Drill Press tolerances

[Tisorp]

I seek advice from Forum contributors regarding the degree of run-out (drill wobble) expected of a $300 dollar 16mm drill press. I have measured 10/1000" (0.25mm) on my newly purchased machine which compares rather poorly with it`s predecessor (a small GMC cheapie). Measurements were made 1.5 cm below the chuck jaws on a variety of drill bits using a dial gauge . Measurements taken from the drill sleeve and the arbor above the chuck show less than 3/1000".
I have cleaned and reassembled the chuck arbor complex without benefit.

Have other members made similar measurements on their machines?
Do better quality after market chucks exist and if so from whom can they be purchased?

Thanks in anticipation
Jeff

[Groggy]

How was it measured? If the quill was fully extended then maybe I'd accept it, but I wouldn't be impressed if the quill was seated.

Did you clean and seat the taper? Sometimes when they assemble them they throw the chuck straight over the coating on the taper. Remove it and give it a good clean, then try again (noted you cleaned the #2, did you clean the chuck seat?).

Another thing to test is the seating of the chuck on the taper with some machinists blue.

[Tisorp]

Thank you Groggy
THe quill was seated when measured (I feared acute depression were I to measure it extended)
All components were carefully cleaned prior to reasembly
Machinists blue?

[Groggy]

Thank you Groggy
THe quill was seated when measured (I feared acute depression were I to measure it extended)
All components were carefully cleaned prior to reasembly
Machinists blue?I recommend you measure the runout when extended because that is its typical position when cutting - may as well know the bad news eh?

The "machinists blue" or prussian blue, or whatever you want to call it (and dozens will chime in here - though maybe not anymore :wink:) is smeared on the taper before fitting the taper in the quill. Then pull it out to see where it is touching. It will help you find high spots that may be making it run out of true.

[Tisorp]

Run-out (as measured above) with quill fully extended is 14-15/1000" This seems to me to be excessive but I would be very interested to know how other presses measure up.

[gerhard]

Hi Tisorp,

forgive me for thinking and quoting European, but those are the systems i grew up with. The drill presses i know are mostly fitted with B16 or B22 conical arbours, with Röhm (German) or LFA (French) or Jacobs being the most accurate chucks you can buy over here. I know from experience that the slightest bit of dirt or rust between the conical surfaces will cause wobble, but an ill fit gives itself away too by the chuck slipping on the arbour or just falling off. If the arbour is threaded, the cleanliness of the circular surface plain on the chuck where it sits tight against the surface at the end of the arbor thread is more important than the cleanliness of the thread itself. But since you've cleaned everything thoroughly, that can no longer an issue.

Anyway, 0.25mm play is far too much, on even the cheapest of drill presses. Should a brand new press have such play, it is not fit for sale as a serious and precise piece of equipment. When the quill was taken out to be cleaned, did you roll it on a glass plate? Whenever i suspect an axle or similar object to be slightly bent, i lightly grease it or smear it with a thinned down layer of paint and roll it on the glass. When it leaves a trace in full width at any moment during its roll, you can be reasonably sure that every bit of the metal has touched the glass and that the axle is straight. If omisions on the glass occurr, the axle was arched at that moment, showing there must be some curvature. You can also clean the quill to bare ungreased metal and let your eye scan along its surface lenghtwise, like you woul judge a length of timber for straightness. The best way would be to span it in a lathe and span a pencil or chalk in the head which normally hold the chisel. You run the lathe, let the pencil touch the axle lengthwise and where the tip touches the metal and doens't on other spots, there is your proof of a bent axle.

Should the play result from the quill fit precision, than it's a construction failure from the factory, not to be remedied by a new chuck. The manufacture than just simply was too coarse. A reasonable European 16 mm drill press from Metabo, Somer, AEG, Myford, Flott or Lurem would set me back 1200 to 1800 Euro's. I don't know how many Australian Dollars that would be, but 300 sounds a bargain.

Best regards,

gerhard

Holland