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Karia posted:How much torque is it actually undergoing? Laser cutting it from acrylic would be the easiest option, I'd bet, you can get a scrap that size for less than $30 depending on thickness. So, about 5 lbs sits evenly balanced on a lazy Susan ball bearing. The internally toothed gear sits inside the ring of the ball bearings. It's rotating horizontally so the gear wouldn't have to bear any of the weight, only rotate it fairly slowly. It's a turret style base that is aiming a directional antenna with stepper motors. The gear will handle horizontal aiming. Acrylic would probably work fine. I don't think I'm going to strip the teeth with the speed and weight I'm working at. The teeth can also be fairly thick because the angle doesn't have to be perfect. It's for a uav project but, if it works well, might also build a nerf gun turret.
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Apr 19, 2016 00:34
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BedBuglet posted:So, about 5 lbs sits evenly balanced on a lazy Susan ball bearing. The internally toothed gear sits inside the ring of the ball bearings. It's rotating horizontally so the gear wouldn't have to bear any of the weight, only rotate it fairly slowly. 1/4" acrylic plate would do you just fine, then, if you've got laser cutter access. A good cutter won't have a ton of taper over that length. You may need to play with the offset in order to get a good fit, though. Another option would be to screw a belt to the rotating section, and have the stepper drive the belt. It limits you on travel since you can't go past the attachment point, but it's easy to do and mostly gets rid of backlash. I've done this on a similar project, worked great.
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Apr 19, 2016 00:47
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I bought another old vise a few weeks ago and wanted to show it off because I have never seen anything like this one, and I have owned a lot of vises. Its an Athol, made in Massachusetts. The handle has a quick release. with the handle pushed in, the lead screw turns, but you can pull out on the handle and it turns independent of the lead screw so you can get it out of your way once you tighten up what you are working on.  Beer for scale. Yes I have a workbench in my apartment.   Closeup of the quick release mechanism. 
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Apr 19, 2016 01:37
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Thanks for the advice, I have some M42 blanks, a flycutter, 2 endmills, and collets on the way, in addition to that $6 textbook. I already had a copy of Machinery's Handbook but having a more step by step textbook approach, in comparison to the firehose that is Machinery's Handbook, won't be a bad thing. I have the horrible feeling that, despite (or because of) having access to a full machine shop and machining center, this will be yet another terribly expensive hobby.
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Apr 19, 2016 02:17
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Karia posted:1/4" acrylic plate would do you just fine, then, if you've got laser cutter access. A good cutter won't have a ton of taper over that length. You may need to play with the offset in order to get a good fit, though. I thought about that but I'm limited by size. I don't want it to extend more than an inch over the 9 inch diameter of the lazy susan. Also, I have a slip ring at the pivot which is why I'm using the internally threaded gear that sits just inside the lazy susan.
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Apr 19, 2016 03:27
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 Check out the sexy bend my new bending jig did! Not a single ripple.
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Apr 19, 2016 03:53
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Waldstein Sonata posted:Thanks for the advice, I have some M42 blanks, a flycutter, 2 endmills, and collets on the way, in addition to that $6 textbook. I already had a copy of Machinery's Handbook but having a more step by step textbook approach, in comparison to the firehose that is Machinery's Handbook, won't be a bad thing. If you ever find yourself building a collection of metric taps, that's the moment to look for a twelve step program. Honestly though you'll probably find yourself chasing the dragon of more and better clamps and fixtures. A less than ideal cutting tool will still remove material, just slower and uglier than if you threw money at the problem. A setup that can't hold your part still is going to break things and hurt you. shame on an IGA fucked around with this message at 04:00 on Apr 19, 2016 |
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Apr 19, 2016 03:54
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Just been offered a free lathe Not even kidding. Free to take away...
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Apr 19, 2016 08:50
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I'll give ya a cool 100 bucks, hell make it 150, you handle freight to ca??Ambrose Burnside posted:Any special rules for grinding and buffing titanium? Do I need dedicated belts n wheels (I remember vague rumblings about 'contamination')? This is gonna have to evolve into tumbling titanium soon, anybody have any experience with that? It finishes up nicely with fine wet/dry paper, light grinding on alox wheels seems okay but watch the sparks and dust, and goddamn poo poo heats up like a mofucker, that's all I got 
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Apr 19, 2016 09:30
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I'm semi seriously considering taking them up on it as an awesome centre-piece for our local makerspace project, but we don't have the new property nailed down yet. They also have three 20 year old Castolin Eutectic mig welders the size of fridges for £250 a pop. They'll lay down a bead thick enough to rival my stick welder. Getting at least one I think.
