Square up small aluminum plates, by hand.

[Salp]

I am modifying my drill press, so the table vertical movement can be moved accurately and not lose its XY reference.


I thought this would be a good project to get started and make something useful, and hopefully only use basic tools.
I'm retiring soon, so no new lathes or mills in my future.
The linear rails are attached to square tubing which in turn is secures by the top and bottom plates, I was able to get this far with a grinder, the DP and many hours with hack saw and file.

The part I'm stuck on is making the small plates that attach the cantilever arms to the linear bearings, these plates are 1-3/4" x 1-1/16" blocks. All the plate material is 3/8" aluminum plate. I cannot seem to cut these plates square, I have tried a few things:
1. Tried the miter saw, parts are too small to hold safely
2. Cut them over sized and then hand file them, (my eye hand coordination sucks, not even close)
3. Build a sliding track saw, but I cannot accurately square the blade to the fence (none of the corners are 90 deg.)

I ran out of ideas and was wondering if anyone here has some advice, I do own wood routers, but I wont even think of using these unless ia have a jig to hold the pieces safely. My last idea was to use a Jig to hold the parts vertical and at the correct angle and manually sand them on a flat surface (I do have a small 12"x12" machinist flat plate, I use it to sharpen chisels).

The Cantilever arms and the mounting plates are the only pieces that need to be square, everything else can be made to fit.


Thanks
Sal

 

[francist]

Hand finishing to dimension is tough unless you’ve been doing it for a while, and even then it can be frustrating.

The absolute first thing that pops into my head is a disc sander. That’d be my first choice if I had to do what you’re doing but I’m guessing you may not have one available.

Second is to go back to the hand file but instead of just freehanding the entire operation I’d look for a vise with crisp, straight jaws and align the blank with the tops of the jaws. They would help me keep flat and also gives a lead-in and lead-off surface for the file. It’s not that you’re actively filing against these guides, but they help you keep on the straight and narrow. Kind of like guardrails on the road — as soon as you touch one it forces you to adjust the other way.

No vise? What about clamping a couple short stubs of something like angle iron on either side and use those as guides? It would take a bit of fussing to align them both on your line straight and square, but it sounds like you’re kind of used to that anyway. Depending on how securely you could clamp them you might get away with doing two at once but that might be pushing your luck.

Of course all of this assumes you can lay out the shapes accurately and scribe a nice set of lines to follow. I’ve done a ton of hand filing and finishing but I still reach for any aids that I can to make the job easier. It does get easier the more you do it though, so there is that to look forward to!

-frank

 

[Salp]

Hand finishing to dimension is tough unless you’ve been doing it for a while, and even then it can be frustrating.

The absolute first thing that pops into my head is a disc sander. That’d be my first choice if I had to do what you’re doing but I’m guessing you may not have one available.

Second is to go back to the hand file but instead of just freehanding the entire operation I’d look for a vise with crisp, straight jaws and align the blank with the tops of the jaws. They would help me keep flat and also gives a lead-in and lead-off surface for the file. It’s not that you’re actively filing against these guides, but they help you keep on the straight and narrow. Kind of like guardrails on the road — as soon as you touch one it forces you to adjust the other way.

No vise? What about clamping a couple short stubs of something like angle iron on either side and use those as guides? It would take a bit of fussing to align them both on your line straight and square, but it sounds like you’re kind of used to that anyway. Depending on how securely you could clamp them you might get away with doing two at once but that might be pushing your luck.

Of course all of this assumes you can lay out the shapes accurately and scribe a nice set of lines to follow. I’ve done a ton of hand filing and finishing but I still reach for any aids that I can to make the job easier. It does get easier the more you do it though, so there is that to look forward to!

-frank

Francist thanks for the tips, at the end I finally realized that the outside of the blocks did not need to be super accurate, the important part was the bolts holes layout. Which ended up putting a point on the bolts adjusted them all to be the same height and then placed the aluminum plate on the bolts and transferred the markings with a hammer tap.

Some time I tend to over complicate things, now I can lower and raise the table with out loosing XY reference.

This is what it looks like so far, next step is to build a better table and then add a screw w/ hand wheel to raise and lower the table accurately.

 

[jwmay]

I was going to suggest “filing buttons”, but I guess you’ve moved on. Usually they’re for filing flats onto round parts, or rounds onto flat parts.