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[cuivenion]

As above I get Very slow gotos when Ustep Gear Changing is disabled, microstep level is set to 32 ustep. Is this correct behaviour, and can I just safely increase the goto speed if it is?

I'm using the beta firmware and config. Apologies if this is a daft question.

[TCWORLD]

I'll check the calculations in the config utility. I'm guessing it is not accounting for the ustep changing being disabled and so resulting in a GoTo speed which is 1/8th of what it should be.

In the mean time, just set the value in the goto speed box higher, it won't do any harm.

[cuivenion]

Ok no probs, there's some strange behaviour at different usteps with the gear changing disabled too. I'll post in the beta thread when I get a chance.

If I want to use 7.4 firmware for actual observing do I just open the 7.4 config and update the firmware from that?

[TCWORLD]

Yes. If you update the firmware with the V7.4 config utility it will downgrade the firmware to V7.4

[cuivenion]

Hi I've updated to the latest firmware and the goto's are still very slow when the gear changing is disabled. I want to disable gear changing as the motors are a lot quieter that way. I can only increase the goto speed to 1200x and that doesn't make much difference to the speed. Disabling the gear change also effects EQMOD slews.

I was wondering what the difference was between 32steps and 4steps. Does the 4step for fast movements increase the torque?

[TCWORLD]

Can you try the config utility I've attached to this post?

Disabling the gear change shouldn't affect EQMOD slews as AstroEQ should report that it is not capable of doing high-speed. I'll double check that.

[cuivenion]

Hi, I tried that new config. Unfortunately the eqmod slews are still as slow, but the astroeq gotos, (parking to home position) are a lot faster. I'm not sure if they are the right speed but they are a lot faster. The gotos with the gear change disabled are noiser than with it enabled, but as I'm still having problems with it at the moment this might be related.

[cuivenion]

Hi, I 've noticed this as well. I'm trying different settings to find the best for my setup. This is what happens when I start sidereal tracking at 16 ustep with gear changing disabled:

https://www.youtube.com/watch?v=2cctRh7BEUc&feature=youtu.be

And when I try to goto or slew:

https://www.youtube.com/watch?v=XpTx83S-bIs&feature=youtu.be

[cuivenion]

Hi, I'm currently using the pre beta firmware as it's quieter, 32 ustep with gear changing enabled works ok in all the firmwares. Could the faults be due to my motors?

[TCWORLD]

The noise is down to the ustepping mode. Movement will be smoother/quieter at higher microstepping levels. With a ustep mode of say 8 it will be much noisier than with 32.

I wonder if there is a mistake in the firmware somewhere with gear changing and ustep modes. I will investigate when I get a chance.

[cuivenion]

No probs, thanks.

[Zh]

I'm using v8.0 firmware from Release downloads page and GoTos working correctly.
My settings are 32usteps, and Gear changing disabled.
RA x800 fast movements (1.8degree stepper) and DEC x500 movements (0.9 degree stepper) are maximum system can handle (obtained in experiments)
works beautifuly, slews are quiet (compared with v7.4) and very precise, target objects always appears in center.

[cuivenion]

Not sure what it could be then. The pre beta firmware is quieter for me and the noise increases when I disable gear changing in 8.0 which I gather is'nt supposed to happen.

[cuivenion]

Hi Tom, I've been testing out the config you recommended, indoors, with mount, no scope. AstroEQ seems to work fine up to speeds of 254x at 32ustep with the gear changing disabled, and so does EQMOD slewing. The motors are very quiet at that speed.

Here's a list of what I'ved noticed when gear changing is disabled at 32Ustep:

- EQMOD slews will not go faster than 254x even when, say 800x is selected. It doesn't stall just slews at the slower speed.

- The Config will only let me choose a limited number of goto speeds and nothing above 507x. The number reverts when I update the RA or Dec settings or close the config. (When gear changing is enabled choosing goto speeds acts normally).

- The only speed above 254x I can select is 507x. At 507x the motors are very noisy.

Could this be due to the motors I'm using? These are the specs:


Electrical Specification

Manufacturer Part Number    14HS17-0504S
Motor Type    Bipolar Stepper
Step Angle    1.8°
Holding Torque    23Ncm(32.6oz.in)
Rated Current/phase    0.5A
Phase Resistance    15ohms
Recommended Voltage    12-24V
Inductance    26mH±20%(1KHz)

Each phase draws 500 mA at 7.5 V

Hope this helps. I mention the motors because other people don't seem to be having any problems.

[TCWORLD]

I'm going to make a guess without knowing the ratios that the calculated IVal for your mount is 507.

The skywatcher protocol uses speed factors based on this IVal. The speed is given by IVal / factor, where factor is an integer.

What this means is at high speed there is low resolution. A factor value of 1 would give you a speed of 507x sidereal. A factor of 2 would give 254x sidereal. There aren't any speed factors in between. As a result you can't go any faster or go at any speed in between.

The reason the goto speed is jumping back when you press the update button is it will do the calculations and round it to the nearest possible speed factor - hence it jumps back to 507 each time you try to go higher.

With gear changing enabled the effective IVal gets multiplied by 8 when doing a high speed slew. This means you get more speed values. For example a factor of 7 would now give you a speed of (507*8)/7=579. The price you pay for that is more noise due to the larger step angle.