Johnwa
Ultra Member
@jcdammeyer i have a 600 ppr optical encoder that I hope to use as a standard. I plan to gear it up by about 1:5 with timing pulleys. That will give me about 3000 ppr which should be good enough.
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Compound needs a better degree dial
- Thread starter Susquatch
- Start date
Is that a 150 line encoder or 600 line? Remember in quadrature the # of lines is multiplied by 4. So a 600 line would give you 2400 edges per rev. That's a resolution of 0.15 degrees.
Johnwa
Ultra Member
I can’t find my order but I think it was this one.
The one I have in hand doesn't really have the sensor dead center. But it is close. Maybe even close enough.
No 3D printer here yet. I'm pretty sure I'll be getting one soon enough though. But first I have to learn Fusion. That might take a while at the rate I'm going. I get frustrated with it and have to start over all the time. Maybe by the time I'm ready to buy, much better ones will be available. Ya, thats my story. It's a perfectly valid reason to take my time......
Note in the description.
Incremental rotary encoders 600 p/r (Single-phase 600 pulses /R,Two phase 4 frequency doubling to 2400 pulses). AB 2phase output rectangular orthogonal pulse circuit
So without any reduction you get 0.15 degrees. If you added a toothed belt with a 20T and 30T pulley then you multiply the 2400 by 1.5 and get 3600 pulses per rev which will give you your 0.1 degree.
From a comparison perspective my Bergerda AC servos come with 2500 line encoders and x4 gives 10,000 pulses per rev or 0.036 degree resolution but you need a more expensive encoder if you want to play that way.
I just received a couple of these CUI encoders for my AR3 Robot Arm at $34.60 each. They can be programmed for various quadrature resolutions; 48 to 2048 PPR x 4.
a smile
Lifelong hobby - cold iron
Proximity switch or mechanically triggered travel switch is a good choice, you can make it linkage control your spindle switch (because your feed power comes from the spindle)
Johnwa
Ultra Member
Here’s an alternative AS5600 board. It’s a little easier to mount.
The corner to corner dimension on that is 32.5mm. My stub is only 26mm in diameter. So that wouldn't fit without cutting off the corners. I'm not against doing that though as long as that does not affect the boards functionality by cutting any circuit paths.
I'd be *very* surprised to see anything electrical anywhere near the corners. I've ordered 4 just to mess around with.
[Edit:]
There are some photos down in the reviews where you can see the traces more clearly.
Me too. But nothing is certain till we see it first hand.
The more I read, the less confident I get about using one of these Rotary Encoders with my DRO.
I did figure out how to align it all though.
I can make an aluminium plug to hold the magnet in the compound. The plug can be turned on the lathe to fit the ID of the compound and the OD of the magnet. This will provide perfect axial alignment of the magnet.
I can also make an alignment cross hair to fit the outside if the compound stub and then move the chip and board till it is perfectly centered. A round window might work just as well as cross hairs.
All that's left after that is to set the gap. I can do that with some modelling clay on the chip to seat the Aluminium magnet holder to the right depth in the compound.
I did figure out how to align it all though.
I can make an aluminium plug to hold the magnet in the compound. The plug can be turned on the lathe to fit the ID of the compound and the OD of the magnet. This will provide perfect axial alignment of the magnet.
I can also make an alignment cross hair to fit the outside if the compound stub and then move the chip and board till it is perfectly centered. A round window might work just as well as cross hairs.
All that's left after that is to set the gap. I can do that with some modelling clay on the chip to seat the Aluminium magnet holder to the right depth in the compound.
The 125mm Z Table I ordered from Ali has also arrived. It's a rather expensive way to get a marked collar with degree graduations but prolly still cheaper and certainly better than what I could make on my own. I've disassembled it (which was no easy feat) and still believe it should work. It's just a bit shorter than what I'd really like. It's only a matter of turning the inside OD to match my compound Plinth and lining it up perfectly. I'm thinking about installing it with set screws so it can be removed and/or adjusted in future. It can be used with my existing scale but it also has a vernier zero built into its base that I might be able to salvage for my application.
I've been fussing with how to mount this piece in my lathe off and on all day now.
