[AnvilJack]

Mate, I've seen lots of things you've done that are ... an "opportunity" for me, not a history. One day, when I grow up ...

Fill it with weld and mill it again? Why not? I'll have a go.

Thanks.

[jwmacawful]

Mate, I've seen lots of things you've done that are ... an "opportunity" for me, not a history. One day, when I grow up ...

Fill it with weld and mill it again? Why not? I'll have a go.

Thanks.

if you do try this some electrodes aren't meant to be machined. something along the lines of 6013 should mill like butter off a hot knife while something like 7018 that has higher mechanical properties may be more difficult.

[delraydella]

You're always going to have some sort of flexing on a piece that thin. Everything that you mill needs to be supported from underneath as best as is humanly possible. If you don't have a good set of parallels or other types of blocks, I suggest that should be your next purchase.

As for the machining marks, unfortunately you'll always have that to some degree. It's just the nature of the beast trying to mill such a large area with such a relatively small cutter. Of course you are limited to how big a cutter you can use by the largest shank the machine will take, but there are ways around it. You can try using a fly cutter, 1st picture below, for wider cuts. An indexable milling head, 2nd picture, would also help, but may be too big for your machine.

Ideally for something that needs to be a beautiful finish like what you want, you would mill the piece to within a few thousandths and then finish it to size on a surface grinder. That's probably not the finishing answer you were looking for, but it is an excuse to buy another machine!

Other Steve

[AnvilJack]

I have one of those large cutters, but not a fly cutter. My mill claims it can handle "max. diameter of face milling cutter: 76mm (3")
*max. diameter of end mill cutter: 28mm (1-1/8")
".

Quite frankly, I would have tried this 76 mm face cutter but I cannot install it, or at least, I cannot uninstall the arbor that accommodates the current MT3 collets and cutters I am using. I have stuffed around a bit, trying to do this, but am very reluctant to force anything, too much. It seems a 30mm open spanner might help me hold the bottom of the spindle so that I can use a soft hammer on the draw bar from above, and so dislodge the arbor.

But this is all theory, while I have a go,

Thanks for your other insights.

[AnvilJack]

I received my copy of Tabletop Machining last night, and began to read it.

How's this: "You should strive from the beginning to make better and more accurate parts than you think you need. Work to closer tolerances than the job demands." (page 7)

"Never cut metal without a plan that includes dimensions." (page 5)

It is a bit like fabricating and welding, too, for that matter. Think. Plan. Be careful and skilful.

It is a pity I have so much work to do that I can't just go into the workshop and chug away all day.

[AnvilJack]

I have updated my list of notes on milling, earlier in this thread, if anyone is also interested in this skill.

Last night (very proud of myself -- though this is like a bead of weld across a flat plate on a table) I made a cube from steel stock, 25.5 mm. Flats are flat (dimensions to within .04 mm -- cutter marks, mostly, I hope), Try square gives feed back I am very pleased with, as do the digital callipers). Wife can't see what the fuss is about.

[delraydella]

This is a great book on machine shop work, sort of like a 'Tips And Tricks" . Lots of good information from an expert die and mold maker.

Here's a link to it on Amazon.....http://www.amazon.com/Machine-Trade-Sec ... 31132272#_

[AnvilJack]

Thanks for that: I've ordered it.

Bought a bunch of aluminium stock today, mostly square bar, in short lengths (up to 1 metre). Could be some different shiny chips flying soon.

[jwmacawful]

our bridgeport slicing down some material for the experimental cell doors we're building. this is a key cutter being utilized for another purpose.

[AnvilJack]

I have updated my notes on milling again. While I will continue to elaborate my notes as I continue to mill and read and mill and read, I will not post any further updates. After all, this is a forum for welders, not machinists.

Any member who is confused by anything I have not adequately explained or defined is welcome to send me an email. Perhaps better, even, would be to search out the concept in question on Youtube.

If you spot anything I have said that is "just ridiculous", please tell me. Thanks.

[AnvilJack]

OK, so how does one remove a lathe chuck that doesn't budge?

[noddybrian]

That depends on how the chuck is fixed on !

Cam lock - not usually a problem to remove unless fitted dirty or has been left wet & rusted - to remove - check all cams are unlocked - now double check ! put a short end of bar in the chuck & grip securely - now find a long bit of the largest bar you can fit up the spindle & use it to tap the chuck free.

Taper fit / screw collar retained chucks - make sure you are trying to undo the collar the right way ! - on some lathes if you keep undoing the collar it comes up against a register & jacks the chuck off - some just come disengaged from the thread & the chuck will come off - tap with bar as above if needed.

Screwed on - gets tighter depending on applied cutting load so can be real tight - usual method is to make up a long wrench that looks like a giant allen key with any large hexagon bar you can find - grip this well in the chuck then carefully engage the clutch in reverse in the lowest gear & allow the wrench to rest against the bed ( place soft packing between to protect it ) hopefully the chuck will wind off - several attempts may be needed - or leave the lathe in lowest gear without motor running ( or in back gear on little hobby lathes ) & hit the wrench with a heavy hammer to shock it - at a push & this is not nice but you can open the chuck jaws place a long crowbar or similar between them - pinch the chuck up just enough to keep it there & wind it backwards or wail on it !

If none of the above makes sense or applies post a picture of the problem - last thought - have I misunderstood & you mean a tailstock chuck ?

[AnvilJack]

Thanks. Headstock chuck, and it all makes sense.

As you might have guessed, I have found a second hand lathe, and now find I cannot unscrew the chuck.

