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You can toy around with using a slightly smaller drill that can spin freely inside the hole, or the 17, but you're right about the concept. Indicator works too. I'm not familiar with mm, but you'd generally use a reamer for this application, so I'd just be careful with feeding. Especially if it's steel.
Volkerball fucked around with this message at 14:12 on Jun 13, 2017 |
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Jun 13, 2017 14:10
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Going from 17mm diameter to 19mm diameter is taking off ~.040" all around a ~3/4" hole, which is more than I'd be comfortable trying to do with a reamer even if it's technically possible.
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Jun 13, 2017 18:38
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Anybody have any ideas for woodworking tools/accessories that I could knock out over a couple evenings in the shop? I don't know a ton about woodworking so I'm drawing a blank beyond something straightforward like a plumb bob. I know he's been bugging me about surface grinders because one of his bigass planes needs some restoration work but I don't think I can swing smuggling it past him. Ambrose Burnside fucked around with this message at 13:47 on Jun 14, 2017 |
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Jun 13, 2017 23:12
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Rotten Cookies posted:The sheet distorts and cutting slowly, one at a time, fixes the problem? So that definitely sounds like you're putting too much heat into the work. When you say you messed with cutting speed, did it help? Did you speed it up to minimize the amount of time you're putting heat into the material? What sort of machine, amperage and voltage? What is your cutspeed like? http://www.metalform.com.au/product/plasmacam-dhc2/ this is the machine in question with the only addition being a water table underneath it to catch the sparks. Cutting multiple actually lessens the problem somewhat from what I've seen. The chart in the manual suggests one a cutting speed of 125 mm/sec but upping it to 140 fixed it to a certain extant. I cut a stack more on Friday for signs and it didn't have as many issues with either slag or the cut being wobbly. As for the initial piercing point the cad software places them when it converts the lines into cut paths. I always make sure that it is on the waste side of cut as it tends to blow a 2mm hole for the initial piercing. I don't know if the cutter has different tips or not as this is pretty much my first foray into proper metal working as everything before now has been .5 mm sheet to make toolboxes that are just bent and riveted.
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Jun 14, 2017 11:01
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Is a combined lead and feed screw that much of a big deal on a lathe? I'm looking at 3 lathes: https://www.machineryhouse.com.au/L141 https://www.machineryhouse.com.au/L682 https://www.machineryhouse.com.au/L689 The first looks good and has a decent reputation in Aus but I've been warned off and told to shell out an extra $1k for the 2nd, notably because of the separation of lead screw and other drives. I'd jump at the second if I had a lot of cash but I don't.
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Jun 16, 2017 15:00
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Mudfly posted:Is a combined lead and feed screw that much of a big deal on a lathe? I'm looking at 3 lathes: Do you need to cut threads? If the answer is no, then go with #1. If you ever want to cut threads, go with #2. You can do a lot with a tap (ID threads) and even a die set (OD threads). With the threading feeds you can also cut weird threads, or big threads. You'll likely not be able to find a 50mm die, where you could easily cut a 50mm diameter OD thread. edit : A quick search shows you can get a 50mm die, but at about $100. So do ten jobs with ten big OD threads and you just bought the engine lathe instead.
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Jun 16, 2017 16:48
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Why do you say that? I see the 'reverse tumblr' but an ex-fitter/turner explained to me (salesman) that on these lathes if you use it to cut threads it wont always work really easily. When you reach the end of the thread and wish to reverse with the tumblr, you may get lucky and the gears will mesh - often though you need to move the chuck slightly while turning it so the gears stop overlapping and will change. If this happens you've just lost your sync between lead screw and the main drive. He also told me all lathes will cut threads just fine, though the last at 150rpm would be trickier at higher pitches (obvious why). And yes, I do want to cut threads. Edit: No tumblr means I can't do left hand threads though? Pressure on the lathe tool while in reverse could unscrew the chuck? Mudfly fucked around with this message at 19:44 on Jun 16, 2017 |
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Jun 16, 2017 19:36
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I've always had equipment on hand that could cut a thread, so I've never had to get creative with something that can't. I just dug through the manual on machine #1 and it can thread, you just need to open a cover and manually adjust them. It looks like it'll do threads, it'll just take longer to change pitch in comparison to number 2. 
