Drill Chuck not running true

[ianmac]

I have a RF30 vertical drill/mill

The milling arbor and collets run true but the drill chuck runs out. By how much i don't know but its about .25 of a mm

Is this normal and if now how would you go about fixing it? below is some of the troubleshooting i have already done

****When i first got this mill the shop attendant told me that you can runt he drill chuck with milling cutters. I was using this for milling so i suspect that some swarf could be in the chuck****

1) check that drill arbor runs true (it does)
2) clean out as best i can the drill chuck

I was thinking that if some junk is in the chuck that it may be repositioning the jaws an so one my be more advanced than the rest which is causing it to be slightly off true!

Any ideas on this one.

[jgb7573]

One dodge you could try when putting a drill into the chuck us to rotate the drill bit in your fingers while gradually tightening the chuck. That way, if you have got some swarf in there, it will tend to go between the jaws, rather than between the jaw and the drill bit.

[havoc]

I would not run a drill chuck with mill cutters, but you can very well hold your drill in collets. I'm slowly converting to working that way.

[circlip]

Oh dear Ianmac, the secret is in the description. DRILL chucks are for - DRILLS, MILLING chucks are for MILLING cutters. Pity I wasn't in the shop where you got this advise. I would have personally given the guy a good A4*se kicking. Never mind all the Bulls4it about "If you're careful". We got some Kiddywinks and newbies on this site and I make no excuse going into a flamer over things like this, but what do I know? That Pr4t obviously hasn't seen grinding wheels explode or milling cutters walk out of chucks.
When you referred to "Junk"did you mean the chuck? Not all Chinese junk froat on water, some of it resides on peoples workbenches and holds cutting tools as well. Is the arbor a REPUTABLE manufacture or a ying tong special? and no doubt the chuck is either a Jacobs or Rohm???
Regards with a scorching keyboard, Ian

[ravensworth2674]

Ian is quite right but you really do have to learn your subject rather than trust to us who don't know other than your perhaps untechnical description or worse, the wa**er who flogged you the drill chuck.
Had you received the mill in the olden days, it would have come without any or extremely skimpy information. You would have been expected to put the machine up to run and gone out to the shop or made the parts yourself on the mill or the lathe. There was no internet or anyone to run to, you were stuck and if progress happened or mistakes occured, these were from your own grubby little paws.It was called the learning curve.
What you would have gleaned and you would have had to shell out a goodly portion of your wage, that drill chucks like everything else are made to a tolerance and that is not plus or minus the square root of bugger all. The better- and more costly the part, the better the tolerances and quality. You cannot get something called a free meal in this life.
If you have confounded me after all these78 years, please let me know!

I might have tacit agreement but it will be agreement!

Norman

[havoc]

he better- and more costly the part, the better the tolerances and quality.

That might have been true years ago before globalisation. But these days it isn't. That makes it only harder if you do not have years of experience.

[ravensworth2674]

My knowledge of Belgium law is sketchy but in England we still have the Sale of Goods Act(1893)

Mais Oui?

Norm

[ianmac]

Hi jgb7573,

I can see any swarf but i suspect that it is deep inside the chuck on the teeth mabey. I know what you mean but its not on the jaws.

Hi Havoc,

I now know better than use a drill chuck for milling. I have no engineering back ground apart from school.....and the things that we did unsupervised was lets just say interesting.

The collets i have are 5-6 7-8 9-10 11-12 but i want to use my size 30-50 drills. Unless i get some very small collets, but enven so itstime consuming to replace the collet each time.

Hi circlip ,

The arbor and collet set runs true and is fine. It was a Hafco collet set cost me 300 from memory. Thats probably entry level but the misses controls the purse strings so i do as im told..

As a newbie you have to ask the clerk what do i do! I was even more anoyed later because if you buy everyting at once you get a discount.........needless to say i didnt get by disocunt!

Hi ravensworth2674,

Agreed, I have come along way though. I didnt know what an arbor was 6 months ago. Nor could i name the parts on the loco i was building (i knew what it did b ut not what it was called).


So is it possible to pull apart a drill chuck while still being able to put it back together?

Ian

[mmaidnz]

Hi,Ian.I wouldn't use a drill chuck for milling,especially since you have a collet set.Use that instead.
Here is a link which maybe of use to you:http://www.jacobschuck.com/drill-chuck-repair.asp
I have to confess I haven't been game to pull my chuck apart.I'm more inclined to think runout in the actual machine is the problem.It certainly is in my drill press.I'll fix it when I get a round tuit,but where do you find one?.

[ianmac]

Just for the record i dont use a drill chuck for milling.

I rectified this very quickly. I use a collet set and it works fine.

The problem is that the drill chuck is not running true and i beleive that there may be some swarf caught in the drill chuck from the few times that it was used to mill.

I also wonder if this did damage to the drill chuck as it is not intended to have sideway forces applied to the device.

The only reason that i used the drill chuck to mill is because i was told thats what you do!

