Thursday, July 24, 2008

In the begining, there was steel.....

After starting this project, I have been asked by many if I was going to make a Blog, so why not.

This being my first Blog ever, I have decided to try to detail this project as I go though, and explain why I make some of the choices and decisions I do, not knowing if they are the best choice until I have done it. I am sure I will have may screw ups along the way, and maybe it will provide some amusement for those reading this :-)

The Birth of an Idea

It all started when I began playing with a metal lathe I bought. Not having the cash nor space for a milling machine (or any other large machine, as the lathe sucked up both fast lol), I discovered a place where I could purchase "build it yourself kits" to add to your lathes usefulness, one being a milling attachment (This is a great place that sells castings and plans for many different lathe attachments. It is called Metal Lathe Accessories, and can be found on the web at

http://www.statecollegecentral.com/metallathe/index.html

Andy was more than helpfull, and gave me many pointers and information).

As I started working on the milling attachment, I had to "face" a casting nice and flat. After discovering that replaceable tip cutting tools don't work well in a fly cutter (screw comes loose and the carbide tip flys off, usually gouging the work), I switched to good old brazed tip tools and spent a lot of time facing (keep in mind I bought the lathe, but had never really used one lol). It was here that I thought, "boy a surface grinder would be nice to make the surface really smooth". That was the start of it all, I mean, what is a surface grinder anyway, just a grinder that's "controllable and movable".

Once the idea hit there was no turning back (as I could see it would involve steel and welding, things I love). As for the concept of the project, well I decided to keep it simple, a standard off the shelf bench grinder, a cross slide table of some sorts, and a lot of steel and bits to hold it together (and yes, another excuse to rack up a huge electric bill with the welder lol). While building the cross slide was possible, I bought a unit off Ebay for about $100.00. With this purchase made, I was already commited (lol) and went about buying what steel I figured I would need. Since I want to be sure this will actually work well, I am not going to bother making it look pretty until Im sure its a keeper.

In the Beginning, there was Steel....


I started off by setting up to build a stand for it, something sturdy but not so big I couldn't find a spot for it in the shop (OK, its a single car garage jammed with 3 times the stuff that should ever be fit in a "needs to be functional" space). So, since I have 2" angle iron left from another project, I constructed a 2' x 1' table out of the angle iron (I had bought a piece of 1/2" plate steel 12" x 30", so made the size based on this chunk. In hindsight, I should have gone a bit bigger, as the cross slide is large). I purchased a Cross Slide, which is nice and heavy and well worth the money spent).
I then thought about what kind of "transporting column" to use, and opted away from a tube type (like a drill press) to a flat bed (similar to a lathe), mainly because working with flat steel would be easier and a lot sturdier. (The Pictures to the left show the table and column with the grinder attached to an angle plate and temporarily clamped on. It also shows the first of two rails I have ground so far. This transport column (way) would need to be strong and sturdy, so I made it with a piece of 1/2" plate steel 6" wide, and two 1/2" plates 2" wide. This made a plate (when welded, as I love welding) of 1" thick at each side, with a 1" gap in the middle (for lead screw clearance). The last part would be the way rails, which would be 1/2" x 1" steel bars with a 60 deg bevel to match the movable carriage, and when mounted on the two 2" plates would give a little over 1" lead screw clearance space right down the center of the Way.
The carriage I made from a 1 1/2" x 6" x 6" block of steel, and cut a dovetailed grove in the bottom (left). The problem I had at this point was I needed a surface grinder to grind the 60 deg bevel on the rails, as they were over 2 feet long, far to big to lathe. So, I now needed the surface grinder to make the rails for the surface grinder..... what a catch 22.

Since grinding a 60 deg bevel on almost 3 feet of steel bar would take about a million hours even with a commercial surface grinder, I compromised and went with the most expedient solution. I used a hand grinder (a 9" monster grinder that shakes the hell out of you) to grind the bevel to as close to 60 deg as I could get it (checking a lot with a protractor). While this only took a few hours (OH yea, hours and I'm still sore) I managed to get it pretty nice looking.
Once the rail was close I used what I had already welded together, and jury rigged up a grinder to it. I used some clamps to get the grinder plate mounted to the rail, and used the center mounting bolt to pivot the grinder at the right angle so I could grind the rails.

I had purchased a Speedway 8" bench grinder (Another Ebay Purchase just after I bought the cross slide) and made a L plate to mount it. I managed to get 3/4 of the rail nice and flat before I had a set back. The Grinder would wobble a bit and at two specific speeds set up harmonic vibrations that would shake the whole thing. I cut this down a bit by welding a side support 3" x 1/2" to one side of the way length to stiffen it up more. The other problem was the grinder would get VERY hot after about 15 min of use, so I worked in bursts and finally called it a day

The next day I went out not happy about the lack of torque this 3/4 HP grinder had (it didn't take much to slow it to a stop), and bit my lip and turned it on. "POOF", a puff of smoke came out and that was it for this sorry excuse of a grinder. Feeling stupid to have bought it in the first place to save a few bucks, I stormed out and hit the nearest Canadian Tire and dropped $90.00 on a craftsman 8" bench grinder (at least it has a warranty and is probably far superior in quality).

I had to take off the covers and wheels, so I could trim back the guards to clear the work face, and move the lights back a bit for the same reason. I then plugged it in and gave it a shot. Surprisingly, it did a fantastic job on the first rail, with no vibration and a fairly good cut depth. I have finally finished the first rail, but I have yet to start on the second one (not looking forward to round two with the 9" hand grinder from hell..... time to break out the Advil). This is where I am to date. I will continue to post as I progress.

3 comments:

MalayGirl said...
This comment has been removed by the author.
smith said...

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