CITIZEN F16
Titanium
- Joined
- May 2, 2021
McMaster usually delivers next day in most locations. Make sure you indicate the drill in no mater what you use to hold it. You want next to no runout on a drill that small.
Well I threw in the towel on this. Nothing but broken drills. Meanwhile, machinist covid test is negative. So he'll be in Monday to clean this up.
Better him than me.![]()
Hi again morsetaper2:
Did you try peck drilling it?
Cheers
Marcus
Well I threw in the towel on this. Nothing but broken drills. Meanwhile, machinist covid test is negative. So he'll be in Monday to clean this up.
Better him than me.![]()
Far worse than invar 36FC is Super Invar. That's even lower expansion, but a real nightmare to machine. What is Super Invar? - Eagle Alloys Corporation A blend of nickel and cobalt from hell.
Yes I did. I was advised by everyone to peck drill it. But I peck drilled by hand, hadn't read your note about using the stop. By that time I had given up.
Called machinist on phone asking for advise, he said lots of lube, but I was running way too fast at 2800 rpm. Said I needed to be down around 500 rpm for HSS and a bit higher w/ carbide drill. Still broke carbide drills and/or dulled HSS drills. I just don't have the speeds and quill pressure right and am hesitant of ruining those $800 optical mounts. So just backed off, I just don't have experience w/ invar to have a good feel for it. And the drills are just tiny.
But thanks all, for your contributing advice.
Dumore not. Boley, mayhap?
Or P&W's Sigourney, Or a Muehlmatt/Hamilton.
Unless used with an add-on rising-table, the E-M is actually clumsy by comparison what with the extra mass of that stone-age variable speed rig - same physics - AFAIK - as the one on my old-but-good Hobart heavy-lifter kitchen mixer. Which does have a crank operated rising BOWL on Z-axis dovetail ways!
More HP than the Burke #4 mill as well. Then again, talk about "earning your crust"?
My ex could crank out round loaves of bread on that machine as if feeding a Roman Legion!
...I'm a RapidTap fan, but you may pick from a wide offering that's out there....
Hi again morsetaper2:
As others have remarked, there's no harm in trying and we live in hope the experience wasn't too awful.
But I do have to smile at everyone who remarked that an 0.043" drill is TINY.
In my world, that's like a telephone pole, and I'll betcha many others on this forum are nodding agreement and chuckling quietly too.
Of course as I recently remarked on another thread, I've got a buddy who thinks a 1/2" drill is too small to use so I guess it all depends on your perspective.
Cheers
Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
BTW: with regard to your spindle speed...you were NOT running it too fast for the material and the drill, you were running it too fast to be able to keep up with the necessary feedrate to keep the drill cutting.
The nominal RPM for your drilling operation in Invar is 40 FPM with HSS drills, so about 3500 RPM, and at a 0.001" chipload (recommended for a 1/16" drill) you'd be feeding around 3.5 IPM which is way faster than you can control.
Your machinist is both correct and not correct (if that's even possible).
I neglected to mention that on a manual machine, you want to run the drill about as he recommended and never ever EVER follow the CNC chart recommendations...you just don't have the reflexes and the control to get away with it.
I would not call a .043 drill tiny in a machine with CNC control, make it out of carbide and drill manually it is real easy to break one that size. That being said I think the smallest hole I have drilled was .012".
Invar: Drilling Small .043 Inch Holes
Machinist at work is out for an extended period. I'm a mechanical engineer, but when odd-ball fixes need to be done I get tapped to do them when its an emergency and machinist is out. I'm no journeyman machinist by any means. Competent in alum, steel, brass, some stainless, various plastics, etc.
I have zero experience working with invar.
I believe the material is invar 36 FM. And the parts are nickel plated. I need to drill 3 small .043 diameter holes in five parts (15 holes). These are expensive optical mounts so I don't want to ruin them.
I'll be using .043 carbide drills. Exact hole size and position is not critical. I read some posts about drilling invar. But none were for drilling small drill holes. Read that it work hardens. I'll be drilling into a tube that is hexagonal on the outside with a round ID. Where the hole needs to go wall thickness is about .100 thick.
Any advice so I don't screw this up? Work will be done on a Bridgeport clone.
Drill RPM for .043 carbide drill?
Drill RPM for .043 HSS drill?
Coolant: oil or water based?
Will it act unusual when drill breaks through to ID?
Thanks.
Plugging the main bore is dangerous...you may never get the plug back out once the burs lock it in.