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CNC milling/router DIY build WIP

Posted by Desertboy 
CNC milling/router DIY build WIP
April 21, 2017 09:36AM
Hi, I want a cnc machine (Don't we all) So I've been Pikeying today and managed to recover these from an old commercial printer, total cost so far £0.00 and about 1/2 a days work stripping them out.

I have over 10m's of this in 3 * 3m+ lengths (4.5cm*9cm heavy duty profile) with the t solts, nuts and angles and have found a place to cut them for me super cheap and super accurately.

Got 2 of these motors not sure what they are but they are definitely bigger than nema 17's lol.

How do I ID's the motors?

Also got 25mm supported rails for the slides (With sbr25UU bearings) will need to cut to length any suggestions the best way to cut the rail cleanly?

I intend to cut 2 1.5m lengths so the y axis and 1 75cm length for the x axis, the y axis will be belt powered to match both motors and the x axis ballscrew (Or lead screw) driven.

I have a friend who will cnc drill the x axis for me and help me with the z axis

Not pictured but I also have a 20cm ballscrew and twin 35mm smooth rod (With bearings) assmebly I intend to take apart and rebuild as a z axis this already has a stepper motor with it the ballscrew is over 2cm thick and the frame is made from tool aluminium 4.5cm thick solid bar/ I think this will make a super z axis much stronger than the rest of the build.

I recovered a load of bearing's and as well, linear slide blocks (Need to see if I can match the profile) and a spindle mount (unsure how useful that will be).

I'm going to order this evening a couple of extra SBR25UU bearings from China so I can have 2 bearings per slide (Is this enough?) plus 2 spare.

This is going to take time to put together as I'm getting the vast majority of parts for free and calling in favours to get the work done for free. I'm hoping to build this for under £250 to get it working and then when I feel a bit richer upgrade the spindle and drive. The CNC machine will be powered by an upgraded ramps/arduino hopefully as I have a spare set. I intend to upgrade the electronics to 24v so I can get the extra torque out the motors.

I want to be able to mill/router wood/mdf & aluminium and a working area of 120cm*60cm.

This is going to be a long haul. I haven't done a cad design yet as I have an opportunity to pikey even more stuff next week so will see what I can get would be nice to go 4*4 but will need to cad it out so I have the x axis and z axis cnc drilled, the y axis I am on my own with my drill press and a lot of measuring and remeasuring and probably cigarettes and coffee.

You would not believe how many linear slides, stepper motors, aluminium t slot extrusion and ballscrews I've let go in the bin over the years kicking myself now but within 4 months I can easily get enough slides, motors, framing and ballscrews to build myself an 8*4 but I figure I'll build a small one first to get my head around it then go for the big one after all never hurts to have 2 winking smiley


Edited 4 time(s). Last edit at 04/21/2017 10:15AM by Desertboy.
Re: CNC milling/router DIY build WIP
April 25, 2017 10:13AM

Changed the bed size a bit so should get 120cm*80cm build area, will be using 2 slides each for both X&Y, at moment looking at side mount for the slides as pictured.

Edited 1 time(s). Last edit at 04/25/2017 11:13AM by Desertboy.
Re: CNC milling/router DIY build WIP
May 02, 2017 05:18PM
Santa came twice today winking smiley

Bearings for the supported rail am very very happy with them making me reconsider how I build the bigger one. When you have 25mm supported rail it's a different beast to 16mm crap they build the chinese cheap ones from.

Hiwin rails are too small for purpose but were cheap 15mm but they are 1500mm long with 4 blocks. They will do for now but they are on the upgrade list and when I do upgrade them I will get another 4 blocks for the rail cut the rails in 1/2and make an oversized 3d printer with them.

got a cnc shield coming for my uno so gbrl for now but will get proper stepper drivers and breakout board.
Re: CNC milling/router DIY build WIP
May 19, 2017 11:04AM
Got ballscrews now, next step make mounting plates & a z axis and we can start assembly.

