Why no South African posts?

[drieslaas]

Hi gents (and ladies?)

I've been playing with CNC stuff for a few years now. We used a 4x8 Sabre at the boatyard a few years ago, and these machines are just so versatile. I had to have one.
I ended up building a 4x8 for my garage, and boy what a learning curve.

So now there is a machine run with steppers, and using Mach 3 for control.I use Alibre for cad and cam, it works fantastically well.
I often program our cnc's at work using Pro-Manufacture ( Wildfire) and Alibre does the simple stuff as well. ( It represent a ninety percent capability of what most users will require in their work.)

My machine is as cheap as they come. You can call me mr cheap if you need to.

Think gate rollers for linear rolling elements, and a length of angle iron for a guide.
I achieve 0.5mm accuracy everywhere on the table. I know this is not fantastic, but it gets the work done.

I needed to get going, so this was the way to go.

I struggled with the Z-axis, which works a lot harder than one would expect.

The latest incarnation works exceptionally well, and took me about a day to put together.

The largest problems at the moment remain dust supression, and the spindle.

I have been toying with ideas around a homemade spindle, it is not going to be straightforward.
I currently use a cheap (there we go again) chinese router as spindle.

There are three carcasses lying in the garage.

The best one lasted several hundred hours, the worst one several minutes.

I include some pics of the latest project off the machine.

There-in lies the rub. Having a machine is one thing. Doing something with it that will generate revenue is quite another. ( die hond sit met die kar se bumper in sy bek, wat nou?)

Most people can not afford to spend several thousand rands on a whimsy that will just be played with. So my personal challenge is to make some products with my machine, and use some of the income to bootstrap the machine up to something really respectable. The hard work is done, the controlling and programming etc is all sorted out.
I'm working on a range of flatpack kids furniture, as seen on the pics.

What do you think of this idea?

Regards,

Dries Laas

[rockhopper300]

Hello Dries
Interesting design you have come up with, gate wheels could do the job, I know. (have used them for a whole lot of apps) I think the flatpack kids furniture could work, just make sure to use good quality wood. Try approaching toy-zone or baby city first, they are not as sticky as the rest.
If you are based in the Pretoria area, you are more than welcome to attend a club meeting.
Cheers

[crixnix]

Welcome Drieslaas
I have major respect for your achievements. I have some idea, as I tried myself. I also considered using gate rollers for the linnear bearings, but started with a smaller machine so constructed my own.

My decision to buy new was because I already had a heap of work lined up for the machine, and 2 of my staff retired, so the machine could pick up the slack. I am also very pleased with the vacum hold down, and the dust capture, which were all part of the deal with the Chinese machine.

I like your kids furniture designs, but I would suggest decorating them in some way. Cut sillouettes or engrave Horses, Cats, Dogs, Dinosaurs, Aircraft, Cars, Monster trucks etc into the backs. Kids would not normally go shopping for a chair, but if they can fit into imaginary games - could become seat in an aircraft, spaceship or saddle for a horse - they might have more appeal. My 2c worth.

[jancu]

Good day.
i,am from pretoria and loves cnc machines.i got lathes and milling machines at home but use them 90% of the time to build my hobby, electronics and cnc machines.My first machine used angle iron and custom alluminium wheels with bearings inside for the slides and still uses it today for my 100% custom build plasma cutter.Currently i am busy developing dc servo drives but takes up a lot of time .My new machine uses linear slides bought from bearing international for a reasonable price compared to other suppliers.I build myself a laser but after testing it i trashed it because of safety aspects 'very dangerous because of revlections etc"RS components stock good servo and steppers for good prices ,check out their webside.Ok enough of myself my question is is there anyone staying in pretoria which will like to meet and got the same passion about electronics and cnc machines?

[david.fick]

Hi my name is David, I am from Cradock in the East Cape.
I build my own cnc mill and i am totally hooked.
I like your chairs, great idea!