It was how you say Bull Sh*te

I will check out those links Ta

Ian

[havoc]

My knowledge of Belgium law is sketchy but in England we still have the Sale of Goods Act(1893)

This has (sadly) nothing to do with it. In days long gone, there was a correlation between price and quality. But these days, there is more likely a single chinese outfit that makes stuff for everyone, just put another name on it. Lots of "manufactures" just sell the same item, sometimes down to the same typenumber but with a different price according to their name and brand strenght aquired long ago. If your lucky, the colour might be different.

[jgb7573]

Hi Ian,

There have been articles in Model Engineers Workshop on cleaning and truing drill chucks. The Index shows
Jan 1995, issue 27 - Truing Drill Chucks
Jul, 1999. issue 59 - Cleaning Jacobs Drill chucks

In Model Engineer,
Volume 188, Issue 4169. "Dismantling Drill Chucks". 17th May, 2002

I may be able to track the ME article down (my mags are currently boxed after a house move) but I won't get a chance to do so until the weekend. Let me know if you'd like me to and I'll have a furtle.

John

[ravensworth2674]

Havoc,
I have to disagree! Under the Sale of Goods Act, an article has to be of 'merchantable quality' and 'fit for purpose'. If there is mis-representation from the seller- not the obscure Chinese gentleman, then the goods can be returned etc etc. If a drill chuck is sold in lieu of a collet chuck then it is pretty certain that mis-representation has taken place. If however, the drill chuck was purchased because a collet chuck and its appropriate holders was too expensive then it is quite another matter.

I kept somewhat quiet about the RF30 mill/drill because I have one. Mine came with a vise of sorts, a milling cutter of sorts but a 1/2" drill as freebies. They were all from Warco and I simply accepted them as they were offered. They were there to be a starter kit and most welcome but I went back for a decent collet set, a 4" Vertex vice and a Vertex dividing head and tailstocjk to adapt to my Myfords and so on. This is not top quality stuff but is perfectly acceptable for the quality of mill drill- and my own abilities!

It brings me, yet again, to standards of accuracy and I was looking at GH Thomas's remarks on drill chucks both in his MEWM and Workshop Techniques. His kit was excellent and his exhibition standards were outstanding but his drill chucks were far more expensive than mine were still far from 'plus or minus nowt' on dimensions.

I could continue with Chaddock and so on, but the points are , or should be patently obvious from what is written.

If you are wanting an outfit which will give toolroom or better standards, you will have to get your hand deeper in your pocket

[Tel]

This might be of more practical help to you Ian.
www.beautifuliron.com/jacobs.htm

Scroll down the page and you'll come to a section on dismantling them

[Tel]

And if you're thinking replacement, you could do worse than look here - pretty good to deal with and super fast with their postal service.

www.mcjing.com.au/engineering/toolframe.htm

[ravensworth2674]

Tel,
Really OT but 'What is Tumbarumba like?
Sorry, fellas but I never met my uncle out there.

[Tel]

I don't think I've ever been to Tumbarumba and if I've been through it I must have blinked at the time. ;D

[ianmac]

"there is more likely a single chinese outfit that makes stuff for everyone, just put another name on it. Lots of "manufactures" just sell the same item, sometimes down to the same typenumber but with a different price according to their name and brand strenght aquired long ago. If your lucky, the colour might be different. "

This is very true, when is was looking for a mill they were all the same deisgn but with dirrent brands"

Thanks Tell for the link to mcjings!

Thanks everyone for your input

[engineeringtech]

I have found that a lot of cheap drill chucks have softer than optimum jaws. If you have let a tool spin in the chuck, you will often have a bit of a burr on the jaws, instead of the tool shank.

Generally, you cannot buy replacement jaws for cheap drill chucks. However, if you can get the chuck apart without too much trouble, you can VERY LIGHTLY stone the jaws of the chuck with an India stone. If you're just knocking the burr off, it won't affect your accuracy. But if you're worried, stone each jaw the same number of strokes and with the same pressure. I am told you can also put a round India stone of small diameter in the chuck and after very lightly closing the chuck, turn the stone. But I have never had much luck with this.

You should be very careful not to distort the body of the chuck when you disassemble it. Most manufacturers like Albrecht, post procedures for disassembly of keyless chucks and Jacobs has disassembly instructions for keyed chucks. The European chucks I have owned disassembled quite similarly.

Make sure the arbor has not spun in the chuck and if it has, you will have to clean out the taper and perhaps stone the end of the arbor..

I understand the best runout spec you will find on a keyed drill chuck is about .003" or .075mm. Keyless chucks about .0016"

A lot of manufacturers of hobby machines will say you can use a drill chuck for milling cutters, but they are not designed for side loading -only axial loading. It is probably ok for light cuts in aluminum or plastic, but it is not recommended by the chuck manufacturers.

[ianmac]

I spent some time looking at the chuck over the weekend.

What you say is quite true and that was my conclusion.

I can see that one of the jaws has rubbed possibly due to tool slip. I am going to have a crack at repairing but i feel that it is probably best to get a new one.

I will not be making the same mistake again

Ian