Stub Mandrel

Just seen reinforcing plate idea...

20 hours ago, Gina said:

More trouble - this time a failure of printed plastic.  Latest pic of escapement.  The anchor has suffered from "plastic creep"  and straightened out a bit.  The RH pallet is now catching again!!!  OK I can redesign the anchor with wider arms but not sure that will cure it.

I would try filleting the inside sharp corners at either side and make the top part larger for increased stability.

<Stub is thinking>.......

On 26/01/2021 at 13:50, Gina said:

It's printed well and seems fine - vast improvement!  Didn't realise stale filament could be so troublesome!!!

When I have moved I will get a food drier to use as a filament drier.

On 25/01/2021 at 11:43, Gina said:

Do you think that would produce better gears with lower friction?  I'm just wondering if printing new gears with lower modulus would make my clock work better.

It's highly controversial but as a general principle involute gears of any size should be better than traditional clock gears. Actual size really chiefly affects power transfer capacity, friction should not be a big issue with well-formed involute gears  - although you could test this.

On 22/01/2021 at 12:09, Gina said:

Considering I'm printing GT2 timing pulleys very nicely I see no problem with mod 1 spur gears.

That would let you double the pinion tooth counts and get a better form.

On 18/01/2021 at 14:58, Gina said:

I've worked out that I should be able to get away without an extra gear pair but with higher ratios - though I have to test that out. 

6:1 from chain wheel to centre wheel with the chain wheel going faster (can do this because the auto-winding can keep up with the faster chain drive).  Then two stages of 10:1 give the overall ratio from centre wheel (60m) to escape wheel (6s) of 600:1.  Or do you think I'm being too ambitious?

The critical thing is how small (tooth count) a pinion can you use? You might consider using 1 mod gears?

If you think the effort of an extra gear pair and design are worth it then I like  the gravity escapement, although I would add a lot of extra material for robustness compared to the gif.

On 16/01/2021 at 18:45, Gina said:

Hopefully the deadbeat escapement will work but otherwise I might have to try something that's more tolerant of conditions such as used in tower clocks.   Gravity Escapement.

Ooh! That is so clever!

I found this on Thingiverse, apologies if I have posted it before. It took some tweaking to get it to run, I can see the clock will be a much bigger challenge!

Apologies for the tongue-in-cheek 'clickbait' video title too!

The bit that is often overlooked is that the tooth passing across the lower surface is what gives a kick to the pendulum.

Hi Gina, just to get me following the thread....

1 hour ago, Gina said:

Maybe a new heater and borosilicate glass plate are indicated.  It's a mains voltage heater and not cheap!

Surely a new thermistor is indicated? The controller will just be underpowering the bed if it's getting false readings.

16 hours ago, Gina said:

Correct - and it was a bit too much for PLA - fine with PETG though.  I think PETG is my favourite filament.

Chapeau!

On 15/02/2019 at 22:19, Gina said:

A couple of photos, camera casing and RPi roughly where it will go and printing the top outer casing.  Printing in cheap PLA, low resolution, for prototype.

You are printing that flange overhung with no support?

53 minutes ago, Gina said:

Another.

Now looks like tilt rather than distortion.

On 24/01/2019 at 20:25, Gina said:

Gina, the variation in 'error' across teh plate is tiny - are you sure you recalibrated the zero point? - Surely there ought to be a start point showing up as green.

51 minutes ago, Gina said:

Darks are a problem as the lens doesn't have a shutter or aperture control.

Can you not cap it?

The historic choice was un chapeau ?

Mine responds very well to darks for those hot pixels.

2 hours ago, Gina said:

This provides focussing using the thread of the lens mount (the lens has no focus mechanism).

Be warned, some lenses will hit the sensor of the ASI 120 models if screwed in too far! May be worth adding a ring below the lens to stall the stepper if the focus routine tries to run the lens too far.

46 minutes ago, Gina said:

Not a problem have CAD software and 3D printer.

You don't say! ?

I haven't used my casing yet... but I just printed a two-part base and glued the halves together. A USB cable goes in through a hole sealed with hot melt, there's a pocket for silica gel pouch(es) and I made a foam gasket for the dome. Hopefully sealed!

Must try it out some time, but I only have the one suitable camera.

It needs proper feet!

Speed of progress is creditable!

Good approach ?