Thread: Dial Graduating Tool !

Looking good John. As stated above, a support would be the go on the shaft.

Hi Guys,

Thank you all for your useful comments !

I agree that the shaft that the dial is supported on needs some support, its far too long and I could have made it shorter. At the time I was thinking more about supporting and securing the plastic gear than the other end. To be honest, drilling and tapping that end M4 for a screw was very much an afterthought, "How do I hold the dial" on the shaft, and then making a sleeve to apply force to the dial trapping it. If you noticed that sleeve is anodised ! It was originally an aluminium screwdriver handle. I just parted the end bit off and drilled it 6 mm.

I'm currently thinking about how to make a mount for a locking pin to go into the space between the gear teeth to get positive locking. Then the task will to be drawing up my changes and adaptations, once I'm happy with them.

I would go a block of steel in either of the top corners bolted, either drill or ream it to suit a round pin.
The round pin sharpened into a V to suit the gear and a shoulder machined near the V to retain a spring between it and the block to push it into the teeth.
Rotation of the pin shouldn't matter as it will find it's own way into the teeth.

You could also cross drill the shaft for a roll pin and cut a slot in the gear to match, which would stop any sort of rotation of the gear on the shaft.
It would be an easy job for any other gears in the future to run a slot through to suit as well.

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Originally Posted by Dave J

I would go a block of steel in either of the top corners bolted, either drill or ream it to suit a round pin. The round pin sharpened into a V to suit the gear and a shoulder machined near the V to retain a spring between it and the block to push it into the teeth. Rotation of the pin shouldn't matter as it will find it's own way into the teeth.

You could also cross drill the shaft for a roll pin and cut a slot in the gear to match, which would stop any sort of rotation of the gear on the shaft. It would be an easy job for any other gears in the future to run a slot through to suit as well.

Sent from my 5007U using Tapatalk

Thanks Dave,

That is exactly what I did See below:

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I used a Dremal abrasive disc to cut a "V" slot, coloured red in the second picture. When the retaining nut is tightened it forces the pin into the slot.

Hi Guys,

Just a few more pictures of the other parts.

23-04-2021-003.jpg 23-04-2021-001.JPG 23-04-2021-002.JPG

This first picture is the new shaft that I machined from a bit of 13 mm round bar that I found in the scrap bin. I'm not sure what it is but it machines nicely. The handle is also made from a parted off piece and threaded M4 so that it screws into the dial. I had made another index wheel from a piece of wood and stuck the printed one to it, but didn't use it.

23-04-2021-006.JPG

I found a plastic gear with the right number of teeth and only slightly smaller. I modified it so that I could use a pin to locate it on the shaft.

Thanks Guys, your support is appreciated

Hi Guys,

I've now made a holder and pin that locks the indexing gear and in turn the dial being graduated.

26-04-2021-002.JPG 26-04-2021-001.JPG

I cut a piece of scrap steel to form a 10 mm thick plate 30 mm by 35 mm. I flycut both sides in order to ensure that the edges were square and both faces parallel to each other before setting up to drill a 4 mm hole all the way through.

26-04-2021-005.jpg 26-04-2021-004.jpg 26-04-2021-003.JPG

These first two pictures are intended to show that the drilled hole was parallel to both the edges and the sides. Getting a straight hole that doesn't wander, particularly with a 4 mm drill isn't as easy as it appears. The last of these three pictures show the method used just after the hole broke through.

I wonder if the more eagle eyed will spot the cracks in the steel in the first two of these three pictures ?

26-04-2021-006.JPG 26-04-2021-007.JPG 26-04-2021-008.JPG 26-04-2021-009.JPG

These pictures are of the graduating tool with the new guide and gear installed. The middle two pictures also show a couple of modifications that I made. One of them is the filed off 45 degree slope on the bottom of the stamp holder. I did this so that I could better see the stamped marks. Since I used the M6 through holes to secure both the stamp holder and the gear indexing pin, I had to shorten the M6 cap screws on both sides so that the screws didn't run into each other. I also turned off the knurling on the cap screws on the stamp side.

I'm now ready to attempt to do the numbering of the indexes.

Thanks Guys:

Hi Guys,

Just a few pictures of the finished calibrated dial !

OK I admit it I went out and bought a new set of 3 mm stamps... I couldn't see the Pryor numbers. I had a go at stamping the 3 mm numbers by hand, as I'm quite sure is obvious. I also blacked the markings with a black permanent marker pen. It worked quite well.

I just need to make a reference line on the top of the TCG front plate. Each line represents 1 Thou.

27-04-2021-004.jpg

I drilled and tapped three 10 x 32 holes for grub screws to hold the dial on the shaft.

02-05-2021-002.jpg 02-05-2021-001.jpg

This is the dial with its handle in position on the TCG.

Now to make a guide for the 3 mm stamps.

Great result John. Those numbers look a hell of a lot better than the factory ones on my old Taiwanese lathe. Well done!!

Hi Guys,

Thanks for the nice comments.

Following my admission that I went out and bought a set of 3 mm letter and number stamps, I've now started to make a guide for them.

02-05-2021010.jpg

These are the stamps that I bought ! No there isn't one missing, its in one of the next pictures.

This set was relatively cheap compared to the 3 mm set from Pryor, however they are nowhere as good a quality or as nice to handle. The letter end is obviously pressed since every stamp has a bulge on the shaft under the letter. They are not that hard either, fine for alloy but I would be wary of using them on steel, particularly if it was a bit tough. The bulge files off quite easily, indicating that they are not very hard ! Typical cheap Chinese made.

02-05-2021014.JPG 02-05-2021013.JPG 02-05-2021012.JPG 02-05-2021011.JPG

You may recall that I had a piece of 12 mm plate that I cut up to make the body of this stamping jig. Well I found this off cut from it and machined it to width on the mill then faced off both sides with a fly cutter, only enough to clean the surface of rust and scale, before cutting a 6.5 mm deep slot with a 6 mm slot drill. The slot was a very tight fit on the sides of the 6 mm square stamp, so I swapped the 6 mm diameter slot drill for a 1/4" inch diameter one and re-cut the slot. As you can see from the last picture it is a perfect fit. Not loose and no tight spots.

Its not quite finished yet, I still have to cut the curved bit off to square it up. I've also drilled and counter bored the screw holes to use the existing M6 cap screws into the existing threaded holes. Without the DRO I feel that I would have not got the holes or the slot spot on like I have.

One of the things that I'm going to try is to make some stamps to put index marks of different lengths on any dials that I make. One of the tool suppliers near me also sell 6 mm (actually 1/4" inch) square silver steel bar so that should make producing indexing stamps easier, and they can be hardened easily.

That's it for now. Thanks Guys for your helpful comments.

Hi Guys,

Following a couple of mods I did to the stamping jig I've made and stamped my second dial !

07-05-2021-004.JPG 07-05-2021-006.JPG 07-05-2021-005.JPG

Here I've just stamped the index marks using the Pryor stamp. I used a paper index glued to a wooden disc and pinned it using the handle hole in the dial.

07-05-2021-009.JPG 07-05-2021-008.jpg 07-05-2021-007.JPG

These three pictures are using the 3 mm stamps that I bought and the guide plate that I made.

I just need to drill and tap for a grubscrew to hold the dial onto the leadscrew shaft.