Author Topic: DIY CNC  (Read 930 times)

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Offline cabbage

DIY CNC
« on: Jan 12 2019 19:20 »
One of the main problems I have is the fact that I am inherently lazy... If more personal proof is required then the fact that I am using my RepRap and Laser Etcher to build the parts for my next idleness expansion.

The frame of the machine is 100 x 45 cm. On the left box are the two power supplies, the nearer one is 12 Volts and the other 100 Volts. Both of these are rated at 10 Amperes.





The printed parts have been tack glued into position prior to being screwed down solid. The tool holder will take the 400W motor and cutter, a dremel, or even a 7 Watt laser.

I am still getting used to the "little" 2Watt horror on my own laser etcher. Either way this is going to have to be used outdoors as the amount of sawdust or the level of smoke would make the kitchen rapidly uninhabitable!!!!

Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #1 on: Jan 13 2019 15:57 »
Now that the glue is rock solid -yes I used resin glue! I have begun to screw the printed parts to the frame. This shows one of the combined smooth rod and screw rod end holders. The smooth rod is simply zip locked to the piec whilst the screw rod sits in a ball race.





The next image shows the printed parts that will have to live on the smooth and screw rods.
From left to right; the two parts of the main carriage Y, (there are two of them), the cebtral colums of the motor and screw fitting to move the Y carriage And finally the "universal tool holder" and its Z axis carriage.





The final shot is of the Ramps board (red) which provides the muscle for the motors and the GT2250 Arduino board which provides the brains (white). This has dozens of plug sockets for dozens of things you can plug into it - I will need very few!!!





 I have yet to get the LCD controller card which takes the SD card with the cutting program on it. I have not yet bought the driver modules for the motors, there are various options to explore in types of torque curve and speed of response. There is even what is claimed to be a "silent" driver card, but how much this would be usefull with a 400W motor turning a cutter into wood at 12,000RPM is debatable....

Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #2 on: Jan 14 2019 13:45 »
The motor with fitted ER-11 collet arrived this morning. Initial tests with a Tamiya race pack shows that it has plenty of torque... They supply a holder for it that might have to get used -despite it weighing in at over 500grammes? Failing that it is an interesting paperweight.

I will have to sit down and design a reaction holder for it. There are four M3(?) screw holes on the front face. Another source of potential worry is that the rear mounted fan appears to be totally centrefugal and it might need some ducting over the motor to improve cooling. Needless to say it will need a fan guard!!!





Regards

Ralph


Offline cabbage

Re: DIY CNC
« Reply #3 on: Jan 16 2019 16:27 »
Another day another fight with the wiring... I have opted to put the main PSUs in the centre section with the contol PCBs in the left section. Yes, I am left handed!





Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #4 on: Jan 17 2019 16:04 »
The base of the frame has been cut on the bandsaw and glued/screwed into position. Tomorrow I will whizz around with the plane and ensure that the edges are all square!

The control panel (as such) consists of a mains on/off and a motor on/off with the ESC knob. The switches a very heavy duty and rated at 16 Amperes the control pot is rated at 2Watts. Incase you wonder they are all from my bits box , and probably date from the time I used to build power amplifiers. Panel design is din std and all the switches operate as ON=UP. In the US of A and the former U of SA it is the reverse...

Some masking tape and rular work give me finger width switches and hand turn room. The box placed up against the frame and location holes drilled prior to punching them out with spoon bit for the frame and a step drill for the box. The step drill is possibly the perfect hole cutting tool as it will turn a screwdriver stab through a distribution box into a beautifully smooth cut hole!!!







Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #5 on: Jan 20 2019 07:16 »
I have glued and screwed the base to the frame and trimmed it to size with the plane. I have bored the cable channels through the frame and put some cable rubs at the end of each hole. The control box is now screwed to the frame.

I have done some initial testing on the two PSUs located in the centre section and the motor responds smoothly to the ESC control system.





Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #6 on: Jan 21 2019 10:08 »
Busy weekend! This is going to be the last entry for a few days as I have to go into hospital to have my left eye fixed and then in a few months time the right eye.

