Member postings for Les Jones 1

Positng pictures of the part that you are trying to remove and the other end of the shaft that you need to remove would be helpful.

Les.

Can you draw a diagram of how you have connected the start winding, the run winding, the capacitor, the centrifugal switch and the thermal cut out switch with letters or numbers on the connection that we can refer to when we reply.
To use the thermal cut out switch you will need an extra 2 conductors in the cable to the Dewhurst switch. (So that the thermal switch isolates power from both the run and start windings.
It would be a good idea to see if the motor runs in both directions without the Dewhurst switch just by reversing the phase relationship between the main and start circuits.

Les

Make sure that there are not 2 grub screws as the sometimes do this to reduce the chance of them unscrewing with vibration. If the pully is made of aluminium heating it is more likely to work as it's coeficient of expansion is higher than steel.
If the Clarke Bearing Splitter will not get between the pully and the motor end plate then making a wooden clamp to grip the sides of the pully might work. Get 2 pieces of wood with a thickness about the same as the length of the pulley and a bit wider then the pulley diameter. Bolt them together with 2 lengths of threaded rod. Then bore a hole through them centered on the joint and a diameter slightly less than the core diameter of the V grooves.. You can then clamp this around the pulley. Then use 2 or 4 lengths of threaded rod between the wooden clamp and the metal plate with the screw to push against the end of the shaft. So you noe have a home made puller thet should grip the pully without damaging it. Also putting "plus gas" (Penetrating oil.) into the grub screw hole and the end of the shaft may help.

Les,

Edited By Les Jones 1 on 01/07/2023 09:36:08

You do not make the significance of the two pictures of the conection boxes clear clear . As the middle picture shows the start capacitor is mounted on the side of the motor I would expect the wires from it to come out to the connection box. I would also expect the wires from the centrifugal switch to come out to the connection box, So I would expect a total of 8 wires to come to the connection box. Show us pictures of before and after your modification.

Les.

I agree with Noel Shelley's post on 24/04 at 22:09. I think a contact on the reversing switch is not closing in the forward direction. The reversing switch reverses the polarity to one of the windings. Depending on the design it may have a center off position in which case it also switches off power to both windings. showing us some good pictures of the reversing switch connections would be a help. Try to take pictures from different angles to make it easier to follow the wired to the terminals. This should help to avoid connections and some wires being hidden by others. Also tell us if the reversing switch has a center off position.

Les.

The next step is take the belt off between the motor and countershaft to see if the motor is definitly the source of the noise. Also check that all the pulleys are not slipping on the shafts.

Les.

I agree that it is most likrly to be an inverter fault. You could eliminate the motor by connecting 3 old fashioned incondescent lamps between the thee phase output of the inverter. (NOT LED OR CFL LAMPS.)

Les.

The schematic of the oscillator that you are using to generate the step pulses would help us with suggestions.

Les.

I don't think the internal error code on the display unit can be caused by the scales being faulty or not connected. From your connector pinout it looks like the sales are pretty standard quadrature scales with the "R" signal being for a pulse which is generated as a reference point near one end of the scale travel. The "A" and "B" signals will be the quadrature outputs. As these signals are not at any fixed value the display unit has now way to know if the scales are faulty. Your scales are single ended output. If they were differential output they would have A+ and A-, B+ and B- and R+ and R-. As the scales are supplied with 5 volts the logic levels will be 0 and 5 volts. (These signal levels are often called TTL levels.) With power to the scales if you look at the "A" or the "B" signals with an oscilloscope you should see them changing state as the scales are moved. You will also need to know how many pulses per mm of movement that your scales provide. This can noemally be set with a setup function on the display unit. If you try to get into the setup function of your display then you may be able to see what the pulses per mm setting has been set to.I agree that Machine DRO will be able to tell you if their display units are compatible with your scales

Les.

I think you have two faults. Getting a shock from the lathe metalwork indicates that it is not earthed properly. (Or you have become charged with static.) Check the resistance between the lathe metalwork and a known good earth.
For the motor fault connect an incandescent lamp (NOT a CFL or LED lamp.) of about 100 watts rating in place of the motor. The speed control should adjust the brightness of the lamp. Check that it works in the forward and reverse positions of the reversing switch if it has one. If this works without tripping an over current breaker or RCD then the fault is with the motor. If it still trips the breaker then the fault is probably on the speed control board.

Les.

If the tank is upstairs then you can probably do the work to insert a valve just by partly draining the system. You may not need to drain it any lower than the top of the upstairs radiators. A picture of the pipework around the hot water cylinder would be helpful.

Les.

Comment for SOD, Thermally the design is quite good. It is built on aluminium circuit board. (The sort you see used on LED modules.) It failed in a very few seconds without ever producing any output under load. Even with no load it took quite a large current for a second or two then dropped down to a reasonable value.

