Microscope for instrument setting

[Milling_man]

Hello colleagues.
In our work, we use face mills with diamond inserts. These cutters are individually adjustable for each tooth so that they all have the same height. The tolerance of even the most accurate indexable inserts is 10-20 microns, and the maximum error should be 1-2 microns. This process is well described here - https://mapal.com/medias/sys_master/...stem-Power.pdf
Diamond plates VERY do not like contact methods of measurement. Microchip occurs instantly on them. Therefore, we adjust the cutter using a microscope with a camera - we put it on the machine, insert the face mill into the spindle. Then we orient the spindle to the desired angle and adjust each tooth. The problem is that our microscope has a very small working distance, about 1.5 millimeters. Therefore, we are forced to look at the plate from the side. At the same time, we see an indistinct edge of the plate - this makes work difficult.
Now I'm looking for some kind of "microscope" with which we can look at the front side of the plates when setting up. The cutter has a diameter of 125mm, so we need a "microscope" with a working distance of at least 45mm (1.77 inches).
I specifically put the word microscope in quotation marks, because I'm not sure that we need a microscope.
Our camera has a pixel size on a matrix of 1.35x1.35 microns. With the microscope we are currently using, we have a magnification of about x11. The camera lens has a magnification x0.5. As a result, when the cutter tooth moves 1 micron, it moves 4 pixels on the screen - this is good.
According to my calculations, we need some kind of optical device that will allow us to mount a camera from a microscope, with a magnification of about x6-x10 and a working distance of 45-60mm (1.77-2.36 inches).
I know we can just buy a $200,000 Zoller But now we've almost solved the problem with a $90 camera and an old microscope that costs me about $300. Therefore, I hope to find something that will finally solve all our difficulties.
I almost forgot one of the most important requirements - this optical device must have some kind of precise surface on the outside so that we can accurately align it with respect to the axes of the machine. The cutter teeth have a radial runout of about 10-30 microns, this runout is not adjustable, and if the axis of the microscope is not parallel to the axis of the machine, this will lead to measurement errors.
Now we have a camera like this: https://aliexpress.com/item/32965556068

Similar Threads:

• Digital Microscope
• centrecam usb microscope
• Carl Zeiss Toolmakers microscope?
• Mach 3 with USB microscope for scanning
• microscope project

[deadlykitten]

hy

Diamond plates VERY do not like contact methods of measurement. Microchip occurs instantly on them

as long as they can cut, it means that they don't like setting with contact methods above a limit that leads to cracking ... in other words, a more gentle contact method should work

The cutter teeth have a radial runout of about 10-30 microns, this runout is not adjustable, and if the axis of the microscope is not parallel to the axis of the machine, this will lead to measurement errors

there are devices with a flat/kind or rectangle screen, thus they can easy handle those 10-30um caused by runout, etc - but they are bigger, etc

specifically put the word microscope in quotation marks, because I'm not sure that we need a microscope.

idea of using a microsope is ok, like it works, but you lose precious time because you set it inside the machine, and also it may be a less comfrtable position for the operator that does that alignment

---

let's try and do that setting outside the machine; please, i need :
... photos with toolholder, so to see the clamping method, height adjustement method, and up/down faces, in order to prepare/check it for outside future setting, because it's one thing to do it outside, and another is to do it inside the machine, so is needed to know how runout changes between outside & in-spindle
... photos with insert
... describe/show those methods that lead to cracking the insert / kindly

[deadlykitten]

and another idea, just kicked me a few seconds ago : somehow is possible to speed up all future settings, by using a custom toolholder and a set of incremental seats on which you mount your inserts

for example, use a toolholder with 3 grooves, labeled 1 2 3 : for each groove, you have a set of seats, numbered a b c d e f, etc

those seats are machined heat treat, with a difference in size of 2-3ums, thus a is 0, b is +2um, c is +4um, and so on

you mount that toolholder in your spindle, bring a dial ( it shoould be a dial on a custom fixture, so to ensure kind of perpendicularity, nothing fancy ), and, when you notice heigh difference, you simply change to another seat; idea behind all this aproach is to achieve a fast&acurate in machine setup

---

another idea is to use a rough and a finish toolholder :
... for that rough one, you leave it as it is, thus forget about adjustments, as long as it is within "normal" range and inserts can take it
... for the finish one, you use only 1 insert ( so to do no alingment ) or 2 inserts ( so to do 1 aligment ), and use it only for finishing; thus reduce setup/alignment type, by lowering the number of inserts

what do you think ?

