While we're talking dial indicators... what do I need to have in my collection?
Here's every single precision measuring tool I currently own. I'm pretty sure I don't have enough to become a good machinist, but I also haven't been able to find a list of "stuff you should have in your measuring drawer if you own a mill and a lathe and want to make stuff with them."
Any advice? And can I buy cheap crap and treat it delicately to get good accuracy, or should I pony up for the "real" brands?
Keith Tanner said:Someone please explain "tram the head" for those of us who prefer to learn from our friends instead of google :)
Okay, I'll take a stab at it... Tramming the Head
One cool part about vertical knee mills is that they're really versatile. And one reason is because you can move the head around like crazy for different jobs. The head can tilt left and right, as well as lean forward or backward (nod might be a better term for that).
One problem: To do normal milling operations, I want the head to be square with the table (well, actually with the work, but that's more advanced). And a 50-year-old dial with degrees marked on it isn't nearly accurate enough. The experienced machinists are probably screaming "NOT QUITE SQUARE, WHAT ABOUT TOOL DRAG WHEN FACING!! etc etc." I know, I know, and we'll get to that another time.
So, you have to tram the head. To do it, you put a dial indicator (or a tramming tool) into the head, then rotate it in a circle to see if the distance is the same at every point. After a few circles and a few adjustments, your head should be square with the table.
Hastily googled diagram to help illustrate the parts that adjust:
Thank you. Now I have learned my useful thing for the day.
DIYing a tramming tool is trivial if you have a welder.
You can make one with a piece of round stock that fits in your drill chuck/collets and a piece of 1x.125 flat stock. There's no need for it to be anything besides somewhat rigid.
I'd suggest a Noga style holder for a dial indicator. much easier to get into the psoition you want.
I don't use dial indicators much on the mill, I use them constantly on the lathe.
For the mill, you'll want a test indicator. They're more sensitive and good for centering on holes when you get a holder that clamps to your quill.
A good cheap tool is an edge finder, I use mine pretty much every time I use machine. Coupled with a DRO, finding edges or centers is super easy.* I think it's also the cheapest Mitutoyo tool you can buy!
Let the papercuts continue!
*It helps when the part you're trying to center on doesn't have burrs and isn't tapered, as I recently relearned in my build thread, damnit!
In reply to Tom Suddard :
I have a round column Bridgeport, similar to the one in the diagram. IIRC, mine is a 1954. Not as sturdy as the newer dovetail machines. But home shop, so all good. Hopefully I'll be able to afford wire for the shop... for now it's just in the way!
Good start on precision measurement devices! As mentioned, an edge finder, a test indicator type, and a set of parallel bars. The rest can come as ya grow.
Great thread. Thanks.
Tom Suddard said:While we're talking dial indicators... what do I need to have in my collection?
Here's every single precision measuring tool I currently own. I'm pretty sure I don't have enough to become a good machinist, but I also haven't been able to find a list of "stuff you should have in your measuring drawer if you own a mill and a lathe and want to make stuff with them."
Any advice? And can I buy cheap crap and treat it delicately to get good accuracy, or should I pony up for the "real" brands?
The big thing for me is having a set or 3 of 1 2 3 blocks and parallels to use with that fancy vice.
A friend has used these harbor freight parallels and if I recall, they were well under .001" flat and wide, well within the tolerance that you'll work within for a while!
The 1 2 3 blocks are another handy tool, they're really useful to have.
Both of those act as a good way to tell how good your other measuring tools are. Use them to measure the parallels and blocks, and then measure it again a few times. See how to be repeatable with how you're measuring using that particular tool, how much variation you can expect when using it, etc. Sweep the blocks with your indicators to make sure things are trammed in, etc.
Also, your mic set likely has a set of gages in it to calibrate them, they're great for checking calipers and such.
Wow, that totally missed the last question. No, you don't need better measuring equipment yet. When you start trying to hold under .0005, then you'll need to step up your measuring game.
We made our own parallel bars in school but we used the schools bars to make them.
I've used the engine crane the last few times I needed to move machine with good results even WAY overloading a cheap crane....quick and easy to move it into place and spin as needed. There is also usually just enough room under the utility trailer axle to roll it into place but having a jack under the axles is needed to pull the crane back out after the trailer is loaded and the tires compressed.
The problem I had with the will was even with the head spun over I didn't have the height to go onto the trailer and out the door so I just pulled the top off...4 bolts and off it comes and through the door is went
All this power feed talk has me thinking...about 10 years ago when I son maybe 3-4 he liked to "help" nd would walk around with tools unscrewing thing. No idea when it happened exactly but the bushed are gone from the powerfeed so its been dead about 10 year and I do miss it.
....and all these years I've been dreaming of a proper vise.......
Honsch said:DIYing a tramming tool is trivial if you have a welder.
You can make one with a piece of round stock that fits in your drill chuck/collets and a piece of 1x.125 flat stock. There's no need for it to be anything besides somewhat rigid.
I'd suggest a Noga style holder for a dial indicator. much easier to get into the psoition you want.
I don't use dial indicators much on the mill, I use them constantly on the lathe.
For the mill, you'll want a test indicator. They're more sensitive and good for centering on holes when you get a holder that clamps to your quill.