[drieslaas]

Update,

There always seem to be a pesky know it all radio control modeller type person around when you need them least . In an attempt to answer a question to one of these exalted beings, I embarked on the next little adventure:

I tried cutting 3mm balsa using a HSS 2mm slotdrill at 30000rpm. The cutter did not even realise the balsa was there. Very chuffed.
Also interesting was the route to reach the toolpaths. I hand-sketched the shapes, scanned to bmp, converted from raster to vector, did a very precursory clean-up of the dxf in draftsight, and imported into alibre for the cam work. Sounds complicated but took a few minutes because all the steps worked.

Have a look at draftsight by the way. It is from dassault systemes, a completely free update of the old dwg editor, and works magically for 2d stuff, which is something without which any cnc router operator cannot get along.

By the way, I also cut just into the surface of a 6082-t6 alum plate with the same cutter to see what it would do, and the results warrant further investigation. Nice diversion.

[rockhopper300]

Hello Jancu.
To answer your question. Yes, the next meeting should be on the sixth of October. I am sure all would like to know more about your laser cnc. If all goes well we should have the sceleton of a four axis cnc lathe at the meeting, and if time permits Prof Rudy would go through the setup of the stepper drives, calibration etc. Hope to see you there.
@Crixnix, I really like your idea of the sillouettes.
@Dries and Loffie. Hope to see you at the next meeting.

[fransfourie]

Hello guys

Im from pretoria-N and been Bitten by the CnC bug also ...hehe Ive been looking into building my own desktop cnc mill for a while now. Ive already ordered most of my parts and just waiting with baited breath for it to arrive. Any1 know how much it costs to laser cnc 25mm steel plate ? ^__^ Wana make it a very rigid & heavy machine as i wana mill alu. primarly & use it 2 build my larger cnc in time. ( 3 axis with a 4/5 axis attachment on table.) *Gulps*

Well also, 10 thumbs up for starting this S.A thread. Now i dont feel so alone anymore. Ill probably start a building thread asap when i got all my things. Btw...if you need ballscrew type shafts...try finding old elec. garage door rails. Got my self a 16mm 2.3m lenth in one and a 20mm in another ...lol alot cheaper to buy them new. got mine for free. Also ....build yourself some furnaces and melt down your own alu to cast & build your own machine. alot of fUn. Well im rambling here.....Its great to meet all of you and hope this thread will stay alive for years 2 come.

Have a Good day guys
Frans

[fransfourie]

Hello guys

Got most of my materials today So ill be starting my build on my 1.5m x 2m build 2morow.

Cant believe how expensive alu. is these days, my gantry, Z-axis & side supports is gona be made out of 20mm 6082 alu. & 76mm steel square tubing for the frame. Just wish they cutted my alu. abit more square .

Got 425 oz steppers, Gecko g540 for electronics & 20mm linears for all axis's.
Will order my 2.2kw spindle in 3 weeks or so....any1 maybe know where i can look for a Vfd 2.2kw ? One that doesnt cost the earth. lol

Just hope it will be rigid enough to handel milling of alu.

Btw...Any1 else here build there own CnC yet ?

[Quentinb]

@fransfourie

Welcome!

I've build one and am now starting a rebuild. The first machine was build using MDF and works pretty well. The alu I used for the rails with V-Groove bearings are wearing alot more than I would like and is causing some play on the gantry and Z-axis.

I am getting my new parts from Greg @ CNC Direct in JHB.

You must send some pics of your build!

Cheers
Q

[fransfourie]

@Quentinb

Thank you very much. Ill post some pictures soon. Just did a test fit "stacking it loose." the gantry + z-axis. I found out i need 2 get my alu. squared out more somehow >.< So ill first take all the parts 2 some 1 who could square it out to a Fine degree, before i continue. wana do it once. hehe As the saying goes....Measure twice, cut once.

Mind uploading pics of your builds ? ^__^. Might give me some extra inspirations.

BTW....why not import some 20mm linear round shaft blocks into the country?
Cost me aroun R1400 delivered for 8 x 20mm linear sliding blocks. Bought some high grade 20mm round shaft (R370 for 6m) and it floats like a butter-fly..Stings like a bee. lol

If you dont mind me asking, you maybe know where i can get a 2.2kw Vfd locally? Or what makes are supported in south africa. Would be much appriciated.

Well...Nice meeting you

Cheerz

[Quentinb]

Where did you get the round bar/shaft from?

