# Advice On Removing Bent Arbor From Spindle



## GavinT (Jun 30, 2016)

I need some advice, please, on a recent hand-me-down. It's a DAYTONA DF-12 (not Dayton), 12 speed, that I think is a Rexon, it's made in Taiwan. The badge on the DP says JT.3 for the spindle.

I thought I could use #3 Jacobs wedges, but as you can see in this picture, the tapers can't get above the shoulder on the arbor and when tapping the wedge in, it rides down over the shoulder. Similar for when I use both wedges below the shoulder to try and remove the chuck, the top wedge rides up over the shoulder on the arbor.







The arbor is definitely bent! Using a dial indicator, I get runout of 0.008 at the arbor below the shoulder, 0.01 at the top of the chuck sleeve, 0.25 at the bottom of the chuck sleeve, 0.05 at the body near the keyhole, and 0.65 on a bit in the chuck.

There is 0.005 front to back movement when measuring the end of the extended quill, which might be expected, though I do plan on replacing the bearings, if I get that far.

Here's few more pics that hopefully help...





















Finally, what is this notch (A) used for on the end of the quill in this picture, below?






Any advice (other than put it on the curb) is greatly appreciated! It has sentimental value and getting it running true again is what I'm after.  If it turns out I need a new chuck, too, then it might not be worth fixing 

Sincerely
Gavin


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## RJSakowski (Jun 30, 2016)

Are you sure that the JT3 arbor separates from the spindle.  Your nameplate states JT3 spindle.  If you had an adapter, the spindle should be designated MT2, e.g.  

On my similar drill press, the JT3 taper is integral with the spindle.  You would want to pull the chuck, in which case, the Jacobs wedges should do it.  

It looks like the notch is just the end of the keyway cut on the quill.


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## Bob Korves (Jun 30, 2016)

The spindle ends with a JT3 taper, which is a Jacobs chuck taper.  There is no Morse taper in the spindle on that drill press for an adapter.   You will need to use spacers between the chuck and the quill to remove the chuck, hopefully without ruining a bearing doing it.  Perhaps the spindle will come out with the chuck still on it, if so, you can work on the chuck and spindle off the machine.  Depending on the length of the taper that does not now enter the chuck, there might possibly be enough metal left to true up the existing taper.  Failing that, find another spindle or try to straighten the bend.  Both of those are tall orders, and straightening the spindle could cause immediate or later danger.  First get the spindle out if possible, get the chuck off, and see what you really have going on there.  The notch in the spindle is an artifact of producing the keyway in the spindle.  The circular cutting cutter needed to go that far to finish the keyway.

Edit:  The existing taper may be able to be ground to a smaller Jacobs taper.  You will need a different chuck then.  I suppose the spindle could be ground and a tapered bushing made to bring it back to the correct size and taper, but that may be too fussy to even try.  I know I wouldn't...


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## Bob Korves (Jun 30, 2016)

That looks like a decent machine, Taiwan made, looks to be in decent condition other than the spindle.  It is definitely worth doing some repairs on it and getting it back in good shape again.  It is also an interesting challenge.


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## GavinT (Jun 30, 2016)

Hi Bob & RJ, thanks for the response. I'll go ahead and remove the quill, spindle, etc, along with the chuck and see what's up. I have a buddy with a shop who I can ask for help truing up the spindle. I read that a good whack on a rod in the chuck can bend it back, probably something easier to do with the assembly out of the head. I'll post progress, though that may be few and far between.

There is one part that has been replaced with a botch job... the quill set screw doesn't have a round dog point to fit in the channel on the quill, it's a grub screw that has 2 sides filed down, which of course won't turn in the channel once it touches the quill. Easy to replace (or round off the end of the grub to rotate in the quill channel.) Yes, an interesting challenge!!

Anyone know where I can find a replacement spindle?


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## RJSakowski (Jun 30, 2016)

Pounding a spindle back into alignment is a trial and error process.  

