[thetrick]

So here it is.
It’s cutting area is approximately 24X36. It is made of steel angle, MDF and gas pipe. My theme here is cheap and sturdy. Also I wanted all the mechanisms to be above the work surface so that I could work on large parts where the bulk of the part will extend below the normal work surface. I have spent quite a while lurking this site, and the design is a mish mash of things I have seen and liked. I plan to power it with a hobbycnc kit, that I have yet to order. The overall cost for the completed router should be less than $1,000.

I feel that I have completed the easy part , now I have to really get into the details of how things move.

I don’t have a set plan or design for this thing, I’m just winging it. I sit at a computer all day and draw plans for things for a living, so I hate doing it in my spare time.

I will try and post more here as things develop.
Todd

[CarveOne]

Welcome to the build logs Todd. Your basic design certainly looks simple and rigid so far. Will be interesting following your progress.

CarveOne

[thetrick]

Ok so a major milestone was reached. I finished all the axis movements. No drives yet, but everything moves. This thing has ended up being VERY rigid, I’m pretty sure I could sit on the Y axis and it would slide just fine. I compromised a little using drawer slides for the z axis, but that’s more of a matter of what I had on hand. I plan on making a better Z axis using the router once it is working.

The welded parts have worked great, and are very strong. It’s not as difficult as you might think. I have no formal training, I picked up a wire feed welder at HD a few years back and it’s been a great investment. I use flux core wire so I don’t have to worry about renting, or keeping gas bottles. I know flux core gets a bad rap from professionals, but for the hobbyist it’s great.

I must add MDF sucks for anything but the most basic structures, and splits very easy. That being said I don’t think I would have made anything different, but it was still a total pain when working on the smaller parts. I might try white oak for smaller parts next time.

I have been looking at different stepper driver suppliers and I am leaning heavily towards the probotix (www.probotix.com) stuff. I have been trying to find some reviews, but I guess they are pretty new. I have not read anything bad about them, can anyone comment on them?

Todd

[harryn]

Hi - nice project work. I agree with you on mdf - maybe a good plywood instead - hard to tell.

My "love" of mdf is actually driving me toward an Al based build. I was surprised to find that it is not that much different to work with, sort of like very aged hard maple.

[BobF]

I can't comment on the probotix. Why did you choose them?
Since this is your first, you might want to consider one of the choices that people here use a lot so you can get help if you need it.

[thetrick]

Harryn
Yea I think I will try and work more in AL in the future. I also have some solid white oak flooring that I might plane down into some useable stock too.

Bobf
First I was going to get the Hobby CNC kit, then I decided that I was willing to spend a little more and get an assembled driver so I was looking at Xylotex. But the Xylotex does not have the circuitry to protect it from an accidental unplugging of the stepper motor, the Probotix does. Also with the Probotix each stepper driver is a separate module which should help with trouble shooting and replacement. Oh and the Probotix is Bipolar where the Hobby CNC is unipolar, and it seems that bipolar is somewhat preferred.

[Mr.Chips]

I am using Probotix, and it was a life saver for me. I wanted a separate driver card (independent) for each axis rather a 3 or 4 on one board, and I still like this feature.
I first bought Xylotex drivers and through my own fault I fried all three boards (at the time I bought them they offered axis independent boards). I looked around and Gecko independent boards were very pricy. I stumbled onto Probotics and found out that they offer independent Probostep drivers ($34.95) that are short and open proof, like Gecko at about 1/3 the cost, which is sliced bread for beginners, and on a budget.
The drawback is that this bullet proof board only supports Unipolar drives, which is not a big issue for me.
I also bought their PBX-RF Isolated breakout board ($45.99). The break out board and driver cards connect together with little jumper plugs so this is another plus for beginners, less chance of making a wiring error. Being electrically challenged I need all the help I can get.
Their site also has full color picture wiring diagrams, I like pictures. Other many other manufactures describe the connection points in cryptic three letter terms, that not always match what is printed on the board. To a electrical person It might not be an issue, but to the beginner, well if you guess wrong you can fry your boards, been there done that.

