removed and put back in the mill table knowing that it will be dead square.

My only criticism of the vise is that I've discovered that the rear jaw is not true vertically. I've only found out recently. The top and front edge is OK as is the slides, however one side is a few thou smaller than the top on one side. I initially I thought that this was a vertical tram error but checking with a square it seems not to be.

Thread: 3-Jaw Chuck not running true - how to fix
21/03/2021 19:07:59

Hi Guys,

This how I get around run out issues with my three jaw chuck. Note, you still have to put something in the jaws to tension them.

18-02-2020-003.jpg18-02-2020-002.jpg

I made three alloy pieces, and drilled and threaded the jaws M6. As you can see from the pictures I use CSK screws to secure them. I made several jaws so that I can simply replace them as needed.

Thread: That little elf under the workbench again
21/03/2021 18:55:26
Posted by Bill Dawes on 21/03/2021 18:31:38:

Well a happy ending for me but before that a disaster, had another go with the magnet on a telescopic stick and lost the end under my milling machine!!

Good news, I found my 6BA socket, it had bounced up and was nestling in some old shirts under a bench I had stored ready for turning into wipers.

Bill D.

You need a bigger magnet laugh

Thread: Broken Electric motor Junction box
21/03/2021 18:53:28
Posted by Oily Rag on 21/03/2021 16:24:57:

Good afternoon all,

Just had an accident in the workshop that has damaged the Brook Crompton 0.37kW electric motor on my Atlas 7" shaper. A heavy bar slipped and crashed down on the motor's junction box (fortunately the shaper was being moved and was not plugged in to the mains! ) the result is the whole of the junction box has disintegrated with only two parts of any reasonable size.

Does anyone know where a junction box to suit can be obtained from?

Motor ref number is HPA 534 TFBH 3A

Pictures of the damage, I guess the orientation is going to be skew-whiff, appreciate it if a mod could rotate accordingly.

img_3705[1].jpg

img_3706[1].jpg

img_3707[1].jpg

Thanks in anticipation,

Martin

Hi Martin,

You have all the motor info, why not just call Brooks and get a new original one !

http://brookcrompton.com/distributors.aspx

Thread: 1" Die Stock
20/03/2021 15:12:12

Hi Guys,

Thanks for your posts !

Nobody pointed out that I had forgotten to do the drawing of the fastening/adjusting screw holes and positions

1 Die Stock-2.jpg

Edited By John Baron on 20/03/2021 15:14:05

Edited By John Baron on 20/03/2021 15:14:32

Edited By John Baron on 20/03/2021 15:14:48

17/03/2021 17:59:26

Hi Guys,

I managed to strip the thread in my cheap Chinese die stock recently, so I decided to make a new one.

I did a drawing to give me something to follow with my new DRO on the mill. I've placed a copy here.

die-stock.jpg

The bits in blue are just in case somebody would like to make one with the corners milled off. The 7 mm holes are for threading M8 for handles to screw into. My existing handles are threaded M8.

Thread: Motor control board
13/03/2021 19:47:14
Posted by Keith Matheson on 13/03/2021 18:28:44:

Hi The OP here. I’m sure we all love a happy ending and some resolution ( and a thread that comes to a satisfactory ending!) Well I put the new brushes in and Ta Daaaahh! She works again . Thanks for the advice and the useful comments. As I kept the old dead board from before I will swap over the diodes I ordered and see if I now have a spare- that would be a result. The only odd thing was that the slot that the original bushes (and the like for like replacements) went in was enormous when compared to the bushes. I would say easily 2mm all the way around. Is this normal or did the motor factory run out of the correct bushes and just whacked in any thing that would work to get it out of the door? Chinese quality assurance? You are assured it is a low price? Best regards Keith MM

Hi Keith,

Your motor may not be identical to mine. The brushes in mine are 3.6 by 10 mm and 15 mm long. I had similar problems getting hold of some brushes, so I made my own.

If you measure the brass sleeve that will tell you the size.

As far as the semiconductors on the power board are concerned, failed diodes almost invariably go short circuit, the more likely things to fail are the SCR's.

If its any help I'm near York.