Years ago, I had made a jig to straighten bent lawnmower crankshafts.  The trick is to undo the bend that you now have.  This means supporting the shaft at the proper point; otherwise you will end up with an S curve.  My jig used a split block to replace the lower bearing and an adjustable block for the upper bearing. They were mounted on a 9' piece of I beam.  A tube was made to fit the lower portion of the crankshaft and a long lever used to apply the bending torque.  A slight bend was made and a dial indicator was used to monitor progress.  I was able to straighten the crankshaft to .001 -.002" TIR which gave me a serviceable crankshaft.

You should remove the spindle and use a solid bushing, well supported, to try the unbend.  I would recommend using a long lever rather than beating it to death (or life).  Do not use the bearings for support while attempting this.

Personally, I would favor having the taper reground, as Bob has suggested.  In all probability, you are dealing with hardened steel and trying to unbend the shaft will add more stress to the already stressed shaft which could cause a fracture.


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## GavinT (Jun 30, 2016)

Thanks for the recommendation to turn the taper down, #2, right? I don't have the experience to know how much force would be needed to bend it back. I know my limits and that's way out there! Or build a jig to apply the necessary pressure in a specific location. Times like this I miss having my granddad around, he had a great machine shop.

I'll keep y'all posted.


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## Spike440 (Jun 30, 2016)

I have a similar machine and it lists a bit more info than your plate does. Hope this helps.
-Spike


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## RJSakowski (Jun 30, 2016)

You may be able to keep the JT3.  The effect of regrinding the taper will be to move it upwards and it looks like you have enough clearance to move the taper up slightly.  At any rate, I would start there.  If you run into a problem, you can cut it to a smaller taper.  If you do cut a smaller taper, consider a JT6.  It is the next size smaller than the JT3 and drill chucks are available with that taper.  It is unlikely that you will find a 1/2" or 5/8" chuck with a JT2 socket.


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## JimDawson (Jun 30, 2016)

IMHO you guys are really overthinking this one.  This is type of job is why dead blow hammers were invented.  Smack the chuck body on the high side with a dead blow.  Check with dial indicator on a drill shank or dowel pin in the chuck.  Repeat as necessary.  I do this on my mill when needed, and have done it on drill presses.  It won't hurt the bearings.


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## John Hasler (Jun 30, 2016)

JimDawson said:


> IMHO you guys are really overthinking this one.  This is type of job is why dead blow hammers were invented.  Smack the chuck body on the high side with a dead blow.  Check with dial indicator on a drill shank or dowel pin in the chuck.  Repeat as necessary.  I do this on my mill when needed, and have done it on drill presses.  It won't hurt the bearings.


Interesting.  I did this to my floor drill press when I first got it and discovered that the chuck wobbled a bit, but I assumed that it was a farmer fix.  It did work, though.


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## jpfabricator (Jul 1, 2016)

Lower your quill all the way down to see if there is a drift hole. If so you may have an adapter.

Lay the dp on its back, swing the table out of the way, Chuck a 3/8" bolt loosly in the chuck with the end bottomed out against the Jacobs taper. Use the chuck to pull the quill out with one hand, and drive the bolt back into the chuck with a hammer in the other hand. The quill will retract rapidly when it comes loose, so don't extend it all the way out.

Sent from somwhere in east Texas by Jake!


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## GavinT (Jul 1, 2016)

JimDawson said:


> This is type of job is why dead blow hammers were invented.  Smack the chuck body on the high side with a dead blow.  Check with dial indicator on a drill shank or dowel pin in the chuck.  Repeat as necessary.  I do this on my mill when needed, and have done it on drill presses.  It won't hurt the bearings.



JD, I'll give this a try, any recommendation on the weight of the dead blow hammer? I think I'll do what Jake suggested and lay the DP down. Easy to swing going down than sideways. Should I chuck a rod and strike the rod, rather than strike the chuck?

There is no drift slot in the quill, so Bob might be right that the spindle is tapered.