This is the tool I use most...like every time I'm on the mill, an edge finder is a close second.
That exact indicator setup IS my tramming tool. I set it to swing the width of the table with the quill centered and you can see .0005" over the 12" and that is plenty good for most ay job. I will occasionally throw a better indicator on (I have a B&S marked to 1/2 tenth but its only like 5 thou total travel) but that is really rare.
But this is also what I use to indicate the vise, quick check the part is sitting right...it is my go-to tool because its so fast and easy.
I'm not playing with the mill today, but that doesn't mean I can't make progress towards machining parts!
I bought all these for $25 this morning. The lathe tools don't help the mill, but I needed some extras and the end mills are exactly what I need to get started with the Bridgeport.
For those following along at home, here's a taste of what end mills cost if you buy them new:
That box of tool bits is worth a small fortune along with all those end mills.
You scored well for $25.
And the award for "densest UPS box ever" goes to...
THE VISE!
I'll post more about why I picked this later, but it did arrive safe and sound.
So, let's talk VISES
First, the basic premise: You need to hold work securely to your mill's table in order to do machining. And just like it's important to tram the head so it's square to the table... it's important to hold the work/stock/etc. securely and squarely in order to do any accurate machining.
There are a few ways to do that, and I won't get into the others now, but almost everybody with a mill will have a vise like mine mounted to the table 90% of the time. Machining vises are measured by jaw width, with my 6" model (above) having 6" long jaws.
If you've been following along with the discussion of dial indicators and measurements accurate to 0.0002"... you can probably see where this is going. Putting a part into your vise for milling isn't the same as putting your axe head into a bench vise for sharpening. Machinists always have to consider tolerance stacking, where slight errors in every step combine to create a part that doesn't work as intended when its finished.
So, it's incredibly important that the vise be perfectly flat and square. And if it isn't, it means that the parts you make won't be perfectly flat and square, and they'll lose that accuracy at the very beginning. That's why "good" vises, with names like Kurt or Orange, aren't cheap:
Of course, there are imported copies. Are they any good? Well... no. This Old Tony can explain:
Of course, there's no way I'm a good enough machinist to notice the difference on day one. Still, Steve Eckerich said I'd be shooting myself in the foot if I didn't start with a used Kurt vise, since that had a pretty good chance of being square and flat. That's why I ordered this (well) used 6" model. If it turns out to be ruined, or if I outgrow it and decide I need something newer, I'll be able to sell it for about what I paid without any issues.
Fedex just dropped off more parts!
In reply to Tom Suddard :
Is that an old Kurt, that someone milled their own logo on for fun? Or an old copy of a Kurt? Even if it's a copy, it's not the current crop of cheap copy's, and is probably as accurate as us home shop guys need. Good score.
Tom, even a certified Machinist with a closet full of tools is only as good as his knowledge of how to use them.
I will donate an Edge Finder; you sing it up to ~3000 RPM and walk it .0005 at a time up to an edge, when contact is made the smaller diameter pops out; a visible signal. It is .200 in diameter, so you move the table .100 and you're on the edge of the piece.
Also a 90* thingie for a dial indicator, mostly used on lathes but it could be handy some day; for zeroing up an inside diameter. I see you already have a Last Word so I'll keep mine.
I also will not use my 1-2-3 blocks in a plexiglass case, you, but the shipping may be more than just buying them locally. The other two I will ship to the cause.
Steve, who actually knows what he's looking at, is pretty sure it's a Kurt based on the photos. And yeah, I think somebody screwed up and went a bit deep with their cut, or was having some fun marking up an old vise.
As far as milling-drilling; you want to buy some Center Drills. Ever had a drill bit "walk" when drilling a hole? You know, right across your beautiful paint job! Center drills don't walk, use them as a pilot especially on cylindrical surfaces and stop puckering.
In reply to 914Driver :
Wow, that would be fantastic! Thank you so so much! I had these papercuts on my list of inevitable purchases, so not having to endure them will be a nice break from the norm.
I'll happily pay for the shipping for the 1-2-3 blocks, as well as everything else. Just let me know what it comes out to and I'll shoot you a Venmo or PayPal.
Oh, and I already have some center drills in a box somewhere. I need to clean out an old toolbox and start organizing all my tooling!
Thanks!
03Panther said:In reply to Tom Suddard :
probably as accurate as us home shop guys need. Good score.
This x1000
Remember, you're not building stuff to go into space.
In high school we had training goals and a few lessons involved milling and surface grinding a block inside a block. You learn how to square up and make blocks and how to surface grind. Next step was parallel bars. Mine was a step below this - learning tools.
ShawnG said:03Panther said:In reply to Tom Suddard :
probably as accurate as us home shop guys need. Good score.
This x1000
Remember, you're not building stuff to go into space.
I mean, if I screw up badly enough the explosion could theoretically send things into space, right? Just wait till I try building a crankshaft!
Tom Suddard said:While we're talking dial indicators... what do I need to have in my collection?
Buy it when you need it. My only suggestion would be long handled telescope gages. Long handles make it easier to reach the bottom of the cylinder to measure diametrical out of roundness. If you cut close tolerance slots, look at sliding blocks. With each of these there is no need to buy expensive stuff, they work as well as the operator; save you money for the after party.
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