Tormach on P20 prehardened steel

[keen]

I thought I would post a few pics of Tormach machining tough toolsteels such as P20 (prehardened -assab 718) and repost K600.

Incase anyone is considering a Tormach and wondering about its ability to do the demanding machining required for tool and mouldmaking etc. (I was looking for this type of reassurance before I bought).

I took a bit of trial and error to find the best cutter combinations , speeds and feeds to suit the Tormach but I can now let it run on this type of work mostly unattended .

[pete from TN]

machining tough steel on the tormach and using the TTS system is a no go. From the looks of that large block you machined there is some serious material removal occurring at your place. The machine is pretty capable when used properly and with the right feeds and speeds and cutter selection from what I have seen....nice work and peace

[300sniper]

hey keen, would you mind sharing what size/type of cutter, depth of cut, step over, feeds and speeds you are using? it looks like you are getting a nice finish on that.

[keen]

Sure - Probably vertical roughing info will be most useful as this is the most testing.

I started with recommended settings and then tweaked as needed. 16mm carb insert cutter 2 flute 12mm x 8mm approx, insert APKT 1003PDRNM90 - I ground the shank down to 5/8" to give clearance (but still full collet contact when up) on deep vertical work. Held in R8 collet with minimum projection for max rigidity. MDS on outside of collet and draw bar thread to maximise grip and minimise R8 taper skuffing - (cutter shank/collet bore dry).

Low 'gear' for max torque - (needed as the tips dull) . 1750 rpm, F225, 1mm deep cuts, 50% step over, climb mill. Full pressure soluble oil flush, chips need brushing away every 5 to 10 mins. Other than that it usually runs unattended.

[benji2505]

I like the splashguards. They seem to be higher than the regular ones and the rear one keeps the worst chip load off the harmonica protection of the y-ballscrew. I like it.

I still have the regular guards and - as a result - chips all over the floor.

congrats for the steel results. Looks good. I found that the carbide mills and the high torque (lower belt setting) are the most crucial thing.

Benji2505

[keen]

Cheers - Yes max height back gaurds are good. I have a couple of different sizes. I am nervious about chips breaking down the covers even slightly - and letting even just contaminated cutting oil on to the ballscrew waiting..........below.......