[Milling_man]

---

another idea is to use a rough and a finish toolholder :
... for that rough one, you leave it as it is, thus forget about adjustments, as long as it is within "normal" range and inserts can take it
... for the finish one, you use only 1 insert ( so to do no alingment ) or 2 inserts ( so to do 1 aligment ), and use it only for finishing; thus reduce setup/alignment type, by lowering the number of inserts

what do you think ?

If it was acceptable to leave one plate, we would have already done it It's very slow. For the same reason, we use diamond inserts rather than carbide inserts. In addition, why reduce the speed of work relative to what we already have now?

and another idea, just kicked me a few seconds ago : somehow is possible to speed up all future settings, by using a custom toolholder and a set of incremental seats on which you mount your inserts

for example, use a toolholder with 3 grooves, labeled 1 2 3 : for each groove, you have a set of seats, numbered a b c d e f, etc

those seats are machined heat treat, with a difference in size of 2-3ums, thus a is 0, b is +2um, c is +4um, and so on

you mount that toolholder in your spindle, bring a dial ( it shoould be a dial on a custom fixture, so to ensure kind of perpendicularity, nothing fancy ), and, when you notice heigh difference, you simply change to another seat; idea behind all this aproach is to achieve a fast&acurate in machine setup

I'm sure it won't work. Pay attention to the procedure, which is described in the document from MAPAL, to which I gave a link in the first post. They first tighten the cartridges to the correct torque, and only then make the final adjustment. In my experience, the position of the cartridges changes by +- 1-5 microns when tightened, unpredictably.

[Milling_man]

hy

as long as they can cut, it means that they don't like setting with contact methods above a limit that leads to cracking ... in other words, a more gentle contact method should work

Of course, not every touch on the plate causes it to chip. But any movement on the plate of something harder than plastic in a direction other than the worker leads to chipping. We have already tried many things. It's not even about the distance of the measuring device, but about turning the cutter against its working rotation. And this is inevitable when lowering the cartridge, the spindle does not hold the position perfectly.

idea of using a microsope is ok, like it works, but you lose precious time because you set it inside the machine, and also it may be a less comfrtable position for the operator that does that alignment

---

let's try and do that setting outside the machine; please, i need :
... photos with toolholder, so to see the clamping method, height adjustement method, and up/down faces, in order to prepare/check it for outside future setting, because it's one thing to do it outside, and another is to do it inside the machine, so is needed to know how runout changes between outside & in-spindle
... photos with insert
... describe/show those methods that lead to cracking the insert / kindly

Our cutter is very similar to the MAPAL cutter from the document in the first post. And the setting is exactly the same. Specifically, we have a Sumitomo RF4125 cutter. I note that the tooth can only be accurately moved down. If you made a mistake and moved it too much, you need to raise it obviously higher than the rest and again begin to gently lower it.
I thought about adjusting outside the machine, but stops the moment of accuracy. The mandrel fits into the spindle with a curvature of, say, 1 micron. The cutter stands on a mandrel with a curvature of 1-2 microns. Due to all these errors, even if we set up the cutter perfectly somewhere outside the machine, this does not guarantee its good installation on the machine. We are far from ideal arbors and not the coolest machines. If we had them, I would probably just buy a Zoller and not break my head over it)))))
There is no inconvenience with setting up on the machine - after all, the microscope has a camera. The operator sees the cutter's tooth on the laptop's tap, and reaching the cutter to lower the tooth is not a problem.

