Problem with chuck runout

[bertterbo]

If I have understood correctly all the correspondence so far, there appears to be
nothing essentially wrong with the drill press itself, but rather points towards
questionable chucks and/or arbor.

probably more accurate, yes

Indeed. You would have thought that a £100 odd chuck would be made to a reasonable standard, but the way the readings increase when taken from a bar held in the chuck certainly suggests that this is the problem. Hopefully the replacement will be an improvement. Otherwise I wonder if Axminster would be prepared to send someone out to look at it for him and see what they make of it.

That would be great if they did. I have heard they do that in some cases, but I suspect only if it's local and probably for more expensive stuff too

 

[Fergie 307]

I'd love to know if you guys with accurate machines
notice more error when turning the chuck by hand in reverse,
say at least checked with a large bit lowered into the table bore,
although the test I made demonstrates this better.

If you do notice an oddity, then anyone care to have a go at speculating or answering why?
Just saying as it might hint at something else at play aswell.

Hard to get an answer because the folks in this game, generally have much sturdier machines, or just use their lathes for this kinda thing.
In other words they aint got time for that, so nothings concrete yet from what I can make out
in regards to getting one of these generic machines a whole lot better.
Or they just haven't documented this for whatever reason.

I was working on some techniques regarding using my drills possible theoretic features,
and done some testing of the possible use of the table in regards to utilizing it as a face plate,
As is, there was too much slop and noticeable movement regarding cinching it up,
but if sorted, possibly with some buiscuit tin or whatever and some filing/lapping,
the same thing could be thought about using a lazy susan with a square table.
This may well be the seceret answer in regards to getting it all tuned up,
i.e those MT's using some fancy adhesive backed abrasive like the 3m stuff.
Edit: the face plate feature might not be of use here, but thinking along these lines is likely
a possibility in regards to what I'm sayin.
I needed some hold downs, so considered these could be used largely for this purpose in future, should it make sense.

View attachment 139615


Just a thought from a non professional optimistic bodger who's got time to think about it.
Hopefully someone might chance answering why my test results are as such.

Cheers

Tom

The usual problem is that there generally isn't any mechanism for holding the table in alignment as it goes up and down. Often it's just the fit of the slot in the collar around the rack, and this allows for some side to side movement so it has to be tweaked every time you move it up or down to keep it aligned. And the rack is often only held in place by being clamped between the base and a collar, so it can turn around the shaft itself! Just not what they were designed for in most cases.

 

[Ttrees]

The usual problem is that there generally isn't any mechanism for holding the table in alignment as it goes up and down. Often it's just the fit of the slot in the collar around the rack, and this allows for some side to side movement so it has to be tweaked every time you move it up or down to keep it aligned. And the rack is often only held in place by being clamped between the base and a collar, so it can turn around the shaft itself! Just not what they were designed for in most cases.

Aye they should at least try, wouldn't be that hard to develop some sort of detent system in the column for indexing features.
It's definitely something to want for, even if it does take some time to setup.
I could have gotten better results if I tried, just interesting to see if I could have gotten away with less, which I learned yesterday defeats the purpose, but still good enough for a washer,
so pleased about it, nice to be able to bumble about with non accurate parts and end up with acceptable results, I must make some parallels for this kinda frequent thing for me sometime.

Tom

 

[Fergie 307]

The only thing I've done on my old Sealey floor standing drill was to actually screw the rack to the column. Just got fed up with it working loose all the time.

 

[bertterbo]

Ok, so new chuck has arrived (replacement from Axminster) and when used with the existing arbor (the one that came with the second replacement), I get about 0.2mm runout (measured at the point where the jaws clamp onto the rod). When used with the arbor that came with the cheap scroll chuck, I get about 0.1mm runout.

However! I also purchased an MT2 to BJ16 arbor so I can test it on my lathe. And would you believe it, it runs beautifully true! .. absolutely zero visible runout at the end of a 150mm rod! so thats probably 250mm from the spindle... so I am now happy that the new chuck is accurate. So the error must be in either the arbor or the spindle.

I'll do more tests on the arbor, but testing the spindle is difficult. All I can really do is test the bit on the inside that the DTI can reach, about 20mm from the end. I can also test the outside, but it doesn't really mean anything as that has no bearing on the quality of the inside where the arbor actually contacts.

I'm hoping I can still do better than the 0.1mm ... we'll see.

