Winky, generally with quality chucks, the key hole that was used to finally tighten the jaws when the factory ground them is market with a x or number. If you always use that hole to tighten the chuck will be at its truest, due to any scrol sideways movement. When you do /did yours adopt the same procedure. Sharpie mark the last hole that you tightened the jaws to grind. Then put a permanament mark and always tighten the chuck using that hole. Good luck. Regards from Australia.
I thought so too... although I had one comment that said the flanges on the dust cover push against the scroll and stabilize it. He might be right but after reinstalling I saw no improvement. I turned the thickness down and the back plate holds it in place now.
18:15 looks like a Zippo lighter. Hey saw a guy make a video and gives you credit on this post ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1hzzVow7MHI.html
I did exactly this when I mounted my 4 jaw chuck. I have a video of the whole process on my channel. I have used the chuck quite a bit over the years. It comes in handy for square stuff. You could get around your bolt hole problem by just drilling 3 new holes in the backplate.
I considered the new holes and might end up doing this. Bob Kelly commented that the dust cover needs to be there. He said the tabs on the cover hold the scroll in place. I need to look at this closer.
I mount my router on my lathe tool post and grind my 3 jaws with a vitrified stone. usually get to a couple tenths. I have used the same stone for many chucks for many years. The mount took a couple days to make. It has proven useful for grinding internal bores too.
I think the lathe tool works nearly as well, at least in the hardness range if my chucks. Also, even if cutting is not a perfect method, there is no way this chuck is repeatable within .005"
Thanks for the video and happy for your success to make it a better product. Many people have given their opinion on how to do things to make it more accurate. Vevor is a company for cheap products and therefore just average quality in my opinion.
Thanks, Vevor is hit and miss. On some products cheap is not an issue. For instance the TIG welder I use will weld just as well as a Miller on steel. Its not the same quality machine but it functions well. I also have a drill sharpener from vevor that is amazing (although not cheap). The normal 3-jaws are okay but not great but this 4 jaw was terrible. So I sort of agree...
Hay buddy I think you missed something ! when removing the dust cover you left the end of the scroll gears able to twist a bit... this will cause them to bind and the chuck will not be as tight as you think it is... yes it's a cheap chuck but you made it worse by removing the dust cover.... the dust cover has protrusions under it that support the end of the scroll gears so they can't twist out of alignment and bind.... you removed that so now they can twist and bind and worse move UP and allow the tightening gears to slip. so you NEED to weld in a metal piece to the chuck to do that now something to support the end of those scroll gears if you use it like that very long it will eventually ware out the scroll gears because they are forcing themselves out of the teeth when you tighten them down. maybe a drilled out nut welded onto the center column of the chuck would do it, I don't know but then you would not be able to get the spryl gear out to clean it good.... I think you worked yourself into a pickle this time.... putting the dust cover back in means making a new back plate.... but I think that is your best option in this case. sorry for the bad news but you have 3 options put it back the way it was, weld on some gear supports to the chuck, or use it like it is and hope it will last ! perhaps you can figure out another way to support those gears eh ? but they need to be supported on the far end !
Interesting and you might be correct. I need to look at this closer. However, I've had a few 3-jaw chucks that had no scroll support aside from the pinion gears. The best fix would be to attach a tube to the back plate with cutouts for the pinions. Doable but not easy. Seeing as how the dust cover was plastic, I suspect it was probably only to stabilize the backlash between the pinion gears and scroll gear while tightening. I doubt there is any danger of slippage but it would likely make the chuck more repeatable. Thanks!
have you tried lightly snugging chuck, then rotating bar until you feel resistance, then do your final tightening? I find it helps on my 13" SB...hope this helps, Paul
The thing about scroll chucks, 3 or 4 jaws, is that the thread of the scroll is what really determines its ability to center work. You can grind/bore the jaws and make it better, if there is an issue with the jaws. However, there will always be runout and it will vary by work diameter. There might be diameters that have zero runout and diameters with .015" runout because the scroll thread is not precise. Given your intended use, I am sure it will work fine.
Taking the dust cover out might make things a little worse. You are now going to have a gap between the mounting plate and the chuck inside the bore. As a result, you could easily end up with small chips getting into the pinions and scroll gear surfaces.
