did the 1100 max feed rate increase?

[300sniper]

i was just looking at the comparison between the 770 and the 1100 on tormach's site: http://www.tormach.com/document_libr...omparision.pdf. i noticed they show the 1100 having a 90 ipm max feed rate. is that a typo or did tormach speed up the feed rates on the 1100?

[wvines]

The feed rate was increased when the new control software (3.11? Or was it 3.12?) was released in Nov.

The X and Y axis max is now 90 ipm. The Z axis limit is 65 ipm.

[300sniper]

interesting. i guess i need to look into updating my software. i have been running the original since i got my machine a couple years back.

[zephyr9900]

300sniper, you said a while back that your machine is a 3-digit serial number. That makes it a Series I like mine with the old axis drives, and you'll need to stay with the 65 ipm rapids to be safe. I tried the new software as released, and the 90 ipm X-Y rapids weren't reliable. The new release does also have the spindle settings for the new VFD. I'm running my copy "unlocked" and dialed back the axis and spindle settings for the older machine.

For me, the new software nearly doubled the effective machining speed, because apparently my PC is quirky in interpeting the gcode and always ran very rough/resonatingly (i.e. vibrated the chip trays a lot) with the 2.42-based Mach but is silky smooth with the 3.042-based Mach. If your machine is already running smoothly on gcode (especially diagonals, which show up any resonance problems better than straight moves) you probably won't get any great benefit from the new release.

Randy

[300sniper]

yes, i am a three digit machine. i think it's #309. that's too bad. i really want faster rapids.

[flick]

would an axis drive upgrade be out of the question?

[zephyr9900]

flick, both the Series I and Series II have the same 220/48V transformer, DC bus circuit board, and 15000mfd filter cap for the stepper power supply so my guess would be, yes, that would be a doable upgrade. Whether it's worth $729.01 ($243.07 per axis) plus tax and shipping to go from 65 ipm to 90 ipm rapids is the real question. I'd personally go for the spindle drive upgrade first for about the same money. If the gcode is efficient so that most of the time is spent down in the cut, the extra 10+% of spindle speed would give a real throughput increase, IMHO...

Randy

[BlueFin]

Originally Posted by zephyr9900 the extra 10+% of spindle speed would give a real throughput increase, IMHO... Randy

If it is the same spindle (bearings, etc.) that will stand up to the 10% or maybe more RPM then why couldn't we just change the pulley to something a little smaller to get 5 or maybe 6K RPM? You could keep the stock one laying around in case you needed to machine steel or something, but the new one would be set up so the new "low" would be equal to the current "high" so you could still use a 1/2" end mill in aluminum. The new "high" would be 5.5 or 6K RPM for the little end mills that don't need any torque.

[zephyr9900]

BlueFin, in my experience the Series I VFD is marginal as it is. When I'm operating at 4500rpm the spindle speed varies audibly. At all speeds, it is hit or miss whether the spindle will brake or coast down, even on subsequent stops with the same tool mounted (ironically heavy tools--i.e. more rotational intertia, like my flycutter or drills in the large chucks--brake more consistently than light tools...) I've gone through the spindle calibration a couple of times, and experimented with the settings that control the deceleration.

What you suggest is certainly possible. You'd need to keep track of the belt length required for the new pulley sizes, probably using a slightly shorter belt to stay within the tensioning adjustment. I did a similar thing years ago with my Taig lathe, designing a new spindle pulley to go with the stock motor pulley (in that case it was actually to decrease the low-end speed).

Randy

[BlueFin]

Originally Posted by zephyr9900 BlueFin, in my experience the Series I VFD is marginal as it is. Randy

Randy, your VFD sounds like the one I replaced when I first got my machine. Sometimes it wouldn't start, sometimes it wouldn't brake (just coast), Tormach sent a new one and after calibration the thing is right on 100% of the time. RPM is very stable at all speed ranges. I was just thinking for $20 or so a pulley could be made up (I guess a keyway could be broached at home) to get up to 6K spindle if the bearings will stand it.