Build Thread- Newbie starting No1

[isvflorin]

Hi ppl,
after months and months of collecting parts I finally started some assembly.
Project is a table router/mill hopefully able to mill Al moulds&parts.

First stage of the build will be a smaller machine thought out to be enlarged later, next year hopefully. First stage working envelope will be 1340x450x140mm, second stage will present a longer Y axis, probably 1200mm of travel.

I'm trying to build as strong&cheap as I can, as you can see the frame is not exactly elegant but all it matters is the rails mounting surface.

X rails are Rexroth 35mm wide, 1670mm long, roller type, with big a** long carriages, stout enough ?

Y will be Rexroth 20's, ball type, normal flanged carriages.

Z will probably be Hiwin 15's, however I got some other Iko's from ebay.
I spotted an ebay auction with a lot of Iko lrx15 carriages and thought there will be rails for them too, but there was only one rail....so who needs iko lrx15's let me know.

Screws:

Z will be a C3 grade NSK
Y will be a C1 grade NSK
X - planning to get 2 screws from 'linearmotion...' and drive the nut instead of the spindle.
I have a few concerns about the X screws - the Nook webpage calculators said a 16mm screw is too small for 1500 lenght, going over the slenderness ratio, so I will have to get 20 ?
Now- question for the ones who ordered from Chai-linearmotionbearings:
the 16mm screws on his site are quoted -antibacklash but the 20mm don't say anything about backlash, is it just an omition or the 20's have backlash ?

Frame is not complete yet, there wil be some lower reinforcements and triangulations for rigidity, it is pretty heavy so far, it will be bolted and with light welds after bolting, just enough to allow grinding and detaching the X rail channel profiles so I can enlarge the Y axis in the future.

Unfortunatelly I don't have acces to high precision mill and lathe to machine parts for it so I will have to imporvise. The mill and lathe I can acces are used for heavy unprecise stuff and in poor condition....

The X rail mounting surfaces will be leveled using epoxy, hope it will work out well as I don't have slow cure epoxy like Mark did on his build. My epoxy will gel in about an hour, hope it is enough time to level the channel face.

Driver is a G540, 500W PSU and 3Nm steppers, that will be pushed to only 2.something Nm due to low amperage of the gecko.

Currently have a 3ph spindle router motor but it has no collet, just a nose type axle, planning to either drive an er16 collet home made spindle, or machine a collet in its axle ? If it is possible ? I don't have the equipment for it, but will look into it. It would be great to machine an er11 or er16 end into that axle end instead of driving something else with it.

I guess this covers the start, don't keep opinions to yourself.

Oh and- need to make some room for it, I think it is too heavy for the floor in the shed, but it will have to do...



Florin

[isvflorin]

The build is going slow, bought most of the important bits, still need a couple bearings for the X rotating nuts.

Got to drill the holes for the x rails, a lots of holes... I borrowed a magnetic stand drill press that made the job a lot easier, now it is ready for epoxy leveling, then taping the holes for the rails.

Question : what type of belts and pulleys to use on the rotating nut drive system ? I have no ideea...
I'm using 8m shaft 3Nm steppers.