chinese stainless steel table - uneven surface

[Mohammed Issa]

hey guys,

so i got my new chinese laser about a week ago. the biggest problem i am facing is the table. it doesnt have an even surface (its not flat).

a picture wouldnt really explain the problem, so i shot a short video and uploaded it to youtube:

http://www.youtube.com/watch?v=gUA8cQxH8RU


there is about 3mm difference from one side to the other. i assume it is a bad welding job from the start.

i tried to contact the supplier, (bodor) they told me to try to use a mallet to flatten it out. i told them that will not help, as it will add more to the problem. so they told me that they will ship a new table if i pay for shipping.

do you guys think its legitimate for me to pay for shipping although the problem is the manufacturers fault?

does anyone have any solution to this problem? i really cant use that table because the focal distance will change from one side to another.

any suggestions on how to either fix, or replace it with something else that i can make somehow?

thanks in advance!!

[Talley Boatwright]

Who did you buy from? I find that alot of the Chinese company will act like it is your fault with the equipment.
If it is a bad weld job, then yes it will be hard to fix. You should not have to pay for shipping.

[Mohammed Issa]

Talley, i got it from Bodor. so far, this company is not recommended at all. i had many problems from this machine, and they were all nice and good until i received the machine. and you are right, they pretty much pin everything on us, while all the problems are from them!! but i guess you get what you pay for, right?

[Talley Boatwright]

I realize this can be frustrating. However, cutting cost doesn't mean buying cheaper quality. Whether we like to deny that fact that we are buying Chinese products, very few products are native designs or production.
My Epilog went down doing the holidays. I had to troubleshoot fast. Only to find out my encoder reader shorted out by a rubbing ribbon cable. $246 bucks later and my honeycomb table is collapsing. Epilog wants $300 for it. My chinese laser honeycomb table is heavy duty than the Epilog; and cost cheaper.

[Rodne Gold]

I would imagine shipping will be far more than the table itself. Is there no one locally you can contact to fix it, would be the best solution re time and possibly expense.

[Steven Cox]

I agree with Rodney, a sheet metal shop should be able to help you out, they might be able to straighten it or shim it up or make a new one and do it quicker & less expensive than mucking around with freight.

[Keith Outten]

Underneath the table you will find adjustment screws that you can use to level the table at all four corners. Possibly you can reduce the problem by using these adjusting screws or maybe it is the screws that are forcing the table to be out of tolerance.

When I received the laser I purchased from Supernova the table was one inch higher on one end, it was a bit of a chore to get it level but I was able to remove most of the error by adjusting the leveling screws. Since most of the Chinese lasers have really large tables these days you will find that it is common for the table to be out of tolerance at least a little bit, the cost to produce a perfectly flat table is very expensive which is a big part of the price of a high end machine.

You can build a vector cutting type table and permanently attach it to the existing table. Use leveling set screws similar to the way router plates are installed in tables to get the secondary table as flat as possible. Honestly it is probable that you will never get the table as flat as it needs to be in order to use it for any kind of precision engraving work IMO.
.

[Mohammed Issa]

Keith, thats what i thought as well so i have completely removed the table from the machine, but the problem is still there. i do believe that they have welded the table supports (underneath the table) just a few millimeters out of place, causing the table to buckle as it is now.

im literally fighting it off with the supplier, and trying rodney's and steven's suggestions; calling local sheet metal shops to try to see if they are able to solve the problem.

[Mohammed Issa]

Thank you all for your feedback, here is the fix i had to go with:

i really didnt want to risk another $180 for shipping charges on a table i didnt know will be perfect or not, so i decided to fix it myself.
i went to a local sheet metal shop and showed them the table. they told me no one will be able to fix it.
so i went ahead with plan B that i had in mind; offsetting another table on top of the current one.
(i will write down all the details hoping this thread will help someone in the future with an uneven table)

i went to Metals R' Us, they supply metal sheets, with many sizes, i went to their warehouse and found many types and thicknesses of metal sheets. i had three options:
steel, aluminum, stainless steel. i cant go with steel, because it will rust with time (and i cant paint it because the laser will go through it), i didnt go with stainless steel for two reasons, the price, and its not easy to work with. i got aluminum!

