Surface Grinder - Disassembly?

[joe_m]

I've finally got a line on a surface grinder that I can afford. It's an older bridgeport 815.
I think the weight is just about the limit of what my little trailer with it's toy sized tires can handle but if I can break it in two then I know I can get it home safely.
It's too far away for me to make a trip just to find out though.

So are surface grinders normally breakdownable? Like is there a single spot where I can undo a couple of bolts and break the top part from the stand or something? If I can get it into just two pieces I'm sure I can get it home safely. Please say yes, and please say yes fast as I need to call the guy fairly soon.

thanks!
Joe

 

[joe_m]

I had to take a break for a week or so - life got in the way of my hobbies, but I'm back! Nobody ever answered my question on disassembly of a surface grinder. I'm sure some of you know but just didn't want to discourage me by telling me the truth - No matter what you disconnect or move or turn it is 1500 pounds of top-heavy pain-in-the-patootie metal and the easiest way to move it is to call some other sucker to do it for you.

So I did. It is now sitting in my driveway. I'm hoping if I leave it there long enough it will find its way back to the workshop.

In the meantime, i'm stuck trying to get the old stone off. Here's a pic. I know it's supposed to be the opposite of righty-tighty lefty-loosey but apparently someone in the past didn't because the two holes for the spanner are stripped on the left side. I tried to loosen it by going the opposite of normal way with a 2-pin wrench in those holes while holding the grindstone itself with my hand - no such luck. Am I turning the right thing? I notice the bigger round piece of metal just outside the inner part has grooves around it not unlike the nut that holes my L-00 chuck on the lathe. Am I supposed to use a spanner on that instead? Or do I need to put a wrench on that one, and a wrench in the holes and turn it left/right/north/south/in/out???

Please advise.....

thanks
Joe

 

[Richard King]

Next time ask the question in my forum as I rebuild machines for my living. You need to lay a piece of wood on top of the chuck and crank the wheel down onto the board. If you have a small Dumore pencil grinder grind the 2 holes round again and then if you don't have a 2 pin spanner put a piece of 1/8 or 3/16 rod or a dowel pin into the right hole and get HD punch say 1" x 6" made from a chuck of cold role and get you 2 pound ball peen hammer and hit down on the pin counter clockwise. Wear your safety glasses. If you can't get the pin to stay in the hole have someone help and insert a longer pin and have them hold it in and you smack it. You can also heat the nut with a butane torch to expand it.

The spanner nut with the square notches is on backwards and that is usually right hand treads and it holds the wheel to the hub. There is a outside washer under it. .

Some times those hubs are stuck on the spindle taper, and you use a gear puller or a hub puller that is made to pull the off. If you don't have one. spray it with penetrating oil and tap on the hub to vibrate it loose a little bit so the spry can penetrate. Then rotate the wheel and gently tap on the wheel as close to the middle of the wheel from behind with a short 2 x 4. Don't hit ti to hard or you will crack the wheel. If it doesn't come off, spray it and wait a day, spray again, tap it, etc.

Do you have more pictures of the machine? Do you have a manual?

Have fun and have a nice weekend. Rich

 

[joe_m]

put a piece of 1/8 or 3/16 rod or a dowel pin into the right hole and get HD punch say 1" x 6" made from a chuck of cold role and get you 2 pound ball peen hammer and hit down on the pin counter clockwise.

Well once again my dumba$$ery combined with my impatience and I butchered the @#$% nut. I read what you wrote above and I thought I understood it - i was thinking this nut would unturn clockwise but it said counter so I put the punch in and banged and banged and banged and then once the nut was about detroyed I went into what I guess was a mini-rage because the hounddog went in and hid behind the couch and the pitbull backed off a few feet to give me some yelling room. After throwing all the tools in the pouch around the yard I picked up the vice-grips and got enough of a grip on the edge to give it a yank counterclockwise, it of course didn't budge. And then I punched the vice-grips, still attached to the nut - and of course it turned right off clockwise. On the plus side, I've now drawn blood with the tool so I guess I got that out of the way early.

The wheel is still on there. I'm done messing with it for the day. I do have a gear puller so I'll dig that out tomorrow. I'd like to get the wheel off without breaking it because it does seem like a nice waterstone.

I may end up putting a help-wanted in that section of the forum to have someone make me a new nut - I'm getting better with exterior threads but I'm not up to female left-handed ones yet.

No manual. I'll take pics once I get all the pieces pulled back into a pile.

thanks for the help
Joe

 

[Richard King]

Well that is so unusual, most grinders have a counter clockwise thread. That's why I always like to find a manual before taking something apart. Sorry I thought it was counter clockwise. I just removed a wheel last week off a Do-All grinder and it was CC.

 

[joe_m]

That was all my fault - you actually described the process correctly and I had a strong feeling I was doing it wrong even as I continued to do it wrong again with just more force. There's an arrow on the wheel cover showing direction of travel and the threads normally are the same, that way they are self tightening. I knew it and just continued to drive on the wrong way.

The jaws on the gear puller were too thick to get between the wheel and the back cover so I used the tapping method you described and it came off easy. Embarassment #2 - what I thought was a waterstone just a very dirty metal disc 9.75" diameter and an inch wide. most of the wheel is steel but the outer inch or so is a copper color. (I cleaned some off in the first pic). The copper part is rougher to the touch so I think this might be a diamond stone? It was originally used to grind telescope mirrors for the Kitt Peak observatory in Tucson.



I don't know how to disassemble the wheel from the taper. I'm thinking if the nut on the arbor was LH, then this might unscrew LH, but I don't want to destroy it too. I don't have the proper wrench for this one and that doesn't help much. I'm also confused looking at the back as to what part is part of the wheel itself, and what is part of the taper adapter. The big round part in the middle sticks out about 3/4" from the wheel itself and is 4" in diameter. Inside that is another piece 2.5" in diameter. Then on the front the widest piece of dark metal is 4" and the opening around the mangled nut is about 2.5". If it's too much of a pain I'm hoping I can just buy another adapter that will fit the stones I plan on using. But then I started reading and it seems there are different standards. Here's my arbor. The recessed area around it is 4" wide and about 3/4" deep - enough for that flange on the back of my current stone to fit into. The arbor itself is about 1" thick at the back fattest part, with 1.5" of tapered part and another 5/8" or so of threads. I'm praying that's enough for me to get confirmation that it is a normal standard taper. The grinder actually isn't a bridgport - it's a Harvel model 815 and I'm finding nothing but pics on the internet, no specs. There's someone on another forum that has one but I'm not going to join just to ask him the taper.

 

[pdentrem]

Diamond wheels are used to grind glass for mirrors. Who knows, maybe over on Cloudynights.com you might find a former user, as there is a large mirror making contingent or they may know where to send you to look.
Pierre