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Apr 19, 2016 10:40
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iForge posted:I bought another old vise a few weeks ago and wanted to show it off because I have never seen anything like this one, and I have owned a lot of vises. [fake Australian accent]That's not a vice. This is a vice.[/fake Australian accent] ...Also my new anvil 
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Apr 19, 2016 11:36
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^^^^^^^^^How much does that anvil weigh?ReelBigLizard posted:I'm semi seriously considering taking them up on it as an awesome centre-piece for our local makerspace project, but we don't have the new property nailed down yet. You should take it. Chances at enormous old lathes don't come around often. You don't want to look back in 30 years and think "drat I shoulda got that lathe"
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Apr 19, 2016 14:53
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I only just learned that AvE's favorite word "skookum" is more-or-less a real word (it's from PNW native/First Nations pidgin, now an all-purpose intensifier in BC slang; I knew the latter, did not know the former).
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Apr 19, 2016 15:13
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Bad Angus! Bad!
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Get that lathe. If you really need to, you can put it in a city park and use it as one anchor for your homeless tent. It's not like anyone's going to walk off with it. iForge, I have an Athol vise in my basement, it's similar to that one but minus the cool feature. Good vises, and made ~50 miles from where I live. Amusingly I bought it in Pennsylvania from a guy who had come several hundred miles in the other direction, and brought it back to its home state.
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Apr 19, 2016 20:20
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My Three Forges I'm moving, and that means moving my shop. I decided to take some photos before things are thrown away. Here's my first forge; a coal forge I made from a turkey roasting pan and some plumbing pipes. The air source was initially an air mattress pump. It had two speeds; off or full blast. I eventually upgraded to a quieter fan controlled by a rheostat. You may notice it's built on top of a wooden board. It never actually caught fire, but it did smoke alarmingly a few times. It's rusted and sad looking from being outside for two years.   Despite it's flaws, I learned a lot with this forge. I learned how to build and control a fire, and how to customize the temperature for the job I was doing. The final straw for this guy, however, was the neighbors complaint about the coal smoke. Since I live in the middle of the city and was doing this out of my garage, I figured that was valid. Forge 2 - home brew. Here it is ripped apart; I needed the burner (a 3/4" T-rex burner) and the insulation, but you can see the overall construction. The outside material is concrete drywall, which was advertised as fireproof. All the bricks are fire brick, the insulation is kao-wool. The glue on the interior is "fireplace cement," the liner is pottery ceramic.   This forge was great. It never got hot enough to forge weld, but otherwise it worked perfectly for almost 18 months, and even then was in better shape than I realized. It got up to workable temp in about 5 minutes at 8 psi of propane, and after 20 or 30 minutes you have a huge interior area to work with. The pottery ceramic was tough, and despite months of being jabbed by a clumsy blacksmith, the interior was still in good shape. Currently - Upside Down Bot. He's going to be my forge welding forge, with a burner at the bottom and a TON of insulation and refractory. These tanks are often available at harbor freight for $30, so they're cheap and safe to work with. They come with handles built in, too.  Unfortunately for forge welding bot, the orders for his refractory have been delayed. He's had to wait upside down for weeks, and it's making him angry. I plan on harnessing his incandescent rage when the time comes. I'm working on a horizontal tank for regular forging, and tinkering with building my own burner. If we can make it work, the Steel Yard will offer "build your own forge" classes where we provide all the materials, and students go home with a working propane forge. Now if only that kast-o-lite would show up... Now my shop is all packed up and in storage. I'm buying a house with a big garage, but I'm living in an apartment in the meantime.  Fortunately, this is a very busy time for the Steel Yard, and I have lots of opportunities to keep busy. If anyone here has questions about building your own forge, I realize I've done it enough times to know what I'm doing. Kinda.
