Tomatobro

The degree of pull out/in resistance is a function of the pressure of the focuser shaft on the tube. If I remember correctly the tension can be adjusted by a grub screw located in the middle of the focuser block. I think its in the same plane as the chrome thumbscrew but towards the scope body. An Allen key is required to make the adjustment .

clutches tight mount tracks, clutches loose no tracking

take a look at https://britastro.us15.list-manage.com/track/click?u=bd3998bbc34253d2383918d5c&id=3c179b08bd&e=2735fcee57 for that latest info

SKF have a table which specifies the percentage grease volume vs load and RPM factors.

Take a look at Deep Sky Tracker. It has a dedicated Comet processing routine which gives you the options of how to display the Comet.

Put the scope on and the counterweights, undo each clutch in turn. adjust the scope position and the counterweights till you get balance in both axis. Lock the clutches and power the mount. Go through the handset questions and when done go to the "Park the mount" and park it. It may or may not move the scope axis. When its parked, undo the clutches and rotate the counterweight shaft till it points down (eyeball with the tripod legs to get the middle) and lock that clutch. Now rotate the scope so its points straight up and lock that clutch. Its now in the parked position. You can be more precise if you have a spirit level where you can rotate the counterweight shaft and get it level and set the setting circle to 90 degrees and then (with the clutch unlocked) turn it so its at zero degrees. Do the same with with the scope. These steps can be done once you are more familiar with the mount, so for starters just eyeball. To test, move the mount using the handset in both axis then goto park and park it. It should go back to counterweight bar down and scope up

With the clutches undone the scope is free to rotate on the shafts so it will not goto or track. The motors turn the shafts that the scope rides on. When the clamps (clutches) are locked the motors can move the scope because its locked onto the shaft.. When locked you cannot manually move the scope. You would unlock the clutches when (say) you wanted to check that the scope was balanced properly The motors are always connected to the shafts.

Tomatoes top brace under construction

Its been a long time since I used a polar scope but from memory your app is showing the position of Polaris as if it were on a clock face i.e. 12 o'clock (at the top), 3 o'clock at the right, six at the bottom etc. In the polar scope you have a cross in the middle, an outer ring and a tiny ring positioned somewhere on the outer ring. This tiny ring has to be positioned to the same point on a clock face as per your app i.e. if Polaris is at 3 o'clock in the app then the ring should be at 3 o'clock (using the centre cross as a reference). You rotate the axis to put the ring to this position. Now find Polaris by adjusting the left right and up down screws and position Polaris so its inside the little ring. Hopefully someone will come in if I have got it wrong. Remember that the polar scope should be calibrated so the the centre cross stays on an object when the axis is rotated. This is best done in the daytime using a distant object.

There is a website called Blocklayer which allows you to print protractors on a inkjet printer which is ideal for the Az positioning. Using Adobe poster print you can produce large (20 inch plus) protractors.

take a look at this....https://www.myastroscience.com/nopolarisalignment

Talking of pillar drills brings back memories of when I collected mine from a guy in the West Midlands. He was a model steam engine enthusiast and a real eccentric in the mould of Fred Dibnah. At the bottom of his garden he had a miniature coke fired blast furnace for melting cast iron. After about three hours of discussion we finally got round to the sale of the pillar drill. I am sure that only in the UK folks like this exist. As I recall he was an accountant and a self taught engineer.

if battery powered voltage droop?

With the first esprit Tomato had to set up each time so the criteria was as follows No modification that would impair the resale value The scope had to fit into the flight case that the scope came in Had to work with a Hitec focuser No backlash Had to have at least a 60:1 reduction ratio Be powerful enough to handle large camera/filter wheel/reducer etc The reduction requirement meant we had to use the 10:1 reduction but the 2mm reduction drive spindle would not handle the belt tension load so the large toothed pulley sits on its own shaft and bearing so imparts no load onto the reduction drive. Drive is imparted by a three pin wheel onto the reduction shaft. Experiments with smaller stepper motors (two years ago) indicated that the system was underpowered so a NEMA 24? motor was used together with a slightly wider toothed belt. Somewhat overkill but that is what we used. The second version uses a narrower belt and while we were at it the larger motor was replaced with NEMA17 types for uniformity. Each drive setup cost less than £50 each but does need a couple of days in the machine shop to construct. I forgot to mention that PTFE bearings, Carbon fibre etc is used to avoid corrosion issues long term

The question I ask myself is why is it being sold. If the seller puts forward a reasonable explanation then the sale is 80% there. But when I read the item is fabulous best ever mega brilliant etc then if its that good why does the seller want to part with it? To a certain extent it also depends on individual circumstances. I have gambled on "faulty not working" at a bargain price and have been able to repair. But that is down to luck. Talking of used equipment there is a 29 inch Dob for sale on Ebay . Buy collects......

Doreen at the window block of flats opposite....

8 amp led strip brightness control, that is some led strip.......

look closely at the dimmer control. There is a decimal point before the 8 so I think this is a 800 ma unit not 8 amps. How about -50-110°C W1209 Digital Thermostat Sensor Temperature Control Switch Module UK from Ebay

My copy will be in your hands tomorrow......

I use D link 4 and 7 port hubs with no issues. They are 5 volt units so I have added a 12 to 5 volt power supply. All my external kit is 12 volt DC.

Flo do them for £28 if I have got the right one

I have a pair of OH 20/40 x 100 bins which look the same as the helios. I find that standard 1.25 eyepieces will not go far enough in to get focus. You might have some success with straight sided 1.25's but they probably will have to be shortened a bit.

Welcome to the astro photographer's slippery slope...asset rich cash poor!

I take it the fuse blew with just the power supply connector plug in? If yes then the board is suspect.

Looking at the picture the connectors (left to right) are 4 pin, 2 pin, 6 pin, 4 pin and 6 pin. have I got that right? And the connectors look like JST types. Looking at the other pictures there is a choke and two electrolytic capacitors in the general area of the two pins so I am guessing that the two pins you tested are indeed the power input. That being the case there is no dead short across these two pins. If it were me I would put the board back in and then just connect the plug on the far right and apply power. If the fuse does not blow disconnect the power and put another plug in (leave the first plug in place) and power up again. If the fuse does not blow keep repeating this procedure untill either a plug connection takes out the fuse or all plugs are in and the fuse remains intact. Post the results when you have them