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A couple years ago, I got the ubiquitous Chinese mini-lathe (some variation of the SIEG C3 7x14 Mini Lathe). I purchased this quick change tool set and everything has been working as expected except the parting blade. It has a lip along one long edge (like a safety razor) that causes it to sit in the tool holder tipped at a bit of an angle along the Y axis like this /. If I try parting with it, the workpiece pushes the blade along the left-right X axis and it doesn't work worth a poo poo. I'm assuming the tool is designed and manufactured correctly, so I must be doing something wrong. Any idea what? Thanks!
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May 26, 2021 04:06
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SkunkDuster posted:A couple years ago, I got the ubiquitous Chinese mini-lathe (some variation of the SIEG C3 7x14 Mini Lathe). I purchased this quick change tool set and everything has been working as expected except the parting blade. It has a lip along one long edge (like a safety razor) that causes it to sit in the tool holder tipped at a bit of an angle along the Y axis like this /. If I try parting with it, the workpiece pushes the blade along the left-right X axis and it doesn't work worth a poo poo. I'm assuming the tool is designed and manufactured correctly, so I must be doing something wrong. Any idea what? Thanks! Can you post a pic maybe indicating what you’re referring to? Also axis for lathes are Z Workpiece rotate about Z) and X (cross slide).
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May 26, 2021 04:16
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Bearing question. I'm replacing some spindle bearings, the original set is Fafnir duplex bearings. They are like $2,000 for a set. Another supplier spec'd out FAG bearings, but said they don't do duplex and all are universal match. They want like $400 for a pair. Can I get away with the FAG pair? What is the benefit to ordering as a duplex set?
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May 26, 2021 12:24
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Ambrose Burnside posted:crosspost from 3d printing thread: i'm using a specialized high-temperature resin to produce casting molds for low-melt eutectic alloys with various tooling applications. here's a test mold, a vector trace of a genghis-era mongolian diplomat's 'passport' Cool tenths of an inch ruler, there.
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May 26, 2021 16:22
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Slung Blade posted:Cool tenths of an inch ruler, there. I have like 3 of them I use at work all the time, they rule (ha)
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May 26, 2021 16:33
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Yooper posted:Bearing question. I'm replacing some spindle bearings, the original set is Fafnir duplex bearings. They are like $2,000 for a set. Another supplier spec'd out FAG bearings, but said they don't do duplex and all are universal match. They want like $400 for a pair. Much tighter tolerance on the duplex set for both radial and axial location of the bearing. Probably going to have to do some math on the loads and tolerance you need on the spindle based on the tolerance each bearing pair gives you to make the determinination. I know duplex bearings come as pairs and need some specific preload. So your upper bearing is two bearings pressed together, as is your lower bearing. Back in the way-back, the bearing catalog said something about 'universal' duplex bearings that are precision-ground but not matched so you can just stack up and you adjust the preload somehow to get close to what the matched set can do? Check with the bearing manufacturer and see, I guess.
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May 26, 2021 17:45
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babyeatingpsychopath posted:Much tighter tolerance on the duplex set for both radial and axial location of the bearing. Probably going to have to do some math on the loads and tolerance you need on the spindle based on the tolerance each bearing pair gives you to make the determinination. Cool, this is what I thought, but good to see it confirmed. Thanks dude. The bearing catalogs for both Timken and FAG were a bit muddled. I did reach out to Timken and decided we're running with the duplex set because this spindle doesn't use belleville washers and is non-adjustable.
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May 26, 2021 18:43
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A Proper Uppercut posted:I have like 3 of them I use at work all the time, they rule (ha) Technically, that's a scale. Rulers are for math and drafting.
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May 26, 2021 20:48
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SkunkDuster posted:I'm assuming the tool is designed and manufactured correctly, so I must be doing something wrong. Any idea what? Thanks! Sounds like a bad grind on the parting tool to me, it should sit perfectly vertical in that orientation. post a pic of it.
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May 26, 2021 21:29
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Samuel L. Hacksaw posted:Technically, that's a scale. Rulers are for math and drafting. Ugh, and you know what, I give people poo poo for calling it a ruler here.