I have thought about using it, but worry that with a big machine it would deflect to much over the length. I want to build a 2.5m x 1.5 machine and wanted to use the round shaft. I also thought about the C style bearings with the mounted round shaft but the whole unit makes it very "high" in terms of the shaft and mounting + the bearing added to it.

my current machine....p

[fransfourie]

Heya m8

a Nice machine you got there

I got the round bar at alert steel. It is sitting abit high...2 sec..measering fast...+\- 60mm from top of the block to the bottom of the support bar for the shaft.

The linear block dimensions are H:37.6mm L:50mm W: 49mm (C - style )

Ill be taking a 20mm flat bar(+\-50mm wide) and mill 2 sides on top down by 5mm(10mm wide centre will be kept at 20mm then take a 20mm ballnose endmill to put a radias on the extruded piece for the rail to lay in. dont know yet if ill get it co2'ed or screw it to the plate. this should keep it nice and strait. Well once i do it, ill let you know if it works. Cant see why it wont.
But first im trying to find some1 in pretoria that can square out my alu. with a waterjet cnc.
Ive added a drawing to show what i mean.

Guess you can also make small shaft supports by drilling into say a block of alu with a 20mm dia drill bit & then sawing it in half then space it through the whole length of the shaft for support. example you have a 1m length of shaft. make support blocks for every 200 mm. Draw a line on your gantry with a vinear, drill & tap? them for you support blocks. Should work also.

Btw...What controllor you using ? stepper sizes etc. ?

Well speak to you soon again

[MickJack]

Hi Quentinb
Where did you get the V-groove bearings from?
What size are they and how much did they cost.
I cannot find a supplier anywhere in Durban for them!
Cheers
Mike

[fransfourie]

Heya jack

What size table you building ?

Got my alu. squared out ) engineering square, strait edge + wood router on a table does wonders ...hehe

If i get time ill drill and tap my z-axis 2morow & upload a pic of it

Quentinb.....Because of you i changed my table also to a 1.5 x 2.5 table xD
Need to go buy 76x76 square tubing this week and guess ill start building the framework the weekend.
Any1 know of a place in pretoria that sells rack & pinions ? very fine teeth??

[Quentinb]

@MickJack

I imported the bearings from the US. I tried all the bearing places locally and nobody could help! Have a look on buildyourcnc.com for some parts and ideas. If you like, I can assist you as I have a contact there - depends how many you need, I have some spare though...

@fransfourie

"What controllor you using ? stepper sizes etc. ?"
I am using the motor and drivers from the above site. I bought a "Combo" that has all the required goodies to make it work. then I am using Mach3 for the control side of things along with Cut2D for the toolpathing.

[MickJack]

Heya jack

.........
Any1 know of a place in pretoria that sells rack & pinions ? very fine teeth??

Nusaf JHB Branch
Tel +27 (11) 885 2523 - Johannesburg
email sales@nusaf.co.za

Cheers

[Quentinb]

Nusaf JHB Branch
Tel +27 (11) 885 2523 - Johannesburg
email sales@nusaf.co.za

Cheers

Nice one thanks! found a few tricks there I have been looking for!

I'll be starting my re-build over the weekend. Will take a few pics of the progress. I will have to have some parts machined as I go so hold thumbs!

[fransfourie]

@MickJack

Ah...CHEERZ m8 thx for that.


@Quentinb

Ill upload pictures in 1 weeks time +\- with my z-axis & x axis done
Got my z-axis done basically, just waiting for my 20mm shaft supports 2 come, so i can mate the 2 halfs to give Birth 2 a New z-axis...hehe

Cheerz

{edit} Here is a pic in inventor. not the whole assembly...will add a picture of a ""Mock fit" of parts. need 2 cut side supports still, fit ballscrews & stepper mounts..etc xD

Yes i know...I need to Make a new Z-axis mounting plate...lol...abit short for my 300mm axis

[Lord_Draco]

Hi guys
I'm looking to start my own cnc wood router, just a small 1mx600mm to start with, and have seen allot of great parts online and I'm just wondering: Does anyone know anything about import taxes and levies ? and where to find out what they will be before i buy things overseas?