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ate all the Oreos posted:Hey metalworking thread, I normally hang out in the electronics thread but I've been kicking around the idea of building a DIY CNC drill and that'll require some rigid metal parts. How thick is the plate?
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Mar 20, 2017 19:29
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ate all the Oreos posted:Hey metalworking thread, I normally hang out in the electronics thread but I've been kicking around the idea of building a DIY CNC drill and that'll require some rigid metal parts. I'm not sure bolting a piece of square stock would help the flatness issue. It'll be a more rigid, but still unstable-curved piece of steel. If it's something like 16 gauge sheet metal, then I'd find something else. Either an extruded aluminum base, like an 80/20 style, or even a good hefty piece of aluminum plate, 3/8" thick for example.  quote:Should I abandon the steel sheet altogether and go with something else? My other thought was that I have an old rackmount server case that has a big heavy steel lid that's very flat and incredibly hard to bend, but it's got some bits sticking out where things mounted to it that I'd have to cut off, and it's got a ridge around the outside that I'd probably need to do something about. If your steel plate is thin, like .060", then I'd look for something else. Your rack case might work pretty well depending on how thick it is.
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Mar 20, 2017 20:35
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Get a 1/4 or 3/8" thick plate. Don't bother with anything still called sheet.
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Mar 20, 2017 21:22
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honda whisperer posted:How thick is the plate? 16 gauge, is that not a standard thickness? Sorry I'm only used to working with gauges of wire, I'll get my calipers on it later today. Yooper posted:I'm not sure bolting a piece of square stock would help the flatness issue. It'll be a more rigid, but still unstable-curved piece of steel. If it's something like 16 gauge sheet metal, then I'd find something else. Either an extruded aluminum base, like an 80/20 style, or even a good hefty piece of aluminum plate, 3/8" thick for example. What the heck is that grooved aluminum extrusion stuff called, I worked with it a bunch back in highschool robotics club and really liked how versatile it was but I have no idea where to even start in terms of google search terms Yooper posted:If your steel plate is thin, like .060", then I'd look for something else. Your rack case might work pretty well depending on how thick it is. I think the rack case is slightly thicker or about the same thickness but seems much more sturdy, probably due to the fact that it has a lip / edge around the outside that seems to keep it from bending. It's also harder i think? As in more difficult to drill through, much more difficult to to cut with the sheet metal shears, etc. Not that it's that big a deal since I'll only be doing it once so I can deal with it taking longer. Brekelefuw posted:Get a 1/4 or 3/8" thick plate. Don't bother with anything still called sheet. This is probably a dumb question but where would I get plate steel or plate aluminum or whatever? There's some metal fabrication shops around me but I assume I can't just walk in and go "hey guys mind selling me your finest hunk of steel?" right?
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Mar 21, 2017 14:24
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ate all the Oreos posted:16 gauge, is that not a standard thickness? Sorry I'm only used to working with gauges of wire, I'll get my calipers on it later today. It's a T-slotted aluminum framing. Most people around here just call it 8020. https://www.8020.net/ It seems cheap until you put in all of the connectors and fiddly bits but can be really nice to work with. They also have an eBay store with seconds and cutoffs. http://www.ebay.com/usr/8020inc?_trksid=p2047675.l2559 Pretty much if you can cut the machine base with shears it's not going to be rigid. That being said I've seen people make CNC router setups out of MDF and aircraft grade plywood. It all depends on what you're doing and your tolerances. Given your situation the 8020 poo poo might be perfect. If you need a plate just look for a steel supplier in your area. Or if you're into junkyard diving go find one and ask to browse the aluminum area. I know my local yard is crazy busy on nice weekends, especially after the local mill does a shutdown.
