Story with PICTURES: Repairing 7" Industrial Angle Grinder

A story with pictures, how I repaired a broken angle grinder.

It is a massive 7" industrial angle grinder with 5/8-11 threaded shank.

formatting link
The story is not yet over -- I cannot identify who made it (the nameplace is damaged beyond recognition) and it needs a power switch. For now, it can run off a foot pedal. So, if anyone knows what it is, please let me know. My guess is that it is Black and Decker -- I hope that they may still have a switch for it.

I also added RSS feed for my projects page, so it is a little like a blog now, people can subscribe to it with a feed reader and get new pages automatically.

i
Reply to
Ignoramus32140
Loading thread data ...

I will try to call them, maybethey have a suitable switch as a spare part...

i
Reply to
Ignoramus4299

Found some trigger switches on ebay, I hope that I could fit one of them in. That's better and safer than using foot pedals etc. These are plastic switches for Milwaukee tools, but I think that with some amount of work I could fit one.

i
Reply to
Ignoramus4299

i, it may be worth considering using a nylon clamp bolt / grub for the cable retention. I'd be worried about the bolt end wearing through the cable sheath and into the conductors (even though the protective earth do its job). Maybe a plastic slug against the cable ahead of the bolt.

Perhaps some form of plastic clamp inside the handle to stop cable pull out might be worth it too. Electrocution is kind of permanent!!

Nice blue spark pics.

Reply to
Borat

Yes, I agree and will do something like that, though the cable does not actually rub against the end of the screw -- but I agree that it is a good practice to provide some cushion.

Well, the cable is actually held very tightly by this. I will insert a cushion piece, as well. It works as well as anything else. I found a trigger switch on ebay and will try to install it, and will add cusion to the cable/screw connection at the same time.

Also, the metallic case is well grounded, with a suitable terminal etc.

I appreciate your comment.

i
Reply to
Ignoramus4299

That would be nice. Anyway, since working used grinders of this size are not very expensive, all this restoration is kind of a waste of time, but I think it's good practice and does not cost much.

i
Reply to
Ignoramus4299

Good stuff, Iggy. I enjoy your posts about the various projects and such. Interestingly, I have both an old drill and an old grinder that look like the ones you posted. The drill works fine, but the grinder has a broken trigger switch. The switch mechanism is there but the bottom part of the trigger shoe is broken off. The grinder works fine but you have to grab the switch between your fingers and pull it out to turn the grinder off each time. Not the safest of situations.

Reply to
wrace

Yes... Thanks... I bought a few trigger switches on ebay, will son try to install one and will share how it worked out.

Called Black and Decker earlier today, spent 40 minutes on hold and gave up.

i
Reply to
Ignoramus4299

Yeah, the bolt tearing into a power cord as a strain relief is a good example of something bad, and not to copy.

Reply to
Cydrome Leader

It is not actually tearing it, I verified it, the outer insulation remains perfectly intact, just compressed somewhat.

i
Reply to
Ignoramus7272

yes.

It has no sharp edges, yes. I did verify what it was doing to the cable, and found that it was not tearing the insulation. I will put some material between bolt and cable, at the time when I install the switch, but it is not strictly necessary.

That insulation, on the particular cable that I used, is very tough.

That seems less tidy, and also, more prone to problems as wires inside could be disturbed if the cable is "pushed in" from time to time.

i
Reply to
Ignoramus7272

I think if it's a fairly large bolt, of a similar diameter to the cord, and you turn the end of the bolt in the lathe to ensure that it has no sharp edges, it's an acceptable thing to do. An alternative which is crude but effective is to tie a knot in the cord just inside the housing.

I have certainly seen far worse. I stayed in a place in Belgium this summer which had exposed live terminals on the bathroom lightswitch, more exposed terminals in the corridor and on the ceiling lights, and wires halfway across a wall connected with those tiny screw-on cups. I told the guy about it but I'm not sure he saw the problem.

Best wishes,

Chris

Reply to
Christopher Tidy

ICan you supply a picture of the switch and dimensions. I have a large collection of NOS powertool swithches and might have one. Email me privately.

Chuck P.

Reply to
MOP CAP

Reply to
Ignoramus24560

When I need to retain a cable in a housing and don't have the proper nylon clamps, or the hole is buggered so the right clamps won't work. I use 2 tiewraps (ziptights, zipties) and just cross them so they bind on each other when the cable is pulled. It works quite well and there is usually room in the housing for the tiewraps.

Glenn

Reply to
Glenn

That's a simple and clever idea. I am still waiting for the switches for this thing, I will revisit the cable locking issue then -- though the bolt is not damaging the cable. I will put some protective material in though.

i
Reply to
Ignoramus30966

Never did receive your private EM re the switch.

Chuck P.

Reply to
MOP CAP

Well, I did send one that's for sure. I sent it to

P i l g r i m 6 @ m i n d s p r i n g . c o m

I am cc-ing this message to you too.

i
Reply to
Ignoramus30966

Still have not received it. I checked both my trash and spam for it also. Please try again. You have the correct address.

Chuck P.

Reply to
MOP CAP

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.