The ones I have are from Enco back in the day and another set from Amazon from a few years back and have been fine on aluminum and cast iron. But I need to do some work on the jaws of a 4 jaw lathe chuck. I’d rather purchase one quality bit than possibly sacrifice what I have now. Thanks.
If the jaws are hardened, then I would use a grinding wheel type bit and not a carbide type. Something like this Norton bit: https://www.mscdirect.com/browse/tn...7tUY0RoCEL0QAvD_BwE&mkwid=|dc&cid=ppc-google-
I have some of those around somewhere. Forgot all about them. Mine have a short shank though like pictured. I’d like a 6 inch shank, jaws are a good 2.5 inches deep. But I’ll check the link and see what they have. Thanks.
Ya know, I’d bought a box of those back when Post Tool was around, kinda a HF place that also sold quality tools like IR, etc. man I miss that place. Anyways this was “pre-internet” for me and I asked them about longer shanks “no, never seen them”. Funny how stuff sticks in your mind for 30+ years and I forget things have changed
BUDGET36, ARE THE BURRS YOU HAVE A DOUBLE CUT? HEARS ONE I JUST FOUND ON AMAZON https://www.amazon.com/YUFUTOL-Tung...uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl YOU COULD ALSO TRY A CARTRIDGE ROLL ON A LONG ARBOR I SEARCHED FOR PORTING & POLISHING TOOLS
The burrs (one set) are double cut, but don’t recall from where they came from. (Enco or Amazon) I’m not sure a drum roll will work for me though. I’ve used them before on intake ports for CI heads. I think they “give “ a bit too much. Thanks!
There's no way you're going to be successful with HSS burrs. It's going to HAVE to be carbide cutters, or that grinding stone. I've ruined too many HSS end mills on hardened steels. Roger
I’ve no issue buying one carbide bit. Do you have a manufacturer you can post so I can see what’s available? Thanks!
You might check out this outfit. I've had good results with what I've bought from them. https://www.shars.com/ Roger
Also, (via memory kicking in) I now know I can use a stone. But the more I use the stone the more it wears and not linear crossed it. I’d be doing rough cuts with several stones change them over and over to get what I want to achieve. If I can do just light cuts with a quality tool, my thought is it’s less work to complete what I need to get done.
HERE'S A LONG CARBIDE https://www.msdiscounttool.com/cata...bg26rRRcRCbv2AktQoSDxARG-LiU7KHxoCP9gQAvD_BwE
After this happened to me, turning 20,000 RPM I no longer buy cheap burrs or arbors. Darn near broke my wrist.
Tell us what you are trying to accomplish and we may be able to help better. Not sure if you are trying to true some jaws in an existing chuck or some major modification to jaw shape. We used to have aluminum replacement jaws that we put in chucks and cut them to hold specific shapes. You can also make a large bushing and split it so it makes a collet shape to hold something you don't want to mar. A lot of the decision on what kind of tool/tools to use depends on how much metal you need to remove. Grinding wheels with coolant will work best for smaller amounts of removal. If you need to make a major change, then it might be better to rough cut the major removal and use grinding to finish. I'm not sure if a burr will give good results with an interrupted cut. Like I said, need to know what you are trying to accomplish to make the best recommendation.
I've not had great results with longer shanks in my die grinder. I try not to use them any longer than I need to get into places I'm grinding. The longer the shank the more it amplifies vibrations, and I have to be sure to stop if I feel the slightest odd vibration and re-check the chuck tightness. They'll actually vibrate themselves loose when using longer shanks, but shorter 2" shanks always stay tight.
So the jaws on this chuck are visually worn. I’m not sure what it was used for in its past life, but I can see daylight on the jaws when I lay a 6 inch metal rule front to back. This makes it near impossible for me to get anything round centered up. In the past using a 4 jaw chuck it would generally take me 20 minutes or so to dial the work to .001. The best I’ve ever got this one is .010 after more time. I don’t need the full length of the shank and will cut it down to work specifically for my needs. In my mind it will be a single use tool that in the future someone will say “why was this cut down”. In the past I’d just take the work to a shop in Modesto and they’d charge me by the hour and it would be done. Life has changed a bit over the last 7/8 years and finding time on a Friday afternoon to take them somewhere and then come back the next week to pick them up is tough. If I’m not satisfied with the results, then I’ll do some “internet hunting” and send them out. I’m trying my hardest to not have to go to plan B to get my 3 jaw chuck mounted just yet. It’s a two person job to remove the 4 jaw I’ve never measured it but it’s at least 14 inches in diameter. This is on an old (big) Hendy lathe.