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Mar 21, 2017 15:16
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Yooper posted:It's a T-slotted aluminum framing. Most people around here just call it 8020. https://www.8020.net/ It seems cheap until you put in all of the connectors and fiddly bits but can be really nice to work with. They also have an eBay store with seconds and cutoffs. http://www.ebay.com/usr/8020inc?_trksid=p2047675.l2559 Thanks, yeah I think I'll try and go with this since it's been easy in the past Yooper posted:Pretty much if you can cut the machine base with shears it's not going to be rigid. Oh that seems really stupidly obvious in retrospect  Yooper posted:That being said I've seen people make CNC router setups out of MDF and aircraft grade plywood. It all depends on what you're doing and your tolerances. Given your situation the 8020 poo poo might be perfect. The drill motor and assembly is small and light so I'm fairly confident that I'm not going to get that much flexing - I'm planning on using this to drill holes in circuit boards so the drill doesn't actually need that much down-force or drilling power, just good positional accuracy. It could probably be done with wood just fine if not for the wood warping when the humidity inevitably changes (I live in Florida and even inside with AC on all the time it still fluctuates a ton during the summer). Yooper posted:If you need a plate just look for a steel supplier in your area. Or if you're into junkyard diving go find one and ask to browse the aluminum area. I know my local yard is crazy busy on nice weekends, especially after the local mill does a shutdown. I do know a few junkyards around here I could check out, guess I know what I'm doing this weekend 
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Mar 21, 2017 15:26
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You'd be surprised, there's a very good chance you -can- get stuff, albeit from the right manufacturer. The best rates on titanium I've ever paid were from a titanium machinist who had serious overstock. On the assumption they actually work with the size of steel you need, they can sell you a cutoff for probably ten times their scrap reclaim rate and you'll still be getting a deal. No promise they'll want to take time out of their day for one little cutoff, but if you catch someone on their lunch or while they're having a smoke they'd probably be happy to make some easy money. ...that said, the typical way you get stuff like that is from a metal supply house, Metal Supermarkets is the typical chain offering in North America. They have cutoff racks that might have what you need, and if not they'll typically pull and chop the stuff to spec for free while you wait so you don't need to worry about doing the cut yourself. I don't know how big you want the baseplate, but if it isn't too wide in at least one dimension you can probably get it in CRS (cold-rolled steel), which'll be stronger/stiffer than equivalent typical hot-rolled plate, and should be more consistently-flat across its surface to boot. Aaaand that aluminum stuff is 80/20 extruded, I've never worked with it but I optioned it for a hot second for a CNC mill enclosure I wanna build. For custom smaller-scale CNC stuff it'd be a no-brainer to use it for a lot of the build, because really, who doesn't love a structural member that comes with infinite attachment points -and- dovetail/V-slots built right in? e: slow on the posting draw. Yeah, if all you're doing is drilling PCBs, you won't need -tremendous- backbone in the thing, the aluminum extrusions should have you covered. I'm not gonna lie, though, once you've got AUTOMATED MACHINING PROCESSES in your toolkit, you're gonna wanna push the envelope until your machine gets cranky with you, so overbuilding something like this never hurts 
Ambrose Burnside fucked around with this message at 15:34 on Mar 21, 2017 |
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Mar 21, 2017 15:30
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That's OK man! Ask away, we've got a pretty diverse set of goons who can offer good advice. One problem in regards to rigidity when drilling is you will break drills. Your drill bit is going to be exerting a force opposite to the axis of movement. Drilling down, it's working hard and tool pressure is headed back up towards the spindle. That movement has to go somewhere so either your spindle will flex, the ways will flex, or the drill-bit will bend. Even though you don't have side loads like a milling tool will exert you'll still experience vertical forces. After you mentioning the humidity and the lack of grinders/cutters/bandsaws I'd go the 8020 route. Keep us posted!
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Mar 21, 2017 15:32
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Also- feel free to pay the CNC thread in here a visit, the nerds in there can probably give advice more specific to what you wanna do beyond just the baseplate.
