2016 POTD Thread Archive

[silence dogood]

This was not enough of a justification to buy a lathe, too? Just kidding. That was a clever way on how you made the fix and it looks better, too.

 

[Tony Wells]

Yes, it does. For brass or bronze, I usually chuck short and turn a 60° point on a bit of waste, and just chuck on a broken tap shank that has a grinding center hole in it in the tailstock. I run it like a dead center, with lube, then cut it off when I an finished.

 

[MozamPete]

Want to get your 9 year old son excited - tell him to come give you a hand building a Laser!

Build thread at http://www.hobby-machinist.com/threads/a3-2-5w-laser-engraver-kit-from-banggood.49953/

 

[Iceman]

Learned a small radius HSS tool in a flycutter will not yield success working with A36 plate - it will however reshape the tool. Doh! Looking for a carbide insert now - learning has occurred.

I am building my first tooling plate, 12x12x1 A36

I understand the need/want of a power x-feed, I would also take a powered a powered draw bar. Projects to design and build next.

Also working on a CNC router from scratch. I married the electronics to the control box the other day.

 

[bmw rider]

Made a couple of tools to do a job on my motorcycle. Needed to replace the stator and rotor which required a puller for the rotor and a locking pin to secure the crankshaft from turning.

First time cutting metric threads, they're M22 1.5; also had to heat treat it as the rotor is quite tight on the taper and is additionally held with loctite. The manual also specifies heating it to 100 C for removal. The lock pin is just a bolt with the end reduced to fit the lock notch in the crank.

 

[JimDawson]

Just a little teaser. I've been working on a little project, OK, not so little, but anyway, one of the pieces is a chunk of aluminum 7 x 60 x 0.5. Working on the slot in the picture. Had to turn it around after drilling the holes on the other end, my x travel is only 32.5 inches.

This picture is just for perspective.


So what I need to do to it next is to put a little ramp on the end like the other piece in the picture. I just set the old piece on the new one for this picture.



This should be an interesting setup, and no I don't plan on rotating or nodding the head. But I do have a plan Stay tuned...

 

[intjonmiller]

Yes, it does. For brass or bronze, I usually chuck short and turn a 60° point on a bit of waste, and just chuck on a broken tap shank that has a grinding center hole in it in the tailstock. I run it like a dead center, with lube, then cut it off when I an finished.

That makes sense. And while I'm sure it wasn't a 60 degree tip (I just guessed at the angle since it wasn't critical and it was off the poorly designed scale on my Logan compound) I'm sure what I had before I filed it round would have worked for such use. For that matter I could make up a simple "reverse center" for that purpose. Infrequent use, reasonably tough geometry (not like the point on a normal center), and not a significant load for this kind of thing, so even mild steel would probably hold up fairly well.

Thanks!

 

[intjonmiller]

learning has occurred.

I love the simplicity of that statement.

 

[JimDawson]

OK, as promised.......... A little show and tell of creative work holding

First I bolted a 2 x 2 x 6 aluminum riser block to the back of the workpiece. This gave me something solid to grab onto with the vice. The riser block was a leftover from another project and already had the the bolt holes in it at the T-slot spacing, as does the workpiece.


First I indicated in the vice and since it's a Kurt I'm reasonably confident that the sides are parallel, at least to each other. I did this with the vice tightened on the part to make sure the jaws were loaded to get an accurate reading.


Then I squared the workpiece to the vice. There is just enough slop in the bolt holes to get things lined up.


Then confirm the angle on the original part. 26° !



Then set the angle on the workpiece to match.



This is done with only the highest precision tools available to mankind. The Harbor Freight sine adjuster and motorcycle jack. Added to that is a high precision 19-10-12 milk crate block along with a 3/4 inch particleboard shim.






A closeup of the high precision, multi directional outboard support bearing. This is a piece of Melamine coated particleboard and a chunk of UHMW. It actually is a really good bearing, very low friction.



And here it is. I had to pull the hand wheel off of the Y-axis for clearance. If the lathe and mill were much closer I would have had to rotate the mill to get clearance.



And in action. 3/8, 2 flute, solid carbide end mill. 0.060 DOC, 10 IPM, 2400 RPM, 40% stepover. About 95 minutes of cut time. Not pushing it very hard with this setup. It's running as I write this!

 

[TomS]

Jim,

NASA would be proud! You have a unique ability to apply the simplist solutions to achieve the desired results.

Tom S.