[deadlykitten]

why reduce the speed of work relative to what we already have now?

hello again that was only a wild thougth ... sometimes, is possible to achieve overall shorter duration with more cuting time + signifiant shorter setup time

Pay attention to the procedure, which is described in the document from MAPAL

sorry, i can't open that link; please, try to attach the file

In my experience, the position of the cartridges changes by +- 1-5 microns when tightened, unpredictably

it may be possible to achieve higher acurracy, by using a different toolholder design

they first tighten the cartridges to the correct torque, and only then make the final adjustment

i am thinking of a method to clamp the cartridge without any after all adjustements; if i get it right, idea behind your current toolholder is to rough mount the cartridge, then fine tune it's position : this approach means more screws and a more complex holder; i would be after high precision cartridges, clamped simpler, rigid, but more consistent

It's not even about the distance of the measuring device, but about turning the cutter against its working rotation. And this is inevitable when lowering the cartridge, the spindle does not hold the position perfectly

my dear milling man, is not ok to setup tools on plate, not even for cheap inserts; a similar method to what you are doing is used in gang lathes, but final tightening is not done when there is contact, but in mid-air, at least for sensitive/small tooling

---

you should replace the plate with a dial inside a custom fixture, above which you continously rotate the spindle back/forth, without the risk of breaking the inserts; it is faster than using a microscope / kindly

[deadlykitten]

something similar to image 01, but maybe more acurate dial + less spring force ?!

is possible to craft it in house, with a smaller flat area above, in order to reduce contact time between insert and this device; you could use a hard steel shank, like o5mm*20-30mm long, with paralel faces, that slides inside bore finally, you can use it for futher checkings, as shown in image 02

if you decide to go with such a device, then consider to always adjust inserts position without reversing spindle sense, because the dial may be less consistent if you reverse the spindle; also, is not critical for the rod face to be paralel to table, thus it can be tilted visually wrong 1 mm or more; what matters is to avoid it's rotation during measurement ( simply use a marker to draw a line across it and housing ), and always consider/record the max value shown by the dial, even if it does not corespond the position where the insert is right in the middle of the rod; such advices are there to avoid extra/useless accuracies when crafting such a thing, thus you can get few um accuracy with a rough device, as long as you use it properly / kindly

[Milling_man]

I am attaching a document from MAPAL to the message.
Believe me, contact methods will not work here. I tried to use them many times in the last 7 years. This always led to damage to the plates (Sumitomo plate price 120 euros). Therefore, only a microscope, or a laser.

[Jim Dawson]

I don't know if this would be useful to you. This is something I built to play with a few years ago.

The camera is a 640x480 CCD, the spindle microscope is 50X, the focal length is about 25mm. The camera lens is 16mm CCTV standard.



The only part I needed to build was the slip-on adapter.


This is the mint mark on a penny. The total image width is maybe 0.75mm? I'm not sure about that, I never calibrated the image. With a higher resolution camera, I think it could be pretty accurate. I wrote the image capture software for a project many many years ago. Much better software tools available today. The crosshairs shown are in the microscope reticle and are about 3 pixels wide and are removable in this case. 1 pixel crosshairs can be overlayed on the image and would be much more accurate.

[steryd]

There are all series of presetters basing on microscopes with contouring cameras. We are using DMG one, but as far as I know haimer bought all the staff from DMG some time ago.

There are also other producers, maybe cheaper, but it is definitely the best thing U can use for cutters setting.

[Milling_man]

The camera is a 640x480 CCD, the spindle microscope is 50X, the focal length is about 25mm.]

Thanks, I didn't even think about the optical sight finder. Alas, the working distance of my probes is also not large, a maximum of 20mm.

[deadlykitten]

Sumitomo plate price 120 euros

hello again please, what part are you refering to ? what is this plate ?

Believe me, contact methods will not work here

for example, if you would setup like in attached image, inserts could break ?

also, please share a link to the inserts that you are using / kindly

[Milling_man]

hello again please, what part are you refering to ? what is this plate ?

