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Member postings for Les Jones 1

Here is a list of all the postings Les Jones 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: DIY magnetic DRO
01/05/2019 09:21:14

Hi Chris,
I have not noticed any mention of the magnetic strip to work with the encoders. You will also need to make a guide system to keep the encoders the correct distance from the magnetic strip.

Les.

Thread: DRO Z-Axis /4th axis "combiner"
27/04/2019 08:38:29

Hi Paul,
There is no real need for a circuit as Kealan gives the connections at the start of his program.
These are the lines that give the information.

Code intended for an arduino nano with the following wiring:
Pins 2, 4 : Scale 1 inputs
Pins 3, 5 : Scale 2 inputs
Arduino Pins 7, 8 : Outputs to DRO A and B pins.

The only other connections will be the power to the Arduino.

You will have to make sure that the signal level from the scales is the same as the signal levels on the version of Arduino that you use'

Les.

Edited By Les Jones 1 on 27/04/2019 08:42:47

Edited By Les Jones 1 on 27/04/2019 08:43:14

26/04/2019 21:32:15

I built a similar device many years ago for my Seig X3 mill and find it very useful. Mine works with the original Chinese scales (2 x 24 bit protocol). Mine is based on a Pic16f628 with a 4 line by 20 LCD display, It displays the reading from each scale and the sum of the readings.

Les.

Thread: edm machines
07/04/2019 09:00:16

I have built an EDM machine based on the bits of information I could find on the web about Ben Fleming's design. It is the capacitor discharge version as I could not fined enough information on his pulse version. (I was too mean to buy his books.) It works quite well.

Les.

Thread: Crabtree B15 3 phase Stop / Start switch
17/02/2019 14:31:54

Deleted.

Les

Edited By Les Jones 1 on 17/02/2019 14:34:14

17/02/2019 11:57:30

Hi Philip,
I just have the stop, emergency stop and interlock switches in the low voltage control inputs to my VFD I just use the switch on the 13 amp socket to switch the power to the inverter when the lathe is not in use. My view is that would be very unlikely to have a fault occur on the stop control input of the VFD at the same time as I needed to use the emergency stop. It would more likely fail with normal use of the stop button when it would be noticed and repaired.

Les.

16/02/2019 20:05:27

I don't see the point of of trying to use this starter on the input of the VFD. If you want to put an emergency stop button on the input to the VFD such as this one will be easier than trying to modify your existing 415 volt starter. The start and stop buttons will be connected to the low voltage control terminals on the VFD. (Some VFDs may require a small low voltage 12 or 24 volts relay as well as the two buttons)

Les.

Edited By Les Jones 1 on 16/02/2019 20:08:43

Edited By Les Jones 1 on 16/02/2019 20:09:50

Thread: Problems with NVR switch
15/02/2019 11:03:49

The lamp should be connected to L1 and L3 which are the two phases that feed the solenoid. I think you should put some markers on both ends of each of the red wires so you know which are the real phases and which is the ghost phase.

Les.

15/02/2019 09:03:43

Hi Miles,

If the light only works when the machine is running I think you have it wired to the output side of the contactor . (The side connected to the motor.) The incoming three phase from the static converter should be connected to the three lower connections (L1, L2, L3) and the motor connected to the three top connections. (A, B, C) If you have it connected with the incoming three phase to the top three terminals I don't see how it could have worked as there would be no power (From L1 & L3.) to power the solenoid. Can you post a diagram of how you have connected it showing which terminals are connected to the three phase from the static converter, which terminals are connected to the motor and how you have connected the start and stop buttons ? (I can't see any wires that look like they go to the start and stop buttons.

Hi Emgee,
I agree that is the most likely way the light would be powered. (That is the way it was done on machines in the factory I worked in in the mid 1960s.) I was thinking it may have been wired with a 240 volt lamp directly to the mains at some point in it's history.

Les.

14/02/2019 22:15:01

Is there a transformer between where the black cable comes out of the bottom right hand gland of the NVR and the lamp ? I think it is very unlikely that the bulb runs directly of 400 volts. (I am making the assumption that the static converter contains a 240 volt to 400 volt transformer and the motor is wired in star configuration for 400 volts phase to phase and not in delta configuration for 240 volts phase to phase.)

Les.

