rrmrd66
Part of the e-furniture
Posts: 339 
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Post by rrmrd66 on Mar 30, 2018 11:53:03 GMT
Good Afternoon..
What is the collective wisdom on "wobblers"?
I have one of those kits in a plastic pouch that looks like something a C.19 Century surgeon would carry to perform nasty operations.
Do Forum members find them accurate?
When waiting for the wobble to stop, whilst locating a datum edge during milling, what are you looking for? Is it the reflection of the machine lamp on the polished surface of the wobbler or what?
I have doubts as to how accurate they really are.
As an apprentice you would go to one of your mates and ask for a Rizla cigarette paper (were they .002" or .0015", can't remember) and use that as a feeler gauge.
The Times newspaper today comes in at .0025'. With help of DRO and the zero button I find this as good, if not more better, than all those things in the pouch.
Happy and Peaceful Easter to you all.
Cheers
Malcolm
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Post by simplyloco on Mar 30, 2018 12:06:58 GMT
Hi Malcolm
I have the same pack. I still use fag papers...
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tony9f
Seasoned Member
Posts: 116
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Post by tony9f on Mar 30, 2018 12:29:03 GMT
Chaps,
I can only say that overall I have found them to give accurate results. All you are looking for is when the wiggler has reached it's target point it flicks off the surface and as the wiggler has a ball or disc of known diameter then moving the workpiece further on by the radius of the wiggler stylus gives you a zero point. The advantage in this instance is that unlike using a feeler, you don't have to consider whether the cutter is of a regular size and more importantly, if there is any run out. I still use fag papers, Rizla silver being the thinnest.
Tony
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uuu
Elder Statesman
your message here...
Posts: 2,860
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Post by uuu on Mar 30, 2018 16:43:54 GMT
I use one. Huffam brand. Stated repeatability is one thou, which I can happily achieve.
Wilf
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Post by springcrocus on Mar 31, 2018 7:53:47 GMT
I use them regularly and, because of failing eyesight, I find it easier to set a light source behind and watch for the gap to vanish. Occasionally I get a bit heavy-handed and go past the touchpoint but then the finger usually flicks to one side. Then I back it of, give it some wobble and try again. I used to be a smoker and used cigarette papers but now deliberately keep temptation out of the way.  Regards, Steve |
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Post by runner42 on Mar 31, 2018 22:16:42 GMT
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Post by Roger on Apr 1, 2018 21:37:44 GMT
I made my own because I wanted a design that had the absolute minimum of grip on the ball. To my way of thinking, the smaller the force it takes to move the ball, the more sensitive it will be. It's a simple thing to make, I used a Carbide PCB drill to drill the holes in the Ball Bearings.
I do occasionally reference off one edge, but wherever possible, I touch one side, zero the DRO, then touch the other side and halve the distance. That guarantees that you've found the middle of the piece, and that's where I usually have my datum.
Touching both sides also means it doesn't matter if you're exactly on the centre height when you're centring a round or tapered workpiece, so long as you do it at the same height.
I reckon you can repeat to 10microns without difficuly with a wobbler, and that's way thinner than a fag paper. I use it for all my setups where I can't clock it. I only have a 7mm ball type, I've never come across a situation where I need the different varieties.
The great thing about wobblers is that runout is of no consequence.
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Post by springcrocus on Apr 1, 2018 22:23:24 GMT
... The great thing about wobblers is that runout is of no consequence. If centre-finding, it's no different with a cigarette paper. Set the dial or DRO at first grab, repeat on t'other side and halve the readings. Regards, Steve |
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Post by joanlluch on Apr 2, 2018 7:01:11 GMT
... The great thing about wobblers is that runout is of no consequence. If centre-finding, it's no different with a cigarette paper. Set the dial or DRO at first grab, repeat on t'other side and halve the readings. Regards, Steve I think that by “runout” Roger refers to this. m.youtube.com/watch?v=tD0FiDtzmS0. With a wobbler or a rotating edge finder any runout is cancelled automatically and does not have any effect for finding a centre. However, when determining a centre with a non rotating method I turn the collet by hand 180 degrees before finding the opposite edges of the part. This is also a way to cancel any runout that you may have on the mill. |
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Post by springcrocus on Apr 2, 2018 7:36:57 GMT
If centre-finding, it's no different with a cigarette paper. Set the dial or DRO at first grab, repeat on t'other side and halve the readings. Regards, Steve I think that by “runout” Roger refers to this. m.youtube.com/watch?v=tD0FiDtzmS0. With a wobbler or a rotating edge finder any runout is cancelled automatically and does not have any effect for finding a centre. However, when determining a centre with a non rotating method I turn the collet by hand 180 degrees before finding the opposite edges of the part. This is also a way to cancel any runout that you may have on the mill. I assumed that my use of the words "first grab" would indicate that I was NOT referring to a non-rotating method.  Regards, Steve |
