Eqmod direct vs SynScan handset

[sophiecentaur]

Most people who have discarded their SynScan handset in favour of a direct connection seem to swear by it. They say it's more 'reliable' and I accept their experience. BUT there is a strange feature of the way the handset seems actually to control what happens to the mount during slewing. 

Send the mount to a target, selected on the SynScan handset menu and the mount goes there relatively quietly and by a 'direct route'. When it arrives, the slew speed drops once, then again , after a short period of jiggling around, and there's no fuss. Using an ASCOM Driver through Eqmod, the route on both my mounts (NEQ6 Pro and EQ3 Pro) take it a very strange route - always involving a Meridian Flip, apparently, right up to NCP and out again and then, when it arrives at the target there is a lot of to-ing and fro-ing 'at high speed' before dropping speed and eventually settling down.

Does this happen to everyone who does it this way?  The procedure sounds so alarming that I'm sure there must be some way of controlling such wild behaviour. I know that ASCOM is a very useful package but is it too generic to take care of things like that?

And, talking of alarming sounds, that EQ3 Pro sounds particularly dreadful and, try as I may with adjusting the motor mounts to improve the meshing, those poor little brass coloured gears really seem to be having trouble. They are not worn out as the mount has only been used in anger a very few times. People on forums have very strong opinions about lubrication but I seriously wonder whether I should get some of the very thickest grease and try to sort the problem that way.

 

 

[Seelive]

When driving stepper motors, it's usual (and normally actually required) to ramp up the speed of the motors over a short period of time rather than just apply an immediate change in the step rate so that steps are not missed. The Synscan hand controller certainly appears to do just that when a slew is requested, but I don't know if other 'controllers' do the same. I've only ever used C2A as an alternative to the handcontroller to drive my mount and it certainly appears to apply an instantaneous step change in the motor speed rather than ramp it up to the slew speed (certainly if the noise emitted by the mount is anything to go by when it first starts slewing!). 

Edited October 23, 2020 by Seelive

[Budgie1]

Are you just using EQMOD to make the slews or do you have another software to tell EQMOD where to slew too, like Stellarium, CdC or APT?

I'm running my EQ5 with EQDIR through CdC & APT and I can't say I'm having the issues you describe.

[sophiecentaur]

On 23/10/2020 at 16:37, Budgie1 said:

Are you just using EQMOD to make the slews or do you have another software to tell EQMOD where to slew too, like Stellarium, CdC or APT?

I'm running my EQ5 with EQDIR through CdC & APT and I can't say I'm having the issues you describe.

I get this effect with Stellarium but also if I press home on the EQMOD control panel. For normal slewing (i.e. when adjusting the scope before syncing) you can choose four speeds from snail pace to noisily fast. I'm just wondering how good Ascom and EQMOD really are. The package claims to be all singing all dancing and I haven't heard anyone actually complain- and let's face it, it's stood the test of time and gets frequent updates so it's still 'loved' by its developers.

I have a complaint that the fold-out control panel is a bit confusing and you definitely have to learn the right approach. The official  YouTube videos I've looked at present it in a convincing way but my brain works differently. I've only used Stellarium in anger but CdC doesn't make the speeds any more sensible. I'm sure it's possible to get inside Ascom if you're savvy enough. It's all open source and has loads of documentation for capable developers.

[sophiecentaur]

On 23/10/2020 at 15:13, Seelive said:

When driving stepper motors, it's usual (and normally actually required) to ramp up the speed of the motors over a short period of time rather than just apply an immediate change in the step rate so that steps are not missed. The Synscan hand controller certainly appears to do just that when a slew is requested, but I don't know if other 'controllers' do the same. I've only ever used C2A as an alternative to the handcontroller to drive my mount and it certainly appears to apply an instantaneous step change in the motor speed rather than ramp it up to the slew speed (certainly if the noise emitted by the mount is anything to go by when it first starts slewing!). 

That seems to be what I'm getting, I think.