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May 26, 2021 22:03
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A Proper Uppercut posted:I have like 3 of them I use at work all the time, they rule (ha) i want to introduce the rest of the world to Linear Precision Measuring Sticks that are actually manufactured to read correctly if you butt the end of it against the part
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May 27, 2021 01:11
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I work for FAG's parent company, everything they make to that level of tolerance is sold under the Barden brand. The catalogs are targeted at OEM engineers and machine designers, just go with the Fafnir. You'd be shocked to see how much SKF and Timken product we have in our maintenance stockroom. shame on an IGA fucked around with this message at 01:36 on May 27, 2021 |
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May 27, 2021 01:34
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shame on an IGA posted:I work for FAG's parent company, everything they make to that level of tolerance is sold under the Barden brand. Cool, that'll work, thanks dude. We shopped around for prices and can get the Timken into the reasonable range. The next adventure is procuring 35mm linear rails in the current supply chain.
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May 27, 2021 02:12
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Bearing Update  Bonus rail.  Rail doesn't look as bad in the photo, but it has ~ 6mm of slop in every axis. As expected every supply chain is broken and I'm down to buying NOS.
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May 28, 2021 13:49
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F. Are you just looking at the big supply houses like MSC and McMaster? The specialty distributors with poor online presence are probably gonna be more helpful, Motion Industries, BDI, Applied Industrial Technologies are some places to start shame on an IGA fucked around with this message at 14:21 on May 28, 2021 |
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May 28, 2021 14:01
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Someone with little or no online presence who answers an old fashioned phone is your best bet. Source: I work for a major multinational everyone's heard of and found a rail I needed in stock in a 1 man shop by word of mouth, 16 months lead everywhere else
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May 28, 2021 14:52
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shame on an IGA posted:F. Motion had the spindle bearing and seals, AIT had the micro v-belts, some rando place outside of Detroit had two sets of carriages, but only one of the matching rails. I procured the remainder from a sketchy looking website that actually came from a company owned by Motion which had way better prices than actual Motion.  edit : And had a price for Fafnir bearings from some place in Florida who was 10% of the price of Fafnir, but it was delivery from China. So yah, not happening on that one.
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May 28, 2021 15:00
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cakesmith handyman posted:Someone with little or no online presence who answers an old fashioned phone is your best bet.
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May 28, 2021 20:35
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I feel you dude, we've occasionally had to play that game for poo poo that we make with the machine we're trying to fix Globalization is a weird trip
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May 28, 2021 21:06
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Kaiser Schnitzel posted:There's a local bearing place I love that sells huge loving bearings to the shipyard and railroads and sells me $.52 of shims. I just bring my XYZ problem in and plop it on the counter and tell them what I need it to do and they solve my problem for me for free. One guy there talked to me for half an hour on the phone about why bearings fail, how to tell if failing bearings are actually why my machine is making a funny noise, and all the things I should look at and preventative maintenance I should to and it was like going to bearing school for free. Yeah, shops like that are the best. I brought in some brakes from our 1958 Mack fire engine to a semi-local well known brake relining place. They sent me in the back with the oldest dude there, who then schooled me in "are you going to really run this truck or will it sit and be in parades? Okay, parade truck, so I'm going to line the shoes with this epoxy and make the rivets this much extra tall which means they wear out faster but won't have rust problems while it sits." and all kinds of other stuff. And showing up unannounced, he was still able to find the book with the specs for them on his shelves in under 30 seconds. Zero internet presence. Free brake relining crash course.
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May 29, 2021 00:05
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I love the old dudes who know a ton about some niche thing that just want to talk to someone who's actually interested in their experience.
