Pendulum Clock

[ddmckee54]

This was supposed to take 12 hours to print, according to the slicer numbers. I checked it twice before I started and got the same time with both. But, for some strange reason, it took just over 15 hours to print .

I think the difference between the estimated print time and the actual print time comes for your acceleration and deceleration settings in your printer.  The slicer has no way of knowing what they actually are so it just uses what the programmer told it to use.  If the programmer's wild-assed guess is different than your printer settings, then every time the printer has to accelerate and decelerate around a sharp corner you're going to have a error between the estimated print time and the actual print time.  If you are printing something with a LOT of sharp corners - a milli-second here, and a milli-second there will add up to a significant difference.

I always look at the slicer's estimated print time as the minimum time the print will take.

Don

[wagnmkr]

Hi Don. That makes a lot of sense, and yes, I did slow the acceleration down a bit thinking it would give a better finish to all the tall, skinny bits. I assumed, wrongly I now know, that the slicer would adjust it's time based on that. The main thing was that the print stayed on the bed. According to the designer, this is one of the parts that can tend to lift before it is finished. All's well.

Thanks for the explanation

Tom

[wagnmkr]

Just a loose fit at the moment, but top and bottom do fit together!

[wagnmkr]

There has been a bit of a pause in the project as I was given a printer that a friend could not get to work. He phoned me a week or so ago and I went to visit. He had fought with this machine for over a year with no results, so he gave me the complete Ender7 along with all he had gathered for it. The stipulation was that if I could get it working, then I would make a couple of things for him.

My first finished part off of that machine is the weight crank assembly for the clock. It is a two piece thing ... the knob is separate, and the arm and column is the other piece.

There has been a pretty good learning curve with the  machine as it it a core xy type which means the print bed only moves in the up / down (z) direction and the print head does the x/y movements. My other printer has the bed moving front to back and the print head going up and down.

I do have to be aware of which machine I am using so I get it all right.

[Kim]

That sounds like a pretty good deal!  You get a new core xy printer and he gets a few parts!

Nice crank handle too!

How do you like the core xy printer?  Does it also have the XY motors moving the head in diagonals?  So it takes both motors working together to move in the X plane only (or the Y plane only)? Look like fascinating printers!

Kim

[wagnmkr]

Kim, so far I like it a lot. The machine is rock solid, with no movement at all at this point. It seems to be doing a superior job of the tall skinny parts like the cylinder on the crank handle above. My other machine tends to have ringing around the barrel when the same part is printed. That could also be driver error on my part.

It is a marginally larger machine with a 250mm x 250mm print bed instead of the 220mm that the other machine is. That difference will allow me to do the clock base in one piece instead of the two it is now.

The 7 is also faster printing, but I am keeping it down quite a bit until I get it all adjusted.

Yes, the two motors are doing the xy moves. It is a machine that will "sing" to you as the motors do their separate things

All in all, I like it at this point. It doesn't / won't replace the other one, but as I have a few more clocks in the line,  it will come in handy for the larger pieces.

Tom

[Kim]

Thanks for the great info!  Looks like a good machine, and for a good price too! 

Kim

[ddmckee54]

It is a machine that will "sing" to you as the motors do their separate things

My printers do the same thing.  I've never minded it, as it tells when something is going wrong with the printer.  (Really bothers some people apparently.)

[wagnmkr]

I look at the "singing" the same way. It lets me know things are working well. I like a machine that"talks" to me.

 

[Krypto]

Good news!  I seemed to have worked out all the bugs in my clock as it's been running in the shop for a few weeks now without any stopping issues. I used a bit of powdered graphite as a lubricant inside the shaft holes of the faster moving gears. I also noticed that it's important to have the pallet centered in the frame as it seems to be rubbing ever so slightly otherwise and that's enough to eventually stop the clock after a day or so.

I also deleted the second hand as I find it distracting and I have more accurate clocks for seconds display.

[Kim]

Congratulations, Krypto! 

So, do we get pictures?  Or even a video? 

Kim

[wagnmkr]

That is excellent news.     I look forward to pics.

My build has stalled a bit I afraid.  I have been having trouble with hip / lower back pain and it is very distracting. I hope to get back to it this week.

[Krypto]

Wishing you a fast recovery with your back issues.

If you want to see pictures and a video of my clock just scroll-up to the my on the 10th and imagine the clock without a second hand and that's how it looks now.

Steve Peterson posted a video with all his clocks displayed at a local maker fair which might be of interest.

<a href="https://www.youtube.com/watch?v=wBkUlUrmNDk" target="_blank">http://www.youtube.com/watch?v=wBkUlUrmNDk</a>

He mentioned he's re-designing SP1 to make it easier to print and assemble.

[wagnmkr]

Thanks for that video. It is nice to see some of the clocks working.

 

[Krypto]

Well, I did make another video of my SP8 "Coup Perdu" with the deadbeat pallet. Here it's displayed in it's final configuration as a wall hanger.

<a href="https://www.youtube.com/watch?v=k3tq-1SvECk" target="_blank">http://www.youtube.com/watch?v=k3tq-1SvECk</a>

The second hand was deleted for a cleaner look and I also printed and installed the optional frame back weight so the clock would balance well on a single nail. Steve uses pennies for weight and a full complement in the back weight balances against the battery box filled with 2 AA's (no optional pennies) whose weight powers the clock.

After the clock stopped a few times, I noticed that half of one of the gears had a little elephant footing on the first layer as the Z offset must had been off a tad when that was printed. A bit of filing in-situ solved that problem and the clock has been working great since.

Since perfection is difficult, I prefer that my mechanical clocks be a tad fast as they are easier to set by just stopping the pendulum. Right now I'm very close to my goal of having this clock stay within a minute per week. The speed is adjusted by moving the pendulum up or down with a nut.

Since the clock winds itself, there's very little do once it's running. I've seen in Steve's clock forums that some people have had trouble with the reed switch becoming magnetized and sticking shut after a few months so I'll see if that becomes a problem. Beyond that, there's not much to do but let it run and enjoy.