Accurate Strong Gantry

[Boyan Silyavski]

Let me know about the data bearing type, size, belt type, size and experienced phenomenon
angular bearing on drive side it can bear more load than single row
20/10 ball screw with Dia 15 machined end -bearing can hold let's say max 1 Tons here

Hey,
no tons here!! You have to read well the belt documentation! Find the belt tension formula on Gates web, calculate the tension for your exact setup and then using guitar tuner / or app on your phone/ tension the belt to the proper tension . This is a must to do it properly.

So the force you apply is not tons. Lets say its the force i can apply with one hand and using as a lever say 15mm screw driver against the motor and the frame. With say 20-25cm screw driver i exceed that force and over tighten the belt easily. Of course i have done it at the beginning with tuner, but now just know how a properly tensioned belt feels and sounds.

That means you have to design it so that you could lever somehow the motor with a wrench , screw driver or make some tightening mechanism. That does not mean introducing unnecessary idlers and tensioners.

I have the second setup in your diagram, with the motor in the middle. It is impossible to get enough tension in the belt without putting big loads in the spindle bearings.
I added a guide to push the middle section of the belt above the motor to reduce floppiness. still not good.

Now if you have read what i posted before and belt documentation may be you don't have the proper belt cord or you have not designed it to be tensioned properly. I tension the belts with one hand only and a screwdriver or a wrench, using them as a lever against the frame. So if you don't have where to lever them, drill a hole and fix something to be used as a support for the lever.

So are you idlers bigger than 20 tooth pulley as per belts specification? Cause if they are smaller, misaligned or whatever not properly followed, may be thats the problem.

Yeah , i advised against long belts exactly cause people don't bother to read carefully 300 pages belts manual and maybe they miss something or do some basic mistake. Yeah, Deans machine works, but he has knowledge and experience so his machine is an example that there is no problem with the design, not that if say you, me or sb else could do it with the same success.

I will give you an example - Honestly how many people know point 6 below. About the idlers size and placement. Most people i have seen on the forums think that they could place idlers where they want and 99% of the idlers are made by 3x 608 bearings stuck together, which in diameter a much smaller than 20 tooth pulley/which is ok for 10mm wide belts but not 25mm as is this case/


Also look at number 4. The machine sides should be stiff enough.




What i mean is RTFM, do everything properly and all will be smiles and sunshine.