Jump to content

Can i trust these readings or is my Timegrapher broken?

AP1875

By AP1875
in Tools & Equipment

 Share

Recommended Posts

nickelsilver Distinguished Member

nickelsilver

Posted
Posted

Seems it is showing the instant rate every 10 seconds or so under the main display bar. It must average it over some length of time; on a regular Witschi you can set it anywhere from 2-240 seconds (the newer ones will go even longer). I don't know if it's adjustable on that machine.

Link to comment
Share on other sites
m1ks WRT Addict

m1ks

Posted
Posted

The numbers on your screen are the seconds - or + per day, it takes a reading every 10s by default but you can change it to every 20 or whatever suits. The white bar is where you're reading the info that's current.

Firstly you need to find your lift angle for the movement to get the true amplitude, I'm guessing with a watch losing so badly the amplitude isn't really around there.

There are charts to find it but there's a manual way, which is a bit long winded to go into here.

End number which alternates between 28800 and 52 degrees is bph/vph indicating it's a high beat movement and the latter is the list angle which is the default and has to be changed to reflect the movement.

First number is the amount of seconds you're gaining or losing daily and this will fluctuate a little (or a lot depending on movement) 8 different positions.

Link to comment
Share on other sites
robmack Watch Enthusiast

robmack

Posted
Posted

If you doubt the accuracy of your time grapher machine, then test it against a known standard.  Use a good quality quartz movement and set the BPS to 1.  Then test the quartz watch on your machine.  It should produce a horizontal line.  If there is any inaccuracy in the internal timebase of the machine, it will show up on the display.

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
8 hours ago, robmack said:

If you doubt the accuracy of your time grapher machine, then test it against a known standard.  Use a good quality quartz movement and set the BPS to 1.  Then test the quartz watch on your machine.  It should produce a horizontal line.  If there is any inaccuracy in the internal timebase of the machine, it will show up on the display.

As mentioned above, nothing is wrong withe the machine. Just that the OP couldn't figure out what the numbers displayed every 10 secs and repeated on the top left means.

BTW, quartz watches cannot be used for calibration of a Chinese timegrapher.

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
8 hours ago, m1ks said:

End number which alternates between 28800 and 52 degrees is bph/vph indicating it's a high beat movement and the latter is the list angle which is the default and has to be changed to reflect the movement.

Let's also remind here that accurately setting the lift angle only affects the amplitude calculation, and by a small amount of approx 1 to 1 degrees. So it is it not a must or even important thing to do in all cases. 

Link to comment
Share on other sites
Pip WRT Addict

Pip

Posted
Posted

Can you post what make and calibre of movement it is, then it’s quite simple to look up the lift angle in a lot of cases. Google for Lepsi Lift Angle and you’ll find lots of info.

 

As for the lines, yep all looks normal (for a poorly running watch). I disagree slightly with some of the above as imho the BE of 1.4 is a bit too high. Sort out that (see if you can get it down to 0.5 or below) and regulate the watch a bit and see what lines you get, I think the amplitude reading is probably miscalculated as the BE and regulation are out. But it’s a good place to start from and I don’t ‘think’ there’s anything wrong with your machine.

 

 

 

Sent from my iPad using Tapatalk

 

  • Like 1
Link to comment
Share on other sites
robmack Watch Enthusiast

robmack

Posted
Posted
On 7/29/2019 at 11:43 PM, jdm said:

BTW, quartz watches cannot be used for calibration of a Chinese timegrapher.

I'm not clear as to why a quartz movement could not be used as a frequency standard to confirm the accuracy. Can you please help me to understand your reasoning?

The creator of Watch-o-scope recommends using a quartz movement to perform the calibration procedure on that product.  The reason is that the internal oscillator on the sound card of the computer (that forms the frequency standard for the Watch-o-scope) is not operating at precisely the designed frequency and needs compensation.  The quartz movement serves as an accurate input frequency standard.

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
36 minutes ago, robmack said:

I'm not clear as to why a quartz movement could not be used as a frequency standard to confirm the accuracy. Can you please help me to understand your reasoning?

I wrote about Chinese timegraphers (the type used by the OP). They only sync to a fixed range of frequency of Swiss escapement,  check  document attached. Calibration is made at the factory with a dedicated input port.

I don't know about instruments or software.

