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skybadger

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Everything posted by skybadger

  1. No longer correct, onstep will support servos as a flavour of onstep X I put the smooth side around the large wheel facing inwards and have two jockey wheels that take the smooth belt , between them is the drive pulley, if you insert the drive pulley between the two jockey wheels, you are pushing on the toothed 'outside' of the belt.
  2. Fabulous. More than I've seen in one place.
  3. No you are right , I was exaggerating for effect. If the persistent hotspot thing did its job, there would be no need for the additional tool he downloads. He does talk about using a phone or external device to provide the external network that Windows needs. Windows doesn;t actually need it if you set up the right type of hotspot - the one that Windows prevents users from creating manually.is a Wifi direct hotspot. The bit he doesn't address is 1, hotspots get created by default as public networks and these then get clobbered by the firewall. 2, Using connectify to create the hotspot creates a wireless direct virtual network adapter that presents as a public network. The answer to all of this is to create a powershell terminal as machine or domain admin and type this command : "get-netconnectionprofile -InterfaceAlias "Local Area Connection* 2" | set-netconnectionprofile -NetworkCategory Private" where "Local Area Connection* 2" is the name of the WIfi direct virtual network adapter on my device. which changes the type of the wifi network from public to private, has the side effect of enabling remote desktop access through the firewall ( which I assume you have manually enabled for your user account. I've tested this through numerous reboots . Hope this helps someone else. Mike
  4. yes but i'd still want to get rid of unwanted external dependencies.
  5. i started down that route, i have one but its 5v 2A and I want to remove it from my power budget and wires nest. I thought i had this sussed by adjusting the local GP tables but its not persistent.
  6. yep, his answer was to use the hotspot from your phone as the internet connection. Thats poor answer and the reason for connectify.
  7. Hi all I have a Pegasus Nyx and bought a mele quiet 3 pc as the mount controller for standalone imaging. It's been a bit of a mare since setting it up for field imaging; getting a working hotspot from the pc for the mount and laptop to connect to seems to be the hardest part. I ended up using connectify to host a hotspot on the pc, removing the win11 issue of Windows disabling the hotspot service if there isn't an internet to connect to. Connectify provides this and starts at boot but win11 considers this a public network so the existing windows firewall needed updating too to allow access from public networks to voyager and the remote desktop. However as the last thing to be be figured, I now find remote desktop keeps getting turned off, presumably by the firewall. I've manually updated the local w11 firewall to allow access from public networks for RDP and tested it, but I only find the problem in standalone mode, not when connected to a KVM.. I can ping and curl services on the pc but can't RDP, so have a working network connection. The RDP is refused. Anyone got an idea how to make this setting persistent between reboots ? My best idea so far is to enable winrm or ssh access and manually turn it on remotely each time. A lot of a faff... Thanks in advance Mike
  8. I think that's a fair shout re the weight once I get back to spherical. It's clear I overestimated the amount of figuring required to get from spherical to parabola. So I will remove the weights and shorten the wets and test frequently at that point. You've also seen the vid of the machine, there's a bit of slop there due to hinges having play. I will be replacing the arms with a bigger mech as I move to the 20" mirrors that should also have far less play but that's what the offset settings are for, to blend and avoid zoning as far as I can see. Key for me is to get to spherical again.
  9. So I did a bit more. Session details: Wet time lap eccentric offset overhang weight 3 8 80 8 55 20 6 4 8 80 15 40 10 6 5 8 80 30 30 -2 4 had to take the weight down by 2kg from 6 to 4kg because mirror was tipping on extremes So I think Im quite close to a sphere, maybe with a hint of turned up edge now. Next steps - 1/3 centre over centre smoothing to spherical using the larger lap. Once I get there, I'll do a gentle parabolising cos I'm itching to start on the 12" mirrors I have accumulated.
