X3 Acceptable Rapids speed

[ronncat]

Here's a question for all you speed demons. What do you deem as a reasonable rapids speed? I'm not trying to break any records, but it seems with my setup, anything over about 50 ipm can result in some random stepper stalling and lost steps. I know some of you claim 70 ipm is painfully slow, but setting up to 35 ipm and not worrying about screwing up a part makes sense to me. My gibs are snug and there doesn't seem to be any binding in the axis. I am nearly maxing out the voltage and currents for the steppers. So...what is an acceptable rapids speed?

[SCzEngrgGroup]

Here's a question for all you speed demons. What do you deem as a reasonable rapids speed? I'm not trying to break any records, but it seems with my setup, anything over about 50 ipm can result in some random stepper stalling and lost steps. I know some of you claim 70 ipm is painfully slow, but setting up to 35 ipm and not worrying about screwing up a part makes sense to me. My gibs are snug and there doesn't seem to be any binding in the axis. I am nearly maxing out the voltage and currents for the steppers. So...what is an acceptable rapids speed?

Sounds to me like you significantly under-sized your motors. Either that, or your acceleration is way too high. If you get lost steps at only 50 IPM, you'll almost certainly be very marginal on torque at cutting speeds. And if you get stalling and lost steps at only 50 IPM on a single axis, you're also likely to see problems at lower speeds on multi-axis moves. Normally, you'd find the speed/accel limit, then back off as much as 50% for normal operation, to account for the dynamic factors of multi-axis moves, reversals, etc..

Regards,
Ray L.

[Teyber12]

Here's a question for all you speed demons. What do you deem as a reasonable rapids speed? I'm not trying to break any records, but it seems with my setup, anything over about 50 ipm can result in some random stepper stalling and lost steps. I know some of you claim 70 ipm is painfully slow, but setting up to 35 ipm and not worrying about screwing up a part makes sense to me. My gibs are snug and there doesn't seem to be any binding in the axis. I am nearly maxing out the voltage and currents for the steppers. So...what is an acceptable rapids speed?

Hey bud

on my x3 i am running 80ipm on the y, 100 ipm on the x, and 60 ipm on the z. i can run much higher on the y but don't find a point, as before i know it SLAM i bang into the other end of the ballscrew only 6.5 inches away. On the x i have double nuts so it can't run nearly as fast, as there is a lot more friction between the ballnuts and ballscrew. I can run it up to 140ipm but sometimes i don't trust it and don't see a point in going any faster. On the z im also double ballnuted. I can take it up to 80ipm but sometimes it stalls. You can fiddle with the z axis gib adjustment. Personally, id rather have tight ballscrews with minimal backlash and "slow" rapids that make my parts take seconds longer

I hear people getting wild speeds here and kind of blows my mind.

if i were you i would keep it at 35 ipm. seems like rapids in our situation is sort of like 95% of the car scene... you get envy and want to make your car as fast as possible, but unless you are one of the few who actually races it really doesn't make a difference..

[hoss2006]

but setting up to 35 ipm and not worrying about screwing up a part makes sense to me.

What's acceptable is what satisfies you and it sounds like you have the right mindset.
Teyber has it right too, wicked fast rapids are for bragging not practical use.
Hoss

[hoss2006]

If you've seen someone on here with the same setup as you but claiming better rapids,
send them a PM and ask for their setup parameters. You may, however, find their practical speeds
are actually much lower.
Hoss

[MrWild]

It depends. As Hoss says, it's an attitude thing most time. If sitting in a boat waiting for a fish to bite doesn't frustrated you, slow rapids won't be hard to take. If you find yourself casting and trolling and pissed when the fish aren't biting, you will need faster rapids. I'm finishing up a JGRO with 1/2-10 lead screws and in testing, the Z flies at 240+ ipm, with the X and Y move at 180ipm reliably. I expected 60 or less. Lot to be said for the G540 and a 48v power supply. I'm expecting far less from the Probotix set up I bought off a Zoner as it has weaker motors, 24v power supply, and anemic drives. If I get 40ipm on the X2, I'll be content.