Sorry, I wrote the wrong word. Of course, it should have been said insert, not plate.
Now we have almost switched to Chinese PCD inserts at $20/piece, but perhaps with an increase in the level of production, we will return to the original Sumitomo inserts again. But the point here is not so much the price of the plate. $120 is the price of 2 hours of work of our workshop. The real problems begin when, due to a micro chip on one insert, all the inserts on the cutter fail. And, according to Murphy's law, this happens on the weekend, when there is only an operator in the shop who cannot change the inserts himself. A day of downtime - $ 720 tells us bye-bye.
Inserts we use SEHT 1204:
https://aliexpress.ru/item/100500136...11de4aa6V7Lz0n - we bought these inserts recently, for testing. I was impressed that these guys can make chipbreakers.
https://aliexpress.ru/item/100500190...11de4aa6V7Lz0n - SEHT120404-flat We have been buying these inserts for a long time and in large quantities. Previously, the quality was good, but now it no longer satisfies us.
Regarding the contact method. We tried to use an inductive sensor with a division value of 0.1 microns (very convenient, by the way - you can see how a car drove 100 meters away). Its force is about 0.02-0.04N. Anyway, this led to damage to the inserts

A couple of days ago, the optician who helps me accidentally found a suitable lens for $45. Now I'm waiting for it to be delivered. I hope this solves all my problems.

[deadlykitten]

hy miiling, i was just thinking of this thread a few seconds ago, then i saw the notice in e-mail

however ... these days, i have been verifing prices and checked failure resons for such contact methods

there are pcd inserts in iso shape and custom shape; most iso are for turning, while most custom shapes are for milling; even more, when it comes to toolholders, the adjustable ones tend to use custom shapes, thus the client will pay more for the toolholder ( in comparison to a normal / non adjustable type ) and may become bounded to the vendor because of custom inserts; not knowing what kind of inserts you use, i don't know if you have been 'traped' or not idea is that a custom shape insert will cost more, simply because it is being manufactured in a lower quantity, and it may be a biger/heavier insert in comparison to iso ones; thus some extra cost may be there with a less comon insert

in short, not all extra prices are justified; this is why i asked for your insert type like exact type, not a general thing like pcd

going with china/other alternatives, even if cheaper, in the end is kind of a ratio : if there had been made 120parts with an insert that costs 120$, then is there also 20parts made with a 20$insert ? or more, or less ? thus if an insert is 6 times cheaper, then it has to deliver at least 6 times less parts, in order to justify it's cost; in reality, in many cases, a cheaper insert leads to trouble, or, in other words, an insert that is 2 times more expensive may deliver 3-4-5 times more parts ....

i have been preparing setups that last long, like months, etc, so in this kind of repetition, there is room for testing inserts, and so on, like getting to know details, or more precise, those details that make a difference; with all respect, from an economy, cost calculation point of view, it does not matter that $120 is the price for 2 hours of that workshop, thus the reference is not that that is mere an average

there may be inserts >20$ and <120$, with a better life time, or so on, etc ...

as for the unexperienced operator, simply prepare in advance 3-4 tools, that you leave him for the weekend, so he just replaces them in the spindle

as for tool cost, etc, you may go with simple classic steel, forged or aluminiun type, crafted in house ?! each one with his own advantages, etc ...

so, there are many things, like special products that are kind of trap to clients, experimenting with different insert shapes in order to lower inserts/tooling costs, crafting your own stuff, etc

in the end, is up to you how much you wana go this line i have been manufacturing tools, various incremental spare parts, etc, so a bit i am into such stuff

is possible to get/craft a few such tools, each one with it's own inserts, that you use to test in the long run, or as spares for the weekend ... as you said, you have beein doing this for 7 years now i generaly go custom for setups < 1 year / kindly

ps : i saw you edited while i was typing ... i will check that later

[deadlykitten]

very convenient, by the way - you can see how a car drove 100 meters away

hello again seems interesting, can you develop a bit ? how does that work ?

