centering scope

[itowbig]

anybody use the enco 45 x fine centering scope if so how does it work?
i think i know u put it in the spindle and look through the eye piece and find your punch marks and or scribed lines.
i was checking it out and thought it would be of good use for finding scribed marks and puting the drills on dead center.
Whats your opinions about this tool?

 

[mklotz]

I've never used one but I have a problem with the concept.

What we're really interested in is the location of the spin axis of the spindle since that is what determines where the tool will cut. An edge finder allows us to locate the spin axis realative to some part feature. A telescope locates the part feature relative to the optical axis of the scope, which may not be coincident with the machine's spin axis.

 

[John S]

Marv, what about spinning the scope and peering thru it every rev ?

.JS

 

[bearcar1]

I have never had the opportunity to use a centering scope, although I have been watching for one to come available at the right price ;D. Having said that, I have read somewhere that the optics in most of them are such that the table motion of the machine is reversed. That is, if you move the table one way it appears to move the opposite direction in the viewer tube. The higher end tools have mirror/prism setups that compensate for this. (I *think*) As far as the tool axis, I can't say that I would have a problem in that area, one would just have to be aware of this fact and machine accordingly.

 

[Tin Falcon]

Itowbig:
I too have admired them in the enco catalog. I believe they work as you said.
I thing for ultra precision work they may be justified provided there is some adjustment. I use a double ended edge finder or a wiggler to pick up locations when precision is needed. as far as holes I mostly eyeball with the center drill installed. but a pointy end on the edge finder or wiggler works here as well . I do not do the pointy ends under power when picking up a punch mark .
A similar device to the enco scope can be made with an inexpensive web cam and an old pc you see the "spindle" view on the monitor. Such a device can be used for quick and close copy a part programming with Mach 3.
You could always buy one of the scopes and write a review.
Tin

 

[mklotz]

Marv, what about spinning the scope and peering thru it every rev ?

.JS

A very British solution, indeed. I wouldn't expect anything less from a bunch of folks who invented the Reliant.

 

[GailInNM]

I had one about 20 years ago that I bought for the express purpose of aligning the guides on a stylus controlled punch press that was being used for greater precision than it was designed. It worked very well for that purpose using precision glass scales.

Afterward, I mounted it in a dedicated tool holder for use in a milling machine. The scope was adjustable to bring the optical axis in line with the rotational axis, however the adjustment was not easy to do and was not very rigid. It would get out of adjustment easily. As I recall, I finally wrapped a turn or two of stretch wrap, like is used in packing, around the two adjustable areas and put some epoxy putty over the stretch wrap. That kept in alignment with the dedicated tool holder. Still it was too cumbersome to use for everyday machining operations. The only real use I put to after that was for measuring interlayer laminate thicknesses on the edge of multilayer printed circuit boards, using a DRO for readout. Since those were relative type measurements axis alignment would not have been important.

I do not have one now. They are a fun toy, but I think that they would find limited use in the average home shop.
Gail in NM,USA

 

[steamer]

Horologists use them rather frequently for aligning on an existing feature or measurement.

Dave

 

[BobWarfield]

I have a cheap one and didn't like it very much. The field of view was narrow and dim.

If I were interested in revisiting the concept, I would prefer one of the webcam conversions to the optical variety. They seem to produce a much nicer result.

Best,

BW

 

[baldrocker]

I wouldn't expect anything less from a bunch of folks who invented the Reliant

Marv
This from a citizen of a nation that had to invent Ralph Nader? :hDe:
BR

 

[steamer]

Marv
This from a citizen of a nation that had to invent Ralph Nader? :hDe:
BR

....... ;D......good one!

 

[speakerme]

Hello,

I have a centering scope and like it very much. It is true that the optical axis is not always lined up out of the box, as it were. It is simple to adjust, with the x/y table locked, drill a small bore crater to mark the test object, remove the chuck and drill, place the centering scope in a collet, use the adjustment screw to correlate the center of the crater, the scope is now dead nuts on the center of the spindle. The view through my scope is bright and clear. You can also use a carbide tip chucked in a drill or R8 collet, instead of a drill in the spindle to mark a spot on a test piece, so that you can align the scope. Just takes a minute or less and you are now at zero/zero. Literature suggest that it is accurate to about .0005"
It is a nice addition to milling, I have not used it on the lathe, but could do so with a set of ER25 collets that fit the tailstock to center a marked piece in the four jaw.

