Author Topic: Pull My Finger  (Read 2652 times)

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #45 on: April 03, 2020, 10:48:14 PM »
And back to newbie world....

I'm trying to drill a hole in some 303 stainless steel rod and it's not going well.
Drill bit hardly goes in (thought it was but it was the part moving back into the chuck).
I tried two drill bits. I used cutting oil.
I thought maybe it had work hardened from a prior parting operation so I flipped the part around. Same result.

It's possible it's not 303 but some drill rod but I'm pretty sure it's 303 stainless.

Is drill rod harder to drill than 303?

What am I missing?

I'm drilling for an 8-32 thread using a #27 drill bit.

Sheesh...ever since I got these new machines I feel like I'm back at the beginning in Machining 101.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline crueby

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Re: Pull My Finger
« Reply #46 on: April 03, 2020, 10:55:56 PM »
Drill rod is harder than 303.


Lets see, start with the most basic - pointy end of the drill bit is out?   :Jester:   Lathe is turning?  Not a left-hand drill bit? Lathe turning in proper direction? Oh - that reminds me, you get the hot belt/pulley issue figured out?


File check the rod - run a file against the metal, make sure it can dig in and cut easily - if it wants to just skate off, it is hardened drill rod. Also, magnet check it - if 303, magnet should do very little. If it sticks, its not 303. Also, 303 wont easily work harden like some metals. All the 303 I ever got was in annealed state, its possible it is hardened.


You mention bit wont go into metal - the tailstock is not stuck, the chuck on it will move? Not already all the way out?

 :headscratch:

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #47 on: April 03, 2020, 11:16:58 PM »
Drill rod is harder than 303.


Lets see, start with the most basic - pointy end of the drill bit is out?   :Jester:   Lathe is turning?  Not a left-hand drill bit? Lathe turning in proper direction? Oh - that reminds me, you get the hot belt/pulley issue figured out?


File check the rod - run a file against the metal, make sure it can dig in and cut easily - if it wants to just skate off, it is hardened drill rod. Also, magnet check it - if 303, magnet should do very little. If it sticks, its not 303. Also, 303 wont easily work harden like some metals. All the 303 I ever got was in annealed state, its possible it is hardened.


You mention bit wont go into metal - the tailstock is not stuck, the chuck on it will move? Not already all the way out?

 :headscratch:

Thanks Chris. Same material was previously turned down to 8-32 and threaded with a die. I did notice, when I flipped the die to thread closer, it was harder.
I checked against a magnet. No attraction (I'm familiar with that feeling).
Tailstock not stuck or all the way out. The part was actually getting pushed into the chuck from my efforts.

I could go to the bigger machines but the idea is to do everything on the Sherlines. And, I don't think bigger is necessarily better in this case.

P.S. I haven't adjusted the mill's belt yet so it still gets pretty warm (hot). I haven't run it enough to worry but I will be looking at it.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Pull My Finger
« Reply #48 on: April 04, 2020, 02:42:19 AM »
Okay, theres just a couple possibilities that I can think of.

1) that piece of rod is too hard - either not annealed like it should have been, which does happen from time to time (I have a chunk of flat bar 303 that is almost uncuttable), or the alloy was screwed up leaving a hard area, or its not the alloy you think it is. Clamp it in the vise vertically, and try cutting in 1/4" with a hacksaw blade. Should cut through pretty easy.
2) Something wrong with the drill bit. Can be dull, or sometimes I have gotten brand new ones that were not sharpened properly. If you look with a magnifier at the tip, you should see the narrow bevels running down the spiral flute edges at the outer edge. That bevel should run all the way to the angled tip. Once in a while I get a brand new one where that bevel is messed up, and the end is too narrow or rounded, so the drill will not be able to cut the full diameter, and it just stalls like you are seeing. Another possible is that the center chisel tip, right at the point, is the wrong geometry, and it cant start the cut there.
Aside from those things, another way to determine the problem is with a couple tests - chuck up a piece of brass or aluminum and try the same drill on it. If it cant cut that, the drill is bad and needs sharpening or replacement. If it cuts that easily, then the steel rod is 'faulty'. You should be accustomed to this kind of fence drawing, as an ex-software guy!

 :cheers:

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #49 on: April 04, 2020, 09:15:12 PM »
Thanks Chris. Apparently both drill bits were either faulty or not sharp. Bummer. I have no replacement.
Somewhat surprising. I don't think I've ever used my #27 drill bits.
Not a biggie for this project. I was trying a work around for the part I screwed up. Now I'll just go ahead and remake the part.

I'm hesitant to order replacements. I read an article that brought up the question whether it's ethical to order non-essential products.
On one hand, it puts the entire supply chain at risk (warehouse to my home) but on the other hand it keeps some people employed.

As for the hot pulley on the spindle of the mill. I think it's sorted. I believe the motor pulley was not in perfect alignment with the spindle pulley and the belt was rubbing on the spindle pulley. Time will tell. I ran it for a while and it got warm but not hot.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Pull My Finger
« Reply #50 on: April 04, 2020, 09:24:34 PM »
Thanks Chris. Apparently both drill bits were either faulty or not sharp. Bummer. I have no replacement.
Somewhat surprising. I don't think I've ever used my #27 drill bits.
Not a biggie for this project. I was trying a work around for the part I screwed up. Now I'll just go ahead and remake the part.

I'm hesitant to order replacements. I read an article that brought up the question whether it's ethical to order non-essential products.
On one hand, it puts the entire supply chain at risk (warehouse to my home) but on the other hand it keeps some people employed.

