T-8 with DRO

[micha]

Dear fellow Tormekers,

I just want to share my attempt of adding DROs to the machine. It's still kind of beta-testing - but so far I'm very happy with the results.

I had thought about DROs for a while, when I found some with very reasonable prices. I ordered one just to confirm it would do the trick.

This is how it looks now:
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I wanted something that could remain mounted but wouldn't get in the way somehow. So I printed some hinge and added a clip for the usb. After some trial-and-error it works really well. It can be folded back (and even down) easily.
(As you can never know the whole device can be taken out from the hinge, it's just press fit.)

The clip coupling, after being reinstalled, gives the same values as it had before. It's repeatable and reliable and precise enough. 

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Because it worked so well, I added another one on the FVB. Maybe I'll change the fixture so that it can be folded down the other way, but I've had no problems yet. (And it can always be removed with one hand, if really needed)



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One thing to keep in mind is that you won't be able to move the readout to a real zero position. Of course there is the hinge and the housing, so you'll have to work with an offset. I calibrate the system by setting the USB to 10cm with a height gauge, then set the DRO to zero. Now I just had to add that offset in the calculator - using TormekCalc made that easy. Recalibration is usually only needed if you change the batteries. (For some reason the DRO notices movements even when it's switched off.)

Well, I know that this may seem a very over-engineered way of doing things.  Anyway, I enjoyed the challenge and the tinkering. And now I have to admit I don't really miss all that fiddling with gauges and calipers while sharpening.

Other thoughts and observations:
- I never turn the machine around, if you do, that might be something to consider as there are some additional wires

- The DROs are Rear:20cm/8", for the FVB: 15cm/6" are more than sufficient

- Both of the DROs were less than 80 $, the plastic parts were 3d-printed as needed.

- the attachment of the hinge required two M3-threads in the zinc housing (might be an issue with warranty), maybe shouldn't be done carelessly.

I hope the concept is fairly comprehensible, if not, please feel free to ask.

Regards,
Mike

[gbeaklr]

Wow, that looks awesome Micha!

[tgbto]

Yup, awesome indeed. It looks like it does the job *and* is practical enough that it doesn't interfere with the sharpening process. Very nice !

[Perra]

Nice work, 

[Ken S]

Well done, Mike! Apparently there can be new things under the sun. Many years ago, our member Grepper posted a photoshopped photo of a Tormek with a digital control panel. Grepper did this as a joke. You have made the joke useful and added a whole new dimension to precision angle control.

Ken

[cbwx34]

Looks good.  (I'd second what you suggested though... switch the FVB one to the other side.)

[RickKrung]

Very interesting.  I love and depend wholly on DROs, on my metal lathe and vertical knee mill, so I can fully appreciate their use on a Tormek.  However, since I use only the distance from the USB to the wheel surface, it is irrelevant for how I work.

Just curious, you say you never turn your machine around.  It appears set up for use from the front rather than the rear, or is that just perspective for the photos?  Displays on the units themselves are facing rearward, but the remote displays on the cabinet behind make it appear otherwise.

I only use mine from the front and never turn it around.  I sit while sharpening. 

Rick

[micha]

Thanks for your interest and the kind words, guys.

@tgbto: Yes, there wasn't any interference so far. But if some problem occured, it could be avoided by just pulling out the DRO from the hinge and put it back in place afterwards. (Values are still precise enough after doing so)

@Ken: Do you happen to have that picture around? I'd love to see it

@cbw: I'll probably add a little platform protruding the FVB and just mount it in the opposite direction. Then it should fold down 180°, however, otherwise it could get in MY way . BTW: Thanks for adding the USB height calculator in calcapp !

@Rick: You're right, I always use the machine from the front. Machine is rather high, so I can stand somewhat comfortably. The linear scales don't have a display on the units themselves. Here is an example, identical in construction and with the same parts supplied.

Here's mine from the opposite perspective:
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So there are just two completely independent displays on a wire .  I made a frame which keeps them in place and allows for decent readability:
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Adding another point to thoughts and observations, which I forgot to mention:

- the attachment of the hinge required two M3-threads in the zinc housing (might be an issue with warranty), maybe shouldn't be done carelessly.

(Guess I'll add that in the first post, too.)

Regards,
Mike

[3D Anvil]

Looks very cool.  Forgive my ignorance, but does this setup actually move the USB to the set height, or is it just displaying the set height digitally?

[micha]

It's just an alternative method to measure distances. You can still move the USB by hand or by the EzyLock nut, respectively. There is no considerable resistance in sliding that black sensor box along the rail.
The only advantage is that you don't have to operate rulers or calipers while setting the USB height, it's a bit more hands-free.

Now adding a stepper motor will be a logical next step

[3D Anvil]

It's just an alternative method to measure distances. You can still move the USB by hand or by the EzyLock nut, respectively. There is no considerable resistance in sliding that black sensor box along the rail.
The only advantage is that you don't have to operate rulers or calipers while setting the USB height, it's a bit more hands-free.

Now adding a stepper motor will be a logical next step

That's what I'm talkin' about.   

Now let's get really fancy.  Put a sensor on the USB to measure the progress across and have the stepper motor adjust the height as you move the jig across the bar to maintain a consistent angle with curved blades.  Programmable curves!

[Perra]

Might be a new rabbit hole... but we like those, don't we   

[Ken S]

  

Ken

[Thy Will Be Done]

No comment on the focus of the thread here but cannot help but notice that your grinding wheel is severely loaded with steel.  I would never let my stone end up that way and frequently dress the wheel to remove this as it occurs.  You'll get more burnishing than cutting in the state pictured, you want the stone to cut freely and this requires frequent regrading unless you are using high enough pressures in grinding to actually cause the stone to release abrasive to refresh the surface.

[micha]

Chris,
I basically agree, stones should be kept in good shape.
But in that picture, well, that's just how the SJ-250 looks after polishing the edges of 2 carbon steel chef knives. I use to clean the Japanese stone with a 1000 grit diamond plate rather than often trueing it.