Build Thread- John's JGRO - Aus

[guerd87]

Hello everyone. I started building my JGRO some months ago. Lack of time and funding has made the project slow, but its getting there.

The bed has been extended to 1200mm overall to allow for slightly larger cutting area. I have been converting the plans to Metric as I go along and have made a few little changes. No MDF threading, all glued and screwed together. The end plates are bolted up through the bed as it was easier to do for me.

I am thinking of going for the HobbyCNC kit, but postage is killer to Aus. Anyone have any other ideas of where to get a decent setup with good postage cost's?

More info and pics can be found at my website. http://www.johnhobson.ws/cnc-router

[tonin]

Looks very good start.Do you think painting MDF?

[guerd87]

Thankyou. I am going to be painting the machine white, I sealed up most of the edges of the MDF today with spackfilla to paint better. I plan on engraving alloy so want to protect the machine from overspray of lubricant that I will try and use.

[epineh]

Looks like you are off to a good start, as for the drives I guess your budget is probably the biggest deciding factor, Gecko's are great value for money, I don't know what their postage charges are like but a lot of Aussie guys use them (not myself though).

If you want really cheap have a look at the Linistepper stepper drives, I have built a couple and was quite surprised with their performance. You can buy a kit of parts for next to nothing or if you are keen make your own boards and put together.

If you like a more plug and play setup, have a look at the G540 :

http://homanndesigns.com/store/index...products_id=80

Good Luck !

Russell.

[guerd87]

Im not too worried if I spend a bit more on the Electronics to know they will last out the machine. The HobbyCNC EZDriver kit with 305oz Motors comes to around $380Aus delivered.

I have been watching these kits on Ebay: http://cgi.ebay.com.au/ws/eBayISAPI....:X:RTQ:AU:1123

3x Gecko G251 Drivers, 50V 3.5A Max
3x Nema 23 269 Oz-in Stepper Motors
1x Switching Power Supply, 48V 8.3A Output
1x Bidirectional Breakout Board (MB-03-V1)

By the time I buy the Powersupply for the HobbyCNC it will not work out much cheaper, And the Gecko's should give me a bit more speed (Not quite as much power though)

Im stuck on what to use for screws. Just stock all thread from Bunnings (around 20TPI I think) or try to source some 16TPI or similar Acme thread in Melbourne. Any ideas or recommendations?

[epineh]

Hi John, I cannot really help too much with the driver side of things, I built my own servo drives for my first machine, hopefully somebody with experience using commercial stepper drives can chip in here...

As for the leadscrews, ballscrews have come down a lot in price, here is an example :

http://stores.shop.ebay.com.au/linearmotionbearings

I used good old threaded rod for my leadscrews as I couldn't even get acme thread at the time without selling my house. I wouldn't really advise it though, things move pretty slowly, even with servo's spinning at 3000 rpm, lol. It is a cheap and simple option though, even if it just buys you a bit of time.

Next machines for me will be ballscrews.

Cheers.

Russell.

[dustin1706]

+1 for the G540. makes things simpler and has a ton of support both officially and in user forums.

This is the kit I went with for the ability to use it on a larger machine in the future.

http://www.cncrouterparts.com/produc...products_id=74

I've been very happy with it and it was extremely simple to setup. A bit pricier than you are looking at though. But if you plan on building a larger machine later, you may appreciate higher torque steppers.

For the rod, I went 1/2-10 Acme, and while it works great, If I were to do it again I would go for 1/2-10 2 start. I would go with 1/2" rod for sure, rather than 1/4" especially with a longer bed.

I had trouble finding ACME in Canada, not sure how you'll make out in Australia...

[guerd87]

I was very much undecided when I first got into CNC's about what to build. I really want something that can cut a whole sheet of timber. I have 2 options here: Joes 4x8 or Mechmate.

Not wanting to spend $3000 on a machine before I knew the process of CAD/CAM correctly I decided to build the JGRO for testing purposes really (while saving money towards the big build). Looking around for options on Motors/Controllers and browsing the Mechmate forums I decided to spend a bit more and get a setup that will carry on to my larger build when its done.

For only $559 US I got 4 x Nema34 Motors and 4 x 7Amp Controllers

2M982 Controllers
86HS9801 Motors

Powersupply will be 45VAC Transformer rectified to 63VDC, 500VA.

Wait - A JGRO with Nema34's?? Yeah, havnt seen that before. I couldnt justify spending $400 for a Nema23 Setup when I would need to sell it to buy a larger system down the track. Lets jsut hope the JGRO can support the power and weight

Payed for my order on the 28th July, Was shipped out of HongKong on the 31st July and arrived at my doorstep in Aus 8am 4th August - nice The company was www.driver-motor.com - also known as Deitech. Was packaged really well, email support was great and shipping was unbelievable.

Also picked up my steel pipes, ordered my Bearings from VXB and a 400x500x19mm sheet of HDPE











John

[guerd87]

Bit more has been done, after ordering my HDPE I canceled when finding out it was going to cost me nearly $65 for a 300x300 piece. I built some adjustment blocks out of 19mm Pine but wasnt really happy with the way they were holding the thread. Off to the local shop and picked up some pre dressed Tassie Oak - about $10 for a 90x19x1.8 length. It is holding threads really well and looks pretty good on the machine.

Done the bottom torsion box, It was made wider so I could put a length of Pine/Tassie Oak along the sides and use this as an adjustable support for the rails. I have extended the bed to 1200mm and was afraid of the pipes sagging, this should fix that problem, sort of a reverse adjustment block. All my torsion boxes are made from 18mm MDF as I had no 12mm on hand, and 12mm in general is a pain to work with. My torsion boxes are all screwed and glued together.

Made up some Motor mounts for the huge ass motors. Electronics are coming along nicely, have had them running on the bench top for testing and seem good. I picked up a nice enclosure for them off ebay for $20, needs some paint and a tidy up but not too bad for the price. The computer was also an ebay bargain, $15 for a AMD 2000+ with 1gb RAM and a 250GB SATA Drive (I installed that) Its freshly loaded up with XP, Mach3, Rhino3D and RhinoCAM. Ready to go

Last picture, A little compressor I picked up off the side of the road during council cleanup. The manifold is a little dodgy and I may replace it later on, the pressure regulated side is cracked so I have the full pressure side only available. An external regulator takes care of this when spraying etc. The auto pressure cutoff switch was set to full on so it just kept on pumping up, a little adjustment and it was back within spec for cutoff. Maybe this is all that caused them to throw it away ?? Works great for free

Not long now until its running.

Cheers,
John

[guerd87]

Not really much of an update, I painted the final coats on and bought the fasteners for the adjustment blocks. I have picked up an old Microwave Transformer for the power supply. Will be winding it to produce around 40VAC @ 10a for the larger machine motors and controllers.

I have been trying to find some decent prices for ACME thread but not available. It seems I cant get 1/2" 10 TPI anywhere in Aus, the only thing available to me is 1/2" 6TPI

12ft 1/2" 6TPI - $77 AU
6 x Nuts to suit for thrust bearing assembly - $60AU

I can however just get some standard threaded rod, 1/2" 12TPI for $17 per 12ft which I think I will go. Has anyone used similar thread? how did it perform? I have heard the stock 20tpi called for in the plans is really slow?

Cheers
John