Trials and Tribulations of a Noob

[Turbo1zz]

I am definitely a noob at machine building and will be chronicling my machine build with many questions for the masters thrown in from time to time. I have been lurking the boards for a long time and am now at a point where I am no longer capable of making excuses as to why I have not built my own CNC Router already.

My Router will be based on a number of excellent designs from this very board. I started out on Buildyourcnc.com and found a lot of useful information. I ordered plans but when I got the plans I was expecting plans for the machine he sells on his site but it was a far lesser machine. With the plans though, I was able to sketch out a few ideas for a machine of my own. I found two other machines that really lit the fire under my behind and got me off the board and into the garage once and for all. The first machine I found was the LionClaw LC50 which I do not believe is being offered anymore as I have not been able to get a hold of the gentleman who designed and built it. The other machine was the boards very own Grunblau's CNC Router design. I liked the integrated table design and the absolute beauty of his machine. I will definitely be using the table design from his build and might take a few other ideas from it as well.

I just got my Gecko G540 and am waiting on my steppers and power supply from Keling to arrive in the mail. I picked up the lead screws (1/2-8 2 start) from McMaster Carr and DumpsterCNC's AB lead nuts. I have a 1 3/4 HP Porter Cable motor that I will be using for the spindle. I have so many more parts to acquire like bearings, collars, motor/leadscrew connectors and the like. I also have to pick up some wire and switches for the limits and home switches. This leads into my first of many questions I will have on here. The motors are Keling's KL23H284-35-4BT and the KL-320-36 36V/9.6A Power Supply. The wire from teh G540 to the Steppers should be what? I would like opinions on the best wire to use for connecting the motors to the G540. I am reading a lot about shielded/unshielded and not coming from an electrical background I am kind of in the dark in this area. I also would like suggestions and ideas on how to mount up the limit switches and if I will really need them at all since I can set limits in Mach3 as well as soft limits.

I should have the table structure finished this weekend and start work on the gantry next week. I am taking my time and making sure everything is as perfect as my rudimentary tools will allow. It took me more than a week to get where I am now only because the battery packs die in my little saw way too fast. I finally broke down and went and bought a corded circular saw so all should be good now.

An overview of my machine

table size: 4x3
Z clearance: Shooting for six inches
Controller: Gecko G540
Stepper Motors: KL23H284-35-4BT
Power Supply: KL-320-36 36V/9.6A
Controller Software: Mach3
Lead Screws: 1/2-8 2 Start
Spindle: Porter Cable 691
DumpsterCNC AB Nuts

I invite any opinions anyone has on my system so far and any ideas anyone has that might make my life a lot easier during this build.

Jeffrey

[ger21]

I invite any opinions anyone has on my system so far and any ideas anyone has that might make my life a lot easier during this build.

Jeffrey

Close the clothes dryer before it gets full of MDF dust.

For stepper motors, use a stranded 20 or 22 gauge wire. If using home/limit switches, shielded wire is probably a good idea. I don't use switches on ine, I home it up to the hard stops. If you do this, make sure the machine is built tough enough to not tear itself apart. To use softlimits in Mach3, you will need to reference the machine position to a very repeatable place, or the softlimits won't be of much use.

[Turbo1zz]

Ahhh yes! The dryer. I've been working on that for a year now. I close it up and the next day it's right back open. Must be that five foot five gremlin I have running around the house.

I'm sure my machine will be plenty strong to stop an axis should it get out of bounds but I want to limit the self induced stress to a minimum. I think I am going to hit up the Local Fry's and see if they have any four wire 20 gauge wire. What is the benefit of using shielded and non shielded wiring? why use it on the switches and not the steppers? I would think the steppers would need to be shielded or is it the other way around. wire shields from outside signals or holds signal within?

Like I stated in my original post, I am new to all this electrical hoopla but I learn quick and all the information I receive here will greatly reduce my chances of catastrophic destruction.

Thanks

[CarveOne]

Ahhh yes! The dryer. I've been working on that for a year now. I close it up and the next day it's right back open. Must be that five foot five gremlin I have running around the house.

I'm sure my machine will be plenty strong to stop an axis should it get out of bounds but I want to limit the self induced stress to a minimum. I think I am going to hit up the Local Fry's and see if they have any four wire 20 gauge wire. What is the benefit of using shielded and non shielded wiring? why use it on the switches and not the steppers? I would think the steppers would need to be shielded or is it the other way around. wire shields from outside signals or holds signal within?