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Apr 20, 2016 13:23
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BedBuglet posted:So, about 5 lbs sits evenly balanced on a lazy Susan ball bearing. The internally toothed gear sits inside the ring of the ball bearings. It's rotating horizontally so the gear wouldn't have to bear any of the weight, only rotate it fairly slowly. Plywood will also work well for this and is super easy to cut.
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Apr 20, 2016 15:25
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Why does penetration matter for non-structural welds? Like building a small welding table why would it matter if you achieved full penetration or not putting the top on? I realize for things like construction and whatnot that need to ensure a lot of stress you want maximal penetration for strength, but how important is it to the life of non-stressed joints?
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Apr 20, 2016 19:30
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Crazyeyes posted:Why does penetration matter for non-structural welds? Like building a small welding table why would it matter if you achieved full penetration or not putting the top on? I realize for things like construction and whatnot that need to ensure a lot of stress you want maximal penetration for strength, but how important is it to the life of non-stressed joints? If you don't have penetration, it's not a joint. For purely cosmetic things I guess it doesn't matter, but why use welding, then?
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Apr 20, 2016 19:47
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Crazyeyes posted:Why does penetration matter for non-structural welds? Like building a small welding table why would it matter if you achieved full penetration or not putting the top on?
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Apr 20, 2016 20:49
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If the weld doesn't penetrate, it's not a weld, it's a blob of metal that you melted onto the surface which will crack off of it too easily. Use hotglue or something if you are planning on making welds that don't penetrate.
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Apr 20, 2016 21:42
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kastein posted:If the weld doesn't penetrate, it's not a weld, it's a blob of metal that you melted onto the surface which will crack off of it too easily. Then you can save on anodization costs.
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Apr 21, 2016 00:40
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Metal isn't something you can play "just the tip" with. You need to really get in there and give that puddle hell. Go balls deep in that steel gap. 
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Apr 21, 2016 05:17
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Puddle? gently caress that, just shove a carbide eggbeater in there. https://www.youtube.com/watch?v=aNbQH8XBgxQ That's basically what you do with hot welding, melt a puddle and let the two pieces mix with each other and the filler metal. A non-penetrating weld is like just running that along the surface. I can see where Crazyeyes went astray: they're thinking of welding like hot glue (or most other glues), but really it's more like that model-airplane glue that partially dissolves the two pieces and when you stick them together they physically become one (see also melting the end of Paracord together to keep it from fraying). The filler metal in welding doesn't make the bond itself, it just adds some extra so you can grind it down and make it look nice. Cf. forge welding, where you just heat the workpieces up and beat on them until they mingle, no filler required.
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Apr 21, 2016 06:20
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This may be an unpopular opinion but not every weld needs to be a "full penetration" weld. There is a big difference between a weld that has full penetration and one that has no penetration, for something like a welding table, as long as you can give it a decent wack with a hammer and it doesn't break, I think you are probably fine. As for some other things that have come up recently in this thread; In my experience definitely wear gloves, preferably leather welding gloves or riggers gloves, when using an angle grinder. An angle grinder can't de-glove you but you can definitely do some damage, especially with 1mm cutting disks, or surprisingly with the fibre backed sanding disks. Also leave the loving guard on it you moron! Dual shield wire is awesome stuff. However, it is totally useless without gas, as such welding in the wind it is as bad as normal MIG wire, gasless or stick is what you need here.
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Apr 23, 2016 14:24
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yumbo posted:In my experience definitely wear gloves, preferably leather welding gloves or riggers gloves, when using an angle grinder. An angle grinder can't de-glove you but you can definitely do some damage, especially with 1mm cutting disks, or surprisingly with the fibre backed sanding disks. Also leave the loving guard on it you moron! Sandpaper Flap disks are surprisingly aggressive, I've cut through small section stock with them when I've been too lazy to get the wrench out and change to a normal disk. I've taken the guard off my smallest grinder to get into awkward corners. Especially inside cubby holes and hatches on my boat, I always wear heavy gloves and always put it back on as soon as I can.
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Apr 23, 2016 14:52
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ReelBigLizard posted:Sandpaper Flap disks are surprisingly aggressive, I've cut through small section stock with them when I've been too lazy to get the wrench out and change to a normal disk. Wrench? Do you not just tighten by hand? I haven't used a pin spanner in years.
