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Beginner question: Runout with a new Chinese drill chuck

V

VicHobbyGuy

Ultra Member
I didn't expect much when I ordered it from Banggood, but the YouTube Banggood shill (Steve Jordan) said the quality was excellent.
https://www.banggood.com/Machifit-M...er-p-1927133.html?cur_warehouse=CN&ID=6317246

Price for the chuck and the 2MT arbor (and chuck key) delivered was about the same as a Jacobs chuck key from KBC. :)

Question: If there's less than .01mm runout at the arbor, what's acceptable runout at the base of a new 5/16 drill in the chuck?
(The chuck was cleaned of grease before using).

I'm seeing 0.35mm runout (.014" ?) using a dial test indicator and rotating/slipping the chuck in the lathe tailstock.

Beginner question: this isn't normal, is it?
 

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Addendum:
I had an old 'Victor' chuck on a MT2 arbor but the MT was pretty dinged up, so I figured I should replace it. "Get something new to go with the new 7x14 lathe..."
I did the same test with the DTI on it just now and got 0.05 mm runout.
"In with the old, out with the new".. :)
 
It can actually be a bent shaft not chuck, a love tap or two can bring it inline. Occasionally even on good equipment it is required either new or as a result of use.

What is important is is the drill bit running true. If it is who cares.
 
Degen said:
It can actually be a bent shaft not chuck, a love tap or two can bring it inline. Occasionally even on good equipment it is required either new or as a result of use.

What is important is is the drill bit running true. If it is who cares.
Click to expand...
Thanks. The chuck body has almost the same runout. I checked with 3 or 4 different new/unused drills (>1/4" sizes) and got the same result; I think it's unlkely that the drills are bent. The chuck is mounted via a MT2 arbor in the lathe tailstock. Indicator on the cross slide.
 
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My 16 CAD Chinese chuck that I got two weeks ago has indicated runout of +- 0.0015. This is much better then used Jacobs, which is more like +-0.004.

Do not use drills to check runout - use endmill and preferably carbide or US made quality stuff. Or use precision ground pin etc. Something you are sure has runout in the tenths. Not a drill bit - who knows what run out that thing has.

BTW, my chuck for 16 CAD looks almost exactly, identical to what you have. It has a B16 (if I remember correctly) arbor to MT3.

Yeah I am almost 99% sure its the same chuck. I have 2 of them, gave 1 to my dad. I only checked 1.
 
Tom Kitta said:
My 16 CAD Chinese chuck that I got two weeks ago has indicated runout of +- 0.0015. T........

BTW, my chuck for 16 CAD looks almost exactly, identical to what you have. It has a B16 (if I remember correctly) arbor to MT3.

Yeah I am almost 99% sure its the same chuck. I have 2 of them, gave 1 to my dad. I only checked 1.
Click to expand...
Thanks, Tom. Do you have a link for where you bought it, please? I paid quite a bit more than $16CAD!
:)
Thanks for the advice about using an end mill or precision ground pin...not something I have here, but I do have some solid carbide router bits. I'll double-check.

EDIT: 5 minutes later....Solid carbide 1/2" shank router bit shows runout of 0.36mm, a.k.a. .014"
 
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Degen said:
It can actually be a bent shaft not chuck, a love tap or two can bring it inline. Occasionally even on good equipment it is required either new or as a result of use.
Click to expand...
'love taps' ?....I don't follow, sorry. You are saying that machinists tap the chuck or the drill bit (with a hammer?) before drilling? Persumably checking the runout with....? Can't see how this would work with a 2mm drill.
As a beginner, I'm extremely slow working on the lathe (bad work sequence plans, etc.) but I really expect to put the chuck in the tailstock, put in a drill of some sort and drill without additional checks.
 
VicHobbyGuy said:
'love taps' ?....I don't follow, sorry. You are saying that machinists tap the chuck or the drill bit (with a hammer?) before drilling? Persumably checking the runout with....? Can't see how this would work with a 2mm drill.
As a beginner, I'm extremely slow working on the lathe (bad work sequence plans, etc.) but I really expect to put the chuck in the tailstock, put in a drill of some sort and drill without additional checks.
Click to expand...
Yes in essence, with some common sense."

First I would check your drill bit by rolling on a flat surface gives you an idea if it straight or not (remember you issue could be the bit) if it is, check runout on chuck and tap chuck to correct, usually one correct does all bits as it corrects the chuck mount. Re-adjustment should only be required if you do something silly. Remember the more you do this the great the chance your shank will fail.

If this fix does work the chuck is junk.
 
Thanks for thse suggetions. I appreciate you taking the time to answer.
I can easily imagine what would have happened to me in Gr 10 shop class in 1960 if I had gotten near a chuck with a hammer. :)
I guess you are talking about a situation where the chuck body is loose enough on the arbor that it could be moved, or the taper in the quill or tailstock is loose. I haven't seen that.
I've convinced myself that in this case it's a faulty chuck since the arbor where it enters the chuck body has about 0.01 mm runout, the chuck body and a good carbide tool in the chuck both show >0.35mm runout. And the chuck and the arbor were both spotlessly clean (not even fingerprints) when they were mated with a twist, set with one solid-but-not-violent strike with aluminum padding (chuck jaws fully retracted). That chuck is not moving on the arbor.
 