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May 29, 2021 04:34
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A few years ago when I started at my first engineering job I was building a 3D model in Solidworks for a nozzle that was to be 3D printed out of inconel. I was advised by the printer to model the pipe threads, as they would be extremely difficult to cut traditionally given the weird geometry of the part and material. Now it might be a feature in newer versions, but SolidWorks 2014 had no built in tool for modeling external pipe threads, so I had to figure it out manually. I spent hours scouring the internet for detailed dimensions of pipe thread geometry, to no avail. Eventually I asked one of our old time engineers and he hands me an ancient and tattered copy of the Machinists Handbook. There it was, first page in the pipe section, all the numbers I needed. The print ended up flawless with no leaks.
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May 29, 2021 04:56
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The engineers black book loving owns
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May 29, 2021 05:47
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Are there any good textbooks or free/cheap online courses I can use to become a machinist? I mean, a fully fledged parts maker. Not so much to teach me the absolute basics, or even the skills - but a list of all the things I should try to tackle as an apprentice. Setting up a 4 jaw chuck, making soft jaws properly, etc.... I know a lot of basics but I'm sort of at the point where I want something a little boring and well subdivided into subject areas when it comes to 'how to be a machinist'. A 'knowledge tree' if you will. I have an unusual situation and opportunity where I will soon own two cnc machines (lathe and mill) in a manual machineshop. The owner, a friend, owns the manual machines there and the shop itself. He's happy for me to store my machines in a corner there and it adds a bit to his business having someone around who can cnc things quickly if someone walks in with a job requiring 50 of something. Thing is, he's a bit eccentric, and while his knowledge of manual machining is pretty good the work flow there is low and he's not the greatest teacher - a bit scatter brained. Sometimes he's amazing, I was chasing 0.02mm on a part in some soft jaws and he was able to narrow down the issue relating to the soft jaw deformation and we got the part running after a few adjustments to within tolerance. Other times I tighten up the vice with a rattle gun and he says nothing - until I mention it. If I don't ask, I don't get told, but problem is I don't know what to ask for, to an extent, and due to the jobs low workflow I wonder if there are other types of things I should be doing .......... Up until now I've been running parts for customers who come in and he's happy for me to take the larger part of the earnings, and throw him a bit of rent if I'm making something. There is the option of me going an doing an apprenticeship somewhere else bigger and more established but obviously they wouldn't let me have machines there and take money straight from the customers into my pocket. Pay as an adult apprentice is miserable, too, I earn more currently doing 2 days a week casual work at my old job and 3 to 4 days at my friends place. Also, his place is more fun, and in 3 years he might not have room for me and my machines......... So may as well try to get a business going with him now. Just after something to read, I guess...... Even a detailed list or competencies of what's covered in college courses machinists go through would be amazing. (edit: another drawback is shops around here tend to want you to push buttons for 3 years and that's about it. Where I am now I'm already running my own cnc programs and coming up with strats to make or produce in batches of 50 the parts myself) Thanks for any advice. (edit2: I worked as a mechanical engineer in a past life, although briefly. I already watch a lot of this old tony, s gotteswinter, and others. Edge precision is my new favourite..... wish I had his machines and knowledge!) Mudfly fucked around with this message at 06:33 on May 29, 2021 |
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May 29, 2021 06:07
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Mudfly posted:Edge precision is my new favourite..... wish I had his machines and knowledge!) You aren't alone. I've heard one of the machinist YouTube guys call him "the smartest person on machinist YouTube." Can't help us much with your questions. Most of the CNC guys I've worked with went to trade school. NYC CNC bootstrapped his way up from an apartment cnc machine and has some online training.
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May 29, 2021 10:39
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Machinery's Handbook and Millwright & Mechanic's Guide should be issued to every human at birth
shame on an IGA fucked around with this message at 12:16 on May 29, 2021 |
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May 29, 2021 12:10
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Mudfly posted:
I can get you some info on core competencies and such, but what you'll find is most entry level machinist programs are designed to get people jobs as button pushers. The more talented among them will move beyond making offsets to doing setups and such but that training is usually on the job. If you can find an old US Navy machinist study guide, or even the older Audels (sp?) books it'll get you some info. But you rapidly move beyond the absolute basics and get into CNC land really quick. The most talented machinist I know started out at a "job shop" where he did everything from turning a lawnmower shaft, threading a turbine for a dam, to pouring lead babbit bearings. The day would start with a foreman handing out prints and then they would just go at it. The width and breadth of his experience came just from tackling wildly different tasks daily. I'd argue for pushing your boundaries with your own production and do so with tighter tolerances or more unique parts. Another option is to work part time as a button pusher in a (high quality) production shop and just sponge up every bit of detail around you. Just being aware and interested will make you pick up on things that others wouldn't. But try to find a shop that handles either a variety, or whatever niche you like. If you came into my shop you'd learn a poo poo load about centerless grinders and OD grinders but nothing about milling or hard turning. I've been in aerospace job shops and they tend to have a very unique and high quality approach to things, I'd aim there first.