From demonstrations I have seen on the internet, the chuck should unscrew toward the operator. Therefore, I should have the reverse gear engaged to jar the chuck loose, hex bar at rear of lathe? I hope I have that much right.

I will try out your suggestions. Wish me luck.

[delraydella]

Try spraying a little penetrating oil in it. That should help too.

[delraydella]

...and it's fine with me if you want to keep a thread open for machining. After some of the machinists forums I've been to, I would much rather discuss it with the fine (and much smarter) folks here than the majority of d*ckheads on some of those sites.

Other Steve

[noddybrian]

Yes - headstock chucks are right hand thread - so to unscrew by hand top of chuck needs to rotate towards you ( anti clockwise looking from tailstock end of bed - they can be really difficult to shock the first bit but should then spin off freely - if doing it under power in reverse once you see where the wrench will contact the bed place something to protect it - keep your hands out of the way - & if it won't move you could pull the wrench round to the 12oclock position & let it have a "running start" - most lathes with gearbox speed selection will wind the chucks off OK - hobby lathes driven by step pulleys/ belt usually won't so you will have to wail on the wrench ( place wrench at 9oclock position & hit downwards like you meant it ! ) if you don't have any big hexagon bar you can put 3 weld beads on round bar to catch the jaws or as I believe you now have a mill you can machine 3 flats or 3 slots to achieve a good grip.

Once you have shocked the chuck loose it helps if you grip a piece of bar that just fits up the spindle - leave about 3" in the spindle so when you run off the end of the thread the chuck hangs on the bar & you just slide it out - saves it dropping on bed & you hand as you never quite know where the last thread is ! if the chuck is heavy you can weld a lifting bracket to this bar to allow for an overhead crane or engine lift to hold the weight for you when fitting / removing ( I think if you look through Keith Fenners videos he made a very elaborate one using a CNC plasma )

Good luck with your new machinery - I own several mills / lathes etc so am happy to help if I can .

[Otto Nobedder]

I think Anviljack mentioned stopping posting on lathes and mills, "since this is a welding forum". Don't, please.

This is just one topic, under "General Shop Talk", a sub-forum created solely for topics RELATED to what welders do, and machining has a place. No one has asked for a separate subforum, just a place to discuss it, and it's fine with me. I'm sure the other moderators and our admins will agree. The topic has certainly earned enough interest to stay, and to remain active.

Steve S

[AnvilJack]

With Christmas upon us I am as busy as a fly on fruitcake, and I haven't had time to have a chat with chuck. Perhaps after dark, tonight.

My lathe is quite small, 800 mm swing and 550 mm between centres. It is solid enough, though, and apparently weighs 105 kg. I really want to focus on the mill for six months, but this came up and I thought it was very inexpensive. (I am finding out why now, with the stuck chuck -- but I hope to get this solved.)

Thanks again for all the ideas, and for support for continuing this thread about lathes and mills.

[jwmacawful]

With Christmas upon us I as busy as a fly on fruitcake, and I haven't had time to have a chat with chuck. Perhaps after dark, tonight.

My lathe is quite small, 800 mm swing and 550 mm between centres. It is solid enough, though, and apparently weighs 200 kg. I really want to focus on the mill for six months, but this came up and I thought it was very inexpensive. (I am finding out why now, with the stuck chuck -- but I hope to get this solved.)

Thanks again for all the ideas, and for support for continuing this thread about lathes and mills.

sometimes welders gotta be more than one trick ponies. for me i'm always glad to help a brother tradesman.

[jwmacawful]

one other quick thought, melted candle wax is a very good lubricant for stuck objects.

[WerkSpace]

http://www.practicalmachinist.com/vb/so ... al-165028/

[AnvilJack]

Good link to un-sticking chucks. (It often surprises me that I can search the Internet, find several examples, but there are always plenty of other great "search results" out there that I didn't persevere and find.)

I have the wood for "catching the chuck", and plenty of room on the spindle to grab. Someone suggested a "strap wrench" on a pulley, a belt like an oil filter wrench, but I haven't found one that I can use on my lathe. I like the idea of aluminium jaws for grasping the spindle: will make one up, as I have plenty of 20 mm aluminium plate.

It is going to be a busy night.

Thanks for the ideas. (How do you get the candle wax into place to do some good?)

[Otto Nobedder]

Hey, guys!

Thanks to a suggestion from AKweldshop, we have a new forum, generically titled "Metal Cutting", with machining specifically listed as a discussion topic. I'm going to move this thread over there, so there'll be no more discomfort over discussing machining on a welding forum.

Steve S

[AnvilJack]

The chuck 1, AJack 0

I know what I want for Christmas.

I am significantly distracted by this bit of cylindrical metal. I have drowned it in Penetrene, repeatedly. I have tried to shock it off with a bar going "over and whack" on a block of wood, reverse gear.

Irwin strap vice. No advance.

I fitted a 25 mm hex bar, right angle out of the chuck, and whacked with a 2 lb hammer.

Tomorrow I might mill some flats on a round bar, lock it in the chuck, and try a long handled wrench.

All your advice has been good and I will methodically apply it all ... unless "the chuck" unwinds.

[noddybrian]

If it's rusted on or has had significant shock loads applied you will need more than a 2lb hammer - absolute minimum 4lb & hit it like you meant it ! seems cruel - maybe it is a bit - but you should never find it that tight again if you look after the lathe - also how are you keeping the spindle from moving while you hit it ? - is it a gearbox drive ? ( if so lowest gear - clutch engaged with motor off ) if it's a step pulley / belt drive you should have a " back gear - engage this while the " direct drive " pulley lock is engaged to lock spindle.