Link to comment
Share on other sites
Pip WRT Addict

Pip

Posted
Posted

I checked a movement on my chinese one against a proper professional Witschi (spelling?) one. There was a difference, but it was only a few degrees of amp between the two. I think over the course of several comparisons the biggest difference I had was 4 degrees iirc. I can live with that.  :)

Link to comment
Share on other sites
nichod WRT Addict

nichod

Posted
Posted

My 1900 version only goes down to 3600 BPS.  At that setting it will read a Citizen Sky Command at around 0 to +2.   Probably close as it's only claimed to be good to 15 seconds per day without the radio signal and only gets that once a day.

Not good for calibration of anything, but will tell you the machine is functioning.

Link to comment
Share on other sites
JohnR725 Distinguished Member

JohnR725

Posted
Posted
On 7/29/2019 at 4:56 AM, AP1875 said:

Can i trust the readings for rate/amp/beat on this timegrapher considering the +/- figures are all over the place? Is there anyway to resolve this?

To resolve the problem with your watch and understand what were seeing we need the background history of the watch the make and model of the watch etc. It's really hard to make diagnostics from just a timing machine display when we don't know the background of the watch what's been done to it etc.

Then if you think you're having a timing machine issue find another watch that you know is working and see what that looks like. But if this is the only watch you have you could purchase the item found at the link below. Designed exactly for this verifying your timing machine is functional. Unfortunately it's probably going to be expensive.

https://www.witschi.com/assets/files/sheets/leaflet_msg.pdf

 

 

 

 

Link to comment
Share on other sites
jdm Distinguished Member

jdm

Posted
Posted
9 hours ago, JohnR725 said:

To resolve the problem with your watch and understand what were seeing we need the background history of the watch the make and model of the watch etc.

I think it's clear, as mentioned above, that the watch merely needs BE and rate regulation. Don't you agree?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • ManSkirtBrew
      1972 Bulova President "E" Sea King 11ACACB movement

      By ManSkirtBrew · Posted

      Oh nice. I have a similar wedge style stump for my staking tool, so I'll give that a shot. Thanks!
    • joelcarvajal
      Gamblin Gamsol for cleaning?

      By joelcarvajal · Posted

      Thank you all for the replies!  Very informative! True enough, the Gamsol took some time to evaporate and does leave a residue. So not all naphtha are created equal!  Need to find alternatives then. i was able to try Hexane recommended by Alex and it seems great.  I wonder what the cons are?
    • GuyMontag
      1972 Bulova President "E" Sea King 11ACACB movement

      By GuyMontag · Posted

      Yeah, I saw that in the tech sheet but I don't see how it can be adequately cleaned with the friction pinion still in place. I've accidentally pulled the arbor right out of the wheel once when I used a presto tool to try and remove it. Mark shows how he does it with the Platax tool. Those are a little too pricey for me so I got one of these from Aliexpress and I just push down on the arbor with the end of my brass tweezers. That usually gets it most of the way out and then I just grab the wheel with one hand the and the friction pinion with the other and gently rotate them until it pops off. Probably not the best way but it's seemed to work for me so far.    
    • Zedster
      Movement inserted from crytal side

      By Zedster · Posted

      Thanks, Jon Sounds like a plan. Obviously I'll have the face on so do you think gripping with the holder will create any problems, but I will check in the morning to see how feasible it is but I assume it only needs to be lightly held. As for holding the movement instead of the holder won't be possible in this scenario as one hand will be puling on the stem while the other pushes the spring down. That was my initial concern is how the hell can I do this with only one pair of hands. All the other times I've had to remove the stem hasn't been a problem, apart from the force required to release the stem from the setting lever, but now I need to fit the face and hands its sent me into panic mode. If it had the screw type release things would be a lot simpler but that's life 😀   Another thing I will need to consider is once the dial and hands are fitted and the movement is sitting in the case I will need to turn it over to put the case screws in. I saw a vid on Wristwatch revival where he lightly fitted the crystal and bezel so he could turn it over, is this the only option or is there another method?      
    • nevenbekriev
      Main spring

      By nevenbekriev · Posted

      Hi Jon, do You think that relation spring torque - amplitude is linear? I would rather guess that the amplitude should be proportional to the square of the torque. I had once idea to check it, but still haven't.
×
×
  • Create New...