Depth of cut

[Eric CoxParticipant @ericcox50497]

On an industrial vertical milling machine, depth of cut is obtained by raising the table a few thou if necessary. On the smaller milling machines used in model engineering the  table is fixed so the head must be lowered. Can the head be lowered with the same degree of accuracy.

[Eric CoxParticipant @ericcox50497]

[Peter GainParticipant @petergain89847]

Hi Eric,

I have a Warco WM16 mill/drill which is typical of the many clones from the Far East. When used for milling, don’t try to control the head accurately, use the quill. The head is brought down such that the cutter is just clear of the work. The head is then locked using the locks provided.  The quill may be lowered by a separate control to that of the head. The quill is fitted with a DRO which is surprisingly accurate. The quill

can be raised/lowered within a thou (or the metric equivalent). The WM16 column is of the box type such that the head may be raised or lowered without loosing orientation. I have no experience of the round column types which allow the head to rotate with respect to the column. Most amateur mill/drills have heads that allow drilling/milling on the slant. Spend as long as it takes ( & it can take a long time) to set the head up accurately perpendicular to the table. Then lock the adjustment & leave it there. Read Harold Hall’s “Milling, A Complete Course”.

Peter.

[wheeltapperParticipant @wheeltapper]

Hi

couldn’t agree more on the column tilt, get it truly perpendicular to the bed, do it up as tight as you can, throw the spanner away and buy a tilting vise .

 

something I learnt the hard way.

 

cheers

Roy

[John Somers 2Participant @johnsomers2]

Whilst I thoroughly agree with Roy and Eric one possibility to consider is to rigidly attach a laser light, say on the back of the mill column, with the beam pointing vertically. I used a small spirit level which featured a laser beam – an impulse buy at my local filling station. Mark the point on the ceiling where the beam is focused and it then becomes a simple matter to return the column to this position following tilting. The higher the ceiling, ie, the distance between the laser source and the ceiling the more accurate this technique will be.

Most of my off vertical milling and drilling is achieved using a cheapo tilting vice from Machine Mart. For those with an iPod Touch you can buy an application that allows you to use your iPod as a surprisingly accurate digital device to measure angle of tilt.

JohnS

[Peter GainParticipant @petergain89847]

Re-cheap spirit levels/lazer beams. Be aware that some of these cheap instruments may be very inaccurate. This applies what-ever the use to which they are put. (Don’t ask how I know)!

Peter Gain.

[John HaineParticipant @johnhaine32865]

Eric, I have a Myford VMB with a fixed table, dovetail-slide head and movable quill.  The quill only has a “drill type” downfeed (for drilling!) so accurate vertical feed has to be applied via the feed screw.  It works fine.  Whether the same will work for other mills I don’t know

[wheeltapperParticipant @wheeltapper]

I’ve got a Chester Conquest mill and it has a 3 armed handle which is pulled out for drilling and pushed in for fine feeds via a calibrated knob on the front.

 

this feeds down with quite good accuracy.

 

there’s a bit of backlash on the feed knob but all the weight is downwards so it hardly matters.

 

for angled working I use a tilting vice and one of those electronic doohikeys for measuring angles.

the vice has an angle scale on the body but there is no datum to line up to  so I removed the scale.

 

cheers

the tilting side of Roy

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