[NobelO]

Hello Dears,

Excuse me, i have a problem in my CNC's X gantry, the problem is if i apply a small force to the gantry it will move back and forth about 1 cm. << it is a lot.

I think the problem is from the foot of the X gantry, as it is only one and 80mm, so i thought if i doubled it , the problem will be solved. << Is it will ?

I did a video explaining the problem, as it will shows the problem in real and it will be more illustrative i think. I am trying to align and fix this for about four months

I apologize for my poor English and poor resolution ..



Please if you have any idea, suggestion, hint or anything it will be very appreciated.

Thank you very much.
Have a great day.
Best Regards

[Jon.N.CNC]

Video doesn't load YouTube for me, just blank tab.

[NobelO]

Ohh,

First of all, thank you for your post.

I will paste the link.

https://www.youtube.com/watch?v=aYENWqUXO9Q

Thanks

[Jon.N.CNC]

What type of drive are you using? Ball screw, r&p or belt? And where is it?

You will get play like that with that type of bearing arrangement, that kind of arrangement would rely on the driving mechanics to stop it from walking (applying mechanical hold to each gantry leg individually and in unison of each other), I.e you need a drive each side so two separate slaved motors for a frame that size.

[NobelO]

Thank you very much.

I am having a 2 meters ball screw located at the middle of the machine below it. As it shown in the video if it is working .

Do you mean, i need two ball screws each at one side of the machine? like this pic:

Attachment 322062
Thanks

[Jon.N.CNC]

Thank you very much.

I am having a 2 meters ball screw located at the middle of the machine below it. As it shown in the video if it is working .

Do you mean, i need two ball screws each at one side of the machine? like this pic:

Attachment 322062
Thanks

Sorry to say it but yes you do.

[NobelO]

Thanks for your help, really appreciate it.

If i not disturbing you sir, please could you explain for me the reason for slipping again, i could not figure it out. I am so sorry :shy:

Thank you very much for your help and time. Really appreciate your comments.

[NobelO]

Thank your very much for your explanation.<< editing the reply.

I got it now.

Thanks so much.

Best Regards

[wizard]

Thank you very much.

I am having a 2 meters ball screw located at the middle of the machine below it. As it shown in the video if it is working .

Do you mean, i need two ball screws each at one side of the machine? like this pic:

Attachment 322062
Thanks

Yes, such a drive will help. Dual lead screws are almost mandatory for such light weight axis assemblies.

I would also look to increase the rigidity in the X axis bearing assemblies. Make the saddles longer and add more bearings. The reason is that after you deal with the lead screw problem I suspect you will have trouble with the saddles rocking. That is your uprights supporting the gantry will rock probably more than you will want. I bring this up because the improvements can all be made at the same time.

[NobelO]

Yes, such a drive will help. Dual lead screws are almost mandatory for such light weight axis assemblies.

I would also look to increase the rigidity in the X axis bearing assemblies. Make the saddles longer and add more bearings. The reason is that after you deal with the lead screw problem I suspect you will have trouble with the saddles rocking. That is your uprights supporting the gantry will rock probably more than you will want. I bring this up because the improvements can all be made at the same time.

Hello dear Wizard, nice to see you here.:wave:

thank you very much for taking some times to see my thread, i appreciate your help really. thanks.

I see, well good to hear that too sir, i will increase the length of the bearings saddles with adding more bearings and doubling the gantry legs for more rigidity as i hope.

I actually get to know that especially my CNC as it is long, it is hard to use it for further materials like Aluminium<<< as i go through the topics and see your replays to people and some another guys too. So, i would like to thank you for your helps, it helps a lot dears.

So, i will try as close as i can to cut aluminium, or keep it for woods only.

Thanks.
Have a great days guys.
Best Regards

[NobelO]

Hello Dears,

Excuse me, i am planning to improve the linear rails to a HIWIN HGR15 did it will work fine with my 2000*1000mm CNC or it is small ?

Thank you.
Have a good day.
Best Regards

[NobelO]

Hello again guys,

I received the extra ball screw yesterday finally.:cheers:

I need to design another way to mount the stepper motor and the ball screw... i got an idea to make the two ball screws inside the frame of the cnc but from the bottom<< is it will be sufficient or MUST BE out the cnc's frame at the two sides?

This is what i mean as the pics shows (actually it is two ball screws but not shown fully)


Any suggestion will be highly recommended

Thanks so much for your helps.
Have a good day.
Best Regards

[aarggh]

That's an awful lot of vertical planes there with bugger all support. You'll struggle to get any decent movement under load without re-enforcing the gantry with some side panels to reduce flexing and twisting. That will make a huge difference. As the design stands, there would be enough flex to cause serious binding issues.

cheers, Ian

[NobelO]

Hello dear Ian,

First thank you very much for your advice, appreciate.

Sorry i didnt get exactly what you meant, did u meant "back enforcing panel" or "side enforcing panel, where the gantry legs are"?

The problem is that i couldnt find any alu. sheet here in my country and if so it cost me thousands of dollars <<< does the 6mm Plywood works as the re-enforcing panel?

I thought that the second ball screw will prevent the twisting/flexing issue... But it will minimize it a lot.

Please if you have any idea for material used for enforcing panel will helped..

Thanks.
Best Regards

[pirate323i]

Hello dear Ian,

First thank you very much for your advice, appreciate.

Sorry i didnt get exactly what you meant, did u meant "back enforcing panel" or "side enforcing panel, where the gantry legs are"?

The problem is that i couldnt find any alu. sheet here in my country and if so it cost me thousands of dollars <<< does the 6mm Plywood works as the re-enforcing panel?

I thought that the second ball screw will prevent the twisting/flexing issue... But it will minimize it a lot.

Please if you have any idea for material used for enforcing panel will helped..

Thanks.
Best Regards

Hi NobelO, any rigid sheet material will work for stiffening-> steel, plywood etc.

[aarggh]

Basically running sheets of anything as rigid as possible at right angles to the sides and front/back, and along the top/bottom, will reduce the amount the gantry can flex in any direction.

Rigidity is the key though. Without it you'll have loads of inaccuracy and machining issues in general, as well as more noise and vibration.

cheers, Ian

[NobelO]

Hi NobelO, any rigid sheet material will work for stiffening-> steel, plywood etc.

Very good.
Thank you very much for your respond.
Appreciate it pirate323i
Best Regards

[NobelO]

Basically running sheets of anything as rigid as possible at right angles to the sides and front/back, and along the top/bottom, will reduce the amount the gantry can flex in any direction.

Rigidity is the key though. Without it you'll have loads of inaccuracy and machining issues in general, as well as more noise and vibration.

cheers, Ian

I see, this is what i was looking to achieve for my knowledge thank you sir aarggh i appreciate it.

I just wanted to be confirmed about this idea and you guys helped a lot. thank you very much for your help and time.

I hope the best for you.

Best Regards

[aarggh]

No problem, just remember any mass and support you can add to the base frame can only be good (it literally can't be too much), and any support you can add to the gantry without increasing the mass to the point where it becomes a problem, is also very, very, good.

cheers, Ian

[NobelO]

No problem, just remember any mass and support you can add to the base frame can only be good (it literally can't be too much), and any support you can add to the gantry without increasing the mass to the point where it becomes a problem, is also very, very, good.

cheers, Ian

WoW, that i didnt aware of actually :shy: << i was not sure about it. Appreciate.

Thanks really for your advice, it is from GOLD.

Good Luck
Best Regards