Member postings for Michael Briggs

It did Baz but didn't post, also Santa's beard and all those unguarded machine drives.

Hello Bernard,

I had a similar problem about a year ago, we also bought a new washing machine. This puller may have been the solution but probably costs as much as 2 or 3 new washing machines !

Link

The notion that my milling machine and lathe behave exactly the same is ridiculous.

Edited By Michael Briggs on 09/04/2020 22:54:57

I do indeed, generally for finishing cuts.

I have a Senior mill but I have no desire to fit a power feed because for me the mechanical feedback from the machine is invaluable. If I did I would make sure it had a sensitive means of torque limitation.

It might have enough power to light the wick.

It is definitely a small block, you can see it under the baseball cap.

Edited By Michael Briggs on 27/03/2020 20:47:52

Good point Neil, in pubs I have seen two legged mammals wobble.

Edited By Michael Briggs on 24/02/2020 20:42:49

You beat me to it Duncan.

Duncan, alternatively if you are not using the alarm relay (a b c) you can change its function with parameter 192. The default setting is 99 = alarm output, if you set it to 0 it will also be a run output, it is a changeover contact so you will not need to invert the signal just connect as required. Michael

Edited By Michael Briggs on 14/02/2020 18:01:00

Hello Duncan, I have had a look at the manual, the RUN terminal is configurable by parameter 190, the factory default is 0 which gives an output when the drive is running. If you change it to 13 it will output on zero current detection, levels set by parameters 152 and 153 which should give you the output you require without an inverter (I think). It is described on page 150 of the manual I looked at.

The control logic jumper sets the inputs to source or sink. Hope this helps, Michael.

Old Mart, that is exactly what I thought before my purchase of a left hand caliper a while ago. I thought it was the answer but despite being reasonably dextrous with my left hand I don't use it as often as I thought I would.

I am lucky to have a few Mitutoyo instruments all of Japanese origin, a bit pricey at the time but I have never regretted spending a bit more than intended for a quality tool built to last.

I bought a Moore and Wright MW110-15DBL caliper about a year ago with the intention of modifying it for use as a centre scribe. For the princely sum of £24 the quality is surprising good, so much so that I can't take it to the grinder, it's too good. The only minor gripe I have is that the auto off timer is too short.

Re auto drivers with their foot on the brake in a queue. I have had automatics from Audi, Bmw and now VW, all with electronic handbrakes. The brake lights come on when the car applies the handbrake and you can't turn them off.

+1 Emgee, I like simple effective solutions.

Hello Dave, by "the exceptions" I meant that there are VFDs that are capable of having the load switched while the drive is running, large and small.

The point I would like to make clear to the forum is that the type of VFDs we generally have in our workshops when at rest and powered are unlikely to start due to failure of internal control circuit but are not safe. I recommend that when you are setting up a job on the faceplate for example, you isolate the power. I don't isolate for everything, that is my choice.

Michael

SOD with due respect, I haven't spotted that VFD's are not all equal, I have worked with them for the last 40 years.

Regards, Michael

Robert,

I am pleased it makes some sense to you, I will do my best to respond to any questions you have to anything that doesn't make sense.

Regards,

Michael

I can Robert :

Bread dough mixer with a 90 Kw motor. The risk assessment required a category 4 safety system, a VFD powered up and stopped is not safe enough to meet HSE requirements. You can of course isolate the supply making the system safe but the VFD was not rated for the required 10 power cycles per hour. The solution was disconnection of the motor from the VFD. The machine was guarded (mandatory) but locked until the VFD brought the motor to a standstill and then was isolated from the VFD so the VFD could remain powered up and the system made safe.

Reverse operation on startup, lock access gates engage VFD connection to drive then start the VFD.

Outcries from the forum "what has that got to do with my machines", perhaps not a lot, a VFD at rest and powered up is unlikely to start by its own accord but it is possible. So when I am setting up on the faceplate for example I isolate the lathe.

For some time there have been VFDs available with a safe off facility that can make the VFD safe while powered up but no need for that in my workshop.

Hope that makes sense,

Regards

Michael

Edited By Michael Briggs on 08/11/2019 21:31:37

A switch between a VFD and the motor does not risk damaging the drive provided that it is only opened or closed when the drive is at standstill though there are exceptions. In industrial installations is not uncommon for a drive to be ramped down to standstill and then disconnected from the VFD output.