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Post by simplyloco on Apr 2, 2018 8:31:56 GMT
I think that by “runout” Roger refers to this. m.youtube.com/watch?v=tD0FiDtzmS0. With a wobbler or a rotating edge finder any runout is cancelled automatically and does not have any effect for finding a centre. However, when determining a centre with a non rotating method I turn the collet by hand 180 degrees before finding the opposite edges of the part. This is also a way to cancel any runout that you may have on the mill. I assumed that my use of the words "first grab" would indicate that I was NOT referring to a non-rotating method. Regards, Steve Hi Steve. My mammaries are feeling the pressure again... Happy Easter John |
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Post by joanlluch on Apr 2, 2018 9:07:38 GMT
I think that by “runout” Roger refers to this. m.youtube.com/watch?v=tD0FiDtzmS0. With a wobbler or a rotating edge finder any runout is cancelled automatically and does not have any effect for finding a centre. However, when determining a centre with a non rotating method I turn the collet by hand 180 degrees before finding the opposite edges of the part. This is also a way to cancel any runout that you may have on the mill. I assumed that my use of the words "first grab" would indicate that I was NOT referring to a non-rotating method. Regards, Steve Thanks Steve, I now realise your intended meaning for “first grab”. No worries here. Take care. Joan. |
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Post by 92220 on May 2, 2018 18:48:52 GMT
I use the fag paper method a lot, and I turned up a test pin, 0.2500" dia x 2" long, in a 2MT collet so the test pin runs dead true to the collet - and it stays in that collet, which is never used for anything else. There is no visible runout when tested with a 0.0005" DTI so I am more than happy using the 0.001" cigarette paper method to find the edge of something on the mill.
For centring a hole though, or the rotary table, I always use my Linear Centre Finder that is supposedly accurate to 0.0005" TIR, and that is more than accurate for any job I am likely to do, and so easy and quick to use. I wouldn't be without it!!
Bob
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Post by atgordon on Jun 28, 2018 0:58:01 GMT
I recently was working at a customer location, using their mill, and was able to use their Haimer Taster .... if I could afford one, I would never use anything else! XYZ setting in one tool accurate to 0.001 (Z is relative, XY direct) Haimer Taster |
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Post by simplyloco on Jun 28, 2018 7:45:07 GMT
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Post by Jo on Jun 28, 2018 8:30:50 GMT
Yes I have got one. I paid about that price from china. They are rather big. I have to fit mine in a 20mm ER32 collet. Which means swopping over drawbars to a metric one. What I need is a straight 30INT holder for holding 20mm and then it would not take up so much space. I normally forget about it and use a wobbler. One of the problems with a wobbler is that when they deflect they can ride up over the work and cause a mark  Jo |
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Post by simplyloco on Jun 28, 2018 10:01:02 GMT
Yes I have got one. I paid about that price from china. They are rather big. SNIP Jo Thanks for that Jo: I didn't realise they were that fat. I'll give it a miss and stick with fag paper. |
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Post by atgordon on Jun 28, 2018 15:57:41 GMT
Yes I have got one. I paid about that price from china. They are rather big. I have to fit mine in a 20mm ER32 collet. Which means swopping over drawbars to a metric one. What I need is a straight 30INT holder for holding 20mm and then it would not take up so much space. I normally forget about it and use a wobbler. One of the problems with a wobbler is that when they deflect they can ride up over the work and cause a mark Jo I have used an electronic "beep" edge finder, and have never been truly happy with it. The beep + light isn't as repeatable as you might think, the LED light will go from very dim to bright over a 2-3 thou movement, and the beep doesn't always match the light intensity ... The unit I use is a relatively expensive Fowler USA sourced (Chinese made, of course!). YMMV! My go-to tool for edge finding is the offset edge finder: you run the spindle at 500 rpm, push the offset pin, bring it into the work until it is fully centered, and then move very slightly until you see the pin starting to moving out once again and you're all set ... I get >0.001 repeatability with this method. (though I would much prefer a Taster ... no need to add/subtract 0.200" from datum coordinates). Incidentally, the dia of my electronic unit is 0.5". Off at a tangent, if you you using ER collets, the inch "full set" of 23 collets will also hold all the usual metric sizes too.  |
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Post by Jo on Jun 28, 2018 17:23:01 GMT
I have one of those but I managed to mistakenly wind it onto the work rather than off of it and stretched the internal spring. It has not worked the same since Jo |
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Post by atgordon on Jun 29, 2018 3:11:42 GMT
I have one of those but I managed to mistakenly wind it onto the work rather than off of it and stretched the internal spring. It has not worked the same since Jo  with an edge finder, you wind it INTO the work with the pin offset once the spindle is running. See the following ov erview ... |
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