i am a bit more free now, so this thread will cover technical details; pls be patient, its dense

[ about non contact ]

seing the reply from jim dawson, made me think a bit more : there are such solutions developed for small gang lathes, where tools are small ( like a nail ), and therefor aligning them is hard, also room for hands inside the cabinet is restricted; latest years have been developed camera systems for such machines, thus you install the camera in there, and jog the machine from outside, also use a pc to see and calculate things:
... input "citizen Tool Setting Microscope - 1.5mm Bar" in your web browser
... also input "citizen genswiss camera"

there is a user on cnc zone : A_Camera ; he can do things, worth try for an opinion

another idea, is to contact precision optic system guys, like the ones in charge with scope design, engraved lens, etc; manufactuing stuff for such, their products are prety tight on tolerances, and they sure know stuff, at least more than i do maybe an analog device is possible ?

[ about contact ]

being fragile, such inserts require gentle hands & gentle equipment; also smooth movement is required only in some directions, thus is not enough to have gentle hands, but also to know the direction towards which to aplly movement, and how to reposition, etc; such stuff takes a bit long to cover, there may be things/tricks

as for gentle equipment, lowest measuring forces comes from :
... test indicators ( small ones, like dial dia < 30mm ) with increased palpator length ( means that the dial will no longer operate at 1:1, thus will no longer show 0.01mm output, if 0.01mm where inputs; longer palpators are changing that ratio, but longer palpators still behave as 1:1 if input movement is small, like few um; in order to master this, is needed to know how to check accuracy/curve of such dials; ratio for radial dials changes with palpator length and motion/distance ); instead of a sphere end, is needed a flat-spoon kind of palpator ( surfaces are grinded, smooth ), because is harder to hit that "sweet spot" of a sperical palpator, for such things as facemills
... magnetic bases with low force adjustement, thus their articulations are hard, strong, while adjustmenr force is finess

*in that pdf of yours, at image 8, that system is rough, is not sensitive enough: that's why they recomand aluminium probe; also, in that photo, is a problem, because that dial is 1um scale, circa 1um accuracy ( wild guess is 1.2-1.5um s ), +-0.05mm range, and the needle, is at 0, thus right in the middle of the travel : this leads to useless extra force; such inserts should be aligned within 5um/3um, etc, so is not needed to hit the middle of the range, but only the mere begining, like make the adjustemnt as shown in attached image 01

[ about alternative toolholders ]

nowaday toolholders are designed for minimal production cost, and maximized profit ( not for you, for the vendor ); their craft tolerance is normal, and this leads to messy solutions for adjusment type toolholders; for example, please take a look at image 02

I was impressed that these guys can make chipbreakers

yup, it seems there exist chipbreakers on pcd inserts normally, this means more $$; if you wish, you can still use normal inserts + high air pressure thourgh tool; such pressure will bend the chip; if your spindle is not equiped with such thing, is possible to add air/coolant right near the interface between spindle and tool; normally, few persons go this way, but if you use your machine for intensive such operations, then is justified, and there are aftermarket coliers that can be bolted on, etc ... thus you add a nice function, but with low cost

And, according to Murphy's law, this happens on the weekend, when there is only an operator in the shop who cannot change the inserts himself

for example, on friday monring, prepare in your spindle a few spare toolholders, with a person that can adjust them; number each one, mark spindle phase ( so to avoid mounting it 180* flipped ), and right down frontal tir on each one; during the weekend, the less prepared operator will only mount a previuos prepared toolholder, check the frontal tir, and if all ok, then it's a go; please check image 03

