[rasta]

As my attic workshop heat up the machine start working byself. So I leave retaping nut's (disassembling near all) to later.
So today I just make some wiring progress. So I added plug for probe and switch to set router Off/On/Auto (under M03/M05 command) Work's nice. The speed controller is "work in head" progress. For now I can live with manual.

Slavko.

Hi Slavkok;
if you want to eliminate backlass in the lead screw nut try this;
machine 2 nuts about 20 long each
in the face of the nuts ,drill and ream 2 off 2mm holes that
are exactly on the same position than the other nut (you can use part of the lead screw to align it.
now fit a 2mm x 50 long steel dowel thru both holes in both nuts , fit a spring outside the diameter exposed in both dowels , effectively pushing both nuts away from each other , that will get rid of your problem
regards
mariano

[slavkok]

That seem's like AB nut.

As I know the spring should have more force than any force in machine is. The problem is that I don't know how to measure(calculate) :withstupi that force. So I can measure force needed to move table. The acceleration/deceleration force can be (i hope ) calculated by weight and speed but I haven't clue how to manage (measure) force introcuced by router/work.

So what spring to use?


These day's I make some measurment and the results are that I have Y backlash in range 0.12 to 0.22 and X backlash in range 0.21 to 0.25mm measured on cold machine (ie ambient temperature in range 19degC to 31degC)
After few rapids (5 minutes) the backlash increase by 0.05 and stay there when continue rapiding (the nut heats up to aprox 40 deg C). When machine cool down the backlash goes down too.

I also find that backlash is dependent on position of axis. But changes are all under 0.02mm.


So this put software compensation out of job. It only can minimize but not eliminate backlash.


The funniest thing is that in Z axis I have 0 backlash all the time. Seems that construction and router weight push nut to be preloaded in one direction only. If I push ruter up I can't feell sloop but hasn't measure it.

Slavko.

[slavkok]

I'm make AB nut for Y axis today.
I'm preloaded nuts with 400N force. The backlash goes under 0.01mm and are probably not caused by nut, but with endplay and coupler flexing. So this works but has BIG drawback that I must set rapids to very low value. Without preload I can go over 5000mm/m but with preload I'm stuck with 900mm/m. :drowning:
For now i will probably make same nut for X axis and try to live with slow motion.

Maybe bigger motor can solve problem. I don't know what motor I already have. Seems NEMA 23 and stack of lamination is 33mm long.

Motor is labeled as:
VEXTA
MODEL C6568-9212K
2 phase 1.8deg
DC5.5V 1.3A

RV7 00416


I'm guessing that is aprox 100N/cm (150oz/in)

Slavko.

p.s.
I just quick put together that nut and now isn't visible. So no photo.

[slavkok]

... just made one part of dust collector.
It's made from floor laminate. Seems that this stuff has very hard surface as destroy my endmill in no time. (Maybe is just end mill of very bad quality as come with router. for 30 Eur I can't expect to have good router and 12 bits of good quality.) I hope that router itself will last little longer

Slavko.

[CarveOne]

That cutter looks like it ran into a large piece of sand in the flooring material. I would not cut much of that stuff.

CarveOne

[slavkok]

That cutter looks like it ran into a large piece of sand in the flooring material. I would not cut much of that stuff.

CarveOne

Probably.. but seems that only top coating have that. I inspect shape of part and on the top is "hanging" edge that is absent in start of cut an then gradualy increase over path of router. So I conclude that there is no one "stone" but sand all over the place. Anyway this is 1'st and last cut on that stuf on router.



Slavko.

[slavkok]

... job continues but I don't like to got bunch of (wrong) posts so I open another thread.


http://www.cnczone.com/forums/showth...355#post647355

Slavko.

[mgrgur15]

This is one my project.

[slavkok]

.... In meantime the machine was near completed. It's in working condition but need's some cosmetic touches. I realy hate dust over around and dust shoes just doesn't pick enought. So I make box all around. It's made from plastic wall cover and piece of plexyglas.

[Ernie34]

Very impressive build. I really like the enclosure you built. After I finish the machine I am working on now I may end up building something similar to this myself....


Keep up the good work, Can't wait to see more.



Ernie:cheers:

[slavkok]

Enclosure works just great...

Just one thing to say. In way my enclosure is build (router suction port is outside of the box) there is must to have vacuum cleaner attached to the enclosure. If not the dust will escape in any gap due presure build with router colling fan.

I call this machine success. The worst is router itself. I had plan to replace router with something better and to leave machine to work on plastic and metal. For woodworking I had another (bigger) gantry machine as work in progress.

The backlash fight is done with stif nut (delrin) and stronger motors.

[Ernie34]

How easily can you machine aluminum now?


Ernie

[slavkok]

... like butter

fast feedrate 600 - 900 mm/min
router at aprox 10000 rpm (dont have feedback)
max 2mm deep roughting pass (more wil stall router)
4mm 2 flute upspiral bit (if something is wrong the machine can snap it easy!)
WD40 and air blow.

I make some test on angle iron.
Work OK just the router is weak point.
I must search my scrap pile and seek if I still have that EMCO3 lathe at home. I plan to use Headstock as spindle.

[Ernie34]

Looks awesome, Now Im excited to see some videos......


Ernie

[slavkok]

Looks awesome, Now Im excited to see some videos......


Ernie

For that you should take long rest. (I don't have time and equipment to make good video and hate to publish crap)

[slavkok]

.. but can post photo....

This is part for QCTP for my 7X12 minilathe

All job done with 4mm flat mill

[pminmo]

Nice work.

[Ernie34]

Looks really good. Keep us updated!!!!!






Ernie

[slavkok]

In mean time this machine got poor man aluminum T slot table. Bellows still not finished all but machine is in good working condition.

[slavkok]

... and to have Webcam mounted as optical centering device.
It's hard to see but can be aligned to have axis center in death center of cam. The backside is from 3 part!

1. Part is glued to router and have pivot in bottom and screw in top
2. Part has hole in bottom and slot in top so can be rotated to adjust X angle
I has 2 bolts in bottom side (left right) and one little above middle. in all bolts have spring on it.
3. Camera box has 3 holes in backside and allow alignment in Y axis (tightening top bolt) or light rotation left/right (tightening lower left/right bolt)

So I can align cam to be death centered. The little problem is that lens isn't centered in original plastic housing so if I wan't to change focus I need to realign the cam. But for now just work with focus on aprox 50mm from cam. The image is ussable betwen 80 to 30mm (little blury but ussable)


What to do with cam?!?

See on another forum..

LinuxCNC.org - Another tab for WebCam - EMC Support Forum

Slavko.