drill presses...morse tapers...lateral forces?

[chocwheaton]

Hi all,

I'm on my second drill press (a jet radial model) after using one of the lower end hare & forbes bench drill presses. With both models I've had constant issues with the chuck and arbor falling out whenever I do anything that applies a sideways force to the chuck. Its not even heavy force, similar to lightly sanding with a sandring drum. And I do mean lightly.

General drilling has not been a problem. Both of these presses have the same type of morse taper to fit the arbor to the spindle.

I've tried cleaning the surfaces, dusting with talc powder etc, but nothing has ever fixed the issue. I'm just sick of it and am ready to kick Mr Morse Taper's for his shoddy invention

Am I asking too much from drill presses? Can that morese taper connection be upgraded to something more stable for horizontal forces? The chucks on milling machines must be fitted a different way as they can take side loads.

Any ideas?

Cheers

Greg

[DuncanH]

I've been using one of the cheap Ryobi bench drill presses from Bunnings for quite a while and have regularly put lateral forces on the spindle when using a wasp sander and sanding drum and have never had any problems. Perhaps you've just had a lot of bad luck

[Ashore]

As it is happening with two diffrent drills I would suggest that the male morse taper on the ( assume ) chuck is slightly damaged
Get some bearing blue and put a very thin filme on the male part put it into the drill remove and check how much contact you are getting , anything over 90% is good 70% will do but anything less is a problem . The fault can often be a bruise on the taper where it may have been accidently dropped , to the naked eye it may still look ok but it can have a small raised area that is stopping you from getting good contact

[echnidna]

I had a similar problem so I lightly lapped the shaft into the hole with some car valve grinding post. Did that a few years ago and haven't had any problems since

[chocwheaton]

I had a similar problem so I lightly lapped the shaft into the hole with some car valve grinding post. Did that a few years ago and haven't had any problems since

Interesting...so you apply a little of that paste to the shaft, insert it into the hole and rotate it around a little?

Cheers

Greg

[chocwheaton]

As it is happening with two diffrent drills I would suggest that the male morse taper on the ( assume ) chuck is slightly damaged
Get some bearing blue and put a very thin filme on the male part put it into the drill remove and check how much contact you are getting , anything over 90% is good 70% will do but anything less is a problem . The fault can often be a bruise on the taper where it may have been accidently dropped , to the naked eye it may still look ok but it can have a small raised area that is stopping you from getting good contact

I think I"ll try that. Where would you buy something like bearing blue? Is that the same stuff they use when blueprinting engines?

[echnidna]

Interesting...so you apply a little of that paste to the shaft, insert it into the hole and rotate it around a little?

Cheers

Greg

Just like lapping in car valves.
Paste on shaft, softly rotate backwards and forwards a couple of times then pull it out a bit rotate the shaft a bit push it back up & softly rotate backwards and forwards a couple of times then pull it out again. Work evenly right around the shaft a couple of times so you lap it in concentrically. The object is only to remove any high spots on the shaft/socket.

[Ashore]

Yep same stuff
For the lapping you cant do that if the male morse taper has a tang on the end

[Rossluck]

Bad machining during manufacturing. It should be a snug fit, and when you apply pressure it should tighten.

I have s special morse tap removing tool (basically a tapered length of steel that you tap into the slot) and I have to use it all the time to remove drill bits. But mine's a very old heavy duty drill press made in Melbourne in the 50s. It's so damned heavy that I have to walk it around the shed to move it, and even that's a trial. I just don't think they make'em as well as they used to ....

[brisbanefitter]

You have some interesting responses here.
Let me offer some humble advice.

Firstly, a morse taper is not supposed to have lateral force applied ot it in any circumstance. The nature of lateral force is that it will always try to pull the drill chuck out as it side loads. You are asking it to do something it isnt supposed to do.

You are right, a milling machine uses a method where a drawbar screws into the top of the taper. It is tightened from the top of the spindle, basically it is a threaded bar that runs alll the way down through the spindle of the machine and screws into the top of the taper. This serves to pull the taper tight up into the spindle, and when side loading occurs it prevents the taper from being pulled out.

