Author Topic: Repeat-o-meter  (Read 805 times)

Offline mattinker

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Repeat-o-meter
« on: June 28, 2017, 03:33:16 PM »
Revised video!

Here is a video about a Repeat-o-meter that I have just built. it is for checking surface plates for hollows in the surface. This build is directly related to the 91cm x 91cmx 15cm granite surface plate that I just bought in preparation for scraping and the Richard King Scraping class in December! I have also been following a Tom Lipton John sanders collective build of the same tool. i realise that I didn't give an explanation about why I used the lathe to grind the feet flat, I don't have a big belt sander or a surface grinder, so it was the only way to get all four "feet" flat!

<a href="http://www.youtube.com/watch?v=o8GU7hRp_Ec" target="_blank">http://www.youtube.com/watch?v=o8GU7hRp_Ec</a>


Curious to have your thoughts, regards, Matthew
« Last Edit: June 29, 2017, 05:41:47 AM by mattinker »

Offline awemawson

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Re: Repeat-o-meter
« Reply #1 on: June 28, 2017, 04:29:42 PM »
I'm looking forward to seeing this in the flesh in December Matthew.

(BTW I'm getting a 12 minute gap from 30 m to 42 m on playing your video)
Andrew Mawson
East Sussex

Offline mattinker

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Re: Repeat-o-meter
« Reply #2 on: June 28, 2017, 04:46:55 PM »
Thanks Andrew!

Offline mattinker

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Re: Repeat-o-meter
« Reply #3 on: June 28, 2017, 04:55:23 PM »
Ooops!

I've made a mistake in the editing, thought I'd checked it through! So I'll swap out the the bad for the good video as soon as I can redo the mix!

Sorry about that! regards, Matthew.

Offline PekkaNF

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Re: Repeat-o-meter
« Reply #4 on: June 28, 2017, 05:33:04 PM »
VERY nice!

Thank you for showing. I found the mentioned first part, but haven't seen the second part yet.

Pekka

Offline mattinker

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Re: Repeat-o-meter
« Reply #5 on: June 28, 2017, 06:17:14 PM »
Thanks Pekka, re-editing, compiling, will repost as soon as i can reload up to youtube!

Regards,matthew

Offline mattinker

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Re: Repeat-o-meter
« Reply #6 on: June 29, 2017, 05:45:17 AM »
VERY nice!

Thank you for showing. I found the mentioned first part, but haven't seen the second part yet.

Pekka

Pekka, I've swapped out the video for the complete version, it's not very different, no blanc space at the end and two shots of the finished painted item at the end.

Regards, Matthew

Offline mattinker

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Re: Repeat-o-meter
« Reply #7 on: June 29, 2017, 05:48:43 AM »
I'm looking forward to seeing this in the flesh in December Matthew.

(BTW I'm getting a 12 minute gap from 30 m to 42 m on playing your video)

Hi Andrew, I've put up a corrected version! Its not very different, no empty space at the end and two views of the finished painted item!

Looking forward to using it in December! Regards, Matthew

Offline awemawson

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Re: Repeat-o-meter
« Reply #8 on: June 29, 2017, 07:29:36 AM »
Very smart Matthew - it just needs a nice polished oak plush lined casket with brass hinges and lock  :wave:
Andrew Mawson
East Sussex

Offline mattinker

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Re: Repeat-o-meter
« Reply #9 on: June 29, 2017, 07:33:17 AM »
Very smart Matthew - it just needs a nice polished oak plush lined casket with brass hinges and lock  :wave:

I agree with you about the case, but it might well be painted plywood with green felt inside (both in stock!).


Offline vtsteam

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Re: Repeat-o-meter
« Reply #10 on: June 29, 2017, 08:48:11 AM »
Looks very nice Matt!  :beer:

One thing I missed seeing in the video is the Repeat-O-Meter in use on the surface plate you wanted to check with it at the start. How is it used, and was the plate flat?

Also..... sorry I'm not familiar with this tool..... if the balls are pressed in, how does the gauge end move up and down? Wasn't there a ball under that one?  And if the two stabilizer bars on the side are loose, what do they do -- or do you tighten them up?