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Jun 16, 2017 22:03
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OK, I think I get it now. NOob here - I assumed the speed change on the first one was a gearbox allowing me to set the pitch of threads I want to cut as well. But you need a gearbox to set your spindle speed, then another gearbox (like the 2nd) to set the speed of the feed in relation to the spindle. So lathe 2 will do two different threads with a few flicks of its other levers, lathe 1 requires gear changing. edit: this also means changing gears for different longitudinal feed rates for normal turning, right? Is this a pain? Mudfly fucked around with this message at 22:49 on Jun 16, 2017 |
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Jun 16, 2017 22:33
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Spindle speed is set via the controls on the front. Carriage feed rate is either set by the handles below the spindle speed controls, or in the case of the one with the internal gearing, you pop open a cover and shift them. We've got some turret lathes that the carriage feed is not connected to the spindle at all and the feed is controlled by a DC motor. Yes, you'll have to adjust the gears accordingly for different feed rates. How much of a pain it is, I'm not sure. They don't have any photos in the manual. quote:To make changes to the gear train, remove the clips, loosen the T bolt and locking nut on the pack. Eh. Maybe it's not terrible. But seems like a pain.
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Jun 17, 2017 01:38
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The half-nuts on my Craftsman 101.21200 (AKA Craftsman Mk2 or Atlas 618 for most parts) lathe are worn. Even after adjusting the carriage pretty loose, (because the main "work area" is loose and right up against the headstock and way out by the tailstock are pretty tight if adjusted at 8" out, the ways are hella worn) trying to do feeds with the leadscrew causes the leadscrew to skip a bit. This happens after a complete disassembly and cleaning and oiling, too. This was a problem with the Craftsman lathe. I know this, because the later versions made the half nuts twice-ish as wide. The MK1 lathe (AKA Atlas 618) has a 3/8 wide half nut, and the MK2 lathe has a 3/4 wide one. I've found replacement brass versions on ebay, but that's holy hell Eighty-Five dollars. The seller states the leadscrew (and half nuts) are ACME 1/2"x 16 Right Hand Thread, which is something that doesn't come up AT ALL in google searches. Is he wrong? Am I wrong? Instead of paying $85 for a replacement from the only guy on the planet that apparently does them, I'd prefer to buy (or make, with a tap) a brass sleeve that's threaded to that thread, and braze it into the stock half nuts after boring them out. The stock half nuts are made of Zamak, which is a bullshit zinc-aluminum alloy that apparently had every accountant rock-hard 60 years ago, and is a crumbly and weak piece of poo poo. I'd like to fix this as I just drunk-spent $125 on a full set of change gears, and would like to do threading. I plan to make my own 1-10TPI threaded spindle adapter for endmills, as I just bought a basic bitch but expensive milling attachment for the lathe.
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Jun 17, 2017 07:31
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Acme 1/2-16 isn't a standard size, no. You can easily measure the screw itself, though. 1/2" OD (or slightly under for clearance) and 16 threads per inch. If that's correct, getting a custom tap will likely be around the same cost as the brass halfnut you're looking at, plus material and time. Victornet is probably the cheapest option, call them for custom taps. http://www.victornet.com/tools/Acme-Taps/11.html
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Jun 17, 2017 14:45
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Metal Geir Skogul posted:The stock half nuts are made of Zamak, which is a bullshit zinc-aluminum alloy that apparently had every accountant rock-hard 60 years ago, and is a crumbly and weak piece of poo poo.  oh god
Ambrose Burnside fucked around with this message at 19:02 on Jun 17, 2017 |
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Jun 17, 2017 18:53
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I'll never understand the hard on some people have for atlas lathes. I'd take a cheapo HF lathe over one any day. (Says the guy with three 9" and one heavy 10 southbends).
