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craynerd
24-03-2012, 09:19 AM
I`ve been wanting a little CNC machine for the last couple of years, not specifically for anything, just to learn more about it really. All the work I currently do on my projects (www.raynerd.co.uk (http://www.raynerd.co.uk)) are on my manual machines.

Despite the constant advice to just go for it and but the bits starting from acratch, I just don`t dare and any machine more complete than this is to expensive, as is buying a bench mill and converting. So this is a cnc build based on confidence and available funds.
I started with a TEP cnc mill which I paid very little for. These are a sturdy machine and quite well made...just a dreadful design and dreadful software which is locked onto the driver hardware!!
I was lucky enough to get hold of the original TEP software from a local chap that has converted one of these (isn`t available from anywhere!!) and it was dreadful. Imagine MSWindows Paint, no numberical input (so no saying I want a 20mm line, 10mm from the origin!!, just simple drag and click stuff!!) Then from that, tell the machine to move.

Here is the machine in its original state:

http://www.raynerd.co.uk/images/tepcnc.jpg

http://www.raynerd.co.uk/images/tepcnc1.jpg

Very very bizzare design and many machine limitations:
Cons:

In my opinion the x axis should be mounted so the slides are vertical parallel, not horizontal.
No z axis, it is just a solanoid motor to raise and lower the spindle to a fixed level.
All hardware is locked so commands can only be sent from the PC interfaced by the TEP software - it won`t talk to Mach or EMC
Stepper motors are only about 50Ncm
Both axis are fixed off centre to allow space at the back for the electronics
Only 12v 5A supply.
Pros:

I had a working CNC machine as a basis/start.
If all else failed, I strip it down and the ally plate on it is worth more than the price I`d payed for the machine ! :D
In truth, there is little going for this other than having a solid working basis to start from....

craynerd
24-03-2012, 02:23 PM
First job was to strip the electronics completely from it. I will be using a TB6560 3 axis driver. I`ve heard nothing but BAD things about these, but I have one anyway and it`ll certainly get me going if I can avoid blowing it up.
I wanted to flip the X axis and although replacing the entire side piece would have been ideal, I couldn`t afford it and had some pieces suitable in stock. I raised the sides and used a plate to join them. It may need some supports bridging the sides later on.
After flipping the X, I could then mount a Z axis. I made the Z axis from a small leadscrew someone kindly gave me and the slides are olite 8mm ID bushes on 8mm silver steel rod slides. The rest is just plate bolted together. There is a problem in that I`ve used a flexible coupling but I haven`t "trapped" the leadscrew. This means that the Z axis compresses on the flexible coupling and moves the relative position of the axis - not good!! This is easy to correct but I haven`t done it yet.
Once i had the X flipped and raised and the Z built, I couldn`t help try it out... it is running of only 12v at the time and the noise from these small motors is horrific, I think the TB6560 is also to blame but since then I`ve jumped upto 24v and the noise is quieter.


http://www.youtube.com/watch?v=vISjtg1zHRY&list=UU8wYh9AFzKN2fMRGK2Bb6ZA& index=2&feature=plcp

At this point, the mill went back to its owner while we negotiated price. Other than electronics that we both agreed wouldn`t be needed, it was all replaced to original, thankfully, if he had seen the work I`d put into it I expect the price would have gone up!
Further updates to come: Now running on 24v from two ATX supplies in series, spindle connected, first door sign engraving done...all good fun! Issues: still not sorted the z axis flexible coupling issue. Is the Z axis height too big. Flex is the spindle.

craynerd
24-03-2012, 05:27 PM
The spindle is taken from Blackburn Marks advice on a brushless DC motor. Using a ER16 chuck with a 8mm shaft and direct replacement adding a bearing house:

camera phone shot.
http://www.raynerd.co.uk/images/brushlessspindle.jpg

Up and running, intial tests:

http://www.youtube.com/watch?v=eZ3BzL82qNg&feature=youtu.be

craynerd
01-04-2012, 01:54 AM
During the last week I`ve stripped the machine to do some mods and in the last few days got it back together. However, I just can`t get my head around the fact that the movement is well out of sync! Just a simple example, say I draw two ovals concentric to one another, they will end up overlapping and even with little flats on them instead of nice curves!

The wierd thing is, I get the same results on both Mach3 and EMC2... so either I`ve got a setting wrong in the software on both or something is wrong with the TB6560 driver?

I`m sure it was working OK just last week and so after nearly a full day trying to correct it today, any thoughts or suggestions would be helpful...I`m totally out of ideas!

Chris

Swarfing
01-04-2012, 02:45 AM
Chris

Check your wire connections to make sure they are all secure, re-insert all the connections to make sure?

Moein
04-07-2015, 11:54 PM
Funny, I just happen to have one of these in front of me and I just happen to come across this thread without searching for it. I cant decide ether to get it working or scrap it for parts, it seems bit of a money pit. Nonetheless I look forward to your progress with this machine.

P.S TB6560; I heard nothing but bad things about these drivers, after wasting money on them I have brought 3 Pololu a4988 with a Arduino CNC shield to use with my TEP unit.

pango2015
06-07-2015, 03:09 AM
:beer:It's from UK?