With all due respect it's a silly chuck. A 4 jaw with a scroll? No! A four jaw that's worth having has individually adjustable jaws. The idea is for clamping on odd shape work and or being able to dial in greater precision than you can get on your 3 jaw. 6 thou runout to me would be worthless. More than 1 thou is not useful to me. 3 jaw chucks with scroll tension and even better if you can get one that allows you to adjust to fine tune the center. My 3 jaw has three possible mounting positions, the best giving me half a thou runout which is acceptable. I used a punch to mark that best position. Same with mounting my ER collect chuck to the lathe. No offense but I would scrap that chuck, or find some other poor soul to give or worse sell it to. It's really hard to believe that the manufacturer thought it was something worth building.
While I do agree that a self centering 4 jaws are problematic, it works great for drilling the ends of square stock or turning the end round. Not perfect but it also depends on what you are making. Also, most the time I'll be using on my CNC wood lathe. A lot of what I turn is spindles with a square ends. Wood compresses so slight discrepancies between jaw sets or wood size are not an issue.
Great video. You could have gone deeper in the backing plate by drilling three new mounting holes. Replace the standard socket head cap screws with low head height socket cap screws. These are a standard fastener from Unbrako. There is another way of restraining your chuck jaws prior to remachining a three jaw chuck. Drill a hole in the front flat face of the jaws. As the jaws are reasonably tough and hard you will have to use a carbide drill. Since your chuck is small a 6mm hole (or 1/4") should be sufficient. Fit a Grade 8.8 pin into each of the three holes. Make a restraining ring from flat 6mm plate. Drill three 10mm holes in the plate at the radius to suit the grind ID. The chuck can be preloaded before maching. The ring is self centering. I saw on a video from either TL or RR that for best accuracy always use the same tightening point. The chuck's centering accuracy changes if a different hole is use. Same hole for grinding and normal use. Hope this helps. Cheers.
I was going to do something similar to what you describe when I cut the ring but the aluminum was easy and probably just as effective. I also considered drilling new holes on the back plate and using low profile of even county sink screw. The later is not the best option however as small position errors try to control the back plate position. Thanks
@@WinkysWorkshop Thanks for taking the time to reply. The major benefit of the drilled holes is that it can be used for any diameter regrind. If you need to regrind at a much larger diameter there is no issue. Also If the hole is tapped. I have seen people use this tapped hole to hold copper soft jaws. Cheers.
I've seen Mark Presling use a vernier caliper designed specifically for scribing. They're inexpensive and readily available from Amazon or AliExpress. I'd like to get one, but the inch vernier scale is in 128ths, which to me is just silly. I'm mulling over ideas for modifying an inexpensive digital caliper to have a similar configuration.
Interesting... yeah, 128ths are hard to deal with. I had bluing on the back plate so it was fairly gentile. I didn't know about the calipers made for scribing.
Thanks for the video. I am not an experienced machinist, I am a mechanic with a lathe, but I have used this Chinese type equipment for 25 years, and I have a couple of these cheap 4 jaw chucks in different sizes. In my experience these Chinese 4 jaw chucks have a "master key hole" and a key hole that is really not usable. So when you get it, first thing is to test runout using each key holes, find the best one, mark it up, and always use that one. I have no logical explanation for it, but it makes a major difference in repeatability and precision, I have a runout of less than 0.01mm on these. And sorry for my English, your videos have reached as far as Denmark :-)
Most of the chucks I used at work had master jaws which were hardened and ground for precision work. The change out would be for soft or harden jaws depending on the job requirements. They were keyed at their bottom. Even those jaw would require grinding, to re true the jaw. I know what you're going through, because I have a 13" South Bend lathe, which I bought a 4-jaw chuck for and I to, tooled out the jaws to achieve less runout. I often see .003 " TIR. and am satisfied with that on the lathe. Unlike the precision grinding equipment which I definitely was working in .0001 - .0002 " TIR. when setting up a job.
Yep, I could not justify the expense of the precision stuff. My south bend 11 is worn quite a bit anyway. I have collets and a 4 jaw independent if needed.