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Apr 23, 2016 15:45
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Working on a boat you don't take chances of things flying off, even slim chances. Because the day it does spin off is the day it hops over the side and into an 18m deep marina.
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Apr 23, 2016 16:58
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ReelBigLizard posted:Working on a boat you don't take chances of things flying off, even slim chances. Because the day it does spin off is the day it hops over the side and into an 18m deep marina. http://www.axminster.co.uk/bosch-sds-clic-tool-less-angle-grinder-nut-202523
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Apr 23, 2016 17:56
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lol the guy on Forged in Fire who ground his entire knife to shape.
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Apr 23, 2016 18:27
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yumbo posted:This may be an unpopular opinion but not every weld needs to be a "full penetration" weld. What usually matters most is if the weld reinforcement metal thickness plus the penetration depth is equal or greater to the thickness of the material. A lifting eye made from 1/2" plate welded on with a 1/4" fillet on each side will not fracture at the weld, so long as some root penetration is achieved and no other defects are present. The weld is stronger than the metal it's holding together. If you don't bevel your welds or back gouge to achieve full penetration, enough reinforcement metal must be added to ensure a joint that's as strong as the material it's holding together. That being said, sometimes material thickness is chosen for stiffness (like in a welding table leg) or durability (such as plates subject to abrasion) rather than needing such-and-such a thickness for strength. In these cases much smaller welds than the material would otherwise suggest are OK. Generally though, welds should be made as strong as the base metal because poo poo falling apart because the welds broke is super embarrassing.
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Apr 23, 2016 18:27
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ductonius posted:What usually matters most is if the weld reinforcement metal thickness plus the penetration depth is equal or greater to the thickness of the material. A lifting eye made from 1/2" plate welded on with a 1/4" fillet on each side will not fracture at the weld, so long as some root penetration is achieved and no other defects are present. The weld is stronger than the metal it's holding together. Would I lift a plate with a lifting lug welded by a beginner welder? No probably not. Would I work on a welding table made by a beginner welder? Yes, probably. I have seen some pretty terrible welds that have been in service for years. There are many factors that influence how and why a weld is done the way it is done, and unless you have weld specifications, you often have to use your best judgement.
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Apr 24, 2016 00:28
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yumbo posted:Would I lift a plate with a lifting lug welded by a beginner welder? No probably not. Every piece of farming equiment out there more than likely has some absolutely hideous "Git-R-Dun" booger welds on it, but they still work and still make money. Ive done some hideous emergency welding with car batteries and stick electrodes to get out of a pickle before, and most of the time theyre still strong enough not to warrant bringing back into the shed to do properly with the MIG
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Apr 24, 2016 00:46
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Ferremit posted:Every piece of farming equiment out there more than likely has some absolutely hideous "Git-R-Dun" booger welds on it, but they still work and still make money. Ive done some hideous emergency welding with car batteries and stick electrodes to get out of a pickle before, and most of the time theyre still strong enough not to warrant bringing back into the shed to do properly with the MIG Making your plow frame keep the plow up when you lift it is a completely different risk profile than holding up buildings or carrying loads over people's heads (or the structures they are in). I'm all about farmer welds. That's basically my skill level. But I know when I should not be the guy doing this thing.
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Apr 24, 2016 01:09
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Doing some practice rings out of some scrap. Not used to forging stuff this small, hopefully I can get better at it. Ring mandrel:  Forge down the thickness. Or try to. (Imgur keeps rotating these two loving pictures, I can't figure out why or how.)  Nip the tip, sand down the sides.  Tiny little brass jeweler's hammer to bend it around the mandrel at the approximate location.  Had to get creative to keep it off the forge floor (the brick is covered in slag and such, don't want to get it all gummed up).  My sanding technique needs some work for things this small, I kinda stopped giving a poo poo for reasons that will become obvious in the last image. Additionally, I can see the cold shut line where the metal folded over when I was drawing it out, bugger.   When I tried to join the ends after getting it to the right-ish size I used my arc welder. Don't do that. The tips loving evaporated immediately. I'll have to get the tig out, if I can drag it from the corner it's stuffed into.  Still, I hit it with some jeweler's files after and cleaned it up a little. I can wear it on my pinky finger fairly comfortably. I shall keep practicing. Anyone have a good source for a skin safe clear coat?
