X limit switch location

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lami3d
Posts: 205
Joined: Sat Oct 29, 2016 7:40 am
Location: Marseille - France

X limit switch location

Postby lami3d » Mon Mar 06, 2017 2:38 pm

Hello,

now that i've replaced all the shafts on my printer, it appears that the original issue i suffer is that the frame (or structure) is a parallelogram instead of a square (that's what i'm trying to show to raise actually). The shafts bent were a consequence of that.
I calculate an angle of 0.8° leading to a 6mm delay of the limit switch on the left... And so, the printhead can hit the left shaft before the screw hits the limit switch.
I'm waiting for Raise3d answers (i've just sent them the videos).

Raise already asks me to check the location of my limit switch and it's at the same location as my new N2.

You can help me by answering to these 2 points :

1- there are 3 holes at the rear of the frame and, on my 2 printers, X limit switch is screwed on the 2 holes on the left (there's one hole that stays free on the frame at the right of the limit switch) : is your X limit switch installed on the 2 holes on the left or the 2 holes on the right ?
It's like raise engineer asked me to install my limit switch on the right holes to solve the issue but 1, i'm not ok because i don't solve the root cause and 2, i think that it's possible to hit on the right if i install limit switch like that

2- when X is at home (X=0), what is the distance between your printhead and the sliding block of the left shaft ? (i have about 8mm on my new N2)

Thank you by advance if you can answer these questions
Attachments
Basic drawing.pdf
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Jetguy
Posts: 1147
Joined: Tue Mar 22, 2016 1:40 am

Re: X limit switch location

Postby Jetguy » Mon Mar 06, 2017 2:49 pm

This is as simple as performing the standard gantry alignment procedure by loosening the setscrews on the pulleys and aligning the system square. And given the original shipping brackets, this would be a trivial task to achieve alignment.

Again, step 1, loosen the set screws on the pulleys for both sides of X and Y axis.
Snap the clips on both axis such that the gantry is now aligned and held.
Tighten the setscrew pulleys to lock in this new alignment.

lami3d
Posts: 205
Joined: Sat Oct 29, 2016 7:40 am
Location: Marseille - France

Re: X limit switch location

Postby lami3d » Mon Mar 06, 2017 3:10 pm

Jetguy,

because it's you, i'm going to do that again
I would like that it's the case but i don't think.

Jetguy
Posts: 1147
Joined: Tue Mar 22, 2016 1:40 am

Re: X limit switch location

Postby Jetguy » Mon Mar 06, 2017 3:28 pm

Just you said you replaced all the rods. I would think that given what you have drawn and measured, that would be my test and adjustment.

Now, it's possible but unlikely during shipping that your machine was seriously bend or damaged, but I would think that would be visible as damage and alignment issues to the upper plastic body when screwed to the frame. Just wondering if you took a framing square with the entire top removed what that looks like to the square milled upper frame. Because it's my understanding that that entire one piece frame is CNC milled to get all the alignments for Z axis rods as well as the XY axis rods. Because it's milled- that determines the bearing pockets and thus rod and hole alignments.

Being a DIY builder, I don't have this luxury of a giant one piece machined frame so I have to manually do all these alignments and relationships whenever I build a machine from scratch. Just saying, unless there is some error I cannot think of- this is just assembly alignment because the gantry was built and installed off square.

lami3d
Posts: 205
Joined: Sat Oct 29, 2016 7:40 am
Location: Marseille - France

Re: X limit switch location

Postby lami3d » Mon Mar 06, 2017 4:56 pm

It could be more understable that this issue comes from a shaft that is not aligned than it comes from a frame.
But, i've spent my week end checking, testing and mesuring things and i conclude that the issue should come for something else...
If the shafts are ok, i doubt about the frame. But maybe, it's not the frame, it's another thing but like i said to raise, i'm really tired with this.. i bought this printer to use it, not to spend 5 monthes to search where my issues come from and replacing the parts ones after anothers...

So, i've performed the procedure 3 times because, the 2 first times, i tried to "cheat" by helping the printhead and its 2 shafts to rotate a little bit in the right direction, to recover a shaft parallel to the frame.
And it seemed to work but it pops from the good position when i adjust the other shaft.
So, if i want to be ok with the "clips", i have to move some pulleys... and when i move these pulleys, the belts are not straight and it's harder to move the printhead.

But, i've got "a new hope" : raise didn't send me the axis that passing through the printhead and maybe, they are also bent and prevent from good alignement ?

I don't know what to think anymore.

I 'm going to make a break and i will loose the screws, the pulleys... and check everything again.

Tx

lami3d
Posts: 205
Joined: Sat Oct 29, 2016 7:40 am
Location: Marseille - France

Re: X limit switch location

Postby lami3d » Mon Mar 06, 2017 7:43 pm

I manage to improve the situation but i feel it blocks all the kinematics if i want it good.
So, i have to get 2 new center rods to replace them and it's possible that it improves the situation again to get a nearly good alignment (it can't be perfect for this printer i think) and a nearly safe operating printer. Maybe not...