It is aluminium with an anodized surface. It scratches fairly easily. When I am done cutting the center out of it, and turning the ID, it will be a ring that is about 3mm thick that should be a tight fit to the plinth of my compound. At 3mm thickness, my jaws will distort it and it will end up egg shaped. I don't want it to slip as that would mar the indicator lines on it. A huge collet would be perfect but I don't have anything that big. So I'm thinking about making a steel ring a fair bit thicker to hold this ring while I work on it. Perhaps with one slot in it to make it modestly adjustable. I'd locate the slot under a jaw.
Anybody ever do something like this and have suggestions for me? Things to do and things not to do?
It is aluminium with an anodized surface. It scratches fairly easily. When I am done cutting the center out of it, and turning the ID, it will be a ring that is about 3mm thick that should be a tight fit to the plinth of my compound. At 3mm thickness, my jaws will distort it and it will end up egg shaped. I don't want it to slip as that would mar the indicator lines on it. A huge collet would be perfect but I don't have anything that big. So I'm thinking about making a steel ring a fair bit thicker to hold this ring while I work on it. Perhaps with one slot in it to make it modestly adjustable. I'd locate the slot under a jaw.
Anybody ever do something like this and have suggestions for me? Things to do and things not to do?
Just spitballing here... what about an aluminum faceplate chucked into your 4-jaw and super glue the degree plate to it and then trepann (sp?) out the part you don't want?
Clickspring does this all the time to deal with thin brass parts
Clickspring does this all the time to deal with thin brass parts
Watched a few episodes to see what you mean. Not bad videos. Mostly meat, well documented, lots of tips.
Love the lathe stock centering tool - sort of like a wiggler to get stock running concentric. I've always used a hammer and halved the difference on an indicator. The wiggler is FAST.
His method might work for my plate if I keep the cut temperature down to avoid losing the glue grip. My primary concern is marring it if it ever came off. I think my steel collar is more certain. But finding a 6" collar to hold the 5" scale is no small task. Might have to make it from plate.
Still looking for other ideas.
140mower
Don
I glued some aluminum wheel spacers to my faceplate...... Skeptical, I was.... work, it did. I took fairly light cuts especially in the beginning.
I suggest trying a piece of scrap aluminum and seeing what it takes to un-glue it. Heat is the enemy of the bond though, so keep that in mind. (look at me telling an engineer to build and destroy.... Lol I do believe that's the life mission of the breed, is it not?)
I suggest trying a piece of scrap aluminum and seeing what it takes to un-glue it. Heat is the enemy of the bond though, so keep that in mind. (look at me telling an engineer to build and destroy.... Lol I do believe that's the life mission of the breed, is it not?)
Yup. I'd try it as I think it would be less sketchy than trying to grip the edge.I glued some aluminum wheel spacers to my faceplate...... Skeptical, I was.... work, it did. I took fairly light cuts especially in the beginning.
I suggest trying a piece of scrap aluminum and seeing what it takes to un-glue it. Heat is the enemy of the bond though, so keep that in mind. (look at me telling an engineer to build and destroy.... Lol I do believe that's the life mission of the breed, is it not?)
I hear you guys. Please consider that the glue would be on the end of a 2.5mm thick tube the inside of which will be bored to a 115mm ID. It's a rather precarious hold. I can definitely take very shallow cuts but at 120mm and that much metal to trepan and then bore there is a lot of leverage trying to pull the glue and ring apart. I don't have a lot of confidence in that compared to what would essentially be a huge collet.
I am even thinking I can index the collet so the inside that holds the degree sleeve is always concentric regardless of the jaw pressure.
@eotrfish - a 6 or 8 jaw is one thing I don't have. Someday maybe one will show up.
@140mower - even as a boy I loved destructive testing. But this is a very expensive ring for what it is. I don't think I'd have the courage to buy another one if this one got wrecked.
I am even thinking I can index the collet so the inside that holds the degree sleeve is always concentric regardless of the jaw pressure.
@eotrfish - a 6 or 8 jaw is one thing I don't have. Someday maybe one will show up.
@140mower - even as a boy I loved destructive testing. But this is a very expensive ring for what it is. I don't think I'd have the courage to buy another one if this one got wrecked.