[CNCer__]

The number of issues with my new PCNC 1100 is already overwhelming, for me anyway. The last one I've currently discovered is the perpendicularity of X-Y motion. I can really make a horror stories videos titled: how badly my machine is made. Backing to the subject perpendicularity of X vs Y motion - I can explain this issue in a few lines as per below, plus a short video. Is there anything else than poor manufacturing to cause this issue? In other words, can it be fixed somehow? I'll be probably forced to return this unit to Tormach for a refund. However, it's a nightmare for me as I'm in Ireland and that's so much hassle to pack it and send back to US with all accessories like an e.g. deluxe stand, etc..

Perpendicularity of X-Y motion:

Allowable error (as per factory certification):
0.04mm per 200mm

Factory measured (as per factory certification):
0.02mm per 200mm

User reading (new machine), calculated from the below measurement:
0.10mm per 200mm

User reading (new machine):
0.075mm per 155mm

VIDEO of the measurement: HI-Res
VIDEO of the measurement: Lo-Res
VIDEO of the measurement with DTI: HI-Res
VIDEO of the measurement with DTI: Lo-Res

Tools used:
- certified (Grade A) Granite Square
- Haimer 3D-Sensor New Generation
added video test with
- Mitutoyo 513-405T Dial Test Indicator (0.002mm Graduation, +/-0.003mm Accuracy)
- Noga NF 1022 Centering attachment

[DubMFG]

Now this may seem a bit stupid, I mean, its a granite square after all. But can you repeat your test with the square strap clamped down onto the bed of the machine, not against the moving jaw of a vise? And use a dial test indicator if you can.

Not affiliated with tormach or anything, but eliminating the stackup of stuff from the bed of the machine is what I would do before testing. That and I dont trust a haimer for run along readings like that. I know its fine, I just use my dial test for that sort of stuff.

[philbur]

Have you checked that the x axis reverses back to zero?
Have you checked the square by reversing it in the vise and repeating the test?
Have you checked the gib tightness?

Phil

PS: also as pointed out by the previous poster I think that the Haimer 3D-Sensor is not actually designed for such measurements.

[tmarks11]

Every machine needs to be adjusted after setup to ensure that it is in tram.

Not necessarily a manufacturing issue.

A $30k bridgeport, once you plant it on the shop floor, is out of tram on every dimension.

Cast iron isn't as rigid as you think it is. Jacking up one foot of the stand 1/8" too high will make your head nod off or lean to one side. Tightening the bolts to the stand too tight? Ditto.

I have a LOT of Chinese and Taiwanese machines. My 1100 is the highest quality of the bunch.

Here is one of the best posts I have seen on here for tramming your machine:
http://www.cnczone.com/forums/tormac...ml#post1645434

BTW, your video looks like you are tramming you vise.... those type of measurements are taken to align the vise to the machine axis (and you tap it with a dead blow hammer until it is square). The vise isn't guaranteed to be precisely aligned to the table even with vise keys. That is why you tram your vise when you install it. Those measurements don't really show any need to align the machine itself.

Putting vise on the table just is inviting a stack up of errors unassociated with the machine itself.

You want to check tram, then you need to take your DTI directly on the table (no vise) and swing it 360 degrees around to check nod and tilt. And then put a precision cylindrical square on the table and check the z axis up and down on each side to check perpendicularity.

[CNCer__]

Thanks guys for your thoughts. My first post is updated with videos test where I've used the dial test indicator. Links are also here:
VIDEO of the measurement with DTI: HI-Res
VIDEO of the measurement with DTI: Lo-Res
New video tests made with:
- Mitutoyo 513-405T Dial Test Indicator (0.002mm Graduation, +/-0.003mm Accuracy)
- Noga NF 1022 Centering attachment

Have you checked that the x axis reverses back to zero?
When DTI will be moved a few times left-right on the measured surface there will be some shift on the reading approx. 2-4 microns but on both ends, so the final reading is still approx. 0.075mm.

Have you checked the square by reversing it in the vise and repeating the test?
The granite square was already verified for the 90deg angle with simple but reliable test:
The measured deviation on the longer cathetus showing the same value and direction of angle with the hypotenuse on left or right side. Verified when I was checking the Z motion in relation to X and Y motions.

Have you checked the gib tightness?
All gibbs were tightened, definitely above the point where the loose of movement starts increases.

Update:
tmarks11 - We are not discussing a tramming issue. It's all about squareness of X motion vs Y motion. This relation: x-axis vs y-axis is generally independent of floor, stand, etc..

[philbur]

Update:
tmarks11 - We are not discussing a tramming issue. It's all about squareness of X motion vs Y motion. This relation: x-axis vs y-axis is generally independent of floor, stand, etc..

I think his point was that it is possible to twist the bed if you don't follow the correct procedure when bolting the mill to the stand, causing the x and y axes to show as being none perpendicular.