I put 2 tools that hold the 2* X block belts (very good tools !) and i untighted the 16 screws that maintain the 2 rods of the printhead and i slowly rotate the assembly to get good at X and Y axis with the clips (i've got 4 clips). If i force, i think i can get it good but it blocks somewhere or, maybe the sum of little manufacturing tolerance limits that lead to a less adjustable system that the average ? i don't know...

mtsmetzler
Posts: 7
Joined: Tue Mar 22, 2016 7:20 pm

Re: X limit switch location

Postby mtsmetzler » Thu Mar 09, 2017 2:22 am

While replacing my x and y drive rods I found that my printer frame was out of square about 5mm. There are a large stack of shims on three corners allowing the gantry to square up a little bit. Many of the holes in the acrylic cover were re-drilled to allow the cover to kind of fit. Both doors are bowed when installed but lie flat when removed from the machine. The smooth Z axis guide rods should be anchored at the top, only one of them had a set screw in it, one had a broken tap, that might work. Using the raise "squaring" method can quite easily give you a parallelogram. Very much impossible to square IF THE FRAME OF REFERENCE IS NOT SQUARE! Squaring to a bent upper frame won't work. These frames were not bent in shipping, they warped while being welded together. (Just like the x and y rods weren't damaged in shipping, just garbage material with no quality control.) Aluminum is tricky stuff and requires significant bracing while welding. Most aluminum frame work I work with is jig welded and allowed to cool in jig then heat treated to further reduce internal stresses before removal from the jig. My machine was poorly welded on a bench and a shoddily squared in a mill. I am a Toolmaker by trade, a Mechanical Engineer by degree. I know junk work when it is in front of me.

Jetguy
Posts: 1147
Joined: Tue Mar 22, 2016 1:40 am

Re: X limit switch location

Postby Jetguy » Thu Mar 09, 2017 4:04 am

And what would it cost if you or your company made this machine?
Instead of less than $3k, it would be about $30k.

Just saying, you are not wrong and yes, you absolutely know the best way of doing it- but, but, but, nobody could afford to pay you to build printers to that spec.

lami3d
Posts: 205
Joined: Sat Oct 29, 2016 7:40 am
Location: Marseille - France

Re: X limit switch location

Postby lami3d » Thu Mar 09, 2017 11:34 am

i would have also bet to a production defect more than a bang during shipment.
i was working in helicopters manufacturing as mechanical engineer and sometimes i had to control complex airframe with laser measuring to find the root cause of an issue because there are issues also, even if the cost is not the same... I know "strange" things can happen in production.

As i will change again some parts, i'm going to check the frame this time but it seems to be better than yours ! As i had no doubt about the frame when i replaced the shafts, i didn't noticed it was welded... I will tell you if it's welded. Every welded parts needs solid process, good tools and good checks, alu in particular. But, if it's not the case, maybe your frame is a old old one or a rebuilt one ?

mtsmetzler
Posts: 7
Joined: Tue Mar 22, 2016 7:20 pm

Re: X limit switch location

Postby mtsmetzler » Mon Mar 13, 2017 4:26 pm

Jetguy, I would take +/- 1mm! Should be able to hit that at this price! :)

lami3d, I was a KS backer, received an early machine. They were quite obviously still dialing in the process of assembly, that thing had a 12 ft long usb cable coiled up under the bed! The upper aluminum frame was welded then machined. They cleaned up most of the welds in a mill but still some evidence left behind.

At a little over 800 hrs., my machine did complete its task in spite of multiple mechanical failures, paid for itself by landing a job and justified the purchase of a more robust machine and was dismantled, re-purposed.

I liked the touch screen machine interface the most, very easy for a print jockey to use with little training.

ABH
Posts: 75
Joined: Sun Aug 14, 2016 7:31 pm

Re: X limit switch location

Postby ABH » Wed Mar 15, 2017 8:06 pm

Price and quality are two interesting variables.
Sometimes you get poor quality because a manufacturer deliberately prioritizes low manufacturing costs and sells a very cheap product.
This choice is kind of acceptable, you get what you pay for.
Sometimes however, you will get poor quality when it would not have been more expensive to deliver good quality, and that is annoying.
My printer also had defects when I received it and I was really annoyed by this because it would not have been more expensive for Raise3D or their sub-supplier to deliver good quality. On the contrary actually, - bad quality costs a lot in handling complaints, guaranty repairs, loss of reputation etc.
Most of us in this community want Raise3D to be successful, so it is really a shame, if they cannot control their manufacturing processes and apply sufficient quality control.
Raise3D printers are excellent printers with some nice design choices. There are no other printers as solidly built as Raise3D, the UI is exceptional and their printing quality is excellent.


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