2+2+3 More Plasma builds, double the joy ! 3X2M and 2.5X1.5M cnc plasma build.

pit34 wrote:

tommylight wrote:

Leme give it a try:
Merci beaucoup!
How many mistakes did i make?
 

Perfect ! You get 20/20

Dang, i was in Paris in 2004, so memory still working!

pit34 wrote:

About linear rails, what are the reasons/advantages you use round shaft instead of prismatic rail like Hiwin ones ? What are your opinion on that point ?

Besides a bit lower price, much easier to install and align, and allow for plenty of lateral movement. The last part is very important here as there is no shop that has a flat floor here so i do not have to worry about breaking the HiWin rails on uneven surfaces.

tommylight wrote:

Besides a bit lower price, much easier to install and align, and allow for plenty of lateral movement. The last part is very important here as there is no shop that has a flat floor here so i do not have to worry about breaking the HiWin rails on uneven surfaces.
 

Interesting ! When you say Hiwin rails can be break by uneven floor, is it because that floor cause prematurely and excessive wear or because that floor can literally bend and break rails on frame ? As my workspace floor are uneven, it worries me a bit.

In case you have already use Hiwin rails, have you ever compared the precision and dust sensibility of this two rails type ?
 

regarding HiWin, i forgot to mention that all my machines are fully bolt on, so they can be adjusted, and that makes them not a good choice for me.
Otherwise, if the frame is rigid, HiWin can be used, of course.
I have used and still use HiWin and THK and NSK linear railrs, they are an abomination when you look at how much dynamic load they can handle, supported round ones can handle less than 1/10 of that, i have new THK 35mm ones with long carriages that can do 17900KG of dynamic load!
As for dust, i had the worst case where the rails were up and full of dust and water and they are still good, but also had a single case where one HiWin HGR25/HGH25 locked after a week of use.
There is also a huge difference in tolerances, linear ones will lock even from plasma fine dust if it gets in, round ones will continue working like nothing happened.

Thanks, Tommy, for this feedback.

I have not yet chosen between welded or bolted frame, so I still can adapt my frame to rail. But yours say make me afraid about this dust vulnerability.
I have found some dustproof accessories on Hiwin site . Wipers go from small to heavy, and a metal scraper can be added to protect against sharp dust. There is top and bottom sealing too. But as the displacement performance decrease as the wiping performance increase, it is difficult to choose the best ratio between both. I think I would have to test some and adapt if necessary.

As you have some experience with stepper motors' power and capabilities, do you think the "high" displacement resistance added by those wipers could cause some visible issues on cut quality ?

I keep using these damn Hiwin rails while my very dusty workshop may not simply allow it...

 

I saw your drawing on the other topic, that will do just fine, for many, many years.
Do not use extra wipers and scrapers, except the standard ones that come with the HGH carriages, they add a lot of friction.
Also a single HGR15 is more than enough for the X axis/gantry if you make the Z axis lite enough. Two for the Y axis, HGR15 also more than enough.
Make the moving parts as lite as possible, notice on my machine everything on the gantry and Z axis is aluminium, except the rails.

Ok. Thanks Tommy for those advices, again.

It is not sure yet, all is still in thinking state, but as I maybe will add a wood router tool on the head in addition of the plasma tool, I think I will go with HGR20 ones. Just to not close a door.