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Jun 17, 2017 19:58
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I just got mine for a good price, mainly because it came with a big workbench and I'm just a hobbyist. More like, as I think I say too much, adult playdoh. Just messing around. Sleeving the stock half-nut with brass seems like a good enough project to do to learn I think. Unless I'm way off the mark. I understand that the lathe is poo poo, but I also daily drive ACVWs so I think this is self inflicted pain.
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Jun 17, 2017 20:30
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Have you ever tried soldering brass and Zamak together? I'd make sure you're comfortable with that particular step of the operation before committing to making the replacement sleeve yourself. Joining dissimilar metals where one of them has a low melting point can be challenging. It'd be a shame to drop the cash on the die and then, I dunno, accidentally melt the Zamak component or otherwise damage it in a way that means you have to buy the whole replacement part after the fact.
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Jun 17, 2017 20:41
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Is buying a lathe far larger than you need because it's cheap a dumb idea? Room 'to grow'? I do work for a school and have access to larger lathes but it's inconvenient and they're probably beaten up. Still, I have access. I initially just wanted a lathe for hobby work and to compliment my 300kg bench mill. The Grizzly G4000 9x19 equivalent we have in Australia is nicely priced at $1400 (just trust me, over here that's cheap for a lathe). I really like metalwork and making things though I've just gotten into it, perhaps room to grow and a great big lathe is a good idea? I asked the internet for advice and most of it was 'double your budget for a decent lathe'. I'm now looking at a lathe for $4k, 14x40, that is Taiwanese made, comes from a TAFE, and retails here for $9000. I'm just finding it hard to justify the purchase as I lose the convenience of a small lathe and it's less things I can buy for about 8 months. The other thing I have to consider is old CNC lathes retail here for about 4k sometimes. Having the money to pick up one of those looks like a far more interesting experience - and that's just one idea.
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Jun 17, 2017 23:01
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The decision between 1970's milling/turning technology meets late 90's CNC is rapidly becoming a thing. I've seen some ridiculously cheap CNC mills and CNC lathes.  The problem is, can you get parts? Can you hold any type of tolerance? Did the machine spend 40,000 hours making the exact same part? How many toolroom monkeys set a -10 Z correction instead of -.10? It doesn't have a USB port. Almost guaranteed to not have a 3.5 disk drive. Likely has a 5.25" floppy or some proprietary machine tool drive. The only plus above is it's a Fanuc so someone out there probably has a guide on how to retrofit it. If a servo drive from a 1994 Fanuc takes a dump, does it even exist anymore? If the answer is no, then prepare yourself for retrofit/repair land. On the plus side you're probably getting a production quality machine that could outlast the Taiwanese iron. There's a lot of CNC retrofit stuff on the market but I don't have much experience other than doing it on grinders. In regards to size, buy what gets you the most time on the machine. My go to machine is the easy to use one, not the biggest possible one. Remember Pareto, you'll do 80% of your work on 20% of your machines.
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Jun 18, 2017 00:30
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Ugh it is 1/2-16 stub acme.
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Jun 18, 2017 01:26
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Yooper posted:The decision between 1970's milling/turning technology meets late 90's CNC is rapidly becoming a thing. I've seen some ridiculously cheap CNC mills and CNC lathes. Speaking of Fanuc specifically, they seem to have been so ubiquitous in the 90s that parts seem to be not too hard to find. We have 3 mid-90s Fanuc wire edm machines that have had boards go that I was able to find replacements for on ebay pretty easily. There's also this big place in the Midwest that has thousands of the things, it's all they do. Also, there are usb emulaters that will either plug into a parallel or serial port, or right into a floppy drive connector. Obviously all the other stuff you mentioned is a huge issue, but for whatever reason with Fanucs the stuff seems to be out there.
