Member postings for John Baron

Thanks for the comments Guys.

Yes ! I have also checked the original piece of hydraulic piston rod in the soft jaws. It measures the same at both ends, so its not bent.

Hopper:

I'm coming to a similar conclusion ! However the chuck is essentially new and unused. I need to do some further checks on the chuck. I'm happy that the face is flat and true, but I want to check the slots on the chuck and the jaws themselves. I've a suspicion that the problem is something to do with the jaws. Though at the moment I'm not sure how I would do that.

Hi Rowan,

Have you tried

Accu [email protected] or https://accu.co.uk

They are at Huddersfield, West Yorkshire. I've bought Acme threaded bar from them and I believe they will supply nuts as well.

Not quite. If I choose the closest point to the tool holder on the tail end collar and rotate the chuck the dial gauge reading moves to just over 30 divisions at the furtherest point.

Now I did rotate the test bar 90 degrees and the reading stayed the same, so the test bar is straight. Actually I tried rolling the two collar bar down a flat surface to see if it followed a curve. For all intents an purposes it doesn't.

Answering some other comments.

The lathe bed is not twisted ! That two collar test bar was skimmed in the soft jaws of the three jaw chuck and the collars are within a couple of tenths of a thou of each other.

One thing that does bother me though, is that I can true the end collar to read dead true, but when I come back to the chuck end, I'm back to it not being true, though its not as great a deviation, only about half that.

I'm about ready to bang my head against the wall...

Hi Guys,

Thanks for the replies.

After I posted I thought I would go into the workshop and take some pictures.

I've added notes under the pictures.

This was the setup that I used to verify that the chuck was running true. The gauge isn't reading zero because I haven't started at this point.

Same setup from another angle. There is less than a needle thickness variation when rotating the chuck.

This chuck is the original Myford one that has not been used from new until recently even though its 40 years old.

This is the two collar setup that I used. Those collars are 44.0 mm diameter within a couple of tenths of a thou.

The shaft they are on is a piece of 20 mm hydraulic piston rod.

This is the collar nearest to the chuck with the lathe rotating.

This is the maximum deviation on the collar nearest the tailstock with the gauge zeroed. I did rotate the bar 90 degrees and remeasured. Oddly the amount of deviation barely changed.

I can't get my head around why I see this behaviour. I only noticed this because I wanted to check that the lathe was still turning true.

Edited By John Baron on 16/05/2020 17:41:34

Hi Guys,

I have a question !

If I set up a test bar in the four jaw chuck, in this case a known true 20 mm diameter bar 200 mm in length, so that I cannot measure any deviation when clocked at the chuck, but find that it is several thou out at the tailstock end 150 mm away.

A micrometer tells me that the bar is exactly the same diameter along its length.

Why !

Hi Stevie,

I would bite the bullet and make a rear tool post for that blade !

Apart from the issue of it being at the front, the angle should be the other way, the tool pointing up rather than down.

This is my rear tool post and holder on my Myford S7LB.

As you can see the parting blade is inverted and held horizontal. I don't use tapered blades, but rather long 200 mm 12 mm X 2 mm ones. This picture is with a new un-ground blade. I usually grind the front face to match the radius of the 6" grinding wheel with the table set at 10 degrees. I can easily part 50 mm steel bar under power. Aluminium is much more difficult, needing plenty of lubrication to prevent pickup.

Hi CT,

These people stock the automotive relays

https://www.beal.org.uk/index.php

look under automotive.

A very common issue with these motors is the brush tails go high resistance and then the springs have to carry all the motor current this can cause stopping and starting at random.

Another problem is soldered joints carrying high currents go bad, particularly with the advent of lead free solder. Three to five years is about the right time frame.

I haven't read the whole thread, but have you re-soldered the battery connections !

I've got/had a couple where the display couldn't make up its mind and re-soldering the battery connections on the board cured the issue !

Hi Guys,

Soft lathe jaws is something that is needed to ensure concentricity and repeatably ! Normally a three jaw chuck will display a few thou run out.

These are mine, I've just replaced them with new ones.

Edited By John Baron on 06/04/2020 19:41:39

Hi Guys,

Here is a picture of a small boring bar that I made recently. It is designed to fit into a 12 mm bore in order to cut several 2 mm wide by 2 mm deep grooves.

This is a family picture of all the parts including the Allen key for the M5 grub screw.

This picture shows the assembled tool.

Looking down from the top. That piece of HSS tool steel is 3 mm square section by 10 mm long.

A close up of the tool bit.

I made this tool to machine the grooves in a labyrinth dust trap for a high speed grinding spindle.

Problem is that it is just text, nothing innocuous about that ! I'm sure that you have seen warnings about dangerous PDF documents.

By the way did you translate the numbers ?

Hexadecimal message in Glyph pictures....

https://gamefaqs.gamespot.com/boards/956856-assassins-creed-ii/52630448

If you look through the file you will see that it contains code sequences that are read and executed.

084 0104 0105 0115 0105 0115 099 0111 0100 0101

Like this. This bit of code is not dangerous, just an illustration.

Hi Guys,

The download is also a dangerous PDF file. I feel sorry for Wins users.

H Sakura,

Have a look at my photo album !

Hi Steviegtr,

A couple of notes that might help ! All the plastic gears were salvaged from a printer, a HP one if I recall, its been a couple of years since I built that one. The gear on the wiper motor shaft was just drilled through so it dropped about halfway down the taper, I used the nut to push it down the splines whilst using a "Cooks Torch" to heat the end of the shaft. Effectively moulding the gear to suit the taper and splines. Be careful here because some wiper motors have a plastic worm inside and you don't want to melt that. I also used a spot of oil on the taper to stop the plastic sticking to it.

The large white plastic block is a scrap of Nylon 60 20 mm thick used as the tumbler carrying the small gears, and is just pivoted on the end of leadscrew housing. Just a few screws and it all comes off ready for the handwheel to be put back on.

I'm happy to answer any questions you might have.

Best Regards.

Baron J.

Hi Steviegtr,

If you have a look at my album, there are pictures on there of how I did mine using a salvaged wiper motor. I used a tumbler mechanism to provide forward, stop, and reverse feeds. I've not bothered with a clutch since the gears run so slowly that it is easy to change direction on the fly without stopping the motor. I also use a variable voltage DC power supply which allows me to monitor both voltage and current. A typical usage voltage for mine is around 5 volts and .75 to 1 amp depending upon load. I've had the motor voltage up to 30 volts for fast traverse without any issue. One tip is that these motors are designed to run in only one direction. Some have a thrust bearing at only one end of the shaft.

Hi Guys,

Varistors are cheap and are easily soldered across the mains supply inside the machine. You need two. One from live to earth and one from live to neutral. 275 volt ones are available from RS or Farnell, in fact almost any electronics components supplier. They should be wired on the supply side of any filter that may be fitted.

https://uk.rs-online.com/web/c/passive-components/variable-resistors/metal-oxide-varistors/?searchTerm=275 volt varistor  NOTE: this is in bags of 250.  Farnell do them in tens, much cheaper.

Edited By John Baron on 22/03/2020 19:23:51

Edited By John Baron on 22/03/2020 19:27:15

+1

Hi Bo'sun,

FWIW, I got rid of my Dickson tool post and three holders and made my own Norman patent tool post. Much cheaper.

I also made one for the rear of the cross slide that is used to hold the parting off blade.