I have only purchased a couple of Vevor items & they do look to be very well-made. I did by a 3 jaw Vevor chuck only to find that one of its jaws was not a match with the other two. Got it because I had purchased another Chinese 3 jaw & left it in its box too long & the warrantee had run out, then when I went to use it the body was terrible & it was all over the place. So I had another set of jaws & with these fitted, the Vevor chuck is very good. You certainly can not machine that bad jaw & get it to fit.
I've had good luck with Chinese 3-jaws but this 4 -jaw is not very good. Vevor seems to be hit and miss. I have a TIG that works great and also a drill sharpener but the mill table for my drill press took a lot of work to make it right. Vevor is kind of like Amazon, they just sell buy and sell.
Thanks for the shout out. I guess that's what we get for buying budget tools, they always need a bit of finish machining. Can't be sure of this, but I think clamping round stock in a 4 jaw relies on the stock being perfectly round, if not one jaw will not be loaded as much and the runout will get worse. A 3 jaw has to load all three jaws the same by comparison. That should be a nice useable chuck now. Good job!
I, like you, have several Vevor products. I have learned to disassemble everything from them, degrease and clean them in my Vevor ultra sonic cleaner to remove all of the machining and casting grit, then debur and reassemble using a good quality grease. Some of the inaccuracy you are seeing maybe caused by a bunch of crud inside. Another great video. Thanks.
@@desertdweller9548 The garbage usually works out well, admittedly this time was worse but given the price tag for a good quality chuck (5x more) I think my time is not wasted.
Nice work, I've only ever seen chucks ground with a tool post grinder. Interesting method I would of never thought of that due to the interrupted cut. I was waiting for the insert to break. Nice job
Mark I am trying to understand what the advantage of having a 4 jaw scroll chuck is? I understand the advantage of a 4 jaw adjustable but not a scroll.
Primarily chucking square stock. I've had several occasions where I need to drill the ends or make them round so it just speeds things up. One big reason I wanted one was to use on my wood lathe. Most spindles have square ends.
@@WinkysWorkshop Thanks Mark. I didn't think about using it on the wood lathe. Now it makes sense. If you have a lot of square stock to turn or bore, then it will certainly speed things up.
Have you ever put your test bars (at least the smaller one) in a collet and checked for runout in your bar? That way you know where you stand with the bar when you use it.
Yep, I was hoping for a little better quality but after fixing the jaws It will be close enough for some stuff. One reason I bought it was to use on my wood lathe (most spindles have square ends) and the accuracy there is not an issue. I think the scroll is a problem for repeatability but I think the jaws were made wrong also. When changing diameters its fairly consistent.
Testing the plate isn't at all necessary. It was turned while mounted on the spindle so it will always be perfect. I did test with a bar. It was not as good as I would like but much better than it was. Mostly it changes every time i lock it down.
I am not a machinist, but I have a question: Wouldn’t the runout change based on where on the internal screws the jaw is engaged? Meaning that if you chuck a 1” bar, you get one runout reading, but if you open the jaws a little, engage a different area of the internal screws, and chuck a 1 1/4” bar, would you get a different runout?
Yes, absolutely and a very good point. I checked the internal jaws with two size bars and they were not the same but close. No self centering chuck is perfect. Most often it will be close enough but if I need perfect I'll use a independent jaw 4-jaw or collets
Yes I considered that too... I weighed the extra time and effort and the benefits and decided against it. I would have gained 1/8" in overhang. Probably should have.
Good work Mark. But you have a habit that bothers me… you slow down the chuck using your hand as the brake. When you did that with the hose clamp flying round I could see the possibility of a badly torn hand - and that might slow your video production! Bad news for all of us.. Take care my friend, safety third, and all that👍 Les in UK 🇬🇧
Mr Winky, not sure how a self centering 4 jaw Chuck is desirable, would have preferred a standard 4 jaw especially as it is a low cost item, also surprised that those jaws are not hardened
The jaws are a step harder than mild steel but carbide does well. I already have a standard 4 jaw and I agree, it's a better choice if you have one 4-jaw chuck. I wanted it for drilling square stock on the metal lathe but the primary reason I wanted it was to use it on my CNC wood lathe. A lot of spindles have a square end and makes ir easy.
