Help needed with Chester 626 turret mill

[Brad AmosParticipant @bradamos40390]

The cheap and nasty switch on my Chester 626 mill needs replacing. I went straight to the Grizzly manual, where the circuit diagram shows that the main ON/OFF switch has 8 terminals. Does anyone know where I can find a switch with that many terminals? All the safety switches from RS and Ebay seem to have fewer. I would have attached my Grizzly circuit diagram here but the software forbad it..

[Brad AmosParticipant @bradamos40390]

How to replace a broken safety switch

[Ady1Participant @ady1]

open the pdf

use the camera icon to take a picture of the diagram page

paste into Windows paint
save as as a jpeg
upload into here

[David George 1Participant @davidgeorge1]

Have you asked Chester for a spare part. I asked Chester for a safety switch for the guard and if came return post.

David

[Brad AmosParticipant @bradamos40390]

Dear Ady1,

Thank you for trying to help me, but……

I have tried to upload a small jpeg, with and without placing it in a Word document. Neither of the Paste buttons work. I just get a message stating that I should 'use Control/V, since my browser does not permit pasting by toolbar buttons or ……context menu option' ( whatever that is). My browser is Firefox and I use it every day to paste jpeg images into all kinds of sites and it has never failed to work.Clicking on the camera ikon tells me to 'insert image from album' but all attempts to drag and drop an image into my album cause the software to crash completely, meaning that I have written this message five or six times, sometimes with more detail that this, and lost it repeatedly. I assume the album is a data cache within the Model Engineer system to which I cannot add images. It seems I can upload nothing except text.

[SillyOldDufferModerator @sillyoldduffer]

Hi Brad, unfortunately the forum doesn't support drag and drop. The way photos are managed on this site is described here , note only JPGs are allowed.

Not difficult once you get used to it, but definitely old-school! Another annoyance is the forum doesn't allow users to rotate photos, but let's cross that bridge when we come to it.

Dave

[VicParticipant @vic]

How old is your machine? I ask as my Warco VMC is about 12 years old and just has a simple switch. Later models have several buttons and the Grizzly seems to have a rotary switch?

[Brad AmosParticipant @bradamos40390]

Dear Moderator ( Neill?) ,

Your instructions worked splendidly. Thank you! Maybe they should be available via a HELP button, since images are so important for Model Engineers.

The image below is from the Grizzly manual, which is for a 626 turret mill very similar to the one I purchased from Chester. When I bought my mill the switch looked flimsy, so I protected it by enclosing it in a diecast box, which perhaps confined the disintegration of the plastic (because of WD40 spray or other fluids) to the front. The switch contains a solenoid device which prevents unexpected startup after a mains interruption. I opened my box and found that the switch plus its ON and OFF buttons can be bought from Amazon for about £50. The product name is KEDU KD11 8pins Waterproof electromagnetic switches JD3 Relay ON-OFF Push Button Switch with Power Failure and Undervoltage protection for Machine Tool Equipment 230V 16 A. If anyone else has to replace their switch I recommend labelling all eight leads according to their position or according to the numbers on the diagram attached to the switch.

[VicParticipant @vic]

The plastic switch housing on my Warco VMC broke so I too replaced it with a die cast box. I don’t mind plastic but the housing really was of very low quality. I must have removed the switch to fit the new housing but I can’t remember how many terminals it had? I probably labelled the leads or at least took a photo for future reference.

[Brad AmosParticipant @bradamos40390]

Dear Vic,

I do agree about the poor quality of the black plastic housing of the switch. If my replacement from Amazon works I will put it back in the diecast box but also make sure that it is protected from cutting fluids, WD40 etc.

Here is a photo of the label on the switch I have bought from Amazon: the photo is is just a screendump from the Amazon page. The label is identical in every way to the label on the broken switch. I will send a photo of the entire Amazon switch from the same source in a second posting.

A guy phoned from Chester, assuring me that the switch I have purchased would not work, but finally asked me to let them know if it did work. I expect to receive it in about two weeks and will report on this forum whether it works or not.

Brad

[Brad AmosParticipant @bradamos40390]

For Vic and others who may want to replace a switch on a Chester 262 mill: here is the Amazon photo of the entire switch taken from one side, showing four of the eight pins. It seems that although the model number is the same as my (nearly ten year old) one, the front of the switch is slightly different, having a latched hinged cover for the ON switch. As promised in my previous post, I will report whether this replacement works

Brad

[Brad AmosParticipant @bradamos40390]

Sorry for the typo in the last message: I meant 626 not 262.

Brad

[VicParticipant @vic]

I wonder if you can change just the guts of that switch. Seems a bit cheaper if you can?

**LINK**

[VicParticipant @vic]

There’s a lot to said, or should that be saved?! In using a simple Rotary switch or would this not work on a milling machine like the VMC/626? If it would work maybe I should buy one on the basis that if I do Sod’s law says the old push button one won’t fail!

**LINK**

[Brad AmosParticipant @bradamos40390]

Dear Vic,

You can buy just the internal mechanism ( including the solenoid) also from Amazon, but it is the external stuff that has failed on my switch, i.e. the ON and OFF buttons literally fell off and the plastic faceplate that attaches the whole caboodle to my diecast box cracked in several places.

The internal mechanism is still working, so I can still turn my mill on and off by prodding the guts of the switch with an insulated rod, but it is not safe: the only thing stopping the guts from falling out of the diecast box is that they are attached by crimp connectors to the electrical leads, which are 8 in number and fairly rigid en masse.

I do not know how the rotary switches operate. Do they have protection against an unexpected start after a mains outage? This is why the JD3 switches (and most modern machine switches) have a solenoid which turns the switch to OFF if the mains fails.

Brad

[VicParticipant @vic]

“Do they have protection against an unexpected start after a mains outage?”

I would think not. But unlike a push button you can see whether it’s set to on or off. Probably no good for industrial use but I would have thought adequate for home use?

[Brad AmosParticipant @bradamos40390]

As promised, I am now reporting that the solenoid safety switch I bought on Amazon for my Chester 626 mill has arrived. I have fitted it (see photo) and it is a correct replacement for the original one supplied by Chester, which disintegrated recently. The new switch works perfectly. It has the same label as in the Amazon photo which I posted, and the original had an identical label. Replacement was straightforward: the labels I had attached to the 8 leads when I remounted the switch in a diecast box about 8 years ago had started to fall off, so I replaced them with new labels ( using white insulating tape and a black Sharpie marker) . I then fitted all 8 crimp connectors to the 8 pins in the new switch in the same 6 + 2 pattern as in the original switch. The switch faceplate has two holes 83mm vertically apart, same as the original, which I re-used to mount the new switch in my existing diecast box.

I will inform Chester of this. I noticed that the plastic around some of the crimp connectors had gone brown, presumably as a result of overheating.

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