This was inspired by Oxtools and NYC CNC. A 12" Rahn RoR is useless on my 18x24 surface plate. To answer some ?s, the feet will affect measurement if they do not fully contact the test surface. Hinge arm effective length is from pivot to surface contact, you can extend this by lengthening the arm and moving the pivots for less angular error. Stan has a very good surface plate, mine look more like an XGame skateboard park. Thx for the comments, criticism often makes a better design (more brains are better than one). Except for a 0.0001 dial indicator, this was built from rems. Cheers, Mike at Catalina Racing
Thanks Mike & Stan for sharing! This inspired me to try something along your lines, and my crude efforts at this is explained here: www.homemadetools.net/forum/repeat-reading-gage-diyswedes-cheap-o-meter-73022#post134042 Cheers, DIYSwede
Thats a tidy little design. Nothing quite like a dedicated tool for the job to save all that messing with a marking gauge / scribing block n dti. Thanks for uploading and sharing Stan.
That is an EXCELLENT tool! Thanks for sharing. It is now on my bucket list and by the way thanks for the plans. I have an old surface plate 36" square by 4" thick that I know is out of calibration, I will soon be able to address that to get it close to a true surface. Adequate for my needs I would think. Thanks again, Cheers from John, Australia.
Thanks for sharing that, and thanks to your buddy at Catalina. It's fascinating to see what other people build for tooling, and this little unit seems to work well!
Hello thank you for your helpful videos. Ihave one qoetion: Its not important if the carbide peaces that you leted on the bottom be different size? Best regards sina
Big thanks to Stan for finishing the mini RoM. Had suggested surface grinding the feet, but Stan using a large diamond lap. Dummy me, had a big diamond lap in the kitchen and never though about using it.
So, if where the knob on the top is. If that were changed out to a second dial indicator and could from there reach thru a hole to zero on the surface plate. Couldn't you zero two spots at the same? time?
The 3 carbide feet form a ref plane. If you zero the indicator on your plate, any indicated deviation when sweeping the plate is referenced from that plane/location. This device finds wear spots and can be used to profile your surface plate with some accuracy. I have a -0.00045" deep trough where a height indicator must have lived for a long time. Gave a RoM to a friend with a AA plate with certs, he thought the RoM didn't work til he over swept the edge. This device is handy when buying a used surface plate, might get the price down if you can live with an A plate.
Old Iron Shops Good question. My intuition says the vertical displacement of the indicator will be whatever it is, meaning however far the front point is out of the plane formed by the back three feet. If I’m correct in that assumption, then the swing arm radius only determines where you’re measuring relative to the location of the base feet and it can be whatever you like.
This was inspired by Oxtools and NYC CNC. A 12" Rahn RoR is useless on my 18x24 surface plate. To answer some ?s, the feet will affect measurement if they do not fully contact the test surface. Hinge arm effective length is from pivot to surface contact, you can extend this by lengthening the arm and moving the pivots for less angular error. Stan has a very good surface plate, mine look more like an XGame skateboard park. Thx for the comments, criticism often makes a better design (more brains are better than one). Except for a 0.0001 dial indicator, this was built from rems.
Cheers,
Mike at Catalina Racing
Catalina Racing 38super thanks for sharing.
Thanks Mike & Stan for sharing! This inspired me to try something along your lines, and my crude efforts at this is explained here:
www.homemadetools.net/forum/repeat-reading-gage-diyswedes-cheap-o-meter-73022#post134042
Cheers, DIYSwede
Thats a nice little machine, looks doable without mills and stuff
Thats a tidy little design. Nothing quite like a dedicated tool for the job to save all that messing with a marking gauge / scribing block n dti. Thanks for uploading and sharing Stan.
Nice Stan! glad the black max worked out for you. Its my go to glue.
ATB, Robin
I noticed the label says "refrigerate" how important is that?
I keep mine in the fridge all the time. It seems to last longer that way.
I also keep my CA in the fridge it helps a lot on the preservation.
That is an EXCELLENT tool! Thanks for sharing.
It is now on my bucket list and by the way thanks for the plans.
I have an old surface plate 36" square by 4" thick that I know is out of calibration, I will soon be able to address that to get it close to a true surface. Adequate for my needs I would think.
Thanks again, Cheers from John, Australia.
Thanks for sharing that, and thanks to your buddy at Catalina. It's fascinating to see what other people build for tooling, and this little unit seems to work well!
Great video! I'm fascinated with Metrology,,,alot to learn! Thanks for sharing.
Thanks for another project. Just downloaded the drawings.
R. Steven Lang, Shark River Machine I know right
Thanks Stan and Catalina Racer. Nifty little tool -Jim
Sure do appreciate you sharing this and the drawings. Thank you.
Great project, nice approach to get it done... Thanks for the schematics...!!!
Thanks for sharing Stan and thanks Mike at Catalina racing for putting it altogether!
Thx for sharing that Stan - super useful.
Not as fancy as John's but certainly seems effective and a simple solution. I like it!
Great! Now we just need the poor man's autocollimator, and the skills to properly use and interpret both tools...
I have far more tools than skills...
Thanks for sharing Stan. I see that being very useful.
Nice little tool. Thanks for sharing.
Another project added to the list thanks Stan!
nice tool. Thanks for sharing.
Thanks for doing a video and sharing.
Hello thank you for your helpful videos.
Ihave one qoetion:
Its not important if the carbide peaces that you leted on the bottom be different size?
Best regards sina
Big thanks to Stan for finishing the mini RoM. Had suggested surface grinding the feet, but Stan using a large diamond lap. Dummy me, had a big diamond lap in the kitchen and never though about using it.
Thanks for sharing Stan!
Hemm. Stan this gives me an idea.
So, if where the knob on the top is. If that were changed out to a second dial indicator and could from there reach thru a hole to zero on the surface plate. Couldn't you zero two spots at the same? time?
Nice!
Great Video Stan.
What are we measuring? The irregularity of the surface under the Carbide Feet or the surface under the Indicator Tip
Under the indicator.
The 3 carbide feet form a ref plane. If you zero the indicator on your plate, any indicated deviation when sweeping the plate is referenced from that plane/location. This device finds wear spots and can be used to profile your surface plate with some accuracy. I have a -0.00045" deep trough where a height indicator must have lived for a long time. Gave a RoM to a friend with a AA plate with certs, he thought the RoM didn't work til he over swept the edge. This device is handy when buying a used surface plate, might get the price down if you can live with an A plate.
Just wondering how important is the distance from the pivot to the indicator on one of those?
Old Iron Shops Good question. My intuition says the vertical displacement of the indicator will be whatever it is, meaning however far the front point is out of the plane formed by the back three feet.
If I’m correct in that assumption, then the swing arm radius only determines where you’re measuring relative to the location of the base feet and it can be whatever you like.
Thomas Utley I wonder what Robyn thinks