As for the hot pulley on the spindle of the mill. I think it's sorted. I believe the motor pulley was not in perfect alignment with the spindle pulley and the belt was rubbing on the spindle pulley. Time will tell. I ran it for a while and it got warm but not hot.
If you are using the drill for tapping, you could always go up one size, it will still work, just be a slightly shallower thread. A number 26 is only a few thou different, no biggie for hobby work.

Glad the belt issue is sorted - that would have shortened the life of it a lot.

Gotcha on ordering stuff - tough issue, sounds like a part that can wait a while.  For future reference, one good place I like that carries the cobalt-steel drill bits at a good price is AirCraft Tool And Supply:
https://www.aircraft-tool.com/shop/detail.aspx?PRODUCT_ID=012-27
They carry the full range, number, letter, fractional, singly or in 10 packs. Price is good, I've had great luck with their quality. A friend of mine who built his own plane (full size, not a model) put me on to them.

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #51 on: April 09, 2020, 11:25:52 PM »
Time for a little picture.

Right side is parts for one finger treadle machine.
Left side is parts for the other finger treadle machine.
Top right are parts I made wrong.
Bottom middle are some buttons to finish the control rods. They still need cleaning up and hardening.
All the screws/bolts? still need to have the slot for a screwdriver machined.

The brass finger tabs were also done wrong. I either drilled too deep or milled the other side too deep. You can see the holes where I broke through.

This is about learning these Sherline machines. But what I'm learning is just how much I've forgotten.

My accuracy is complete crap. I should spend some time just machining simple rods and blocks and learn how to measure better (as well as get a better caliper).

Still need to make the shaft, flywheel, and base.

I've been using a 1/4" reamer for a number of holes but I'm thinking it cuts a bit smaller.

Stay healthy.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Pull My Finger
« Reply #52 on: April 10, 2020, 12:02:47 AM »
Excellent, great starter project.   :popcorn:

Offline awake

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Re: Pull My Finger
« Reply #53 on: April 10, 2020, 01:08:41 AM »
Parts done wrong, eh? I don't think you get through this hobby without a few scrap parts. Here's my pile:

https://images.pexels.com/photos/128421/pexels-photo-128421.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940

:D :D :D
Andy

Offline crueby

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Re: Pull My Finger
« Reply #54 on: April 10, 2020, 01:11:53 AM »
Parts done wrong, eh? I don't think you get through this hobby without a few scrap parts. Here's my pile:

https://images.pexels.com/photos/128421/pexels-photo-128421.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940

 :D :D :D
:ROFL:

Offline Mike R

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Re: Pull My Finger
« Reply #55 on: April 10, 2020, 01:26:02 AM »
Yeah - a few bad parts?  I've started to hang "shop ornaments" around my machines to remind me of the mistakes I've made.  If you're going over to CNC there's a whole new world of making scrap parts waiting for you! 
Mike

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #56 on: April 10, 2020, 04:46:32 AM »
Good one Andy.  :ThumbsUp:

Good idea Mike. I can give as gifts. The receivers won't know what they are. I'll call them 'a bauble'.

I have a wall of learning. Actually a couple-three walls. I plan to build a vacation home. Then sit in it and admire my boo-boos. Sad.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline zeeprogrammer

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Re: Pull My Finger
« Reply #57 on: April 14, 2020, 10:28:13 PM »
I have to put this little project on hold for a while.

Main issue is I've injured my left hand again. I suppose it hadn't healed fully when I played with the lathe.
I could use some hints on using the tommy bars as that's what caused me to re-injure myself.

Other issues include not having the tools or parts I need and I'm not comfortable ordering non-essential goods yet.
One of the tools is either an arbor for my slitting saws (I suppose I could make one) or slitting saws for the arbors I have.
The part I'm missing is a hefty enough flywheel (actually two of them). The ones I have are aluminum and don't provide enough inertia.

So I've turned to learning more about CNC. More on that in my CNC thread.

In the meantime...stay safe, stay healthy, and just as importantly...stay sane. We're all quarantined, missing their loved ones, and people are starting to have difficulty sleeping, keeping busy, and understanding that everyone around them have the same problem.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Pull My Finger
« Reply #58 on: April 14, 2020, 10:51:27 PM »
Bummer about the hand!  One thing I did years ago was make the tommy bars longer - added a thicker rod to the end, rod was drilled to fit the bar and loctited on. Much easier on the fingers, though you need to take care not to over-tighten things with the extra leverage.

For the arbors, I am guessing the issue is the hole in the blade is not the same diameter as the step on the arbor? I wound up turning the end of the arbor to form a couple of steps for the two hole sizes I have on different blades. The Sherline arbors are not hardened (at least mine were not) so that was easy to do. The steps do not have to be very deep, just enough to center the blade.

Offline Flyboy Jim

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Re: Pull My Finger
« Reply #59 on: April 15, 2020, 03:30:51 AM »
I did the same as Chris and lengthened my Tommy Bars. Also, if you use the right holes, you can get them in a position where you can squeeze them together with one hand to loosen whatever you're trying to loosen. Also, to loosen a chuck I just insert a Tommy bar in the spindle and rotate it around so it contacts the ways. Then I can gently pull on the one is the chuck to loosen it.

Take care of that hand.

I wouldn't worry about ordering stuff. I notice Amazon has a notice that your order might be delayed while they ship more needed things. Other's probably do the same.

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".