Quite an Unusual one

[Boyan Silyavski]

Hi, long time i put this off, but now that successfully finished my first build i am back on the track with my machine build.

Now i have all the electronics, motors and major part/linear rails and ball screws/ sleeping at my garage. This time i will build it much faster.

Having learned a lot from the first build, i reconsidered many things and am trying to finalize the drawing stage, so i can buy the steel profiles next week.
Many changes were done, simplifying, strengthening and all this having in mind the common materials here in Spain.

1. Decided that the machine will be on no long legs. It will rest on the floor.
the benefits:
-I work alone so lifting heavy materials will be a problem in the future. As it will be multi functional, there will be removable plasma torch and 1000x1000x100mm removable water bed also, for the not so rare cases i need some parts from steel done until i make my self proper plasma table.

This is how it will look:



2. I wanted to avoid as much as possible laser cut pieces/$$$/ and use instead the profiles themselves as i would do the cutting at home which saves me quite a lot in fact. Only 3 types of steel will be used-100x100x4/the darker ones/, 100x100x3/ the lighter gray/ and 60x60x4/ the gantry verticals and reinforcement pieces/



The gantry support legs from 100x100x4 / so i can reach and screw the HIWIN blocks to the plate/:





The ball screw end supports from 2 pieces of UPN100 soldered together. I have the believe that this part is very important to be extremely sturdy in all directions as there wil be very heavy pull there, starting from the tightening and later when the gantry accelerates and so. Additional 2 100mm thick plates for reinforcement,one bellow and one for the face of the beam, so there will be no further doubt there :-).




3. The rotating ball screw nut
Attached to 10m steel plate via screws , the plate is soldered directly to the gantry sides. I couldn't help and add 2 ribs to the plate, just in any case.



basically the 30T HTD 5 pulleys are 90mm center to center, so 330m belt will fit according to this calculator http://www.bbman.com/catalog/belt-le...alculator.html
The problem here is that the servomotors have much larger central cylindrical part, so there is no more that +-3mm up and down for adjustment. that means the calc has to be very exact with servo motor, as oposed to steppers where i achieved +-6mm adjustment in both directions.




The other thing is that i can not find Alu pulleys HTD5 30t. Only steel, i am not sure but it could impact the inertia as its 3 times more heavy.

4. Back to the gantry. In a way i am proud of it
Now the gantry is where i took liberties with the design, hopefully for good. As i said before there is extremely small overhang. Unluckily there was no 120x100 profile available, though when i started the drawing they said that there is . So i redesigned it again. 100x100x4 and 60x60x4. As i started the gantry from scratch and put a lot of thought in there, i believe it will not only be very successful but in the future will serve as an inspiration to all that want the benefit of closed aluminum gantry but don't have the means or money and go with steel. I mean - take away half of the reinforcements and vertical reinforcements /remember-i will mount impact hammer/ , and it still will be heavy duty normal gantry, couple this with the gantry sides like i did them, and you will have cheap very nice gantry that you need a way to cut the profile and solder +2 plates for the HIwins.
In short I believe that's the ideal High Heavy Duty DIY gantry. I hope you will like the design idea. Hidden and short screw, motor inside, all cut from profiles including the sides. In a normal HD variant, there will be less vertical profiles, less support triangles and one less profile each side of the gantry sides.




FYI : On this picture bellow you can see that the distance i left from front to the vertical supports is 100x100 -60x60/inside verticall supports/ = 40mm. But if the ball screw supports have to be mounted on the vertical bars, no additional plates as i made them, then the distance must be 43mm. Even so the vertical supports will protrude at the back only 3mm which can be masked by soldering, so 100x100 and 60x60 is ideal combination for HD Gantry




This is how i envision a normal HD gantry, that will be comparatively very light for what it is and no need to go in the servo territory. I would like to hear critics or opinions on this :-):




5. The Z
This is on what i am checking and working today. have to check again if the cheese holes are right on spot.

As i said above, with servos i can not design a plate with more than 3mm of movement in both directions to tighten the belt. So i had to do something i dont like and split the Z motor plate to be able to additionally adjust the belt. Still have to calculate again the exact length. And so the days go by...

Will update the Z pictures, when i finish counting cheese holes :-)





6. The machine bed

Some changes here. Instead of vertically soldering 3 x 2 /100x100x3/ profiles i decided to lay them all in one plane, so the distances between them are very small-200mm. So the bed is really strong, even using cheap bed material.






Quite a long post, but i am excited