Robert, I have not traced out the schematic so I don't know if it is foldback current limiting, It uses a TL494 controller IC so I should be able to work out if it is fold back current regulation. I think it is just a bad design taking such a high startup current even with no load on the output.

Les.

I bought a boost regulator like this one thinking it looked suitable to power one of the Plessey LED modules.

They seem to be sold by a number of ebay sellers. With 12 volts input I set the output to 44 volts with no load. It did take a large current at switch on (About 3 amps.) I then connected a 65 ohm resistor to the output to simulate the LED module. (It would draw about 680 mA) The regulator was trying to draw more then 5 amps which is the maximum current limit my bench power supply can be set to.
i then tried to supply it from a car battery. It then drew so much current that the solder on the input connections then melted.
Although it should have been running within it's advertised specifications it had destroyed the power mosfet in the regulator. I would not advise anyone to buy one of these regulators to power the Plessey LED modules.

Les.

Possibly 4.5 mm metric fine which has a pitch of 0.5 mm (Which is 50.8 TPI.)

If you have a screw and nut you could measure how far the nut moved for a number of revolutions (Say 10) That may give you a more accurate value for the pitch.

Les.

Edited By Les Jones 1 on 20/01/2023 14:21:44

The two of these that I ordered also arrived today. I first tested one with a 64 ohm resistive load and the voltage across this was 44 volts. (Which is a current of 687.5 mA
Here is a picture of the inside just using the flatbed scanner. (The main cover is removed in the same way as the terminal cover by pressing down on the place where the clips are with a small screwdriver.)

I notice that the price of these drivers has now gone up to £7.00.

Les.

Thanks Michael for the last link. It seems to contradict the datasheet regarding polarity and the use of heat sink compound.

Les.

I don't understand why a good finish is required on a chuck key. If you wanted a polished finish why not just use emery paper ?

Les.

The answer to that question is probably yes. For a definite answer we would need to see the manual on the VFD. When you get a definite answer to that question you would probable then need to ask us how to connect it. The main concern we all have is that the VFD may not work well enough with a single phase motor.

Les.

Here is a link to a mains powered LED driver. I have never used this supplier but I am tempted to order one.

lMAAOSw4qFiY5tO&amdata=enc%3AAQAHAAAA4J4rVp%2FK3ZcF2lBT2Bc%2F7lwrMr%2Bjz7VIv4uLLsUqSrBAcweCy%2B1RYDjPHal%2BiuzvC2VGkCpvkeRoJAJYB2N%2FfeycYyFAsDXsKClTCvZ7E5ZrBykuxkwuEiDuRUeEMf7%2BpynvxPsv7kzuer2QQA6i80tH2CcjnSy640jylMjLIVnbiQaJRewmURsSuk2crbzI1K0ilnFgB%2B7GBayucwYGyJISjrDmvAfoh0p5awmfsOq5%2BGSOyd%2B4wgf9somBBGrfo%2FTi7QHzn3LESLVFRyWdyk%2FKwftwreUkf28EW7TkX05v%7Ctkp%3ABk9SR5bM1YS2YQ">https://www.ebay.co.uk/itm/195351986113?hash=item2d7be2bfc1:glMAAOSw4qFiY5tO&amdata=enc%3AAQAHAAAA4J4rVp%2FK3ZcF2lBT2Bc%2F7lwrMr%2Bjz7VIv4uLLsUqSrBAcweCy%2B1RYDjPHal%2BiuzvC2VGkCpvkeRoJAJYB2N%2FfeycYyFAsDXsKClTCvZ7E5ZrBykuxkwuEiDuRUeEMf7%2BpynvxPsv7kzuer2QQA6i80tH2CcjnSy640jylMjLIVnbiQaJRewmURsSuk2crbzI1K0ilnFgB%2B7GBayucwYGyJISjrDmvAfoh0p5awmfsOq5%2BGSOyd%2B4wgf9somBBGrfo%2FTi7QHzn3LESLVFRyWdyk%2FKwftwreUkf28EW7TkX05v%7Ctkp%3ABk9SR5bM1YS2YQ

I could not get the link inserted in the normal way. So the ebay item number is 195351986113

Les.

Edited By Les Jones 1 on 14/01/2023 12:46:24

Edited By Les Jones 1 on 14/01/2023 12:50:28

Edited By Les Jones 1 on 14/01/2023 12:55:10

Edited By Les Jones 1 on 14/01/2023 12:59:11

Re your post at 15:43 on the 13th. I am not clear if you are using the motor to drive a grinding wheel. If so 500 RPM seems too slow unless the grinding wheel is a very large diameter. A better description of what you are trying to do may give us the option to to suggest a solution to the original problem rather than your proposed solution of using a single phase motor with a VFD.

Les.