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Jun 18, 2017 02:10
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A Proper Uppercut posted:Speaking of Fanuc specifically, they seem to have been so ubiquitous in the 90s that parts seem to be not too hard to find. We have 3 mid-90s Fanuc wire edm machines that have had boards go that I was able to find replacements for on ebay pretty easily. There's also this big place in the Midwest that has thousands of the things, it's all they do. I've been in this boat and yes you can always find spares on ebay. ...whether the spares work or not is a total crap shoot.
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Jun 18, 2017 02:44
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We had one machine with an ancient Anilam controller that spares wasn't an issue. Contrast that with a 1984 Studer S50 OD grinder with a Siemens control... it was impossible to find electrical parts. Though the Siemens tape data storage still functioned...
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Jun 18, 2017 14:07
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I inspected some lathes at an auction today. 2012 - 2013 models, Taiwanese made. As the were at a TAFE (in US they're called trade colleges?) , they had a fair bit of wear and tear. One had a really low oil level - is this a concern? Another was tippable - if you pushed it, it tipped a small amount. The bolt wasn't pushing into the ground enough - possible damage to the bed? I can imagine a lot of TAFE students rocking it for fun.... One had very tight quick change gear knobs, I ruled this one out - not sure if I was too harsh. Another had a good 1/2 turn of slack and quite a bit of cross slide movement - too used I thought. The rest all had far less, and new they have barely any. Still not sure if I want one of these giant 14x40 machines, the 10x22 new ones look pretty good for a hobby guy like myself, and won't have any surprises new. One more day to inspect them - should I take along a dial indicator and measure the inside of the spindle's runout? Mudfly fucked around with this message at 09:10 on Jun 19, 2017 |
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Jun 19, 2017 08:33
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Mudfly posted:I inspected some lathes at an auction today. 2012 - 2013 models, Taiwanese made. Tafe machines if they're anything like the DET equipment they should have been looked after even if it's only once a year. Most of the fixed equipment in TAFE's and schools gets looked at by maintenance dudes once a year. The downside is they have a day to keep everything on track so your milage may vary. I had the return spring in a drill press break 18 months ago and when I pulled the cover off it was bone dry meaning either the nipple was hosed or it hadn't been greased properly. The replacement I pulled out of an unused drill press was packed in massive amounts of grease. I know that the standard issue hercus lathes that where issued to schools in the 60's and 70's sell for $4000-$5000 at auction after being in a school for 40+ years. I believe they're southbend in design but built in Australia. Main downside is the gears are all manual but they've probably not been punished as much as some of the other examples on offer locally.
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Jun 19, 2017 11:38
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They looked in various stages of use. Some had more slack in the cross slide than others. I think I'll pull the trigger on one but I still have one question.... Would an $1800 550x250 Optimum lathe be more accurate for smaller parts? These things I'm looking at are 700kg monsters, the Optimums are 160kg and have a decent rep for good build quality. I'm well aware the bigger lathes have obvious advantages (can make bigger things, and they're stiffer) but are decent smaller machines better for precision on smaller parts?
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Jun 19, 2017 15:35
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I work at an educational facility and our head shop maintenance guy bought a bunch of old lathes and mills for himself as they were replaced by newer machines. despite griping continually about all the abuse that gets poured onto stuff. Students are rough as hell on everything but the flipside is that they get quite a bit of attention and upkeep as a result, and (unlike idk say a used machine from a production environment) will generally be maintained such that the lathe can actually do everything it might be called upon to do. If you know what to look for in a lathe and have multiple machines to pick from, I'd feel comfortable buying from that kind of environment.