14/02/2019 18:14:15

I suspect that a thermal overload has tripped and needs resetting.The round knob on the right looks like it could be to set the thermal overload trip current. I expect there to be something in that area that needs resetting. I would also suggest measuring the resistance of the solenoid coil in case it has gone open circuit. (I am thinking it could be a 240 volt coil which is intended to be powered between a phase and neutral but has been connected to be powered between phases.) You could also check that all safety interlock switches are closed and that the stop buton is not open circuit. (The stop button will be normally closed contact that opens when pressed.)

Les.

Edited By Les Jones 1 on 14/02/2019 18:28:10

Thread: Telephone / Internet Scams
14/02/2019 07:47:56

Update on the scam call I had on 13/02/19.
I reported the problem to "Weebly". Several hours later I received an email from them saying that they had closed that website down.

Les.

13/02/2019 11:56:58

Hi Chris,
That's what I would normally do. I tried asking for an extension number so I could phone BT back from a number that I could find on their website. I have contacted my ISP and also Weebly so they can look at the user of that website address but I have not yet had a reply from them.

Les.

13/02/2019 10:45:16

A couple of days ago I had a phone call claiming to be from BT. They first call was from 01807603475 which I ended as it sounded like a scam. They then rang back from 02085876419 and spent about half an hour trying to convince me it wasn't a scam. They wanted me to go to this url "www.btsecurityservice.weebly.com". The fact that the format was very similar to my weebly website (www.lesjhobbies.weebly.com) convinced me it was a weebly website made to look like it was a BT website so I ended the call.

Les.

Thread: Aluminium black
10/02/2019 18:14:24

It it possible that it is designed to be used on anodised aluminium as the anodised surface can be dyed.

 

Les.

Edited By Les Jones 1 on 10/02/2019 18:14:52

Thread: Keyway cutting
25/01/2019 12:27:30

This is a very crude thing I made to move the saddle backwards and forwards for slot cutting in the lathe. It avoids putting too much load on the rack and pinion.

img_1549 (medium).jpg

The lever pivot part is clamped to the lathe bed with blocks of wood and lengths of threaded rod.

Les.

Thread: Occasional usage Sand blaster
16/01/2019 11:00:12

Hi Graham,
It's nice to see you back on this forum. Hope you are well and enjoying retirement.

Les.

Thread: AM25LV mill wiring
07/01/2019 19:58:58

One side of the stop button should be connected to one side of the start button. I think this point will be connected to 13NO on the contactactor, I think the other side of the start button will be connected to A2 on the contactor. The other contact on the stop button will go to the last item in the chain of reverse switch, chuck guard switch emergency stop switcch. Can you check if this is the case ?
Do you think it is possible that the live feed to the contactor had not been inserted under the screw (3T2) and was just making contact with the top of the screw untill it fell out ?

One thing you could try is to connect the live feed to 3T2 via a 100 watt filiment bulb, Disconnect the wire from 4T2 and tape up the end. (This is so the motor can't start ) You could then see if the contactor would pull in and all the interlocks work. If they did then it should be OK to connect the live feed to 3T2 and re connect the motor.

Les,

07/01/2019 18:11:40

Hi Peter,
I don't think the live mains input will connecto either 5T3 or 6T3. I think those two connection are a set of contacts that are not use when the contactor is used on single phase. (They would be used on three phase.) I cant find any schematics on line. I would NOT expect the reverse switch, the chuck guard micro and the emergency stop switch to all be connected directly to 3T2. I would expect one of them to be connected directly to 3T2 and all three othe contacts on these items to be connected in series and also in series with the stop button. The wires you mark on / off switch I would expect to be connected to the start button. I SUSPECT that the live input went to 3T2 but do not suggest trying it until you trace the wiring to the reverse switch, the chuck guard micro, the emergency stop, the stop button and the strat button,  Check if the screw in 3T2 is so loose that there would have been room for an extra wire.

Les.

Edited By Les Jones 1 on 07/01/2019 18:14:34

Thread: Chester 10vs lathe 3 phase upgrade ....should i do it
30/12/2018 14:40:26

1200 watts is about the same as 1.5 HP so you are not gaining any extra power. Changing the drive ratio as suggested by Bazyle will give you more torque. An alternative way would be to use a two step reduction as on the Chester DB-10G lathe. This is a picture of my lathe before I fitted a three phase motor.

rim00009.jpg

I had to make a new toothed belt pulley and three step pulley as the shaft on the three phase motor was a slightly larger diameter. Remember if you reduce the speed of a motor (DC or three phase.) you have also reduced the power. So if you run your 1200 watt motor a a quarter of it's rated speed it will only be capable of producing 300 watts of mechanical power. (About 0.4 HP.)

Les.

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