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May 29, 2021 12:42
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Had noticed This Old Tony has been absent a while now. Apparently there was a death in the family:quote:First and foremost, THANK YOU! Impossible to believe a million of you enjoy hanging out with some guy in his garage... but more on this later.
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May 31, 2021 14:02
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Mudfly posted:Are there any good textbooks or free/cheap online courses I can use to become a machinist? I mean, a fully fledged parts maker. Not so much to teach me the absolute basics, or even the skills - but a list of all the things I should try to tackle as an apprentice. Setting up a 4 jaw chuck, making soft jaws properly, etc.... I know a lot of basics but I'm sort of at the point where I want something a little boring and well subdivided into subject areas when it comes to 'how to be a machinist'. A 'knowledge tree' if you will. It sounds like you're already making parts from scratch and are looking for a way to find if you have any blind spots you don't know about. 8 years in for me and I still get blindsided sometimes with oh duh I should have known that simple poo poo. I'd say if you have a proto CNC business already going and it's making you money lean into it. Every parts a new and interesting puzzle, and every time you solve it you'll have more mental tools for the next one. If you can post some pics of the parts you're working on and a rough outline of how you're approaching them. I'd be happy to throw in my .02
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May 31, 2021 18:45
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I've been doing it for 20 years and I'm still figuring stuff out. Everything I learned, I learned by doing. In the USA there aren't really many resources for learning that kind of stuff. Hopefully you can get friendly with local job shops and take some of their overflow work or something. Just gotta jump in.
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May 31, 2021 20:26
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More questions for trying to up my welding game: I picked up some Lincoln 7018 rods 1/8" diameter AC-DC +/-. I've looked and looked on the box, and there is nowhere that lists what If yes, does this go for other rods as well? Like 6011, 6013 and so on? Assuming they are not some special rods for some fancy bullshit of course.
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May 31, 2021 22:04
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AmbassadorofSodomy posted:More questions for trying to up my welding game: 7018 is 7018 for the most part. There may be subtle differences in the flux binders between brands but you should be able to run them interchangeably. With my welder I run 122A DCEP for 1/8 7018 and turn it down by 5 or 6A when welding vertical. Usually it is about 1A/0.001" of electrode diameter. DCEP is the normal way to run these rods and running DCEN would be for special applications. AC would only be used if you only have an AC welder. Also note that 7018 should be kept sealed until just before use or in a rod oven if you want to keep the low hydrogen feature. They will still work if left out, but the weld will be more susceptible to cracking due to hydrogen embrittlement. If you are just practicing it does not matter but it could cause you to fail a bend test. Whenever I weld anything critical, I open a fresh box of 7018 as I don't do that too often.
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May 31, 2021 22:36
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AmbassadorofSodomy posted:More questions for trying to up my welding game: The basic rule of thumb I learned for amps selection is you want to start at the decimal equivalent of the rod diameter. So 1/8" rod would be .125" or 125 amps. Start there and adjust to personal preference and base metal thickness. Only rods this doesnt work as well for is the cellulositic rods like 6010 and 6011. If i remember right i used to run those starting around 100 amps at 1/8" rod size. Its been years since I ran 6010.
