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RF30 Basement Install
- Thread starter YYCHM
- Start date
I use center function a lot, very useful.
One thing to get burned in the noggin is edge compensation. For example if your DRO X reads conventional direction meaning increasing positive numbers as spindle goes right, then when you contact the left edge of your block with a 0.200" diameter edge finder, you enter <negative> 0.100 so it registers zero over the edge and positive numbers to the right. If you edge find on the RHS of block you enter +.100 and now read negative DRO numbers relative to that edge zero. Its not a big deal but something to be aware of when you are working from drawings with different reference dimensions. Good drafting & machining practice is whenever possible utilize a predominant feature as a reference datum & make the dimensions relative to that. I'm told some people prefer the Y to read negative coming towards you, some prefer (or maybe machines are set up?) opposite to that. My brain is simple so I revert to standard Cartesian coordinates. My DRO box allows me to set positive direction either way.
One thing to get burned in the noggin is edge compensation. For example if your DRO X reads conventional direction meaning increasing positive numbers as spindle goes right, then when you contact the left edge of your block with a 0.200" diameter edge finder, you enter <negative> 0.100 so it registers zero over the edge and positive numbers to the right. If you edge find on the RHS of block you enter +.100 and now read negative DRO numbers relative to that edge zero. Its not a big deal but something to be aware of when you are working from drawings with different reference dimensions. Good drafting & machining practice is whenever possible utilize a predominant feature as a reference datum & make the dimensions relative to that. I'm told some people prefer the Y to read negative coming towards you, some prefer (or maybe machines are set up?) opposite to that. My brain is simple so I revert to standard Cartesian coordinates. My DRO box allows me to set positive direction either way.
As I rolled out of bed this morning I was thinking about that edge finding stuff in my foggy head so your timing is great. Thanks
What's edge compensation called in DRO jargon? I don't see such a feature in my DRO manual. I know some DROs allow you to enter tool diameter, mine doesn't.
historicalarms
Ultra Member
Craig, I like the depth stops mounted to the jaws in your vise. I thought about doing that when I first bought mine but decided I would be forever having to remove them for irregularly shaped work pieces.
For "workable" alternatives I have collected a bunch of square cut keyway chunks from 1/4 to 7/8 sizes and a collection of ground flat bar for thinner needs.
A question, does your "movable jaw" lift 3-4 thou when you tighten onto a work piece, mine always does. Very infrequently does it make a difference on the accuracy I require but it is there and you have to watch for it if perfect accuracy is required.
For "workable" alternatives I have collected a bunch of square cut keyway chunks from 1/4 to 7/8 sizes and a collection of ground flat bar for thinner needs.
A question, does your "movable jaw" lift 3-4 thou when you tighten onto a work piece, mine always does. Very infrequently does it make a difference on the accuracy I require but it is there and you have to watch for it if perfect accuracy is required.
Depth stops? Not following what you're talking about.
The jargon is my own, I'm just trying to walk you through a common example of DRO usage. Basically you just need to be able to 'enter' a number like plus 0.100 or minus 0.100. The +/- sign is important for reasons I mentioned. The 0.100 in this example corresponds to the half diameter of your edge finder. So if you happened to have a different edge finder with 0.250 diameter stylus then compensation would be 0.250 / 2 = +/- 0.125". (A 0.200" diameter stylus is common for classic reasons, because half is 0.100 which typically an even turn increment on the hand wheel when using the manual mode graduations. Which is why you would not normally want a metric edge finder LoL)
Another common thing is entering zero like when you have found the center of a hole using DTI & now need to displace relative to that. On my box I can enter a value '0" or double click the X,Y,Z button & it nulls to zero as a bit of time saver. Each box is different.
Z can go one of 2 ways. You can contact the surface with an end mill, zero, then progressive removed material displays as -0.005, -0.010, -0.015" for example.
Another way is if you have measured the material to be 0.325", you would touch your end mill down & enter that 0.325" value directly. Now when you remove material it shows the actual reducing dimension like 0.300, 0.275 etc which is usually more meaningful. But this gets back to what I was saying above, you need to have the axis +/- DIRECTION set up so down quill = reducing DRO values.
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I got ya now, it's called "Preset Data to designated axis" in my manual and ya that would be handy alright. I've never used it before. @RobinHood showed me how to land the tool on a piece of paper then pre-set back 0.004" on the dial, back off, start up, and when you advance to 0.0 the tool should start cutting. Worked like a charm.