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Jun 19, 2017 15:40
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Dumb newbie question: I have some catcher leg guards I'd like to affix metal to for a costume. Trouble is, they have a somewhat irregular surface: These aren't exactly the leg guards I have (mine include a vertical length of the raised surface that runs top to bottom on the shinguard) but are reasonably close. Any suggestions for how to take a sheet of metal and produce something that will match the shape of the shin guard as closely as possible? Thank you friends!
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Jun 19, 2017 18:06
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Does anyone have experience etching metal? I have etched circuit boards before, but what I want to etch now is round, so I can't just print out the design and iron it on. One website suggested getting vinyl sheets cnc cut, but keeping it 'in house' would be ideal so I can try out many things.
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Jun 20, 2017 00:26
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Brekelefuw posted:Does anyone have experience etching metal? Mask the area you don't want etched wth a non conductive/nonreactive material. Silicone is used to protect the marking areas of some parts I've worked on.
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Jun 20, 2017 00:46
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I understand how masking works, but I am not sure what I can use to transfer a design to be etched, since I can't just iron on a laser printer thing like you can with flat material.
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Jun 20, 2017 02:44
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For artsy things, a common technique is to mask the entire area with asphaltum and then scratch the resist off the areas to be etched- doesn't help with the transfering thing, but if it's a simple enough design to do freehand it'll work fine.
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Jun 20, 2017 04:47
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When you say "round" do you mean compound curve?
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Jun 20, 2017 10:00
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Yes. Tapered tubes, and trumpet bell flare shape. Also some cylinders.
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Jun 20, 2017 17:18
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A lathe I'm looking at has a cross slide travel of 110mm but a swing of 250mm. SHouldn't the cross slide travel be half the swing, at least? Is this an issue? http://www.machineryhouse.com.au/L689 I've checked it in person.
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Jun 21, 2017 07:43
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Eh, those numbers seem reasonable. A 110mm travel means you can face the end of a part in a single operation out to 220mm in diameter, which gives you 15mm of clearance above the ways. How often are you going to be working on things that size anyway? Also, remember the compound rest -- the cross-slide isn't the only thing that moves the tool. You can set the cross-slide to the general area you're working in and then go in and out another 50mm or whatever with the compound rest set at 0 degrees. Sagebrush fucked around with this message at 08:53 on Jun 21, 2017 |
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Jun 21, 2017 08:51
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Oh god how did this get here I am not good with ebay   M6-501. First thing to make: Vice jaws for it.
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Jun 21, 2017 09:36
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Sagebrush posted:Eh, those numbers seem reasonable. A 110mm travel means you can face the end of a part in a single operation out to 220mm in diameter, which gives you 15mm of clearance above the ways. How often are you going to be working on things that size anyway? Thanks. How are smaller lathes like this 160kg / 350lb lathe at cutting steel? Aluminium obviously is fine but I don't want something that will be maddeningly slow or vibrate excessively with steel. It's a 10x22" unit with a 5.31" bed width. http://www.machineryhouse.com.au/L689 Pretty much ready to pull the trigger and buy my first lathe.
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Jun 21, 2017 14:02
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My 20lb sherline cuts steel fine, so you shouldn't worry.
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Jun 21, 2017 21:12
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As a hobbyist I don't think you'll be significantly limited by a machine of that size unless you're already accustomed to a much larger machine that can take monster cuts without shrugging, or expect to do a lot of work pushing the machine's work envelope. e: Brek, how d'you like that Sherline, btw? I've got the Turning Bug and will eventually want something for home but a Taig will just frustrate me, as affordable + apartment-compatible + cute as it is. Ambrose Burnside fucked around with this message at 22:01 on Jun 21, 2017 |
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Jun 21, 2017 21:59
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I love my sherline machines. I have two lathes and a mill, and they are perfect for 90% of the work I do. I have just about every accessory for them, and bought the larger bore spindle so I can hold 5/8 through the headstock. I use the lathe every day at work, and am pretty rough on it and it still runs well.
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Jun 22, 2017 12:35
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