Once you have the scope centered then larger holes, in your work piece can have their center found by the scope by optically centering the line in the scope in two perpendicular axis by moving the table in one direction, then the other till the line visible in the scope is in the center of the hole in both x and y. To check it you rotate the scope in the collet by 90 degress. If you are "on", the line is in the center of both halves of the circle. Set the DRO or your measuring rings at zero and you are on the money. This method is not quite as accurate as the one described above but if you have to go back and find a center for threading, chamfering, or whatever it works well. In fact very well IMOP.

Best Wishes

Chuck M

 

[steamer]

Thanks Chuck,

I have one also and though I can't say I have used it in anger yet, your description is consistent with the "manual" that came with the unit.

I got it for my small mill, but I am sure it would work well on the lathe too.

Dave

 

[putputman]

I have a center scope and seldom ever use it.

They are very accurate once you have centered the cross hairs. You use just like an indicater, that is you rotate the spindle and read from four directions. Not always easy to to get your head in back of the spindle.

If you are just going to use it to pick up on a center punch mark or scribe mark, a pointed wiggler and a magnifying glass is just as accurate and much faster.

 

[John S]

I have one, a Russian toolroom model, nice thing about these Russian ones is you don't need an exterior light source because they glow in the dark ;D

I don't use it because I find it too infuriating, it's like that Blake Co-ax indicators, they are too long.

You have to wind the table down fit the scope or co-ax, wind up centre the part, wind down to clear, remove and then wind all the way back up for the tool to reach.

In that time you could have achieved the same thing quicker in another way.

Something else is that unless the head is trammed exactly vertical then the point where a long scope of indicator reads central is not the same point a small cutter touches the work.

JS.

 

[itowbig]

OK then . i read that the thing is adjustable. i was just thinking that it would be easy for me to use cause i scribe lines but find it hard to hit the mark when its time to drill. i don't have a dro too much $$$$$ i can barely buy metal most of witch i got to scrounge for. thank you for all your input's I'm going to give it a lot more thought before i fork out cash for this.
i know that i need something to help me hit the mark.
again Thank you all

 

[mklotz]

There will always be a need to do layouts directly on somes part but, for small models, it's often easier to just use an edgefinder and the handwheels to locate features via coordinates.

While I may do a rough (i.e., ruler and Sharpie) layout to prevent mistakes, I do most of my parts by locating by coordinates dialed in on the handwheels. I don't use a DRO although I do have two 2" DIs fitted to ease the compensation for backlash. (Prior to fitting the DIs, I used just the handwheel calibrations.) I can't remember the last time I centered on the intersection of two scribed lines.

Locating by coordinates, done carefully, can be amazingly accurate. Even if you don't want to completely give up laying out directly on the part, give it a try. It's also much faster than fitting/removing some over long (JS was spot on about that) mechanism every time you want to locate another hole or whatever.

 

[itowbig]

marv i have figgered out how to use the hand wheels corectly yet its confusing to me. one day im sure to figer it out.
also with the back lash ( ithink its called) its very frustrating. i have the 2x mill harbor freight speacial.
one day maybe i can get dros. im learning. ive got to practice with the hand wheels more and measure as i go in order for me to understand how the dials work ect. i keep reading hear and there and pratice what ive read im sure ill get.
thank you. ill pratice with the hand wheels.

 

[Mainer]

I bought one from MSC a few years ago, tried it, found it unacceptably inconvenient to use, and sent it back. The concept is great, but I found the reality lacking.

Re: backlash. Once you get used to it, allowing for backlash (always take up motion in the same direction) becomes automatic. You won't even think about it.

 

[John S]

Re: backlash. Once you get used to it, allowing for backlash (always take up motion in the same direction) becomes automatic. You won't even think about it.

Once you have driven a Reliant overcoming backlash is so automatic you have to read others reports on it as you no longer have to worry about it. Above 35 mph you don't steer a Reliant, you aim it.

JS.