 

[okeydokey]

Good morning all - I have read this thread through the various iterations and as a diy type person am amazed at the level of accuracy demanded by those involved. Wow 0.1mm or 1/10th of a mm - is this about 4 thou? - I find it hard to imagine that level of accuracy outside the scientific community - but then again I only make holes in wood every now and then.
As a separate comment so ok the drill/arbor/chuck is very accurate then you put a drill bit into the chuck and the accuracy disappears unless drill bits are made to that level of accuracy?

 

[deema]

I apologise if this has already been suggested, I’ve only skimmed the previous posts but didn’t see it advocated.

First you need to establish what is wrong, the spindle with the runout of 10 micron isn’t a problem. So, do the following
1. With the clock on the spindle pull and push the chuck to see if there is play in the bearings / seats.
2. Mark the spindle, chuck abd test rod at 90 degree increments, ie 4 marks. Now note the runout of the test piece at the 4 marked points turning the chuck. Now take out the test piece and reinsert turning it 180 degrees. Re-check the runout. Still the same? Then it’s not the test piece.
Now remove the chuck and rotate 180 degrees reattach and measure the run out at all 4 points. Still the same? Then It’s the spindle ground spigot.

 

[bertterbo]

Good morning all - I have read this thread through the various iterations and as a diy type person am amazed at the level of accuracy demanded by those involved. Wow 0.1mm or 1/10th of a mm - is this about 4 thou? - I find it hard to imagine that level of accuracy outside the scientific community - but then again I only make holes in wood every now and then.
As a separate comment so ok the drill/arbor/chuck is very accurate then you put a drill bit into the chuck and the accuracy disappears unless drill bits are made to that level of accuracy?

Then you haven't read it properly

The 0.1 - 0.2mm was measured at the jaws of the chuck. At the bottom of the rod (or drill bit) it was measuring 1mm of wobble, which is bad even for woodworking. And as was mentioned, the rod being used to measure was perfectly straight. I also tried several drill bits including high quality Fisch bits.

 

[okeydokey]

I feel a little bit corrected - but not much - for my purposes1mm wobble at the drill bit is fine!

 

[bertterbo]

I feel a little bit corrected - but not much - for my purposes1mm wobble at the drill bit is fine!

Ideally I want no wobble, but this was ridiculous. When the drill bit approached the work it would make the whole lot vibrate.

I've got it to a level I am happy with now .. I think.

Whilst I mostly do woodwork, I do drill metal every now and then, and with the amount of wobble I was originally getting it made it very difficult to get the bit the bite in so to speak.

Yes you can argue its not an engineering drill press, but to that I would say how come my £40 Wickes bench drill performed better?

 

[Sandyn]

I just saw a good idea on the Myford Facebook page for getting an accurate rod for checking alignment. Any old equipment with a linear stepper drive, or linear bearings will have precision ground rods in them. Old printers/scanners and the like. I just had a hunt in the loft and found an old hard drive with a linear shaft drive on the heads. A perfect little rod to check run out.

 

[bertterbo]

I just saw a good idea on the Myford Facebook page for getting an accurate rod for checking alignment. Any old equipment with a linear stepper drive, or linear bearings will have precision ground rods in them. Old printers/scanners and the like. I just had a hunt in the loft and found an old hard drive with a linear shaft drive on the heads. A perfect little rod to check run out.

I purchased a stainless steel rod off ebay for a few quid. It's perfectly true as I tested it on my lathe.

 

[Fergie 307]

Did you get the second replacement chuck yet? What difference if any did it make.

 

[bertterbo]

Did you get the second replacement chuck yet? What difference if any did it make.

Yep - see post #65

Ok, so new chuck has arrived (replacement from Axminster) and when used with the existing arbor (the one that came with the second replacement), I get about 0.2mm runout (measured at the point where the jaws clamp onto the rod). When used with the arbor that came with the cheap scroll chuck, I get about 0.1mm runout.

However! I also purchased an MT2 to BJ16 arbor so I can test it on my lathe. And would you believe it, it runs beautifully true! .. absolutely zero visible runout at the end of a 150mm rod! so thats probably 250mm from the spindle... so I am now happy that the new chuck is accurate. So the error must be in either the arbor or the spindle.

I'll do more tests on the arbor, but testing the spindle is difficult. All I can really do is test the bit on the inside that the DTI can reach, about 20mm from the end. I can also test the outside, but it doesn't really mean anything as that has no bearing on the quality of the inside where the arbor actually contacts.

I'm hoping I can still do better than the 0.1mm ... we'll see.

For now though, I am just using it as is. When I get bored, I might do some more testing.

I wonder if the amount of times I have removed and changed the bits is adding wear onto the spindle?

 

[deema]

The nose should be hardened and ground, the bearing journals shouldn’t be affected, so I don’t think you have anything to worry about.