  10. Where I started the session 15th May Session details: Wet time (mins) lap (mm diam) eccentric (mm) offset (mm) overhang (mm) weight 1 8 80 30 50 10 4kg 2 8 80 30 50 10 4kg ie I was using a large swing to provide a chordal stroke across the outer zones with a little overhang #Result of session: Inside focus , ROC and outside focus. As an outcome, I moved back towards spherical a bit but need to do more on the outer zones. there is a small hole in the centre and the large central zone is still not quite spherical
  11. The answer to that is that I spun polished back to near spherical and then set to parabolising again with CoC strokes and ended up over corrected. The spin polish intent was meant to find out if that was an effective way to smooth out the surface I had which had becomes very rough and since I was getting nowhere with a 50mm lap. The 50mm lap is just too vulnerable to skipping, even after warm and cold pressing. So the images are from the return to spherical and the KE settings are from the result after parabolising again. I used some additional weight on the parabolising strokes so I'll remove that next time around. The intent now is to spin polish back to spherical ( or to reduce the over correction significantly ) and carefully parabolise again. I have some useful ronchi gratings at last and the foucault readings are now repeatable. Cheers Mike
  12. Found the pics I was looking for. These were the result of parabolising from spherical using CoC strokes through the centre, starting with large eccentric of 35mm, resulting in 10mm overhang, and reducing through 4 wets down to 10mm or so. The 70% zone looks raised and could do with a little scrubbing. I measured the mirror this afternoon and these were the results. So my aim is to return to more spherical again - this is is overcorrected - checkout the knife movement range. Doing so will prove that it is overcorrected and let me start comparing the ronchigrams with RonWin. I'll also see if I can lower that outer ridge without lowering the edge.
  13. Got some images from the 5th May . Inside focus to outside. Lines are straight until they reach the edge indicating returned to spherical but still with a bit of TDE 'hook' at the end. The hill at the 40% zone and the one in the centre are both reduced. Can see the kink at 40% in the right hand images outside ROC. This concentric bulls eye pattern has gone in subsequent working but no images of that yet.
  14. The ke does indeed move away from the mirror as the in focus zone moves from centre to edge. That takes about 8mm movement to do that. I shall run a smoothing spin polish on it again to return to sphere and very gently correct it this time. This is what I mean by getting experience. I don't recall seeing this sort of advice in books.
  15. Voyager advanced. Bought into this to get multiple cameras imaging at once. Upgraded to advanced for the powerful sequencer. Got loads of data last year using it to manage the obs. Just as well considering the weather. Still waiting for the array version to work with advanced scheduler though. Should be soon. Can run two instances, have to run monitor script over the top to run two main cameras in tandem and both be mount and dither aware. I haven't done that yet.
  16. Been quiet of late due to pressures of work. Been working on smoothing the mirror back out using a larger lap which had the effect of taking it back to spherical. Since it was now almost all spherical, I started parabolising from the centre outwards and , voila, the tde seemed to be gone. Continued a bit more and there it was again but parabolising is in progress. Using sessions of 10mins with CoC and inspecting after 4 wets out to the edge. Ill post some pics to show what I mean in detail. It'll be a week though, off away again.. Key question for me is, the early Foucault measurements were high in range and reducing over time. For spherical they are essentially zero. The target readings for my 6" f/5 mirror are 0 to 1.8mm but I get 0 to 8mm. Does this indicate strongly overcorrected or strongly under corrected.? I'm working on the theory that it's under corrected since I need to move knife edge much more to get to the desired zone position on the caustic and if it was over, I'd get there very quickly. Thoughts ?
  17. But looks great, didn't say that. Nicely done.
  18. You know you can already get them for very low prices from FLO ? Come with mounts for usb hubs and mini pcs.
  19. Voyager assumes you have already focused to within its operating HDF range and will take it from there. It took some playing with mine to get it to focus too. My HDF is from 25 down to 8 and success is less than 6.
  20. Here's the lates set of foucault images after the zonal polishing with the new lap. Essentially a mixture of chordal strokes at greater radii from the centre and then small circular loops over the outermost zone and a bit of larger lap smoothing. The centre 50% is close to spherical again but the rest shows paraboloid in the Ronchi. The aim now I think is to continue to reduce the outer zones and then smooth out the surface by stepping up to using the largest lap again.