Jake, I'm not following you on your suggestion, why whould the 3/8 bolt be loose is the chuck? How would hitting the bottom end of the taper (via the chuck) with a loose bolt exert the right force to bend the spindle back? Don't I need a perpendicular blow and not a latteral blow?

Thanks for all the advice guys!


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## Randall Marx (Jul 1, 2016)

Gavin
JP's advice was a way to remove the chuck from the spindle. His advice assumes that there is a hole through the chuck so that you can access the end of the Jacobs Taper with said 3/8" bolt.


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## GavinT (Jul 1, 2016)

Randall Marx said:


> Gavin
> JP's advice was a way to remove the chuck from the spindle. His advice assumes that there is a hole through the chuck so that you can access the end of the Jacobs Taper with said 3/8" bolt.



Ah, I get it. I'll have to check if there's a hole through the chuck to get to the spindle. So the blow on the bolt, assuming it's touching the spindle, will drive the spindle and quill back in while holding on to the chuck. What's the best way to hold the chuck when striking the bolt/spindle? Don't I need to prevent it from returning with the rapidly retracting spindle?


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## chips&more (Jul 1, 2016)

You will need two wedges (or maybe more to stack to get the height). Modify yours, make new ones or buy some. I would NOT assume any findings until you get the chuck off. Those import chucks are not the best. I would get a good Jacobs chuck and check the spindle bearings. Then do a little testing.


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## JimDawson (Jul 1, 2016)

GavinT said:


> JD, I'll give this a try, any recommendation on the weight of the dead blow hammer?



I normally use a 3 or 4 pound.  Just bought a new 4 pounder yesterday.



GavinT said:


> Don't I need to prevent it from returning with the rapidly retracting spindle?



Just the inertia of the chuck is enough to get the spindle and chuck apart.  Another way is to use a small hammer (6 or 8 oz) and a flat punch (cold chisel with the the sharp edge rounded over).  Hit the spindle just above the chuck, the vibration will cause the taper fit to pop loose.  This is how you get chucks off of straight arbors.


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## GavinT (Jul 1, 2016)

JimDawson said:


> I normally use a 3 or 4 pound.  Just bought a new 4 pounder yesterday.
> 
> Just the inertia of the chuck is enough to get the spindle and chuck apart.  Another way is to use a small hammer (6 or 8 oz) and a flat punch (cold chisel with the the sharp edge rounded over).  Hit the spindle just above the chuck, the vibration will cause the taper fit to pop loose.  This is how you get chucks off of straight arbors.



Hi JD, so I'm assuming you recommend removing the chuck first and working directly on the spindle with the dead drop? If the chuck is junk, I can't measure off that anyway.

To remove the chuck, I'm going to try tapping the spindle in the high side of the runout with a cold chisel. See if that budges it.

I'll try wedges next, and I'll need to pack between the wedges as I don't want to buy more. Anything I need to be careful of with the base of the quill? Is that the bearing housing?

If that doesn't budge the chuck, I'll drill the back of the chuck, tap and try that.

If the dead blow is successful, I'll put the chuck back on and measure again. If it's off, I guess a new chuck. 

I've learned more from this advice, y'all, than googling! It'll be a few days before I can tackle this, so any last minute "gotchas" are appreciated. I'll take pics and let you know how it's going. 

Happy 4th! Have fun and be safe.


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## RJSakowski (Jul 1, 2016)

All of my keyed chucks have the end of the taper exposed but the keyless chucks do not.


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## jpfabricator (Jul 1, 2016)

Remove the chuck and check the JT for run out. 

Sent from somwhere in east Texas by Jake!


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## JimDawson (Jul 1, 2016)

GavinT said:


> Hi JD, so I'm assuming you recommend removing the chuck first and working directly on the spindle with the dead drop? If the chuck is junk, I can't measure off that anyway.



I have never done it with the chuck removed.  The spindle is so short that you wouldn't be able to do much with a dead blow.  You need the leverage of the length of the chuck body to be able to move things around.