[neilw20]

My Syil SX3 (factory CNCed out of the box) will run at 120 IPM (3000mm/min) but I limit it to 60 IPM (1500) so that even if the pulse stream is interrupted by DMA stealing time from the Mach3 low level driver I do not lose steps due to instantaneous decelerations.
I am machining expensive material and for the sake of 7 seconds per machine cycle I will live with the slow rapids.

Who wants to cut air at high speed any way.

60 IPM is ultra reliable, using a 48v supply and Mach3 running at 35KHz with a 2G Celeron and 256M ram running 6 hours per day, 4 axis.

At only 25KHz (for some un discovered reason) I get more clunking.
Clunking is instantaneous stopping of the pulse stream for short periods of time. I surmise that at 35KHz the clunks are of a shorter duration, so not as noticeable. Still clunks (more quietly - almost un-noticed compared to 25KHz), but it works OK.

I use 45IPM (1100mm/min) rapids for the Z axis.
My microstepping is set to 10 which is more than enough precision for my needs. 1000 pulses/per rmm
The bigger the divide ratio (more steps) will limit your rapid speed, but improve accuracy. If you can decrease accuracy you can have faster rapids.

I am using Mach3 version 2.26 as I have had unexpected 'hangs' in later versions. None of the new features seem to be an advantage to me. Reliability is EVERYTHING when machine material that has already had $50 worth of work already added before I machine it with a 2 minute cycle time.

[Torsten]

Most of all it has to be reliable, then there is a added advantage to slow rapids as it gives you a chance to stop when you see it take of in the wrong direction before you scrap a part.
As a general speed I feel been able to travers your longest Axes in about 30 seconds is adequate for my machining needs, so it will depend on the size of your machine.
Industial strength Rapids at over 1000 IPM will save some time in mass production.
For most small quantity stuff it makes little difference, setup times will dominate most of the time spend.

[yantra3d]

I wish I knew how to slow mine down! I'm getting over 200ipm rapids and don't like it. It rocks my whole x3 and table like a toy. I keep hand tweaking my gcode to replace the G00 rapids with a G01 feed for a more reasonable speed of 90ipm.

I'm using servos but to give you an idea; the nema34 torquemaster servo that I'm using on the Z axis has a peak torque rating of 896oz/in and a continuous stall torque of 100oz/in @ 4600rpm. I'm using smaller nema23 servos for the X and Y axis which are rated at 50oz/in cont, 355 peak and 35oz/in, 260oz/in peak (respectively). Not sure if that helps you much.

I purposely upgraded to more powerful motors than my machine can handle and I really like it that way, but I really wish that I could slow the rapids down somehow. I don't want to limit the current or modify the servo tuning parameters to achieve this though - just want to slow the rapids down. Does anyone by chance happen to know if this can be done in Mach?

[Teyber12]

I wish I knew how to slow mine down! I'm getting over 200ipm rapids and don't like it. It rocks my whole x3 and table like a toy. I keep hand tweaking my gcode to replace the G00 rapids with a G01 feed for a more reasonable speed of 90ipm.

I'm using servos but to give you an idea; the nema34 torquemaster servo that I'm using on the Z axis has a peak torque rating of 896oz/in and a continuous stall torque of 100oz/in @ 4600rpm. I'm using smaller nema23 servos for the X and Y axis which are rated at 50oz/in cont, 355 peak and 35oz/in, 260oz/in peak (respectively). Not sure if that helps you much.

I purposely upgraded to more powerful motors than my machine can handle and I really like it that way, but I really wish that I could slow the rapids down somehow. I don't want to limit the current or modify the servo tuning parameters to achieve this though - just want to slow the rapids down. Does anyone by chance happen to know if this can be done in Mach?

you can change it under config- motor tuning at the bottum (at least with steppers)

cheers

[neilw20]

Even without config, on main Mach3 screen set feed override to say 25% and the rapids will slow down too. The g01 will only go at 1/4 speed too.

Hit the tab key, and set the feed window to say 10% to make the arrow keys less scary.

Shift and the arrows will go at full speed.
In Config >motor tuning you can set maximum speed each axis.
You must hit the 'save' button for each axis as you change it.

[yantra3d]

Thanks guys! I'm saving this info for when I finally get plugged into mach (soon I hope).