  21. I made a pair of 50mm laps at the weekend. Cut the circles, drilled the machine foot hole, varnished them and then pitched them up. I normally use a sink mat with a rectangular grid to make my surface grid on the lap. I used that this time too. However in use it was skipping a lot in spite of a warm press and not readily revolving on the machine ball foot. Thinking this was due to the uneven distribution of the large grid on the small lap, I re-pressed them by taking them back to plastic in a bath of hot water and re forming using a mould of a punched rubber mat resulting in the spots pattern you can see in the picture. Again it skipped and grabbed. So I repressed cold and then scarified using a wire brush and that improves things so it moved well but ... The Foucault view is now quite scary. The central spherical zone is enlarged and the edge raised zone is reduced but the surface quality is awful, cos siting of surface scars in a concentric pattern. I did 4 wets at 80 to blend the zones, centered on zone 6 followed by 4 wets gradually moving the small lap out from zone 4 to 7 Another couple of wets to smooth and blend using the 80mm. I'll post the scarigrams later once I have them. So far I've just eyeballed them. I also did a wet by hand using the circular motion with just the slow platter rotating, I'll give that another go, was quite grabby.
  22. Cant agree more. I actually measure from out to in and then offset in a spreadsheet. I have a digital vernier to remove user error , I just need to work out a way to fit it.
  23. Always good input. thanks Nigel. That was why I was asking. I plan on making a 50mm lap tonight to do that job. The latest set of figures after polishing in the above method are below. The surface error plot tells me I have a conic of about -3! Which might explain the difference in sizes of figures betwween ideal and measured. Overall Im happy that I am getting a better understanding of what is going on, getting better at manipulating laps and the test tools and starting to get some repeatability in my foucault measurements. The Foucault sequence is shown below moving from zone 0 to zone 7 outwards. : zones 1, 3, 5, 6, (8) And finally a ronchi just outside RoC
  24. The pin locations are from both the stellaphane web calculator and the calculator in figureXp. I marked a sheet of polystyrene plastic using a compass and used a scalpel to cut the fingers out by allowing some materialaround each mark. Means a new mask per mirror but styrene sheet or just plain card is cheap.
  25. Further progress According to my grinding diary I took these after the last two wets of 5 mins which are digging out the hill from the centre and attempting to smooth out the trench before moving on to take the curve out to the edge. The pin mask lies across 7 zones and shows the trench being on the inner edge of zone 2 I used the small lap across the centre to reduce the hill and added some offset to blend that outwards. I also took some actual measurements but not all make sense - I clearly wasn't reading the micrometer correctly. more practice required in the dark garage. Here's the table data from Figure XP First Q: the difference in range between measured zone focus distance and expected is real. Why is it so different ? I haven't polished away all those mm since I started near spherical. I set the zone settings to moving slit. I will double check with a second micrometer to validate. Regarding the Dall null test- I read up on the test on optics.net but I think I have enough contrast to see the shadows as I currently am. I am aiming to being the line of shadow bisection to the centre and measure the null when its on a zone marker. for example. the null in the right hand picture is between zones 1 and 2. I am getting more familiar now with what I am looking for! Second Q: Considering Zambuto describes the most effective polishing 'sweet spot' for the lap as being where the lap has greatest effect at 80% diameter of the lap and then uses offsets to target the zone requiring work, I should be offsetting the lap to make the sweet spot coincide with the zone I want to reduce - which means for an 80 mm lap , using a -30mm offset for the central hill and a +15mm offset for the zone 3 reading. Sound about right ? I did some more wets last night . the first 4 for small lap fixup and the second for blending across the mirror. Cold pressed for 5 mins with 5Kg Time Offset Eccentric (Overhang) Notes 80mm lap 5mins 0 25 0 forgot to rotate blank 40 mins in total 5mins 15 20 0 forgot to rotate blank 5mins 30 10 forgot to rotate blank 5mins 45 5 rotated blank Moved to 120mm lap - warmed for a warm press before use. channels not closing up yet. Probably not warmed enough yet. 5mins 5 20 ~10mm at extremes rotated blank 5mins 15 15 ~10mm at extremes rotated blank 5mins 25 15 ~10mm at all times rotated blank 5mins 30 10 ~10mm at all times rotated blank I hope to measure the outcome of this, this afternoon and I'll show those measurements here..
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