Now the tangent is done, it's time for a re-build of the Dec axis...with lots of thanks to Steve, sl, I now have a beautiful 10" Mathis gear and worm. The tangent is going...after hours of work to be replaced by this slipclutch and worm with a stepper motor
To get electrical I bought a digital multimeter from Jaycar and via youtube have found out which wire is what on a few steppers I have around. An old Hurst motor for the Dec axis from the Gaunt works, and I hoping I can get a gearbox for the newer g11 motors, a pair of which Erik in Lakes Entrance has sold to me...thanks Erik.
Photos show the back and front of the RA worm with motor wires ending in a terminal block for both axes. The Ra is OK...will probably solder the wires together and get rid of the terminal but the Dec wires come straight out of a 6 wire telephone cable type ending with a RJ-45 plug on the other. Is there any other way to do this? The wires are thin....something a bit more substantial would be good, if it exists.
For the Dec axis I'm working out a worm and motor mount. This mount can have GOTO added in the future if wanted.
A month later and I have nearly finished part one of a pier for the mount. Basically an Aluminium box that solves how to keep the RA gear worm and motor out of the way of a pier or tripod....it's on its own mini pier. This bit will be bolted down to a pier somewhere in the not too distant future.
Matt
Edit: One year to the day since starting a pic of where I'm at. Working on the Dec gear, worm and motor mounting.
Have mounted the gear and worm on top below the OTA. One small issue,perhaps, is the OTA will be 5" above the RA gear which I can reduce to 4" by cutting down the QD bush. Just the motor to mount and this then will be ready for use...after I build a pier...does it ever end?
I have been waiting on a collar that has arrived The dec gear and motor is now going down at the counterweight end, meaning I can lower the height of the OTA by 4" Now I'm working out how to mount the worm, in a better way than the pic.
After this it's build the Azimuth adjuster plate and pier plate...nearly done
Been 'fecunding' in the shed again and have come up with this for the Dec axis...All I need is to wire the thing up make the base plate and Az adjust mechanism then build a pier....paint, polish and lacquer the brass...
Of late I have been testing this mount in the shed. It works Not a lot else to say.... just need a pier and then it will be useable under the night sky. Having the Mathis 10" gear on the Dec axis instead of the tangent arm means I'm able to use two 5kg counterweights instead of three...a good thing. No problems with the telescope slipping in any angle. I have started the base plate and Az adjust....then its build a pier.
A special thanks to Alex for introducing me to the word fecund....
My shed, for the first time in 3 years, is aluminium shaving free.
Well that is the easy part out of the way Matt. Now you just need to dismantle it, prime and paint or clear coat all the components and try to remember how it goes back together.
A cheese night...good idea Dan Might do a bit more than cheese too However its going to take a while(months) until I build the pier. I like the clear finish too, but due to my lack of cutting skills gaps have been filled with my ol friend JBweld...so black paint and lacquered Brass it will be.
Any other colour choices I should consider? British Racing Green? Sky Blue?
Recently got back into the shed to do a bit more to the mount. A week or so ago I had the 10" Newt out for a trial run, still sitting on a wooden box.
Tracking is pretty good, hard to tell with rough polar alignment but at least the Dec and RA motors work. Keeping the scope East heavy was a tiny problem so I bolted a 1kg piece of brass to a rod to help with this...brass weight goes on when the CW shaft is on the East side and comes off when the OTA is on the East side. Will trim the rod to size at some stage.
I have re-built the RA motor which is now bolted to a plate that makes it easier to adjust the gear mesh. I also put a Losmandy G11 stepper on with the 6 pin RJ45 connector with a view to replacing the flimsy wires at the terminal blocks soon.
Have bought all the aluminium parts I need to make my own 1.5 meter high pier, which will put the Refractor high enough to view at Zenith sitting comfortably Hope to have this made in the next two weeks....
Pics...East heavy brass weight and new motor plate.
Gday Matt
Considering the Steampunk nature of your beast, i reckon you could also use a lead weight on a brass chain to provide an East heavy preload.
That way, you can balance perfectly first, and then the preload wouldnt need to be changed unless you changed the scope.
Back to making aluminium chips Pier sides are cut as are the side angles.
Azimuth plates have also been cut out. Bottom square plate is 380x380mm and built from a 6-12-6mm sandwich of 6mm and 12mm aluminium. Round palte is 6-6mm JB'ed together. To make things easy I bought a Dewalt 8" slide compound mitre saw...great saw....cuts prefect 90º angles, unlike my dead Ryobi mitre saw.
Nice idea for East heavy Andrew....Chrome chain and a big Brass Padlock perhaps
Nice idea for East heavy Andrew....Chrome chain and a big Brass Padlock perhaps
Even a nice flexible stainless wire would suffice, and a fancy brass fusee type mechanism between the pillowblocks would fill out the space in there. Can never have too much brass.
I tried this method once with my LX200, and it worked well.
The big benefit is ( assuming you balance close to perfect first ), it keeps the RA worm under a constant preload, no change is required as you slew around
Now I get you
A fussee….had to look it up. I have a brother-in-law who did an apprenticeship as a clock maker, he would be impressed. Not exactly sure how to employ this idea yet, but love it.
TBC….
Gday Matt
You wouldnt use a true Fusee mechanism unless you also used a spring mechanism ( like in a clock/watch ) to provide the preload.
If you use a hanging weight, ie where the torque stays constant over time ( unlike a spring ), the "fusee mechanism" would be a simple cylinder that provided a constant torque from the hanging weight.
Again the more brass bling, the better :-)