Carbon Brush

Looking for suggestions, or maybe advice from someone who has done something similar. I have an Orion Optics (UK) dob mount, intended for their 10" offering and wish to fit a Skywatcher 10" tube. I already have both items so the cost to me is fitting effort & parts. The scope gives good views and the OO mount is superior to the Skywatcher 'MFI' mount that I don't have anyway. The Skywatcher 250 tube has the standard rings, intended to fit to the dovetail. The OO tube rings are quite thin and bent to the diameter of their tube, which is a bit smaller than a Skywatcher tube. One choice is to slightly straighten the OO rings, fit a spacer to extend the hinge and a longer clamp screw. This solution also involves machining a couple of millimetres off the OO spacer blocks as the assembly will be just a bit too wide for the frame. Another choice is to mill the SW rings flat in the region of the fixings and drill more holes to match thee OO block. Possibly thinning down (milling) the OO blocks as well. The above options mean that the OTA can be moved in the rings for balance. If I drill the OTA for the OO blocks and add a shim, that would work. That means fitting a balance mechanism. Adjusting either weight or location to suit different eyepieces from 1.25" plossl up to 2" jam jar types. I will try to get some photos of the bits later today, or tomorrow. Suggestions and ideas please...... David.

Some years back I bought the (then current) Canon 1000D. Out of the box it was good in daylight. I tried it for astro. But the number of setup changes between day & night was a pain. Especially navigating the buttons in the dark. Screen off, shutter lock up, etc. So I bought another that had been astro modded. This allowed me to leave them in their best setup. More money than sense? Perhaps not. They were both used cameras and not too expensive. I still have them. HTH, David.

If you managed a full W10 upgrade and observatory software running short of only a key - WELL DONE. I never seem to have things run so smoothly.

Hi Tim. Welcome to SGL. The best astro forum in the world! David.

They look like water stains from your photo. Or maybe a bit of surplus glue from any mirror pads? If so, definitely unexpected. But not doing harm. It is the front of the mirror that matters. Some more pics would help. David.

Hi Richard. If you are going for mains powered then it is always easier on cabling if you run 240V from the house to near the scope and keep short 12V lines to the scope, the camera, the dew heater, hot air blower, the laptop/tablet. Yes AP kit grows! Put your mains supply on a low table or similar off the ground to prevent damp. A table helps with accessory storage. When using a linear power supply as described earlier, the self heating in the supply will generally keep it dry for the session. Always ensure there is a residual current breaker, or RCD, or (incorrectly named) earth leakage breaker in the mains power line from the house. Domestic mains circuits (unless quite old) include one (or more) in the consumer unit. If in doubt, fit a plug top variety. Think that is enough to get you started. hope this helps, David.

Another thought is essentially the same tripod with 2" legs. No harm in future proofing. A few years back Skywatcher EQ5 came with the 1.75" tripod, but the Celestron equivalent came with a 2" tripod. Not sure about the top fixing though. Best to measure up before buying. There are sometimes minor differences on the mount/tripod interface. HTH David.

Have considered Skywatcher Equinox on the used market? HTH David.

So Mr Skywatcher has presented these new scopes somewhere. Look at the background and you can see a row of chairs. Some sort of sales or marketing event? But FLO (the UK's largest astro retailer I believe) find out about these scopes from social media, rather than the manufacturer. My interpretation is that Skywatcher must regard the UK market as unimportant and insignificant. Someone please prove me wrong. David.

Thanks for posting. I remember at the Jupiter Voyager 1 & 2 encounters that the number of moons increased from the known 12 to about 20. Saturn had a similar boost. Less than half a century later the count is 161 between them. No doubt there will be more to follow in the coming years.

Ref John. The propellors were probably a Be/Cu alloy. No hazard until ground up and inhaled! Be/Cu alloy is often used in electronics to make springs with excellent electrical conductivity. For James Webb. I think the $$$$ per Kg of payload launch cost would justify thinking of materials other than glass. The effort of lifting a big dob into the garden is a bit different.😁 David.

A few years back I found myself having to dispose of a hundred or so computer CDs. I idly wondered about making cheap simple brackets and fastening the discs to my gutters, fence tops and other places. Send the light back to the source. Basically if it is a neighbours light, blast everything at their door - at eye level! My argument is that I am not generating light trespass or pollution. I am simply returning a neighbours waste. A bit like giving him the tree clippings back. David.

If your prescription is only a focal length correction, without astigmatism, then you don't need bother. You will just have the focus tube in a different place to when you are using glasses. Observing without glasses means one less piece of (sometimes poor) glass in the way. You can use eyepieces with short eye relief. That is your eyeball has to be close to the eyepiece. For a given quality, these can cost less than long eye relief eyepieces. HTH, David.

