Member postings for John Baron

I would check very carefully for missing teeth. The original Aldi bandsaw blade lost several teeth within a few cuts, the new blade is far better.

Just to add, I had forgotten that I used 6 mm thick felt carpet to line the inside walls of my camper when I built it. You can buy it by the yard or if you have a camper place anywhere near they might give you some off cuts.

Where about's are you located, I'm near York, I've a few spare pieces left.

Almost any felt material will wick oil as long as it is capable of absorbing the oil. Some felts are water/liquid repellent and wont work. I've use cotton in the past to wick oil up and over and down a central tube. My Myford S7 uses a wick to lubricate the main spindle bearing.

Hi Pete,

There are usually a number of different size first surface mirrors in a laser printer head unit !

I made a similar thing using an old washing machine tub pulley ! I did put a handle on it to aid quickly unscrewing a tap.

More pictures in my album.

Hi Guys,

It seems that most internet providers,

A: Want you to leave your router permanently switched on.

B: They use your router to expand their WiFi coverage at your expense.

C: Have back doors into your router.

D: Don't like you using or trying to use a third party router.

I agree with securing your computers and other internet enabled devices. I have a Smart TV and it continually wants to have an internet connection, which is hard to prevent since there are so many WiFi connections around. Even switching WiFi off it switches it back on again, usually silently. I think some of these TV's even have cameras.

Hi Colin,

So do I ! I'm in North Yorkshire. I do have access to s couple of scrapyards around here and I did used to have access to one in Birmingham which unfortunately seems to have closed down and the land is currently being sold.

But I do agree that it is becoming harder to find places that will let you wander around them. One that I go to will put stuff on one side for me if I let him know what I'm after. There was an old lathe in there a few days ago. I expect that it went into the cast iron scrap pile.

Hi Guys,

I mentioned earlier that I had been looking at a thermal switch that used a ceramic element to open and close a switch, I've taken some pictures so that you can see the parts and the arrangement of the device.

This picture is an over all view inside the plastic case. The thermal mechanism is at the top and there is an auxiliary switch at the bottom of the picture. The auxiliary switch is not thermally activated it is a straight on/off one.

I've outlined the ceramic element in green and the switch contacts in red. There is a spring on the right bearing on the ceramic strip, and an adjusting screw on the left which can be adjusted with an Allen key through the top. I did notice that the adjusting screw is connected to the live mains input ! So this is just for factory adjustment. The cam on the switch shaft brings the thermal device into play.

I tried to photograph the ceramic strip. I broke out the bit of plastic so that I could take a picture of it. You can see the voltage rating and the printed resistive element which measures about 15K ohms. You can feel the heat radiating off it after about 15 or 20 seconds. The contacts short the ceramic element out when the switch operates.

Quite ingenious !

Milling cutters tend to be standard sizes whether screwed or plain shank ! So I don't see any need to change to ER collets just to use them, particularly if you have the full set of collets for the Clarkson.

Hi Eric, Guys,

You can make a fly cutter quite easily and more rigid than most you could buy.

This one is a simple disc 20 mm thick on a 20 mm shaft, using a piece of 6 X 6 mm square HSS as the cutter. This on will cover about 65 mm. The tool bit is held in an 8 mm diameter hole using an M6 grub screw.

Hi Steve, Guys,

Yes I used to do that as well ! Plus giving the oily felt a good wash and soaking in degreaser and then a soak in hot oil to re-lubricate the felt. Record player motors used to suffer in the same way.

Hi Guys,

FWIW I do tend to use the back gear to lock the chuck when unscrewing it, although the S7 does have a locking pin to stop the spindle being turned when removing the chuck. I've never found the need to use anything more than the chuck key in order to loosen the chuck.

I do have a 125 mm three jaw on a backplate that is a lot harder to loosen than the original Myford 100 mm chuck. Plus it overhangs the bed much further than the slim body Myford one.

Hi Chris, Guys,

[quote]A screw-on chuck, as on the Myford or Boxford type lathes, will always unscrew unless specially secured. I have had a chuck fly off when I accidentally knocked the Dewhurst switch lever over and threw the Myford into reverse.[/quote]

This can only happen on a machine with a three phase motor ! Switching to reverse whilst running forward will not stop the motor, it will just keep running. The single phase motor speed has to slow down enough for the centrifugal switch to drop out reconnecting the start winding.

Hi Ian, Guys,

I've very recently seen a thermostat that uses what appears to be a ceramic strip with a printed on resistive material that heats up and causes the ceramic strip to bend and open a pair of contacts. Rated at 15 amps as well.

If you have ever opened a microswitch, the mechanism looks to be very similar, the ceramic strip replacing the phosphor bronze leaf as in the microswitch.

Hi Ricky, Guys,

An excellent source of small induction motors is the scrap yard ! I've salvaged many "Shower Pumps" that have seized up pumps but the motors have all been OK. The hot side pump usually leaks and lime scale build up causes them to seize. Very occasionally water migrates into the bearings, but they are common, cheap and easy to replace.

I've salvaged motors from 175 watts (1/4 Hp) right up to 900 watts, (just over 1.2 Hp). All have been two pole motors (2880 rpm). There are some that are universal brush motors, but you don't always find that out until you pull it apart. I tend to take those back to the scrappy after I've salvaged the useful bronze parts.

That is why I made a statement about keeping the threads and register scrupulously clean and well lubricated.

It takes very very little in the way of dust, dirt or other debris to jam the threads.

Hi Guys,

These thermal switches use a PTCR device to which is in series with the mains supply and the rest of the circuit to generate enough heat to keep the switch open as long as the mains is connected. There is no neutral connection as such.

The circuit path is through the on/off switch through the thermal switch, through the elements and then out to neutral. The thermal switch is still live when the heater is switched on and connected to the mains supply.

NOTE: The PTCR is often a black pellet of resistive material that heats the bi-metal strip.

Hello Martin,

I too have a Myford S7 with a screw on chuck ! I have never had a problem with it unscrewing whilst threading in reverse. In fact I try to do all my threading away from the chuck. It is also the best way to do internal threads as well.

I do know of one chap that managed to unscrew his chuck, but that was his mistake trying to part off from the front with the tool upside down, jamming the blade in the cut.

A properly tightened chuck should not cause a problem.

A note on jammed chucks: Always make sure that the threads and register are scrupulously cleaned and oiled each time you change the chuck. It doesn't take much to cause a jamb !

Hi Peter, Guys,

The way I would make that split cotter is like this.

Drill a hole say 10 mm deeper than the collet length with a tapping size drill say 5 mm for an M6 thread.

Open out the hole to the collet diameter for the length of the collet.

Thread the 5 mm diameter in the bottom of hole.

Drill the collet right through 5 mm tapping size for M6

Drill one half of the collet M6 clearance, and thread the other half M6.

Thread an M6 screw into the collet and screw the whole lot into the bore.

Tighten up so that the collet is locked in the bore.

Then mark out and drill the cross hole making sure that you leave a mm of clearance between the outside of the M6 collet through screw.

Disassemble and clean.

Cut the collet in half by either sawing or parting.

Make sure that you properly deburr the edges of the scallop after parting in half.

If you do it properly it will take a quarter of a turn or less from loose to locked solid on the shaft.

Here is one I made for my Norman Patent tool holder.  12 mm diameter, M6 through screw.  Note the edges at the bottom of the scallop.  Any burrs will cause those edges to dig into the bar that its clamped onto and make it hard to loosen.

Edited By John Baron on 05/02/2021 20:39:24

I agree with Hopper, the screws are counter sunk ones ! Since I no longer use my Myford four way tool holder any more, I've removed it and not missed it at all.