Denford Triac VMC w/ ATC conversion

[JAZZCNC]

In terms of drives, I did talk to Gecko. They are coming out with a new G214 that has a maximum resolution of 256 microsteps, which is much lower than Leadshine.

The G215 is out already which I think is the super seed of the G214. It's a Max 10 x Ms drive(2000 steps per rev) which also does Sub microstepping at lower speeds dividing each Micro step up further into 32 pieces. This gives equivalent to 320Ms drive (64,000 steps per rev) while at low speeds. When the speed starts to increase the drive kicks in another feature called Morphing. This gradualy switches the drive from Microstepping at low speeds where it helps with motor smoothness back to Full stepping at high speed to increase Torque where Ms isn't helpfull and Robs Torque.
So in affect the G215 range is between 320Ms and Full step over set Speed range.

Now this all sounds great but I can tell you because I had G203 drives fitted on my machine for 3yrs that the Morphing isn't really noticable and makes very little difference compared to good quality Analog drive. I changed to Leadshine Digital drives Both AM882 and EM806 and they Knocked the spots of the Gecko's in every department.
I saw a noticable difference in Smoothness at lower speeds and greatly increased performance at higher speeds. My Max Rapids went from 9mtr/min to 14mtr/min with no changes other than drives. Thou I didn't require those speeds and didn't use the extra speed this still translated into higher torque at 7.5Mtr/min I run at.
Motor heating was considerably less at lower speeds and the whole motor sound changed. This was instantly noticable the minute motors started to spin.

So other than the Sub micro stepping which I haven't experienced yet and if honest I'm sceptacle about how affective they'll be real world use due to most Low/Med quality Step motors inabilty to resolve to such fine Ms amounts. Then I'd still probably say go with the AM882 or EM806 given previous experience of the Geckos morphing being less than impressive. Thou I will say Gecko's service and after sale warranty is second to none, Thou I did kill 2 x the supposedly Un-killable G203Vs.!! They replaced both times and both were out of warranty period.

The Leadshine also have tuneable Resonance thru software which for some machines can be a life saver if affected by resonance at any part of the motors speed curve.

Thou If you want to buy some G215 and send to me I'll gladly check them out against AM or EM drives and compare.! . . .

[uli12us]

If you know the leadshines, I have seen, they offer a microstepping of 1000, 2000 and so on.
Do you know, if this works good. My machine have at the moment with 400 Mikrosteps a resolution of
1/100mm or 0,4thou. I must determine, if its metric or inches, But because all screws are metric, I hope the spindles are as well. With 2000µstep, I'll get a resolution of 1/1000mm that should be much better, if I want to make a real circle, or a tight fit.

[JAZZCNC]

If you know the leadshines, I have seen, they offer a microstepping of 1000, 2000 and so on.
Do you know, if this works good. My machine have at the moment with 400 Mikrosteps a resolution of
1/100mm or 0,4thou. I must determine, if its metric or inches, But because all screws are metric, I hope the spindles are as well. With 2000µstep, I'll get a resolution of 1/1000mm that should be much better, if I want to make a real circle, or a tight fit.

Depends on the figure your quoting is that 1000 PPR or 1000 x .? . . ie 200 x 1000.
The AM & EM have Max Stepping of 51200 PPR or 256x (200 x 256) They can be set in 2 ways Via Preset values With Dip switches on the drive Ie 400,800,1600 etc or using software in which case you can set to any Ms amount you like.
This parameter Configurabilty esp regards Resonance is what sets them apart from drives like Gecko's etc that leave you stuck with there preset values. In practise 99% of the time you don't need to change any of these parameters and software will Autotune it's self to the motor but in cases where you do they are life savers. Or if you want to tweak the machine to gain the best possible performance from the motors then you can if desired.

Also Don't think of Micro step as increasing Resolution that's not it's main function. It's more useful for motor Smoothness at lower speed. Having the Ms set too high just stresses the Pulse generator for very little to No gain in performance/resolution.
Having Ms set above 16x or 3200ppr is pointless with normal steppers has they won't resolve any hgher than this. It also has a Negative affect on Torque at high speed.
Ms of 8x (1600ppr) is more than good enough for any stepper system using Hybrid steppers and will give reliable stable system. If you want more resolution the either apply a ratio or fit screws with smaller pitch. Trying to Use High Ms will only make your machine unstable and lower peformance.

[uli12us]

I know, that µstepping don't enhance the real resolution. But in the case of an exact circle, it'll enhance the circular form. And maybe I can reach a little bit better fit. with my little Emco, I have only
72 ppr, so i have a minimal distance from 0,0277mm in diametre. Thats a bit big if I want a tight fit for ball bearings or similiar parts.
Thats only, because the normal *4 or *8 µStep brings a bit strange results, that can't display on a
standard XYZ-display of a machine.

[JAZZCNC]

I have only 72 ppr, so i have a minimal distance from 0,0277mm in diametre. Thats a bit big if I want a tight fit for ball bearings or similiar parts.

That's a strange Number for Stepper motor.? That's 5 deg per step.! Are you sure.?

[uli12us]

Yes, thats a 30Year old machine. they used bergerlahr 5fase steppers, with a strange driver as well.
But as long as the machine run without problems, i don't change the control and drive parts of it.
The precision is rather limited, but I don't need often H7 or smaller. In the mill its another thing,
if I want a bore for a bearing, it must be within 1 or 2/100mm. I can't easy grind it to the next tolerance end.

[JAZZCNC]

Yes, thats a 30Year old machine. they used bergerlahr 5fase steppers, with a strange driver as well.

Even stranger then because 5 phase steppers give much lower Step angles due to having 10 poles. This is why they were used because the gave greater resolution and lot smoother running because of smaller rotor steps. They also increase in torque when Ms rather than loose torque like 2 phase steppers do.
The down side being more PPR required compared to 2 phase motor.

The first Smaller leadshine Hybrid Servo motor used 5 phase steppers for this reason. 2Nm Hybrid servo motor gives a 3nm 2 phase motor a run for it's money and is lot smoother.