I've had the motors (Nema 23's all round) running from an Uno, CNC shield & Polou stepper combo with 24v but will be buying a proper driver/breakout setup soonish and will get a 2.2kw spindle next week.

Making a simple gantry design

I haven't cad in the ballscrews yet as I needed to wait for them to come from Hong Kong now they are here I can work out how to fit them to the frame then once fitted take the measurements I need to modify my cad model for the ballscrew mounts to the blue plates for the drive so it can move lol.

Once happy hopefully Monday I shall put the order in for making the plates from 10mm aluminium although I might make it myself by printing to scale and gluing the print onto the plate to be drilled.

Edited 4 time(s). Last edit at 05/20/2017 07:20AM by Desertboy.
Re: CNC milling/router DIY build WIP
June 04, 2017 11:09PM
finally started to put it together

Mounting plates will be made this week winking smiley

Some of the bearings were wonky

Edited 3 time(s). Last edit at 06/04/2017 11:25PM by Desertboy.
Re: CNC milling/router DIY build WIP
June 04, 2017 11:22PM

quick fix with a vice and some scrap aluminium

one of these bearings is 1 of the fixed ones can you tell which winking smiley

Edited 4 time(s). Last edit at 06/04/2017 11:30PM by Desertboy.
Re: CNC milling/router DIY build WIP
June 12, 2017 06:48AM
Slowly getting there

Left to right
BF12 mount to T slot extrusion
Nema 23 mount to T slot extrusion (Will bolt into 2 rows of T nuts)
Last 2 are DSG16 to gantry mount drives.

Will print to scale to manufacture these but the gantry will be CNC'd.

Ordered a 2.2kw spindle today

Re: CNC milling/router DIY build WIP
June 12, 2017 10:49AM
Mine looks the same, but mentioned 4 bearings. Don't know if it makes a difference?
Re: CNC milling/router DIY build WIP
June 12, 2017 12:22PM
Mine looks the same, but mentioned 4 bearings. Don't know if it makes a difference?

From what I heard on other forums the 4 bearing ones are quite a bit better I'm hoping this is a 4 bearing one (There are clues in the listing but we shall see). I'm pretty certain whatever I get I made the right decision going with a spindle instead of a router, next is get a collet set and some end mills winking smiley
Re: CNC milling/router DIY build WIP
June 14, 2017 10:01AM
Thinking about upgrading to 4 TB6600 drivers (~£20) to get more out my nema 23's.

I have 3* 3 amp nema 23's 1.9nm and a 350w 24v power supply already, I have a smaller nema 23 which I might use on the z axis or I might get another 1.9nm nema 23 (£21 delivered).

Edited 2 time(s). Last edit at 06/15/2017 01:48AM by Desertboy.
Re: CNC milling/router DIY build WIP
June 15, 2017 02:18AM
I'd prefer the M542 stepper driver. It does up to 128 microsteps, which would reduce noise. ( With an 8bit CPU 1/64 might be tops )
I've seen them for less than 20€, but considering the prize it would probably be better to go for a DuetWifi/DuetETH. Their drivers are unmatched and you get 32 bit.
Re: CNC milling/router DIY build WIP
June 15, 2017 10:38AM
What puts me off the duetETH (Or similar) boards is the built in steppers if one blows you have hassle. Not sure if you can bypass the onboard stepper drivers easily. Although cut the right traces and creative soldering anything can be done winking smiley

When I start spending over £50 I start to think about buying second hand stepper drivers I see on ebay for ~£50 each and a suitable board (Ethernet based probably) would cost about twice as much as a duetETH but the stepper drivers will push 8amp's at 70v so future proofed and of course I can use linuxcnc or Mach 3. I would use Linuxcnc though as I'm a big believer in open source been a Linux user since 2006 although I do still have a Windows pc because my cad program doesn't work with linux. I've heard the learning curve is higher than Mach 3 but the thing I learnt recently is that everything is hard until you do it once then it's easy lol.