Home: http://www.probotix.com/index.php?view=home
Drivers: http://www.probotix.com/stepper_moto...ers/ProboStep/
BOB: http://www.probotix.com/breakout_boa...reakout_board/

The best thing to do is what you are doing, ask people, read a lot and make an informed decision.

Good luck

[BobF]

Depending on your time frame this may be another alternative.
http://www.cnczone.com/forums/showthread.php?t=51083

[thetrick]

Mr Chips

Thanks for the review. I’m not sure when they came out with them, but now Probotix offers a Bipolar drive too. http://www.probotix.com/stepper_motor_drivers/SideStep/

BobF

Thanks for the link that is a very interesting product coming from Gecko, I hope they give a date for it’s availability soon. Reading the posts from Mariss Freimanis (Gecko designer) has been VERY informative and interesting. I think anyone that wants to learn about stepper drives should read that thread.

[Mr.Chips]

Mr Chips

Thanks for the review. I’m not sure when they came out with them, but now Probotix offers a Bipolar drive too. http://www.probotix.com/stepper_motor_drivers/SideStep/

BobF

Thanks for the link that is a very interesting product coming from Gecko, I hope they give a date for it’s availability soon. Reading the posts from Mariss Freimanis (Gecko designer) has been VERY informative and interesting. I think anyone that wants to learn about stepper drives should read that thread.

Their drive that supports Bipolar steppers does not have the overcurrent and open circuit safegards as the one I used.
Like I said "The best thing to do is what you are doing, ask people, read a lot and make an informed decision."
The new Gecko $29.95 drive is for sure one to checkout.

[thetrick]

MrChips

BIG thanks, I did not realize their bipolar driver did not have current protection, that changes things.

[ecnerwal]

Hi ,
I built a Rockcliff based gantry router last year and was driving it with bipolar drivers which I built myself...motors were steppers salvaged from various old printers and copy machines .... they worked but not to my expectations.

I looked around and ended up buying the Probotix 3 axis bipolar kit.... I am in Australia so I don't have a big choice over here.

I am very pleased with the kit.... I am cutting at around 15 in/ min ,,, I have'nt tried to go any faster and fast moves are at 30"/ min.

They work flawslessly.
My main reason for buying this kit was that it had separate driver boards , and contained all the required parts,...... power supply, drivers , motors , breakout board, cables,all matched and all for less than it had cost to build from kits available in Oz. I run mach 3 by the way.
I heartily recommend the Probotix products and the service that Len provides is second to none.


lawrence

[thetrick]

So I have built my ghetto Z axis. This is the last part I am building out of MDF in my quest to user better materials. The first think I plan to make with my router once it is running is a new z axis. I got my steppers from Probotix, and started building the drives. I made shaft couplers out of some hex aluminum I scavenged.

The pillow blocks ended up being a bit of a challenge. First I had 2 pillow blocks per drive, then I went to one with the other end of the shaft using the stepper for support. I plan to fix this too once I have the router running and can make more accurate parts.

I found a quarter sheet of ¾ cabinet grade birch plywood, and have been using that to make some parts. It’s much stronger and actually has some structure, unlike MDF.

[thetrick]

Ok so a lot has happen since last time. First off it’s now running. I got my drivers and motors from Probotix. The router I am using is a piece of junk and will certainly die soon.

I had a bent x-axis lead screw that I had to replace, and then I needed to rebuild the x-axis stepper mount. I had some issues with mid-band-resonance stalling the steppers, but fixed that for the most part by changing the driver from 1/8th step too 1/2 step. I would like to get some 2 turn acme screws soon so that I can speed things up.

It is a very solid machine except for the z-axis which works, but had more play in it than I would like, plus I build it with too little upward clearance to the bearing block. Basically it can extend 3 inches below the table surface, but only about 3 inches above it too. Oops

I am in the process of enclosing the lower cabinet so to keep out the dust from all the electronics.