I'm sure there are answers to all this, once you own one. But your video is the only thing I know about it!  :clap: :clap:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline mattinker

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Re: Repeat-o-meter
« Reply #11 on: June 29, 2017, 09:27:30 AM »
Looks very nice Matt!  :beer:

One thing I missed seeing in the video is the Repeat-O-Meter in use on the surface plate you wanted to check with it at the start. How is it used, and was the plate flat?

i hadn't tried it when I filmed it, i thought I'do a video of mapping out the plate to follow!

Also..... sorry I'm not familiar with this tool..... if the balls are pressed in, how does the gauge end move up and down? Wasn't there a ball under that one?  And if the two stabilizer bars on the side are loose, what do they do -- or do you tighten them up?

The steel balls are pressed in and then ground flat, I finished them with wet 'n dry abrasive paper, once the balls were nice and smooth, I made a flexion by drilling a hole close to the bottom edge and slitting from the top down into the hole, leaving 1.2mm+/- so that the single ball/foot under the dial gauge can move up and down (within the elastic limit of the flexion!) whilst the three that remain under the mass of the body sit on a flat area of the surface plate. Them two "floppy" bars on the side are there to stop the lower front bar from "drooping" as there's nothing there to support it but the flexion. I think that these are more of a safety feature than anything else! I included a link to a Tom Lipton video that explains the us of the Repeat-o-meter 


I'm sure there are answers to all this, once you own one. But your video is the only thing I know about it!  :clap: :clap:

More coming, regards, Matthew

Offline vtsteam

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Re: Repeat-o-meter
« Reply #12 on: June 29, 2017, 10:13:50 AM »
Thanks Matt!

So the ball under the gauge is not pressed into place like the others, but is free to move up and down? And the side bars effectively put a limit on the upper and lower range of movement of the indicator -- hope I have that right?
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline mattinker

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Re: Repeat-o-meter
« Reply #13 on: June 29, 2017, 10:20:24 AM »
Thanks Matt!

So the ball under the gauge is not pressed into place like the others, but is free to move up and down? And the side bars effectively put a limit on the upper and lower range of movement of the indicator -- hope I have that right.

Nope! All four balls are pressed in, there is a flexion that is situated next to the two central balls, this allows the 20 x 50mm bar to bend near the middle, three of the balls under the heavy end provide a reference point, the remaining ball is under the dial gauge indicator. The side bars are there to stop the flexion bending too much and going beyond it's elastic limit!

Regards, Matthew

Offline PekkaNF

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Re: Repeat-o-meter
« Reply #14 on: June 29, 2017, 10:24:31 AM »
Nope, the upper part is (semi) rigid beam, that screw disc is only for adjustment.

The lower body is split half - there is a flexure (hole cut free from other side). All balls are rigidly attached. Three balls support the back of the meter and this "beam" on the top. Front part is sort of tailgate, this flexure allows it to follow countour of the surface plate.

Those loosely attached arms on the side work exactly the same way that tail gate keepers on pick-up truck. Prevent that part from dropping down when the instrument is lifted.

Purpose of the balls is to give a defined contact, when flat is not flat enough - you can describe a plane with three points, then you fourth somewhere and indicate how much it it is different.

Hope this helps,
Pekka

*Nope, was to VT---- :lol: Matthew beat me just narrowly :wave:

Offline vtsteam

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Re: Repeat-o-meter
« Reply #15 on: June 29, 2017, 11:18:49 AM »
Okay, got it!

Or as we used to say,

Click.

 :lol: :lol: :lol:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline mattinker

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Re: Repeat-o-meter
« Reply #16 on: July 16, 2017, 05:51:49 AM »
Here is a video about using the Repeat-o-meter, a little fuzzy in parts. I'm slowly getting the hang of this video stuff!

<a href="http://www.youtube.com/watch?v=wG6sJuhZlUs" target="_blank">http://www.youtube.com/watch?v=wG6sJuhZlUs</a>

Offline awemawson

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Re: Repeat-o-meter
« Reply #17 on: July 16, 2017, 08:43:23 AM »
Nicely shown Matthew - I look forward to seeing the result of you sliding it over my 4x8 foot surface table when you come in December - I've no idea how good or bad it is  :scratch:
Andrew Mawson
East Sussex

Offline mattinker

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Re: Repeat-o-meter
« Reply #18 on: July 16, 2017, 08:52:55 AM »
Andrew,

Looking forward to it!! If somebody has a good long straight edge or maybe I can find or make on by then, I could make a "Planekator"

regards, Matthew