Slightly away from topic. In the UK contact lenses can only be prescribed by an optician are subject to on going checks. I have always (15 years) found the prescribing opticians to be very good at explaining risks, and warning signs to prevent serious problems. HTH David

Good link from Geoff Barnes. Somewhere on SGL there is a very good cleaning video by member Steppenwolf. Essentially the same techniques (from memory) but with the benefit of moving pictures to follow. I have used the washing up bowl, mild detergent followed by deionised water method with success and improtantly, no discernible damage. The worst mirror I cleaned had been left facing up and uncovered in a shed for a year or two. It came up really well. To finish rinsing, I have used a mix of deionised water and IPA (isopropanol or isopropyl alcohol). This has the benefit of reducing surface tesnion, to discourage droplet formation, and making a lower than water boiling point mixture that will easily evporate using a a hair dryer. Just take care. Don't rush and get all your cleaning stuff to hand before starting. If there is a bit of stubborn muck, leave it. You won't notice it in the views. HTH. David.

I'm no expert on this but here is my limited understanding.... At any magnification, astigmatism is an issue. But, as exit pupil size reduces, the problems caused by astigmatism reduce. Unfortunately a tiny exit pupil introduces other problems. If high magnification planetary views are really what you want, then go for a longer focal length scope of a similar diameter. If you are happy with a newt, that will give you most light gather & magnification for your ££ spent. Having said that, CA in a long FL scope is less of an issue. This will give you higher magnification and allow you to consider the need for other eyepieces. Another thought is dealing with astigmatism either by a contact lens, or a TV dioprix, or simlar approach. The dioptrix will only fit certain eyepieces so can be a big cost of ownership! Not exactly the answer you asked for. But a different approach. David.

Hello Annie. Where to start? You have some good equipment there. 2nd hand prices tend to be up to 2/3 of new price, assuming things are in good working order. It would make sense to bundle certain items for sale. An obvious example being the Canon camera and the accessories. I hope that a member near to Chesterfield will come along and offer to help you to sort things out. That would raise maximum funds for you. Alternatively, was your father in law a member of a local astronomy society? Someone from there who knew him might be a good idea. A person who deals in used astronomy kit may come along and make an offer for the lot. This is the minimum effort/hassle route. But not necessarily raising much money. I'm sure an SGL member local to you will be along soon. Hope this helps, David.

Sorry I can't find the source right now. But I remember reading that almost 50% of house break ins were during the day. In other words daylight, security lights or dark make little difference!

I considered (a long time back) an eyepiece/adapter that deals with astigmatism. But never bought one. To me having to keep the EP aligned to your eye may be a bit of bother when the scope moves around the sky. Then what if (like me) you have different astig in left/right eyes and you swap eyes while viewing? The solution I opted for was contact lenses. They sort the differing astigmatism in both eyes and can be used away from the scope. They are for distance & astig correction, which means cheap reading specs for small fiddly things around the scope. Following the thread with interest. David.

A once only spend of £100 on grass mats or........ £20 on shoe polish. £20 on grass seed. £20 on ear defenders - required PPE after treading mud into the house. £20 on carpet cleaning. Same again a week later.... A word of encouragement. I have had no regrets about the spend on the garden and workshop matting. Fit, problems solved, then forget. David.

Amazing image. Two thoughts come to my mind. First, a mag 14 object is going to defy discovery by accident. The search by Clyde Tombaugh was looking in a (mathematically) predicted location. Second. Less than a hundred years after Pluto's discovery, after less than half an orbit around the sun, things have moved on so far that an amateur astronomer can see the object.

Hi Jake and welcome to SGL. The best astronomy forum in the world. M31 can be difficult. I remember spending ages trying to find it without success. Then one night it literally jumped out. After that I could easily point binos straight there and, depending on the sky, sometimes get the visual 'smudge'. Keep trying and the more you look, the more you will see. HTH David.

If you post a photo of the mains inlet, ideally with a rule alongside, I may be able to give a pointer. David.

There is no solution to unexpected clouds. But having viewing options as advised in earlier replies is a big help. Also experience counts. A bit like going camping or on holiday. After a few outings, you get used to what you need to take and can have everything ready to go in a short time. The same aplies to the on site setup time. After a few outings, you get to be able to assemble the kit with your eyes closed - or a on a dark site! Hope the replies help to keep you enthusiastic. David.

I have used the grassmats type of product with success at home and at work. Some are rubbery. Some are a semi rigid plastic, rather like wire mesh in appearance. Some are rigid and interlock like lego bricks. All of them allow drainage, and allow the grass to grow and give you a harder surface to walk on. In some cases it has been a heavy duty mesh to prevent vehicle damage. In another a light duty mesh to bind soil over a rubber pond liner, around the pond edge. The rubber mats are in use at home to provide grip on slippery concrete, and at work to provide a floor in a messy workshop. A set of rigid tiles make a path to my observatory. At first they just sat on the surface. They are gradually sinking as the rain softens the soil. After less than a year they are virtually invisible. The rubbery or semi rigid are best for uneven ground. The rigid types are great on level ground. Hope this helps, David.