[ about faster setup ]

outside the machine, prepare a few spare cartidges with inserts on them; measure each insert tip, with experienced personal, and write value on cartridge

inside the machine, measure the cartridge ( not the insert ) with mechanical contact, with less experienced personal, and if value is away with 4um, then select from the table a previous preparated cartridge, that has a reference value <4um, like 0 or 1, etc; also, imagine using an optical system and previous preparared cartridges : thus instread of going for few um adjustement, you simply change the cartridge and view result; changing is much faster than adjusting

in other words, this method is relying on previous high accuracy measurement, and is needed to use high acuracy cartriges with a flat surface/shoulder, that acts like a reference surface for measuring

if you wish, is like having a revolver, but you are not allowed to fill it with bullets as you like, but acrodingly to a list

i hope it was usefull

[Milling_man]

Hello.
Lately, I've been working on this problem a little. Fortunately, my problems are complete nonsense compared to the problems of people in a neighboring country ....
On the advice of a professional optician (who once worked on lasers for the Soviet Star Wars), I very happily bought the lens for only $55. The characteristics of this lens are similar to this one from Mitutoyo: https://shop.mitutoyo.ru/web/mitutoyo/en_RU/mitutoyo/1358419146666/ML%20Objective%20Lens%2010X/$catalogue/mitutoyoData/PR/375-039/index.xhtml First of all, I assembled the simplest system from a plastic pipe from the sewer. At one end of the pipe I fixed the lens (you can never have too much adhesive tape), at the other end of the pipe I fixed the camera. As a test sample, I used a reference hatch mark for calibrating microscopes.
A miracle - this creepy, crooked and assembled from improvised materials scheme worked! I am attaching a photo of the line measure. The distance between two large strokes is 100 microns, the length of the red line is 306 pixels. The resolution turned out to be about 3 pixels / micron. This is slightly less than what we have now (3.5-4 pixels / micron), but quite acceptable.
Now I am busy making a normal, accurate body for the lens and camera.

[deadlykitten]

you don't have to worry for no-one, those are big games

just do whatever you wish ( who said that is right / wrong ? ), officialy, then file it and lock it for a period > then your life spam, is that easy

you see, a while ago, talking to optic techinicians, could lead to valueble infos, as their equipment is for places with more importance, so there is a chance to find out things

today, briefing, no longer occurs in the classical military defense area, or, if you wish, if before it was only about military, now it may not even involve a single shot, but a mouse click

you can chose what side you are on, it does not matter ...

if you don't do nothing, you remain without information, but if you do, you could get missinformed; it's dynamic there are colaterals, but some things are staged, and most of them are old, is not like they happen now for the 1st time, but with different players ...

whatever your opinion is, things matter only if you decide to do something, and in that regard, look for those that have the potential to change something (the way you also think ) and join them ( i am not reffering to social media groups )

[Milling_man]

Hello. I will continue the story of my experiments to deceive reality
Last week I completed the optical tube, and together with our technologist, we adjusted the diamond inserts on the face mill. I must say right away that the result of the work of the mill turned out to be good. In my experience, the accuracy of the inserts in the face mill is within two microns. In my experience, the accuracy of the inserts in the face mill is within two microns.
But, as you can see from the photo below, the picture quality is far from ideal. The edge of the plate is not clear.
Our rechargeable flashlight, which has always been used to expose inserts, turned out to be disastrously weak for this optical system. As a result, I had to use the flashlight in my smartphone, which, it seems, can send an SOS signal if I find myself on a desert island.
What I plan to do in the future:
- buy a powerful source of directional light and fix it so that the light beam is directed exactly at the center of the lens
- add a green or blue light filter to the light source
- I need to try to shine on the insert from the other side. Now the light hits the back surfaces of the insert, and it seems to me that the light can "go to the sides" and because of this the edge is not so sharp. Perhaps, if you shine on the front surface of the insert, which is strictly perpendicular to the light beam, the result will be better.
- I need to try to work in reflected light, and not in transmitted light, as it is now. It is possible to apply a combination of reflected and transmitted light.

The pipe from the inside must be made matte black. Of course, it was possible to give this part for anodizing, but the pipe is made of aluminum, and the bushings at the ends of the pipe are made of steel. I wasn't sure if anodizing two different metals would work well. So we just rolled up a sheet of matte black paper and stuck it inside through the hole for lens.