My spindle came today, weighed the spindle and mount at 6.5kg's OUCH! With my Z axis going to be 10kg's+ so Epoxy resin is now not looking an optional upgrade but a necessity lol.

I also had an excellent find a THK C3 ground ballscrew with C3 bearings and mounts! Cost me £145 4 years ago from ebay.com bought from Japan but was lost at work I'd written it off and assumed it had been thrown in the bin years ago.

So although I did pay for it I think of it as free lol, thinking it might become my z axis screw.

Edited 3 time(s). Last edit at 06/17/2017 06:22AM by Desertboy.
Re: CNC milling/router DIY build WIP
June 15, 2017 04:41PM
On microstepping something for perspective for ballscrews only, belt drives are different beasts.

I have a 1605 ballscrew which means 16mm wide 5mm per rotation travel.

So I take a standard 1.8° motor which is 200 steps per revolution

with microstepping single step resolution's are
1. 5/200 == 0 microsteps 0.025mm
2. 5/1600 == 8 microsteps 0.003125mm
3. 5/3200 == 16 microsteps 0.0015625mm

I could go on but I think it's obvious stepping above 16 is essentially useless to a 1605 ballscrew user if for resolution alone, there might be other reasons to increase microstepping levels but torque is reduced. I don;t really know much about microstepping except that torque is reduced when making fine movements.

8 Microsteps looks like a sweet spot to me with torque vs resolution but even 0 microsteps it's 1/4 of what most people aim for (0.1mm accuracy).

Edited 2 time(s). Last edit at 06/15/2017 04:46PM by Desertboy.
Re: CNC milling/router DIY build WIP
June 16, 2017 02:06AM
The DuetWifi has extra pin headers for external drivers, but you can also ( let someone ) replace the driver chip with a good hot air solder station.
For extra torque with 5mm lead screws, I'd go for a pulley reduction and short closed loop belts. If noise is no problem, you can then go down to 1/8 microstepping. Keep in mind, the 8bit CPU usually has less than 100kHz of step pulse rate. ( another reason to choose 32bit..)

I was also shocked, when I saw my 4.5kg spindle, but even the smallest 800W 3-phase motor weights 2.5kg, so it doesn't make sense to downgrade.
I did some math and my z-axis would be able to lift 25kg, theoretically. I made some 10kg weight lifting tests and could reduce stepper current to from 1.8A to 0.5A, before the stepper skipped steps thumbs up. ( I'm using M8 leadscrew with 1.25mm pitch, so do the math with 5mm pitch )
Re: CNC milling/router DIY build WIP
June 16, 2017 06:38PM
I'm direct driving if I find torque is low I will up the motors but only after I deal with the electronics winking smiley

I'm going to fill the cavities in my extrusion with
35% epoxy
15% carbon fibre powder
50% aluminium powder
which will add 4kg's and cost ~£50

my gantry will weigh close to 20kg's in total lol but I think the rail will take it without blinking and make the machine far more capable.

Edited 2 time(s). Last edit at 06/17/2017 06:25AM by Desertboy.
Re: CNC milling/router DIY build WIP
June 21, 2017 09:06AM
Checked out my spindle today it does indeed have 4 bearings so happy with that winking smiley

My friend is going to start making my plates this week first we're going to do the nema 23 & ballscrew mounts for the bottom axis and then work up from there.

Stripping the frame down and having it drilled by KJN then will rebuild with 10mm A2's like this using spare extrusion I had lying around.

Re: CNC milling/router DIY build WIP
June 21, 2017 09:20AM
To me it looks like you put some sideload to the Y-linear bearings. Wouldn't it be better to mount them on top of the extrusion and use angled iron for the sideplate connection?
Re: CNC milling/router DIY build WIP
June 21, 2017 12:11PM
Yes I have sideload on my Y (With Hiwin's side load makes little/no difference but with SBR it does which is what I have for the Y axis) but there's method to my madness the easiest way to explain is through photo's so I will get one tomorrow then you will see exactly why I did it winking smiley

When you start your cnc build in the scrap yard you have to make compromises winking smiley
Re: CNC milling/router DIY build WIP
July 04, 2017 03:05PM

Also have (Not pictured) 2 1.3m rails and 2 88cm rails as well with carriages winking smiley

When people say they can't afford proper rails I do have to wonder how hard they really looked.