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Mar 21, 2017 15:35
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Yooper posted:That's OK man! Ask away, we've got a pretty diverse set of goons who can offer good advice. Oh yeah I realize, I've broken 5 tungsten carbide bits so far and that was just doing it by hand. I have a few ideas kicking around for how to handle this but I'd like to get the X/Y movement out of the way before that so I don't get bored and lose interest Yooper posted:After you mentioning the humidity and the lack of grinders/cutters/bandsaws I'd go the 8020 route. Yeah I went ahead and put some bids down on that ebay page. I do remember it being an absolute joy to work with in the past so hopefully that wasn't just my imagination. Ambrose Burnside posted:Also- feel free to pay the CNC thread in here a visit, the nerds in there can probably give advice more specific to what you wanna do beyond just the baseplate. Didn't even notice that existed, thanks!
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Mar 21, 2017 15:46
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One thing with drilling is that if you're going through thin material, there's not a lot of room for variance in the table to affect the work piece. Like if you drill through a quarter inch piece of stock, and it's slightly raised on one end, the hole is still going to measure pretty center on the top and the bottom, as well as side to side. If you measure the top of the part to the diameter of the hole, and flip it over and measure it the exact same way, .005 is a massive amount of variance. That is a hosed up table/fixture. But if you're talking about a hole location that is +/- .020 with an allowable .015 centerline, who gives a poo poo? It's going to measure in tolerance everywhere, and be fairly straight. It just depends on your application. If all you are doing is punching holes through soft material and they aren't critical, you might be able to cut costs there. The spindle needs to be stable as hell regardless though.
Volkerball fucked around with this message at 20:01 on Mar 21, 2017 |
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Mar 21, 2017 17:23
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Couple more milling questions... Should I be concerned that when I inspected the model I was interested in the gibbs came out the top of the machine when I wound it up to its top point? It was a demo model. Also, on the other machine it has a fairly short x-axis (430mm). If I want to mill the top of a longer part (say 700mm) flat could I do it with two vices, and reposition the vices as I mill the length? I am guessing simply repositioning it on the bed might introduce twist since you're regripping it. Is there a good way to mill the top of a part flat that's longer than your bed?
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Mar 22, 2017 12:04
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Mudfly posted:Couple more milling questions... Erm. Like this part sticks out at one extreme of travel?  Maybe one of the mill guys can add more comment but that seems kind of weird to me. Not to say there's not some weird design reason for it. On our machines they get adjusted and are locked in place. Unclamping-reclamping long parts is always lovely. Even if you match it up really well you're still likely to get a step or dimensional change along with a visually noticeable transition line. I'd keep the vices locked into place and just slide the material in the vice. For some bonus points you could traverse an indicator over the reclamped part and try to make sure you're on the same plane.
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Mar 22, 2017 12:58
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The gibs on my sherline machines stick out a bit so you can adjust them when needed.
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Mar 22, 2017 18:39
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One gib was completely flush, the other gib was poking out. There was a lot of resistance moving the machine to the top part of its travel and in fact we didn't try getting it to there.
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Mar 22, 2017 20:45
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Mudfly posted:One gib was completely flush, the other gib was poking out. There was a lot of resistance moving the machine to the top part of its travel and in fact we didn't try getting it to there. Huh. This tells me that there is an issue with straightness along the way. At one point it's nice and straight, and further along it tapers so that the friction becomes high enough to dislodge one of the gibs. I'd be worried that the gib you know, wouldn't seat, once you moved back through your travel. Also it's kind of weird that you have two gibs. I've seen this :  And the tapered gib style : 
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Mar 23, 2017 00:47
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Yep, I was wrong, there is only one gib. The protrusion is apparently a design feature, the exact reasons which I cannot recall but they seemed sound when the sales guy explained it. I pulled the trigger and ordered the RF-45 clone, on condition they match 0.0002" spindle runout, 1.5 thou deviation across x-axis (max) and 2 tenths of a thou deviation across y-axis (max). Not sure how ridiculous this is, I may just receive an angry reply email. The x by y table size is 28.7" by 8.3".