I just tried pre-set to compensate for my edge finder and re-measured my 3-2-1 block and came up 0.4 too long LOL.
Me thinks, this will take some study.
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Yes, I suspect what Rudy was showing is setup for milling. When the EM grabs the 0.004" thick paper, you call that 0.004" offset from the edge. So dial that value in the DRO as <negative> 0.004" because at 0.000 EM should make contact and anything positive means its cutting. The paper serves another purpose, you aren't marring the surface with the rotating EM looking for surface. Paper thickness varies BTW & keep your fingers in the safety zone.
You might not use an edge finder for this milling application because its an extra tool to insert & maybe collet too. But the other factor is even if the spindle knows where the zero edge is, the EM itself may have a slightly different physical diameter vs its nominal size (say 0.499 or 0.501" vs 0.500"). They typically have close tolerances but kind of depends. If its an important dimension, stay shy, measure & adjust accordingly.
An edge finder is more common pre-step for doing say a series of holes. You indicate off reference X and Y edges, then drill holes some relative distance away. And goes without saying, deburr your edges from overhangs which will trick your edge finding. I like to use vise stops to relocate part into same vise position because often times you can't measure in-situ, therefore the part has to come out & you don't want to go through the edge finding rigmarole all over again. Once you've experienced DRO, its hard to go back to manual mode, backlash compensation etc. Those old timers had some skills!
I use my edge finder to quickly find rough center of holes. Traverse inside the circle in X direction contacting either side of bore, use the 1/2 function, lock on X=0. Then repeat procedure for Y. So gets you close quite fast & usually center its within couple thou compared to DTI traversing the ID perimeter (which is still more accurate method).
You might not use an edge finder for this milling application because its an extra tool to insert & maybe collet too. But the other factor is even if the spindle knows where the zero edge is, the EM itself may have a slightly different physical diameter vs its nominal size (say 0.499 or 0.501" vs 0.500"). They typically have close tolerances but kind of depends. If its an important dimension, stay shy, measure & adjust accordingly.
An edge finder is more common pre-step for doing say a series of holes. You indicate off reference X and Y edges, then drill holes some relative distance away. And goes without saying, deburr your edges from overhangs which will trick your edge finding. I like to use vise stops to relocate part into same vise position because often times you can't measure in-situ, therefore the part has to come out & you don't want to go through the edge finding rigmarole all over again. Once you've experienced DRO, its hard to go back to manual mode, backlash compensation etc. Those old timers had some skills!
I use my edge finder to quickly find rough center of holes. Traverse inside the circle in X direction contacting either side of bore, use the 1/2 function, lock on X=0. Then repeat procedure for Y. So gets you close quite fast & usually center its within couple thou compared to DTI traversing the ID perimeter (which is still more accurate method).
historicalarms
Ultra Member
The two bars attached (at least it appears to have a screw holding the one to the stationary jaw) to the vise jaws that prevent the 3-2-1 block from going deeper than it is.
Brent H
Ultra Member
Parallels: https://www.amazon.ca/s?k=parallels&ref=nb_sb_noss_1
they are super great to keep your work all even
they are super great to keep your work all even
As Brent said, parallels. They come in precision ground matching pairs. I'm kind of surprised you don't have a set?
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Have you checked to see if the DRO setup programming allows #.000 as opposed to #.0000
I know some boxes work that way because machinists may prefer say X&Y with 3 digits & Z with 4 or some other combination that makes sense to them.
Or just train your eye too look at the first 3 numbers after the decimal. Because the chances of physically finishing a part to a tenth consistently is pretty darn hard on most hobby machines, so consider it as wishful thinking for now LOL
I know some boxes work that way because machinists may prefer say X&Y with 3 digits & Z with 4 or some other combination that makes sense to them.
Or just train your eye too look at the first 3 numbers after the decimal. Because the chances of physically finishing a part to a tenth consistently is pretty darn hard on most hobby machines, so consider it as wishful thinking for now LOL
All three axis twitch when you lock them down LOL.
Clearcutter
Member
One strip of black tape across all those 4th digits should do the trick! LOL It would drive me nuts as well. Would be interesting to see if you could shut that off like Peter says
No settings option to control number of digits displayed.
@DPittman the setup resolution is for setting the scale resolutions.
I may do the tape thing yet LOL.