If the chuck is junk then the only way to solve the problem is to remove the chuck and check the spindle taper.
.
.


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## brino (Jul 1, 2016)

Hi Gavin,

Welcome to the forum!

I just wanted to jump in and make sure you caught the drift of this:


jpfabricator said:


> Lower your quill all the way down to see if there is a drift hole. If so you may have an adapter.



See the first method at this link:
http://www.ereplacementparts.com/article/3425/How_to_Remove_and_Reinstall_a_Drill_Press_Chuck.html
if you lower the quill and see an oblong window, then a flat wedge can be used to remove the chuck and arbor.

That is, if you have a female taper in the spindle and a male-to-male tapered arbor for the chuck.

-brino


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## 4GSR (Jul 3, 2016)

Back about 1980, dad bought two of these Taiwan drill presses off of a traveling tool truck that you used to see advertizing coming to town next week.  Come one, come all and buy me out!  Anyways,both drill presses were supposed to be alike until you started checking them very closely. Both had No. 2 MT in the spindle. Both had drill chuck with a fitted shank that was supposed to fit the taper.  One was out about .008" the other was a little better.  But get this, one had a slot for the drift key and other did not have one.  The one spindle quill missed getting put on the mill and the slot put in.  I don't remember what happen to the drill presses. They were sold off later in life.

As for removing a keyless chuck.  There was one on a old drill press I wanted real bad that was fixing to get scrapped.  There was enough room to get a adjustable wrench shoved in between the spindle quill and the keyless chuck.  Tried to pop it off wouldn't budge by hand pressure.  A 5 lb engineers hammer popped it off and flying thru the air.
I would shove the thickest open end wrench I could get in there and do the same. Give it a hard pop with a hammer and see if that would break it loose. 
BTW, the spindle is probably running true, it's the chuck that is showing runout?  Using my method may/could bend the spindle.


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## Rootpass (Jul 4, 2016)

If you remove the spindle, Kieth Fenner had a video 2 years ago where he checks a spindle a viewer sent in and goes through the steps he uses to straighten one. I don't remember him using any real special equipment or anything. Might be fun to watch.


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## GavinT (Jul 6, 2016)

I'm going to try and remove the chuck with a gear/bearing puller rather than hitting the chuck or the spindle from inside the chuck. I got a Yuasa chuck from ebay, cheap. Hope it's runs true.

If the Yuasa chuck is good and I'm still getting runout, I'll remove the quill and spindle. I'll be able to see if there's an arbor with a morse taper in the spindle, perhaps even with no slot for a drift key!

As the bearings are good with no spindle travel in the quill, I'll decide if I should replace the bearings once it's out of the head.

As I still think the spindle (or maybe arbor) is bent, as I get runout on the shaft at the top of the chuck, I'll try the dead blow hammer. If that doesn't work I have a buddy who can re-taper the Jacobs. 

My fingers are now crossed that it does have an arbor (sans drift slot), in which case I'll get a new arbor.

Thanks again for the advice, y'all.


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## GavinT (Jul 9, 2016)

Update. It's off! I used a 3 jaw gear puller on a deep socket through the chuck,  just enough gap above the chuck to grab on to it. Bob was right, 


Bob Korves said:


> The spindle ends with a JT3 taper, which is a Jacobs chuck taper. There is no Morse taper in the spindle on that drill press for an adapter.








As for the bend, it's 0.007 at the end of the spindle, and it hadn't moving in the slightest with a few good thumps from the dead blow. Bob, said


Bob Korves said:


> Depending on the length of the taper that does not now enter the chuck, there might possibly be enough metal left to true up the existing taper.


 and there's 0.3" to that Yuasa chuck I got on ebay.

I have a friend with a lathe to re-taper, any idea on how much shorter the spindle will be, based on the .007 runout? (i only do "simple" math). He's suggesting threading it and making a JT3 adapter. He's certainly got the skills and a machine to thread. (He's building CNC in his garage), though I'm wondering if that's really a good idea to add complexity.