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Mar 23, 2017 08:06
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0.0015" across a 29" bed is a pretty high expectation for something that's going to be shipped to you. That much inaccuracy (0.0005 per foot, roughly) can be caused just by mounting the machine out of level with the floor, or by rough handling in shipping. Not impossible to achieve, and if the machine is out you can probably bring it to that level with careful adjusting and shimming, but I dunno if it's a reasonable expectation from the factory given the price.
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Mar 23, 2017 08:14
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Assuming he comes back with "that's too hard to meet, but we have this" what should I accept then? edit: I need to do very accurate work, such as this: https://www.youtube.com/watch?v=NyerD4jHu9A (I just wanted to share this link) Mudfly fucked around with this message at 08:49 on Mar 24, 2017 |
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Mar 23, 2017 09:00
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ive been turning stuff on manual lathes every week for like 6 months so far and somehow havent said as much: lathes are fun as hell
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Apr 3, 2017 03:55
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Agreed. 'What are you making?' 'Swarf'
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Apr 4, 2017 08:16
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Lathes are great. I enjoy making little brass/bronze cannons out of scrap bolts and off cuts. I never measure, just form the shape of each one by eye. Solder on some trunnions, mill a flat and a touch hole with the old milling machine and then load the fucker up. https://www.youtube.com/watch?v=DP2256zTK-Q Great project to fill an evening with.
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Apr 4, 2017 11:03
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I wonder what this nightmare I had says about me.... dreamt that I bought a 2nd hand welder, think it was a MIG.... Anyway it came with a big old gas cylinder and for some reason I did not pick up on it until after I had it home and looked over it, so there I was, worried to heck I'd blown my money on this old thing because the local gas monopoly (AGA) stopped allowing people to buy such big cylinders way back in the 70s and this was probably stolen and poo poo I am never gonna be able to refill this thing argh! Then I woke up. Remembered I had a purchased smaller bottle, phew...
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Apr 5, 2017 06:32
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Well I thought I'd do a little trip report after installing my first mill. Before I do, to anyone reading this and thinking of moving it themselves - 700lbs is really, really heavy. Here I am at the shop with the mill onboard a friend's ute:  We ran out of metal beams to keep it against the left side of the car (and stop it flying off the right side and killing a family) so we put a jack in there clamped 'securely' against a piece of steel I found. Miraculously after travelling below the speed limit for the most nerve wracking 30 minute ride of my life we got it home in tact.:  Getting it off the ute was really difficult as our engine crane was 10 years old and prone to dropping things suddenly. We built a ramp, but after trying to drag the mill 10 cm towards our hastily improvised death slide we realised how heavy 700lbs / 300+kg was and decided to go with the crane. The crane worked without a problem. After this it was on the footpath. The cheap dolly I bought, rated to 800lbs, broke immediately. We tried to slide it but the friction of wood on concrete was unreal. 1 hour of fooling around later we tried to do it the way the Egyptians did, by rolling the pallet on cylindrical barbells. This worked really well. 4 hours later I had it in the room it was to be in (30 metres away).  After 3 days of work I've made a dodgy stand and managed to get the mill up on it where it's going to reside:  Thanks to people who helped advise me on the mill and answer questions. The x-axis is within 0.01mm height across its 475 length of travel, the Y is 0.03mm (needs shimming?) Overall lots learnt and I wish I'd just bought a professional stand and hired professionals to move it myself. Now are there any good 'making your first chips' guides? I've found a lot of good info for advanced / intermediates online but no 'so you've just bought a mill' guides.
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Apr 5, 2017 14:11
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Not helpful now I know, but moving my Bridgeport mill we have always used concrete anchors in the floor plus comealongs and a strap around the mill itself low down to slide it around on wood - basically the wood staying still and the mill sliding on the wood. Definitely an undertaking though - your 4 hours to make it travel 30 meters actually sounds pretty good.
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Apr 5, 2017 14:39
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Watch AvE's video of moving the mill himself. Now that's scary.
