This test piece machined nearly perfect, but now I have run into a unpredicted snag,
I need to flip these parts 90 degrees and drill a perfectly centered 9/64 hole through the flats. My dilemma is, how can I flip these and keep the flats horizontal for drilling.


Thanks much

Ken

Thanks Ward

Ken,

Your image has to be max 700 x 700. It is under the "Manage Attachments" radio button. Then navigate to your file and "upload".

Now that IS a problem.
Didnt you read the manual about inserting images? ( A Mach2 pdf joke )

Just in case you cant find the manage "attachments button". You will need to scroll down a bit. Maybe you have low resoluition monitor and didnt realize it was there.

Thanks Benny, I guess I was distracted by the "Insert Image" icon :)


Ken

I could mill a small single flat on the OD for orientation prior to the machining.

How many do you need to do Ken?

And how are you holding them now?

My quick off the top of my head suggestion would be to make a male part with long flat section (Sort of like a T handle) and use that to index the part between operations

If you just want a couple done, I would leace the back end long by maybe 1/4" (6mm) and mill a good reference flat on it. Then clamp in a vise by holding on the faces. Indicate and drill.
If is a production part spend half a day and make a fixture.
You could also drill the 9/64 hole in your round blank first and then fixture that hole for to machine the square (this would be an easier set up)

Thanks IJ. and Darebee for the input,

Only need eight so a fixture in not out of the question but not practical. This test piece was just clamped in the vice with the square up, all eight will fit nicely in the vice. Thought I had the operation all planned out until I got to the drill part, then uh-oh, think something has been overlooked. It seems that a flat may be the simplest approach.

Thanks again for the input guys.

Ken

Ken,
I'd machine a male square to fit the square hole in the part. If you need two holes at right angles, then hold this fixture in an indexer so you can do the 90 degree index.

Once you set up to mill the square on the fixture, and drill the hole in it, then do not disturb the fixture. Just slide your real parts over it and drill them, too.

It appears as though your part has an axial hole lengthwise through it, so that means you could add a threaded stub to the end of your male square fixture, to retain and clamp the part whilst it is drilled.

Thanks Murray,
I will try to keep that method in mind for future use, it may be a bit more complicated for me then eight of these are worth. Remember, you know what to do and how to do it while I have to put all this together from scratch. I am finding that the CAD/CAM can be the easier work and the fixtures to hold the part that can take a lot of time.

I am going to mill a small reference flat length wise on the round stock prior to cutting them to length for machining, got the cad and cam work done (OneCNC-XR is a pleasure to work with) even more so now that I am getting more familiar with basic CAD/CAM principles.

Ken

Heres my idea. Make a vice jaw that has a square boss that fits that square hole on your part and is parellel to the vice bed. Then just slip your part on, clamp the vice so everything is squared up and tight, drill, remove -replace, repeat drill cycle. It would make indexing to the other side easy too, just unclamp and rotate 90 deg.

Dave,
I had thought of something similar as well, but the hole needs to be drilled first, I kinda put the cart before the horse in my first effort, drills have a tendency to wander when drilling though another hole. I also wanted each setup to machine all eight which total length fits in my vice perfectly.

Thanks

Ken,

I had a similar situation needing to drill and tap holes 90 degrees to each other, one needing to be directly above a keyway. My instructor told me to put the key (in your case an appropriate sized key or piece of flat stock) in and have part sticking out to rest on top of the vise jaw to orient the flat of your square recess parallel to the top of the jaw, clamp the faces in the jaws, edgefind the center and centerdrill. Turn 90 degrees and repeat. Hope it helps.

Regards,
Rick

Ken: Agreed the Cad side of things is a breeze, working out how to hold the workpiece you've designed is the black art ;)!

For your 8 pieces I would make a square peg 10 mm longer than the hole in the parts.

I would use a 9mm parallel strip under this in the vice to give me the 90 degree indexing.

You can bore a receiver hole in the square peg for drill clearance.

Just as I suspected, lots of good, yet different information for me to consider. :)

I would mount the piece in a square collet chuck with enough protruding from the end to drill your hole afterward. Then, square the collet chuck up in your vise, mill your square pocket. Next, lay the chuck down, find distance from edge and drill hole. Done! These chucks are about $30 from enco and supremely useful. Get some more value out of those 5C lathe collets to boot.

Joe
www.gardnerguns.com

I have been looking at those for months Joe, and imagined their usefulness, there is a hex version as well. Too late on this job but I think I might just get a set for later use. I like your idea.

I had been to your site sometime back and looked at the neat manual machine gun you manufacture, it tweaked my nostalgic interest enough that I went web looking for other reproductions and I could not believe it when I saw there is a place not 10 miles from me (Lexington, Ohio) that makes some version of a Gatling gun. (forget the name, or model, sorry, remember the price though $5000 :D

Thanks
Ken

Hi ken,
Don't hesitate on getting the collet blocks, they are supremely handy little tools.

There are a lot of guys doing the Gatling, but almost no one doing Gardner, Nordenfelt or Hotchkiss guns. I'm hoping to do some others as I get going, but the Gardner is my real passion at this point. I've wanted one for over 13 years now and I'm finally in the home stretch.

Joe