That chuck has crud and filings all along the jaws, so could do with a clean. Any advice?

Thanks!
G


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## Bob Korves (Jul 9, 2016)

It is a precision job with a limited amount of material to play with.  The spindle will probably be hardened, a little or a lot.  If it is hard you will have to grind it.  You really should grind it regardless, or you will not get full contact area.  Trying to get the runout fixed without running out of length of the taper will probably only give you one shot to get it right.  The bare spindle should be mounted between centers and the correct taper applied to the part or tooling slide, carefully confirm that the taper setup is correct and the bearing seats are running true, and then gently grind the taper using a properly dressed wheel.  A lathe and tool post grinder can do the job, assuming the skills to do it right.

Edit:  Before you do any of that, confirm that the runout is in the spindle, and where it is located.  Make sure the spindle is not bent between the bearings.


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## 4GSR (Jul 9, 2016)

You have it torn down this far, take the spindle apart and confirm what Bob said to do and replace the bearings with good quality bearings.  I bet those bearings have some issues, too.


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## GavinT (Jul 9, 2016)

Thanks for the advice, Bob & 4gsr. I'll definitely check between the bearings, seeing as they act as a possible fulcrum when it bent, and also replace them. Round or roller prefered?

Any advice on cleaning the debris in the chuck?


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## Bob Korves (Jul 9, 2016)

Put back the same part number bearings (or equivalent) that you take off.  Don't buy the cheapest ones, get decent ones.  They will have numbers on them.  Most of those machines use standard, commonly available bearings.  I can help if you give me the numbers on them.

As for the chuck, I have no experience with that brand, so I do not know how to disassemble it.  If you are just trying to get the swarf out of it, blow it out with an air nozzle, use a little solvent to loosen the crud up if necessary, lighly oil the moving parts you can reach, and let it go like that until you can test it.  With many chucks, BUT NOT ALL, you press the shell off the jaw end of the chuck.  I would try to avoid that unless you find someone who has experience with that model and has instructions on how to work on it.  You can easily ruin the chuck if you do the wrong things.


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## GavinT (Jul 11, 2016)

Bob Korves said:


> I can help if you give me the numbers on them.



Hi Bob, the bearings are marked 6201z, any advice on what brand and where to purchase? I assume they're the same top and bottom? The number came from the top bearing, as I can't read the number on the bearing near the quill.


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## Bob Korves (Jul 11, 2016)

GavinT said:


> Hi Bob, the bearings are marked 6201z, any advice on what brand and where to purchase? I assume they're the same top and bottom? The number came from the top bearing, as I can't read the number on the bearing near the quill.


6201Z bearings are very common, the Z stands for single side shielded, ZZ would be both sides shielded, and you can get them for dirt cheap all over the 'net, at least the double sealed version.  I recommend the double sealed version because it keeps contamination out better.  The common number for a double sealed version would typically be 6201-2RS.  Just because they are available cheap does not mean you should buy the cheapest ones out there.  I would try to find some decent ones made in Japan or the USA (if we still make them...)  Edit: Or European.  All of them will fit and work, the difference is in the quality control of the components, the care in assembling compatible pieces into a whole, and final testing for quality control before they go out the door.  The cheapest bearings eliminate many of those steps to keep the price down.  Here are some choices for you:
http://www.ebay.com/sch/i.html?_odk...0.A0.H0.X6201-2rs.TRS0&_nkw=6201-2rs&_sacat=0
You can also find them locally at a bearing shop or industrial supply house, but they will likely cost more.  6201 bearings are only 32 mm O.D. (about 1-1/4"+), and that sounds small to me for a drill press of that size.  I would expect 6203 bearings in that drill press.  Make sure that it says 6201, or give me the bore, O.D. and width measurements in mm, and we can be sure.
6201 is 12 x 32 x 10 mm.

Edit:  They are not always the same top and bottom.  Often the bottom bearing is one more suited to axial thrust loading.  Get the numbers and sizes before proceeding.


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