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May 31, 2021 22:37
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Ziggy Smalls posted:The basic rule of thumb I learned for amps selection is you want to start at the decimal equivalent of the rod diameter. So 1/8" rod would be .125" or 125 amps. Start there and adjust to personal preference and base metal thickness. Only rods this doesnt work as well for is the cellulositic rods like 6010 and 6011. If i remember right i used to run those starting around 100 amps at 1/8" rod size. Its been years since I ran 6010. Yeah, I think I remember reading that somewhere. 1A for every thou of diameter. If given a choice would you use 6010, 6011 or 6013? I've had pretty nice results with 6013 but its supposed to be a pretty forgiving "beginners" rod. My masculinity isn't affected by using a "beginners rod" so personally I don't give a gently caress, but I find those the easiest of all to use, and will continue to use them when I feel like it. That being said I've had good results with 6010, and 6011. ZincBoy posted:
What sort of special applications? Are you talking overhead? Or when welding fancy types of steel? Is heating them with a torch "good enough" for most applications or should they be heated evenly (like in an oven)? Is there a special reason for AC only rods? Like yeah, I know that AC only welders exist, but other than price (?) is there any reason to run an AC only welder, and AC only rods? Ninja edit: Also, Thanks for the replies goons.
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May 31, 2021 23:45
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AmbassadorofSodomy posted:That being said I've had good results with 6010, and 6011. You can only use DCEN if the electrode specifies it as an option. It would be used when you want less penetration of the work so if you were welding sheet metal. I have never used DCEN as I only use stick for structural welds over 1/4". Counterintuitively, overhead uses the same settings as flat. I don't think you could dry out rods by hitting them with a torch. You need time for the water to evaporate and you couldn't keep the rod at an even temperature. From what I have heard, once the rods get wet, you shouldn't use them even if you dry them out. I suppose if you had a hermetic storage container that would work as well. I have a rod oven that I use if I am working on something big that will take a few days. I think it is set to 130C. Price is the only reason to have an AC only welder. The only application I am aware of for AC stick welding would be to avoid arc blow on magnetized work pieces. This can be a factor when doing heavy structural welds with lots of passes as you can end up magnetizing the work.
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Jun 1, 2021 05:03
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AmbassadorofSodomy posted:Yeah, I think I remember reading that somewhere. 1A for every thou of diameter. 7018 is my all around favorite stick electrode. They're all good rods but some have more specialized uses. For general purposes 6013 is a fine rod though I've never heard of it being used for structural purposes. Its got decent penetration and is pretty easy to use. 6011/6010 are most commonly used during the root pass of an open root weld because of its strong arc force. That arc force can also help you burn through paint, heavy mill scale, or rust. 6010/6011 are only different in that 6010 is for DC current and 6011 is for AC current. As for 7018, its the standard structural rod due to the low hydrogen properties and added iron powder in the flux giving increased weld deposition rates. 7018 is great once you get used to starting the arc. It has a tendency to stick when you try to strike it. I used to have a couple AWS structural certifications with it. Also as already mentioned, don't try to dry out 7018 with a torch. I imagine the direct heat could mess with the flux. I've seen guides online to using a home oven to drive the moisture out.
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Jun 1, 2021 07:21
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echomadman posted:With all that mini late tooling its quite common to get parts that are not quite up to spec. Been a long weekend, so sorry for the delay. I checked the vertical orientation with a square and it seems to be completely vertical, so my guess is that my cross slide isn't square to the workpiece. Maybe a dumb question, but I do I have the parting tool installed correctly with the thick side on top (leading edge)?
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Jun 2, 2021 01:50
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Yes thick goes on top. I'm not Mr lathe so correct if wrong. Also iirc it needs to be on or below center of rotation to work right. Above and it will rub the relief.
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Jun 2, 2021 02:26
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Currently ordering all the gear to build a steel knife vice. Just need to get the handles, fasteners and we're good to go
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Jun 2, 2021 07:08
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McSpergin posted:Currently ordering all the gear to build a steel knife vice. Just need to get the handles, fasteners and we're good to go Educate me here, Google brings up a lot of different "knife vise".  I found that guy while searching, probably not what you mean but that is a sweet looking vise.
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Jun 2, 2021 11:58
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