 

[Fergie 307]

Yep - see post #65


For now though, I am just using it as is. When I get bored, I might do some more testing.

I wonder if the amount of times I have removed and changed the bits is adding wear onto the spindle?

pleased that you have seen a decent improvement, chasing that last 0.1 will probably be fun and games.

 

[hugov]

I have a similar model of Axminster drill, and had a similar problem. Without having read the whole thread, it sounds to me like the bore in the spindle is centered (co-axial with the bearings) but not bored straight (i.e. not drilled parallel along the length of the spindle).

My Axi-supplied chuck was about as bad as yours. I ended up buying a decent keyed chuck from Vertex (a good Taiwanese manufacturer) that claimed 0.08mm runout (about £35 from eBay). (That was after I bought and returned a Röhm made in Germany chuck that failed to meet its 0.15mm runout spec...). I much prefer keyed chucks in a drill press – I find it awkward to tighten keyless ones fully.

My spindle also did not appear to be bored straight, but after a few rounds of trial and error rotating the arbor, spindle and chuck relative to each other, I was able to get all the inaccuracies to more or less cancel out, and I now get better than the 0.08mm specified runout for the chuck.

To the people wondering if fractions of a mm of runout makes a difference: yes, it really does, even in wood, and especially in metal. The holes it drills now are so much better with sharp clean edges, and drill bits last longer and stay sharper.

 

[bertterbo]

I have a similar model of Axminster drill, and had a similar problem. Without having read the whole thread, it sounds to me like the bore in the spindle is centered (co-axial with the bearings) but not bored straight (i.e. not drilled parallel along the length of the spindle).

My Axi-supplied chuck was about as bad as yours. I ended up buying a decent keyed chuck from Vertex (a good Taiwanese manufacturer) that claimed 0.08mm runout (about £35 from eBay). (That was after I bought and returned a Röhm made in Germany chuck that failed to meet its 0.15mm runout spec...). I much prefer keyed chucks in a drill press – I find it awkward to tighten keyless ones fully.

My spindle also did not appear to be bored straight, but after a few rounds of trial and error rotating the arbor, spindle and chuck relative to each other, I was able to get all the inaccuracies to more or less cancel out, and I now get better than the 0.08mm specified runout for the chuck.

To the people wondering if fractions of a mm of runout makes a difference: yes, it really does, even in wood, and especially in metal. The holes it drills now are so much better with sharp clean edges, and drill bits last longer and stay sharper.

It's very frustrating isn't it

Can I ask where exactly you're measuring that 0.08mm? at the top of the drill bit?

 

[Fergie 307]

I have a similar model of Axminster drill, and had a similar problem. Without having read the whole thread, it sounds to me like the bore in the spindle is centered (co-axial with the bearings) but not bored straight (i.e. not drilled parallel along the length of the spindle).

My Axi-supplied chuck was about as bad as yours. I ended up buying a decent keyed chuck from Vertex (a good Taiwanese manufacturer) that claimed 0.08mm runout (about £35 from eBay). (That was after I bought and returned a Röhm made in Germany chuck that failed to meet its 0.15mm runout spec...). I much prefer keyed chucks in a drill press – I find it awkward to tighten keyless ones fully.

My spindle also did not appear to be bored straight, but after a few rounds of trial and error rotating the arbor, spindle and chuck relative to each other, I was able to get all the inaccuracies to more or less cancel out, and I now get better than the 0.08mm specified runout for the chuck.

To the people wondering if fractions of a mm of runout makes a difference: yes, it really does, even in wood, and especially in metal. The holes it drills now are so much better with sharp clean edges, and drill bits last longer and stay sharper.

This is not an uncommon issue, especially when you are chasing down those last fractions. Just a case of marking everything so if you ever need to remove it you can put it back in the sweet spot. <0.01 is good going for a hobby type machine.

 

[hugov]

Can I ask where exactly you're measuring that 0.08mm? at the top of the drill bit?

With a DTI running against a piece of silver steel rod (also called drill rod) in the chuck, towards the top of the rod nearer the chuck. I turn the chuck by pulling on the belt, as there is some wobble in the rack and pinion the spindle runs in when not loaded, and that will swamp the measurement if turning the chuck by hand. The DTI is mounted in a magnetic stand off the table.

This is not an uncommon issue, especially when you are chasing down those last fractions. Just a case of marking everything so if you ever need to remove it you can put it back in the sweet spot. <0.01 is good going for a hobby type machine.

Yep, marking it is definitely a good tip! Made that mistake before