G0704 max 125 ipm

[CL_MotoTech]

And mine was dripping with sarcasm.

[DJEkim33]

I love how they are not even comparing the same materials, end mills or even parts for that matter. Not the first time I have seen that video. I never knew most shops were actually trying to take longer to make parts then they could be.

[lcvette]

If you want to higher speeds grab a set of closed loop steppers, they are not saddled with the shortfalls an open loop stepper is with requiring oversizing to avoid lost steps and can turn considerably higher RPM without torque fall off.

However, as mentioned I can tell you that you will have far bigger issues with tool pull out at higher feed rates and aggressive cutting than you will with anything else on these R8 machines using TTS type tooling. I have tons of power and speed and it's only as good as the TTS clamping will permit. So if you want a peak at what's on the other side of 125ipm... It's just another set of issues to resolve.. so plan on a custom bt30 spindle replacement if at any point you want to use an endmill larger than 1/4"at the faster feed rates..

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[109jb]

If you want to higher speeds grab a set of closed loop steppers, they are not saddled with the shortfalls an open loop stepper is with requiring oversizing to avoid lost steps and can turn considerably higher RPM without torque fall off.

However, as mentioned I can tell you that you will have far bigger issues with tool pull out at higher feed rates and aggressive cutting than you will with anything else on these R8 machines using TTS type tooling. I have tons of power and speed and it's only as good as the TTS clamping will permit. So if you want a peak at what's on the other side of 125ipm... It's just another set of issues to resolve.. so plan on a custom bt30 spindle replacement if at any point you want to use an endmill larger than 1/4"at the faster feed rates..

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You are assuming that the OP is using TTS, which I don't see that he mentioned. The simple solution if you want to avoid the TTS tool pullout issue is to just not use TTS. I use mostly R8 tooling including end mill holders, drill chucks, ER collet chucks, etc. They have absolutely no issues in regard to tool pullout. I do not use R8 collets even though I have a set. I have found that removing and re-inserting a R8 tool offers very repeatable tool lengths. Closer than I could measure reliably.

There is absolutely no reason to have to go to a BT30 spindle for tool pullout reasons.

[eldata]

Is the OP talking 125IPM cutting feed rate or rapids? I'm of the opinion it's the latter.

[lcvette]

You are assuming that the OP is using TTS, which I don't see that he mentioned. The simple solution if you want to avoid the TTS tool pullout issue is to just not use TTS. I use mostly R8 tooling including end mill holders, drill chucks, ER collet chucks, etc. They have absolutely no issues in regard to tool pullout. I do not use R8 collets even though I have a set. I have found that removing and re-inserting a R8 tool offers very repeatable tool lengths. Closer than I could measure reliably.

There is absolutely no reason to have to go to a BT30 spindle for tool pullout reasons.

I couldn't take dealing with changing tooling that slow with what I do.. I solved it by going to a true VMC with ATC so it's a none issue for me anymore, but had I started with the G0704, I certainly would have upgraded the head casting and popped in a belt drive bt30 single with pneumatic hydraulic drawbar.

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[109jb]

I agree and also disagree with the notion that anything above 125 IPM is unnecessary on a G0704 size machine.

Higher feed and acceleration will mean lower cycle times regardless of whether the actual speed in cutting is increased. Many of the cutting strategies used these days have many rapid traverse moves, so increasing speed through those will reduce overall machine time. If using in a production mode, this may be very important.

The size of the machine doesn't really matter, as larger production machines with faster rapids are often tasked with making smaller parts that would easily fit a G0704 envelope.

As I said, I agree and disagree, and the above is obviously the reason I would disagree, but most G0704 converted machines are destined to wind up in hobby use where a little difference in cycle time won't really matter. In these cases the 125 IPM may be fine. However, I would also say that if using the same motors, drives, etc. and you can't get the same rapids as others then this may indicate a problem with something either mechanical or electrical.

[lcvette]

I agree and also disagree with the notion that anything above 125 IPM is unnecessary on a G0704 size machine.

Higher feed and acceleration will mean lower cycle times regardless of whether the actual speed in cutting is increased. Many of the cutting strategies used these days have many rapid traverse moves, so increasing speed through those will reduce overall machine time. If using in a production mode, this may be very important.

The size of the machine doesn't really matter, as larger production machines with faster rapids are often tasked with making smaller parts that would easily fit a G0704 envelope.

As I said, I agree and disagree, and the above is obviously the reason I would disagree, but most G0704 converted machines are destined to wind up in hobby use where a little difference in cycle time won't really matter. In these cases the 125 IPM may be fine. However, I would also say that if using the same motors, drives, etc. and you can't get the same rapids as others then this may indicate a problem with something either mechanical or electrical.

I agree, that as long as you can cut faster, go for it! It also as mentioned depends on what your making, if you are cutting a while table fill of parts on a few hoodie raps start making a really big difference.. to that end so does not losing steps because you stand to risk scrapping a lot more parts of it skips a beat and if it's only a brief stumble you'll likely not know until is to late when your in QC after the fact. I would suggest grabbing some closed loop steppers for that reason, they run fast and no worry of lost steps, if they for some reason do have an issue where the drive can not resolve the step count the drive will fault and can output an alarm signal to happy the machine before it chew through your stock, time and sanity...lol. They just make the best sense and don't cost all that much more than open loop setup especially if you are a big picture thinker.

That said in a hobby environment, you'll likely never notice or care beyond the scope of bragging rights if you can cut faster or have higher rapids. For me it's throughput that matters as the novelty of a hobby CNC machine has long since worn off years ago. Now it's a matter of hoping to run through a day's work without a hiccup, that's the stuff off a good day, but then I've dialed in my cam so tight that there isn't anything to be gained without hitting those hiccups..lol. is very different as a hobbyist where almost every part you'll make is a one off.

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