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Apr 5, 2017 15:27
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Brekelefuw posted:Watch AvE's video of moving the mill himself. Now that's scary. It's the little things, like midway through where he's stopped talking because it's getting tricky and all you can hear are the girders he's sliding the thing on groaning under the load and him stress-panting
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Apr 5, 2017 15:37
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The most important thing when moving extremely heavy things is fully internalizing that no matter how much money you spent on it, if it starts to go, you just loving let it go, you do not try to catch it.
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Apr 5, 2017 22:25
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Leperflesh posted:The most important thing when moving extremely heavy things is fully internalizing that no matter how much money you spent on it, if it starts to go, you just loving let it go, you do not try to catch it. 100% this. When the point of no return has hit, get the gently caress away.
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Apr 5, 2017 22:46
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but guys it was expensive and i can totally catch it In seriousness, replacing a piece of equipment you broke in a silly way is always cheaper than a trip to the hospital (and also replacing that piece of equipment).
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Apr 5, 2017 22:50
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If you catch a bridgeport you'll be going to the morgue, not the hospital.
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Apr 6, 2017 13:20
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Magres posted:but guys it was expensive and i can totally catch it In one of those compilation videos of cars sliding around on ice in Portland, there's a guy who realizes he's about to slide sideways into another car, so he opens his door and sticks out his leg like he's rolling on a wheelie chair and he's just going to deflect himself back the other way with a good kick. he does realize at the last second what he's about to do and pulls his leg back inside just before it's shattered into a pile of meat and bone fragments.
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Apr 6, 2017 18:11
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I've been training myself over my career to never catch things that fall off of my bench because they will inevitably be freshly heated with an acetylene torch, or be a brand new razor blade.
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Apr 6, 2017 19:53
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Im off sick from work and bored out of my mind so i've been watching machining videos on youtube. Now im trying to justify in my mind spending money I dont have on a mill. Im pretty sure I REALLY need a 3000kg Cincinnati Horizontal/vertical mill in my home workshop. Honest! If only bridgeports werent going for $5-6000 i'd go and get one of those in a heartbeat. loving ridiculous pricing in AU for old iron.
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Apr 7, 2017 04:46
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Ferremit posted:Im off sick from work and bored out of my mind so i've been watching machining videos on youtube. Even the ridiculously expensive machinery dealer websites don't have much. I think I found the 3000kg monster you're looking at, it's a thing of beauty. 
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Apr 7, 2017 12:42
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Brekelefuw posted:I've been training myself over my career to never catch things that fall off of my bench because they will inevitably be freshly heated with an acetylene torch, or be a brand new razor blade. I'm scared shitless of dropping my angle grinder and instinctively reaching down to catch it. A friend of the family almost lost a leg doing that exact thing with a loaded firearm. How do you train yourself to not do that?
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Apr 7, 2017 21:50
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SwitchbladeKult posted:I'm scared shitless of dropping my angle grinder and instinctively reaching down to catch it. A friend of the family almost lost a leg doing that exact thing with a loaded firearm. How do you train yourself to not do that? Kept all his fingers but got a lot of stitches on his palm.
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Apr 7, 2017 22:08
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Yooper posted:Even the ridiculously expensive machinery dealer websites don't have much. I think I found the 3000kg monster you're looking at, it's a thing of beauty. Are horizontal shapers expensive in Australia? You can hardly give those things away in the states.
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Apr 7, 2017 22:22
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SwitchbladeKult posted:I'm scared shitless of dropping my angle grinder and instinctively reaching down to catch it. A friend of the family almost lost a leg doing that exact thing with a loaded firearm. How do you train yourself to not do that? Work as a blacksmith long enough, you'll soon treat EVERYTHING as if it's hot enough to burn you. I have the opposite habit; I now no longer try to catch anything. I'll stare in mute stillness as the glass falls.
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Apr 7, 2017 22:49
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| # ? May 23, 2024 16:34 |
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Yep! My instincts now are to watch it shatter, or sometimes try to catch it on my boot before it hits the ground, but never with the hands.
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Apr 7, 2017 23:44
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