the piece of aluminum i got covers the exact dimensions of the current table. 300mm*500mm and i went with the 1/4 inch thickness (pretty thick). i thought i would pay a lot of money for it, but it turned out to be not too bad; i paid $28 after taxes!! not too bad eh?

i went with 1/4 inch because i wanted to make sure that this new 'slab' of aluminum with not bend out of shape and aluminum is still easy to work with.

the plan:

i want to drill 6 holes through the aluminum and thread them with a tap. then use 6mm screws that will go through the old table holes and up to the new aluminum table. there will be a space of about 3/4 inch in between the two tables for calibration.

there will be a screw on each corner of the table and 2 screws in the middle for support. (the aluminum was concave 1mm downwards, so pushing the middles screws a little will fix that problem)

the stuff i got:

6x 6mm screws (45mm in length)
18 nuts
6mm tap
5mm drill bit
file
square ruler

the process:

marked the holes with the old table
drilled the holes
tapped the holes
applied one nut on each screw, placed screw from underneath the old table
then applied another nut above the old table (to lock the screw in the desired place/distance)
then applied another nut to lock the aluminum table
(all the nuts are loose at this point)
screwed in the aluminum table (it is already threaded) - made sure the screw is JUST flush with the top surface of the table
then i tightened the last (top) nut to make sure the screw doesnt go through the aluminum table
at this point, i have a floating aluminum table on top of the old table
then i levelled the table and tightened the other nuts to the desired hight
the table is not floating anymore, but was as level as possible
i installed this new contraption on the machine
loosened the Z-axis belt
calibrated the 4 feet of the table by moving the gear (on the bottom) of each leg up and down until all 4 corners had the same focal distance between the table and the laser head
readjusted the Z-axis belt
now i finally have an even, flat, consistant table!!

as you can see in the pictures, i used the square i bought and taped it down with double faced tape in the left top corner of the table to give me a consistant home position
(i kind of emulated what i saw is a great idea with epilog, its definitely not as accurate, but works for now)
i just used double faced tape for now, to see if i find it practical, if it is, i will tap some holes in the table and screw the ruler in (this will allow me more room to calibrate the ruler)
with some careful calibration, i made sure the laser's position is exactly at the inside corner of the ruler. (pressing the ORIGIN button will allow me to use this as a 'home' position every time)
i went to Laserworks software, i wrote down the coordinates of the 'current position' so that i can recalibrate at any time through the software.

thats it!!

what do you guys think of what i did? i really hope this helps someone with the same problem

should i repost this in a new Thread?

thanks all!
photo 1.jpgphoto 2.jpg
it wont let me upload anymore pics, i will upload more in the next post

[Mohammed Issa]

photo 3.jpgphoto 4.jpgphoto 5.jpg

if you guys need more pics, just tell me of what, and i will be happy to take some more!!

[Khalid Nazim]

This is good work. Thanks for posting these details.

Regards
Khalid

[Dan Hintz]

For the time and work, here's what I would have done: measure at various points along the main table to determine how far off of mean level it is. I would select a grid size that is easy to work with, say 3". At every grid point, epoxy a small piece of metal shim that would bring that spot up to mean level. Lay aluminum sheet on top of shims. No drilling.

[Mohammed Issa]

Hey Dan,
thats a good idea. but i dont really work with epoxy. i just found it easier to get 1 piece of aluminum the size of the table and attach it to the old jig. it actually took me more time to write up the details above than finishing the table.

[Mike Lysov]

Are you using this table for cutting or engraving? If it is for cutting may I ask why did you get a laser supplied with a table like this? It won't do any good job for you if you cut something on it.

[Mohammed Issa]

hey mike,
i got it for both. i have another honeycomb table for cutting.
the thing is, when you cut something, you really dont have to be so precise to the alignment as you do when you are engraving. so i cant really use the honeycomb for engraving, because its not that high-precision either.
so the new table i made, give me a lot more control over the precision.
hope that answers your question