Sometimes the arbor can be the issue. The taper that engages the spindle/socket, the taper that engages the chuck, or both. Ideally if you can insert it into something that rotates like a spindle & measure runout on the chuck end taper (independent of the chuck). You still have (ideally slight) bearing runout to contend with but it might highlight arbor issues. If the arbor has +/- 0.001" runout, then even a zero runout chuck will run out too witnessed on the dowel pin since its going along for the ride. If you don't have a matching spindle you might be able to mock it up with Vee blocks but you have to have some way of standardizing the lateral position. Where this can get interesting is when both chuck & arbor have runout & can act to cancel or exaggerate one another depending on how its assembled. Or the runout can be OK but the seat taper angle is out a bit & the chuck/arbor can seat a bit cocked depending on how you assemble. If it varies with each re-assembly this is a clue.

In terms of lateral tapping, personally I'd be careful there especially on a lightweight machine. Not healthy for bearings in case of spindle or bellmouthing/distorting the quill socket or knocking tailstock out of alignment... etc. Not worth beating your machine up over parts than aren't very true.

Personally I think this is why people have mixed chuck results. Some are good & some are not even same brand/model. Its bag of parts with looser tolerances. QC variation especially the jaws & scroll. If the celestial bodies align you have a winner. Or, the opposite. Then Tom's dad gets it, LOL

Its good to have a reliable pin in the shop for this & similar applications. Something you know is true within tenths. Some of the bearing suppliers sell singles of what are roller bearing pins quite inexpensive. Then you don't have t second guess if the pin is eccentric or the holding device is out. Just to make life miserable, chuck can also vary by the diameter of what its gripping.
 
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VicHobbyGuy said:
Thanks for thse suggetions. I appreciate you taking the time to answer.
I can easily imagine what would have happened to me in Gr 10 shop class in 1960 if I had gotten near a chuck with a hammer. :)
I guess you are talking about a situation where the chuck body is loose enough on the arbor that it could be moved, or the taper in the quill or tailstock is loose. I haven't seen that.
I've convinced myself that in this case it's a faulty chuck since the arbor where it enters the chuck body has about 0.01 mm runout, the chuck body and a good carbide tool in the chuck both show >0.35mm runout. And the chuck and the arbor were both spotlessly clean (not even fingerprints) when they were mated with a twist, set with one solid-but-not-violent strike with aluminum padding (chuck jaws fully retracted). That chuck is not moving on the arbor.
Click to expand...
Its not about being loose but bending (tweaking) the arbour back to true.
 
I posted this in the 'economical tools' thread where there was some discussion about the quality of Chinese tools and (the level of) buyer protection when dealing with Aliexpress and banggood.
I don't make a habit of double-posting, but here goes:
Banggood chuck update....I contacted banggood, explained the excessive runout problem with the chuck, and uploaded pictures of the runout indicated on the DTI. It's impossible to upload a video to banggood, so I couldn't send the 30 second video I'd recorded. Then, no response for 4 days till this morning when I get an email that they will close the 'Ticket' since they haven't heard from me in3 days! So I go to banggood and they want: photos of the original parcel wrapper (which is gone) and a Youtube video! So, an hour plus of faffing around and I have the video uploaded to YouTube and sent banggood the link.

This matches with what I've read online about banggood - lots of promises but when it comes to a real problem they set enough obstacles in the way so that the buyer just gives up. I didn't believe the 'Buyer Protection' BS anyway... :)

@Degen I may give the hammer treatment a try. :)
 
Looking at your video it looks like your shaft (arbour) is a touch bent, this is more common than you think (and even happens easy enough during regular use). Tap on the side that is high and bring it in slowly.

The more you have to do this the weaker and easier it goes out of line.

Good luck.
 
Degen said:
Looking at your video it looks like your shaft (arbour) is a touch bent
Click to expand...
Thanks.
Perhaps we are using different terms for what's visible in the video, but I can't see the arbor there. I think of the arbor as that piece of metal with a Morse taper and a Jacobs or similar taper to match the chuck on the thick end. I put the DTI on the arbor where it enters the chuck and there's practically zero runout.
If you are talking about the drill shank in the chuck- wher the DTI is touching, it was suggested that it could be bent. I re-tested with some solid carbide USA made 1/2" router bits and got the same runout.. >0.35 mm.
It IS possible that I mounted the chuck 'crooked' on the arbor though it certainly seemed to seat very cleanly. So it's operator error on my part or poor QC at the Chinese factory as the two main possibilities, I think.
 
My banggood er40 r8 chuck fell off my mill table and landed on my rubber mat. It bent so bad it won't go in the spindle. LOL just junk. It is dead soft so i guess i'll turn it down to 3/4" shank or something and buy a better unit with r8 for the mill.
 
Just for interest, how does runout on the body compare to the shank in terms of deflection & clock position?
Have you separated the arbor from the chuck & measured runout of it independently yet?
 

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PeterT said:
Just for interest, how does runout on the body compare to the shank in terms of deflection & clock position?
Have you separated the arbor from the chuck & measured runout of it independently yet?
Click to expand...
Peter- Thanks for your interest in this saga! :)

I mentioned this in post #11 earlier in the thread:
I've convinced myself that in this case it's a faulty chuck since the arbor where it enters the chuck body has about 0.01 mm runout, the chuck body and a good carbide tool in the chuck both show >0.35mm runout.

I have no idea how to separate the chuck from the arbor at this point. My reading on the internet (!) seemed to indicate that drilling through the bottom of the chuck and driving the arbor off was the only way to separate them if they were properly mated together.
 
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