 

Edited By John Baron on 13/03/2021 19:49:36

Thread: Two or three axis DRO
12/03/2021 07:41:42

Hi Guys,

I've just fitted a DRO to my Chinese copy of an Optimum mill. I put a glass scale on the column so that I can read the head height. My mill also has a readout on the quill for drilling depth.

20-02-2021-008.jpg

I used a pair of aluminium brackets to mount the scale. I also used a spacer plate between the read head and mill head to match the thickness of the brackets.

20-02-2021-007.jpg

I think the protective plastic dust cover is a nice touch ! Keeps greasy fingers off the membrane buttons.

04-03-2021-003.jpg

Like all things, I should have got one years ago...

Thread: ML7 Topslide Angle Limitations
12/03/2021 07:25:42
Posted by John Barber 5 on 11/03/2021 23:49:06:

I'm a relatively new ML7 user, and this evening I realised for the first time that the top-slide clamping arrangement doesn't give you the full range of angles. It can't come within 30 degrees or so of being perpendicular to the lathe axis, as would be required for turning a blunt taper. This must mean that there are certain turned components which it is impossible to make on an ML7 - a truly shocking thought!

Or am I missing something?

That is why they changed it on the S7 so that it rotates through a full 360 degrees.

On the S7 it is secured by two screws, one on each side of the cross slide.

Thread: Bandsaw overhang
11/03/2021 10:24:01
Posted by Peter Ellis 5 on 10/03/2021 22:17:49:

I have a shortish 75mm bar I need a slice off. I am minded to bolt it to something that the vice can hold better. What would you do ?

Hi Peter, Guys,

When I refurbished mine I made a blocking piece to fill that gap ! The short end cannot now disappear through the gap and the material is supported right to the end. However beware that very thin pieces may get dragged into the gap between the blade and guide, jamming the blade.

04-08-2019x005.jpg

Before !

09-08-2019-001.jpg

After !

09-08-2019-006.jpg

No more lost or unsupported pieces.

Thread: Motor control board
10/03/2021 09:03:46
Posted by Michael Gilligan on 10/03/2021 08:45:25:
Posted by John Baron on 10/03/2021 07:41:44:

[…]

The theory and the math is there on the Internet !

.

Ah but ... this is on the Internet !

MichaelG.

True !

10/03/2021 07:41:44

Hi Andrew, Guys,

The Device known as a voltage-dependent resistor (VDR), is not a resistor at all It is a semiconductor device more akin to a voltage sensitive diode. A similar mechanism as a Zenner diode but it has the same electrical characteristics for current in both directions. In other words it is not unidirectional as a diode is but Bidirectional.

FWIW a resistor is a linear device. The behaviour is according to Ohms Law.

As far as discussing motor brushes is concerned, I've better things to do than going round in ever decreasing circles !

The theory and the math is there on the Internet !

09/03/2021 19:42:39

Hi Malcolm, Guys,

Resistivity "resistance" is a constant ! It does not vary with voltage. There are however resistive devices that increase or decrease in resistance with temperature.

For any given resistance the current through it will increase with voltage.

I do agree that the current drawn by a motor tends to increase as the motor load increases. Motor brushes are very low resistance devices, fractions of an Ohm in most cases, loading them with copper increases the hardness of the brush, in turn improving the wear resistance, usually at the expense of the copper segments of the commutator. Actually the arcing that one often gets at the brush/commutator interface can wear the brush as much as just the friction between them.

But as you imply quite a complex subject, much of which has been alleviated with the advent of brushless DC motors.

09/03/2021 14:51:07
Posted by Macolm on 09/03/2021 10:30:35:

The brush material resistivity is mainly a function of the supply voltage.

No it isn't ! In fact it has absolutely nothing to do with voltage. Material resistivity is a function of the material ! It is a measurement of conductivity, the ability to conduct electricity.

 

Edited By John Baron on 09/03/2021 14:54:09

Thread: T slots
09/03/2021 07:26:42

Hi Stevei,

Very nice protectors for the mill table ! I'm just about to make some new ones for mine !

I've just fitted a set of scales for the DRO on mine and am doing some servicing whilst I'm at it. Surprising what you find when you start stripping a Chinese mill to bits.

I'm about to investigate sorting out the quill bearings ! They feel fine in the machine, but quite lumpy with the quill out and turned by hand.

 

Edited By John Baron on 09/03/2021 07:28:48

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