The arduino board (white) and the Ramps board (red) have been fitted to the left hand section. The arduino board has the sockets to connect to all the limit micro switches and powers the LCD display and takes instruction from the SD card reader. The Ramps board is the heavy duty power controller needed to take the heavy duty nema 17/60 stepper motors (four at 1.9Amperes each). Yes the arduino and Ramps boards each have seperate PSUs!

The next phase does involve a lit of soldering of small plugs and cables - hence the delay whilst I am without stereo vision...

But everything is on track - but I still don't know if it will be ready for the AGM
 If not you will have to be satisfied with the RepRap and the Laser.





Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #7 on: Jan 25 2019 12:47 »
I guarentee you that it is no fun being a cyclops! Despite being  two dimensional being I have made very limited progress.

The 316 stainless rods have arrived and been placed into postion, cutting the other pices to length will have to wait. The Z axis mount has been trimmed and drilled and the X axis motors bolted (roughly) into position. It will be a couple more days before the feeling returns in my left hand and I can do some real work. So at the moment I am having to work right handed...







Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #8 on: Feb 03 2019 13:07 »
Now that I have stereoscopy again... The wiring has progressed and the device is starting to take form. The LCD screen and control knob/selector has arrived and the main arduino board been taught some basics. It now knows that its name is "Horatio"(!) I lack the roller races for the threaded shaft ends but they are en route from Rugby. I have to go shopping at B&Q for the wood to make the Y&Z frame.







Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #9 on: Feb 03 2019 20:16 »
To answer the question sent to me... The standard arduino system operates in physical layers. These are PCBs that stack like sticklebricks onto the main PCB. These additional boards are called "shields". There are dedicated shields for various things, there are 3d printer shields, cnc router shields, robot shield etc.

There is a program loaded onto the main PCB which is called " the Firmware". This is a detailed list of instructions that tell the main board about what it has connected to it.

The main Firmware for a 3d printer is called "Marlin", the main Firmware for routers and lasers is called "GRBL" (pronounced Gerbil).

Is it possible to run a router or laser using Marlin - the answer is yes. Is the reverse possible, the answer is -maybe...

This is because Marlin has more command links than GRBL.

Marlin has the links for XYZ motion and two printer heads plus things like; temperature sensors and printer head rates. GRBL has things like; rotation, cutting speeds, coolant pump rates, vacuum cleaner settings etc.

I will try and bring a printer and router shield to the AGM.

Regards

Ralph

 

Offline cabbage

Re: DIY CNC
« Reply #10 on: Feb 06 2019 13:41 »
One of the obvious things that is never covered in any computing or electrical course - seems to be  "How to make a Wiring Loom"...

The principle is simple take the wires, gather them into a group and fit them. Having inspected several " installations" made by people , and *screamed* at them. Here are a few simple guidlelines.

Do not have AC lines next to DC lines closer than 30cm. This "de-rates the AC line". Otherwise make sure they cross at a right angle.

Always include a star earth line in the bundle. You may never use it -but it can save your life!

Attach the sleeve for the loom inside the cabinet. This will ensure ease of movement around the cables.

I use expandable nylon weave to loom with. The ends are taped together then I heat ahrink them solid.







Regards

Ralph

« Last Edit: Feb 06 2019 19:05 by John Candy »

Offline cabbage

Re: DIY CNC
« Reply #11 on: Mar 01 2019 18:35 »
After three days of fun in the sun iy is back to kitchen table... The major parts for the router are here but some of the minor parts (like strange types of bearings) are in short supply with the suppliers...

But out with the bow saw and mitre block!!!

The frame is made of 15 x35 pine with re-enforcing screws and printed blocks.





Regards

Ralph

Offline cabbage

Re: DIY CNC
« Reply #12 on: Mar 02 2019 09:29 »
This is the frame on its supports. The screw rods await the bearing(!) Then I can begin testing. The four stepper motors respond to command line requests but nothing is proven...





Regards

Ralph