With regard to fixing it, you could try changing your drill chuck and arbor assembly, it may be undersize slightly, however still I cannot guarantee this will prevent it from falling out under side load.

I would not try lapping it, this will be almost impossible, given it will have a tang on the top of it you should not be able to rotate it when it is pushed up into the spindle almost all the way home.

I wouldnt try changing drills again, if this is your second machine and you have the same problem, I would think that means it isnt the drill.

Another thing you could try is using a piece of wood and a mallet and GENTLY tapping the drill chuck up into the spindle just a little bit. This may help, not eliminate.

Basically, at the end of the day, you are using something for a purpose it is not designed for and as such it is not only potentially dangerous (drill chuck coming out while rotating) but inany case probably not going to work to well even in the best of circumstances.

[Ian Smith]

.
Basically, at the end of the day, you are using something for a purpose it is not designed for and as such it is not only potentially dangerous (drill chuck coming out while rotating) but inany case probably not going to work to well even in the best of circumstances.

Damn -
Now I know that, my Wasp sander will never work again

[BobL]

Damn -
Now I know that, my Wasp sander will never work again

Do not despair. I don't use my WASP much but here is what I would do if I did.

Drill and tap the bolt at the bottom of WASP and add a small router bearing. You can standing the bearing off the bolt as much as you want using washers or a suitable length collar. Drill a hole in your DP table (or in a piece of wood that you can clamp to your DP table) that neatly fits the router bearing. The bearing then takes 90+% of the lateral load and WASP away to your hearts content!

[brisbanefitter]

I didnt say it wouldnt work at all, just that it wouldnt work very well.
I am from a fitting and maching background, where side loading is usually a result of milling operations in a milling machine with drawbar.

Bobs answer makes sense, supposrt the bottom of the WASP or whatever else you want to side load.

Its hard to convert, if not impossible to convert, a drill press into a drawbar setup as found on a mill. Last thing, if you did manage to somehow get a drawbar into a drill press, the bearings used in the quill of the drill press wont react well to side load, milling machines tend to use different type of bearings with some kind of preload on them.

[gerhard]

I agree with Rossluck and Brisbanefitter. A well finished morse taper is a very snug fit indeed. It doesn't "suck itself shut", of course, but it comes close to that. The slighest bit of debris or grease will worsen the fit and a tapered drill bit or adapter chuck assembly will drop out by its own weight. Thorough cleaning and degreasing of tapers is the general advise prior to using them. They are not ideally designed for tangential forces, but these forces must a pretty large to loosen a good taper fit. When you inspect the outer and inner taper surfaces, you may find slight imperfections like dents or protrusions or maybe nearly invisible spots of oxidation. Using sealants or fillers or fixatives like Loctite is not recommend. You may have a very hard time to loosen the tapered bits again in case you would want to. Tightening a taper by very mild hammering can help. Use a wooden mallet or de plastic headed momentum hammer and not a bare steel one. One controlled blow often is enough. Take care of bearings and other delicate bits; if possible counteract the blow by placing a heavy steel hammer or other metal mass on the opposite side of the arbour. In a drill press, the upper arbour side often protrudes a bit above the pulley assembly when the arbour is in rest (top) position, and if so, it is in easy reach.

Greetings

gerhard

[brisbanefitter]

They are not ideally designed for tangential forces, but these forces must a pretty large to loosen a good taper fit.

thanks gerhard, somebody else who understood what i was saying.

bob had a good idea as well and understood what i was saying.

if it isnt designed to do it in the first place, any issue with the fit will make it much worse.
me personally, i dont side load drill chucks, they hurt when they hit you at speed as i once discovered when drilling under normal conditions with an old drill that decided to let go off the chuck as i let the spindle return home.

its up to whoever is on the end of the drill whether or not they wish to use it in a manner for which it is not designed.