Ok, now I see what you want. My first suggestion given the size and weight of large chucks would be to build a small "jib" type crane. I struggle with a the chucks for my 15" lathe. Make a simple I-beam straight up the wall behind the lathe (if there is one) and then a short section of I beam welded to it and braced to a couple ceiling trusses. Get a HF trolley and ratchet chain hoist and no more struggling. Them chucks can hurt you. A simple way to true the jaws would be to dykem blue them and scribe some lines to cut to. Then put a square on a belt sander or one of those disc sanders with a table. Gently put each jaw against the square and dress the end of it. This would not work with a 3 jaw chuck but with a 4 jaw all you need to do is get it square. If you want to try grinding while the chuck is mounted and spinning......I would get a round ring that you can slip over the outer steps on the chuck, ergo the surfaces used when clamping a part internally. Just snug it initially so it doesn't deform much. Then use a dial indicator to see how round you can adjust the ring. That puts some tension on the jaws so they don't move when grinding and centers them as well. Then I would use a grinding stone with atleast a 1/4 shank. I would use a short round stone with a larger diameter. That way the stone will have less tendency to become tapered as you grind. I would use coolant too. If you have a tool post grinder, thats great. If you don't then you can make a simple adapter for a die grinder to mount to your tool post, like the one below. https://www.grainger.com/product/NORTON-NORTON-Vitrified-Mounted-Point-2D906?gucid=N:NSaid:GGL:CSM-2295:4P7A1P:20501231&gclid=CjwKCAjw9J2iBhBPEiwAErwpeS0PnJIRhlW0Jusd3u1nBaNV06ce5ooD8cJwvw0tTwp7RFpQIKozjhoC740QAvD_BwE&gclsrc=aw.ds I would buy more than one stone . Edit: Let me add that by a "larger stone" I mean one somewhere in the 3/4 to 1" diameter so there is not so much space between the rotating jaws when grinding.
Are you reading my mind? Awhile back I had watched a video of a guy restoring an older chuck, he did exactly as you described. I don’t have a tool post grinder, but got to thinking of rigging up my die grinder on the crossslide. I meant to add re:removing the chuck (which I’ll need to do another day anyways) I used to have an engine hoist across the rafters, it was a 3 handed job though to swing the chuck away from the machine and get it down. The last time I had it off/on was maybe 10 years ago. It was way harder than when I first put it on 25+ years ago. My third hand isn’t what it used to be
Yes they can. Thing is the only machine shop in town is for engines, and they told me “no” last year. Working my shift I really only have a Saturday to run to Modesto, but nothing is open on Saturdays for me to take them in somewhere. That would be the best solution, but doesn’t work out for me.
Hey Mike , Isn’t there any tool and die shops near you ? That would be an easy grind on a surface grinder . Tommy
I’d have to look, nothing like that in my city though. I’m going to do some rigging up when I’m off. If it doesn’t go as planned I’ll start looking for a place to send them to.
The nice thing about the jury rigged grinder is that you can finish other parts that you want a slip fit on. Its sometimes hard to get one part to fit perfectly into another part.....especially when you only have one shot at getting it right. The grinder makes it easy. I'd just make the top part (rail) of the crane where it sticks out past the lathe a few feet. Then the trolley lets you move it out and sit it on a cart. Doesn't need to swivel the beam like a real jib crane. Just a straight 4" (or larger) piece of I beam. You can just attach it to a support crossing several trusses and it should easily hold the lathe chuck. Here is a similar one for lifting engine blocks into the derusting and cleaning tanks. An engine block is over 200 lbs so I doubt if your chucks are any heavier than that. or something a little more elaborate if your shop is narrow.
I remember having a surface grinder available at the shop I trained in at Murray St. U. in Ky. Most vocational shops would probably have one if they do custom work for training purposes. Al H.
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