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Apr 24, 2016 03:51
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I also practiced today, welded some strings (7018). Getting started at first was a hassle. Starting the rod and not getting stuck is the hardest part of welding so far. But I guess my welds will show where I need improvement, started at the bottom and worked my way up. Had plenty of starting issues at first, then it went a bit better. For the last 3-4 rows I changed from my 3/32nd electrodes to some of the cheap 1/8 ones I got with the welder when I bought it, seemed to be easier to weld with those. From what I understand you want the rod at the correct angle when dragging it across the surface you are welding, it's often times easier to start it without sticking if I orient it straight up.
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Apr 24, 2016 20:11
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Slung Blade- oxyfuel will also probably also do ya just fine, at least if you've got fine enough tips and an oxygen regulator that will actually deliver steady pressure at single-digit PSIs (most cheap single-stages won't cause they're only expected to be used for high-pressure cutting nowadays). I actually took a crack at doing a steel band from 1/8" stock ages ago and got satisfactory welds with OA by just butting the ends up tight, bevelling the upper edges some, doing the top weld and adding an excess of filler steel into the weld puddle, and just zipping the bottom edge shut with no filler (and then hammering the indentation on the bottom side out on the ring mandrel, making use of the extra filler metal to keep band thickness the same). If you're decent with the tig try that first, tho. As to clear-coat- there really aren't any topcoats that will hold up to the really heavy wear rings experience, unfort. Everything will wear through, it's only a matter of time (and it won't be long with a daily-wear ring). If it's something that'll realistically end up in a jewellery box most of the time, you stand more of a fighting chance. I default to Renaissance Wax- goes on effortlessly, provides acceptable wear resistance for an easy-on coating, and is basically invisible compared to most other similar products- but you need something much tougher for a finger ring, and I don't have experience with those products.
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Apr 24, 2016 22:46
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Thanks Ambrose. Hmm, I wonder if nail polish clearcoat would work. Easy for my friend to get ahold of to replenish at least.
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Apr 24, 2016 23:02
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His Divine Shadow posted:From what I understand you want the rod at the correct angle when dragging it across the surface you are welding, it's often times easier to start it without sticking if I orient it straight up. I can guarantee you that you have to worry more about your arc length then anything else. Then worry about your speed and angle. It's all about the arc length, specially with 7018. It's kind of like shooting a handgun... if you get your trigger control down you will do well, all the other stuff people to tell you to do will just make you better. If you can get your arc length down, the rest will follow. With 7018 you should really shoot for the tighest, smallest arc you can possibly humanly do without sticking. It should look you are almost dragging the electrode. You are wasting perfectly good steel. When you do practice welding you should "pad the plate". Which basically means you weld one bead on the very edge. You use that edge to help you weld in a straight line. Then you weld on top of that bead, bisecting the angle between the bead and the plate, just like you would if you were filling in a multi-pass butt weld or fillet weld. When you fill the ENTIRE surface of the plate up with weld, then you turn it 90 degrees and continue. This helps you to learn in a straight line, bisect welding angles as if you were doing real joints, and waste little steel. That is padding a plate. That's how you get good, along with a few 50lb cans of electrodes and an investment in time.
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Apr 24, 2016 23:12
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https://www.youtube.com/watch?v=IDRd2E3Q5Q8 Because why not?
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Apr 25, 2016 02:41
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AbsentMindedWelder posted:You are wasting perfectly good steel. When you do practice welding you should "pad the plate". Which basically means you weld one bead on the very edge. You use that edge to help you weld in a straight line. Then you weld on top of that bead, bisecting the angle between the bead and the plate, just like you would if you were filling in a multi-pass butt weld or fillet weld. When you fill the ENTIRE surface of the plate up with weld, then you turn it 90 degrees and continue. This helps you to learn in a straight line, bisect welding angles as if you were doing real joints, and waste little steel. That is padding a plate. That's how you get good, along with a few 50lb cans of electrodes and an investment in time. I was thinking I could go back over it later. I wanted some separation between the different attempts to better highlight any possible errors I was making as well as the differences of the 3/32nds and 1/8" rods. Though I think I know why I had such issues with them now, I ran them at 65-75 amps, going on memory that they should lie somewhere in there, but noope they're 90-110 amps.
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Apr 25, 2016 12:56
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