hi Chris if you climb mill on a conventional mill it will drag the work into the cutter depending how much backlash you have in the leadscrews upcutting will push the work away .it is recommend to upcut on conventional mills.

Geoff

It's easy to find on the web

web

In the apprentice workshop I was tought never to climb except on materials that work hardened. I have remained faithful to that teaching.

During a previous discussion, on this forum, about climb milling I ask a couple of friends who had worked in tool rooms whether they had climb milled. The reply, in both cases, was never.

I think you would need a large and very rigid machine to climb mill anything.

JA

A conventional feedscrew will almost certainly have some backlash and acquire more with wear, attempts to control backlash can be mechanical or hydraulic, a recirculating ball feedscrew and nut is a successful way to minimise backlash. Because the finish when climb milling is usually better than conventional I will risk a very light final cut with the axis locks used to add some extra drag, this is a risk and getting it wrong can trash the job and break the cutter. Developing some feel for the machine will give a better chance of success but as this will be a finishing cut you could spoil some hours of work in a moment. I have seen a powerful mill haul the job out of an 8” vice and put gashes all along the job, not with me driving though.

Mike

I currently use an Emco F1 cnc mill equipped with ballscrews on all axis and always use climb milling so small mills can climb mill without the problems sometimes experienced.
Link below shows climb milling 6082T6 aluminium with a 12mm 4f HSS endmill

Emgee

https://youtu.be/udDhZlu53e0

Edited By Emgee on 23/09/2020 15:23:37

I will climb mill on my little CNC (Novamill) with no problem as it has ballscrews and is very rigid.

On the bigger VMB I only climb mill when finishing ali with the side of a cutter – take the last main cut normally then wind back without moving the cutter or maybe just adding 0.1 mm more. This gives a much better finish and so far hasn't resulted in grief.

On steel on Chris' little mill especially making pinions I wouldn't even try.

Chris climb and conventional really only applies when using one side of the cutter upto about 1/3rd of its diameter.

In your sketch if looking down the spindle then the part of the tool between 9 and 12 o'clock is conventional and from 12 to 3 o'clock is climb and the two forces will cancel each other out so no real risk of the work being drawn into the cutter. In fact the area from 11 to 1 o'clock will have little effect in the Y axis but if a very deep cut were taken there is a chance the tool could flex to the left.

Edited By JasonB on 23/09/2020 18:35:37

Chris, the first hit on dave's web search gives a good image of cutter in relation to each sid eof work for external cutting.

Emgee the straight arrows are the direction of the work, compare my video on previous page with what's shown in the drawings and it's conventional. See the text that goes with it

Edited By JasonB on 24/09/2020 12:28:39