Edited 2 time(s). Last edit at 07/04/2017 03:28PM by Desertboy.
Re: CNC milling/router DIY build WIP
July 05, 2017 01:36AM
I can't look on scrap yards for parts, because I consider selling my machines as kit ( bundled in a 3D-workshop ). So I need reliable sources.
Re: CNC milling/router DIY build WIP
July 11, 2017 07:52AM
Time to get the plates made winking smiley Blue outlines are pieces that need to be made.

getting a little loony toons piecing the puzzle together lol but almost there.

Edited 1 time(s). Last edit at 07/11/2017 07:59AM by Desertboy.
Re: CNC milling/router DIY build WIP
July 12, 2017 04:37AM
Hopefully I'm about there winking smiley

Have to check the alignment as I haven't modeled the ballscrew just grabbed the relevant measurements from the engineers drawings online.
Re: CNC milling/router DIY build WIP
July 23, 2017 02:23AM
Today going to finally start on getting the plates made, will have to see how well we get on.

and the back side

Re: CNC milling/router DIY build WIP
July 31, 2017 08:03AM
Got frame back today, just ordered some M10's to assemble the frame should be here tomorrow so I can bolt the thing together, aluminium plates should be ready at weekend. Picked up some CY cable for the nema's and spindle and ordered the energy chain.

Hopefully this weekend we might start seeing movement on the axis winking smiley She's finally coming together.
Re: CNC milling/router DIY build WIP
July 31, 2017 02:18PM

Finally got it back took a week for them to process but had some issues all sorted it the end very happy with the customer service.

Cost £35 to drill these holes and counter sink them so not cheap but worth it I think.
Re: CNC milling/router DIY build WIP
August 05, 2017 08:53AM
You've been framed winking smiley

Re: CNC milling/router DIY build WIP
August 06, 2017 07:07AM
I think I need to beef up the frame more like this

I think if I don't I will get too much flex in the MDF board I'm going to use as the bed.

Edited 1 time(s). Last edit at 08/06/2017 07:10AM by Desertboy.
Re: CNC milling/router DIY build WIP
August 07, 2017 02:30AM
I'd try cross bracing first. Adding more and more parallel beams won't change much.
Re: CNC milling/router DIY build WIP
August 07, 2017 11:38AM
I'm going to lay a sheet of MDF on top of the braces which will be my bed I'm not adding them for strength to the frame but rather to stop the bed flexing when the spindle is pushing on the part from above. Adding the extra aluminium reduces the span from 26cm to 10cm between the beams. Ihave 2 pieces of the aluminium for this but would need to buy 2 pieces for £24.

I'm going to add a 25mm MDF sheet then I use the router to make it into a Vac table like this

The holes align to the beams so they are dead centre between the beams will use 16mm holes as I have caps to block off the parts of the table that's not in use.

For now will use a vacuum cleaner but will upgrade to a proper vac pump and tank setup. I have a vac pump somewhere and a tank I can recover for free from a lorry.

The recess is just slightly less than a 1/3 of a sheet of ply 1220mm*800mm (1 cut) that way I can cut ply/mdf to that size and drop it in, need to sort out the homing but it's essential it's accurate and repeatable so nothing like my 3d printer switches lol.

Edited 5 time(s). Last edit at 08/07/2017 12:22PM by Desertboy.
Re: CNC milling/router DIY build WIP
August 08, 2017 02:41AM
I have the same idea with MDF and drilling holes by the router. But I found the router wont reach the outer limits.
I want to use clamps to hold down the part and they need holes outside of the working area too.

How do you cool tool and part without ruining the MDF base plate? Anything else but air cooling ( from the vac-cleaner )?
Is that enough for metal works?
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