Phil

[CNCer__]

I was also considering this scenario but how bad the twist has to be to affect x-y squareness? With this relatively light machine it's hard to make. Also tramming Z-Y is actually perfect (measured on 3 points of X-axis, start/middle/end). The Z-X is quite terrible but not twisted so no risk of affecting the X-Y squareness by the bad tramming. The PCNC and deluxe stand were also properly leveled with precision 0.3mm/1m and also the machine was correctly installed on the stand. Believe me or not but I'm paying attention to details like these. The leveling precision of 0.3mm per 1m was recommended as the maximum (even not worth the effort) by a professional toolmaker/machinist with tons of experience. This machine is too light and not accurate enough to go crazy with the leveling as he said. He was also suggesting to slightly tilt it to the left to help drain the coolant (and this should not affect the accuracy tramming, etc. for this machine ).

[tmarks11]

I think his point was that it is possible to twist the bed if you don't follow the correct procedure when bolting the mill to the stand, causing the x and y axes to show as being none perpendicular.

No, I missed that he was concerned about the X and Y axis weren't operating perpendicular to each other (despite that statement in his post). Not really an adjustment for that.

Call Tormach and see what they have to say.

[CNCer__]

Call Tormach and see what they have to say.

I'm calling them since 09 of August 2016 when I've received this machine. The only visible results of their support so far is my developed insomnia. The machine is still not usable. It's not made to spec. in a few points. When your small business depends on the condition of the machine situation like this really hurts.

[Steve Seebold]

After watching your first video, I'm not surprised you'd be out of square.

When you clamp a part off center like you are in the video, especially with the long edge against the movable jaw, your vise jaws are not going to close parallel.

The shape of the part you are trying to hold is going to make it very difficult to achieve what you're trying to achieve.

[CNCer__]

After watching your first video, I'm not surprised you'd be out of square.

When you clamp a part off center like you are in the video, especially with the long edge against the movable jaw, your vise jaws are not going to close parallel.

The shape of the part you are trying to hold is going to make it very difficult to achieve what you're trying to achieve.

Steve please read my first post again, think what is under the scope, verify the method and see the video once again. It's not a part, it's the engineering square (grade A). The engineering square will not even twitch during this test.

[TurboStep]

Steve, I know you're a big fan of Blasocut 2000 but you haven't started drinking it?... Have you ??
Step

[Steve Seebold]

Steve please read my first post again, think what is under the scope, verify the method and see the video once again. It's not a part, it's the engineering square (grade A). The engineering square will not even twitch during this test.

I realize it's an engineering square. I'm not saying the square is the problem. I'm saying the way you're HOLDING it is the problem.

[SCzEngrgGroup]

I realize it's an engineering square. I'm not saying the square is the problem. I'm saying the way you're HOLDING it is the problem.

And how is it possible to hold to such that one side reads perfectly parallel to the Y axis, yet the X axis is NOT perfectly parallel to the X axis, unless either the square or the machine is NOT actually square?

Answer: It's not. The way he's holding the square may not be ideal, but it CANNOT explain what the video shows. Since he indicated the square is high-quality, the only logical answer is the machine is out of spec.

Regards,
Ray L.

[CNCer__]

Steve, I fully agree that the holding method is not the best choice. However, the granite square has a short flat section on the opposite side to the measured long one. It's enough to clamp it well in the vise. See the full shape of the granite square:


Hi-Res Image

[mechfeeney]

EDIT: I read through the previous posts, this was obviously mentioned. I agree that it doesn't matter about the vice and square so long as the square doesn't move.

I would still try a precision block as a sanity check.

[CNCer__]

That is not a great object to clamp in a vice. You are clamping on a large face and a very small face, which is most likely causing rotation of the granite relative to the vice. Try using a 1-2-3 block as a sanity check.

Rotation you saying, ...OMG

[SCzEngrgGroup]

I would suggest the test be re-run, with the square clamped to the table, supported on 1-2-3 blocks, if necessary, to get the square up to a more convenient height. I would align the long side of the square to the X axis, then measure the Y axis, then flip the square over left-to-right, and repeat the setup and test.

This will eliminate any possible misalignment due to the vise, and flipping the square will also prove that the square itself is accurate. It's always best to eliminate as many variables as possible, and to PROVE the accuracy of your tools, rather than accepting the manufacturers specs as accurate.

Regards,
Ray L.

[CNCer__]

My equipment was already verified, I've never trust manufacturer specs., certifications, etc. That's why I've started checking my PCNC and I've found so many o.o.s. or faults.
Update:
Measurement with the engineering square (grade 00) showing the same numbers, unfortunately it's not the equipment or measuring method.

[Steve Seebold]

Steve, I fully agree that the holding method is not the best choice. However, the granite square has a short flat section on the opposite side to the measured long one. It's enough to clamp it well in the vise. See the full shape of the granite square:


Hi-Res Image

I don't think the square is your problem. I think the problem is the way you are holding it.

Turn the square around and put the long edge against the fixed jaw and retry your test. It's possible to tweak the movable jaw when you clamp a part the way you are holding it.