Like I stated in my original post, I am new to all this electrical hoopla but I learn quick and all the information I receive here will greatly reduce my chances of catastrophic destruction.

Thanks

Shielding braid, or foil, will attenuate signals from getting in or getting out of the wires inside the shield. It doesn't completely stop the signals, just reduce the levels enough that they don't have enough interaction with other wires to affect operation. Homing switches operate on lower voltage and currents than the steppers, and the logic circuits they connect to are easily given false triggers by interfering signals.

CarveOne

[Turbo1zz]

Ok, So I am back from my vacation in San Francisco and the motors and power supply were waiting for my return. I unpacked the contents only to find that one of the motors was damaged in shipping. The sides of the box were collapsed in so the loose motor floating around the box had no chance. I have to contact Keling about a replacement and hopefully it won't be a long process. I got a three prong plug and wire for the power supply and about 50 feet of four wire cord for the motors. I was able to find only 3.3K 1/4 Watt resistors and will try the local electronics supplier after work tomorrow to see if they have 3.5K resistors, but for now the 3.3 will work.

I am a tad bit confused about the wiring of the steppers. The motors came with no instructions or wiring diagram so I do not know what wires are what. I've searched around but it seems everything I find is for 8 wire steppers. The steppers have red/green/blue/black wires and I know that they represent Phase A, /A, B, /B, but which wire is which? I would like to get all the electronics wired up and tested before I install them on the machine. I would hate to have everything installed and find out I have a problem later.

Now back to the garage to fill my lungs with more MDF. :-D

[Turbo1zz]

I found a wire diagram for the G540 and the Keling steppers on.. of all places... Keling's web site. DOH!!! haha. Well, I am going to include a link here for future searchers looking for a diagram.

http://www.kelinginc.net/G540WD.pdf

I was not able to find the resistors anywhere local so I will be ordering some from digikey and using the 3.3's till they come in.

Now that I have the neccessary diagram I can go solder away. My lead screw support bearings came in as well so I am off to fine a forstner bit the same diameter. Rockler here I come. I hope to have more progress photos up later this evening.

[Crevice Reamer]

Hi Turbo. Everything looks good except the 36V PSU. This will seriously limit your rapid speeds with the 64V 387 motors.

If you can exchange the 36V for a KL-350-48/7.3A, it would do much better with the G540.

Also, the Newest and best motor for G540 is the 54V KL23H2100-35-4B, which will give improved performance over the 387. Maybe you could swap the defective 387 for one of these and use it on the longest axis.

CR.

[Turbo1zz]

Hi Turbo. Everything looks good except the 36V PSU. This will seriously limit your rapid speeds with the 64V 387 motors.

If you can exchange the 36V for a KL-350-48/7.3A, it would do much better with the G540.

Also, the Newest and best motor for G540 is the 54V KL23H2100-35-4B, which will give improved performance over the 387. Maybe you could swap the defective 387 for one of these and use it on the longest axis.

CR.

Thanks for the input CR, I am going to consider the power supply swap but for now the motors should be sufficient. I think the 48V PS will be the ticket in the long run. I'm kind of wishing I had seen the CNCRouterParts web site before I ordered everything because I would have saved money and gotten the right stuff to begin with. Like the thread title reads.. Trials and Tribulations of a NOOB!!! )

Well, I got quite a bit done this evening. I got the Z axis all together and started on the Y axis gantry. I soldered up the three wires and got them ready to connect up to the servo motors. I'm really getting excited seeing all the pieces come together like they are. I'm definitely going to be happy when this thing is built and I can start letting it do all the drilling. I haven't drilled this many holes in I don't know how long.

I am already thinking a larger table will be a must for my second machine. I am going to lose about 4 inches around the perimeter of the table making my final work area 20" in Y and 44" in Z. This will be fine for all my clock gears but some of the kinetic sculpture ideas I have will exceed the limits of the table. I am think maybe a 4x6 table next time around will work out better.

Now I have to work out how I am going to mount the lead screws, AB nuts, bearings and collars. The X axis is going to be a piece of cake but the Y and Z axis are quite tight.

Tomorrow I hope to get the X axis bearing mounts built and get the gantry mounted. I have to pick up another sheet of MDF for the legs and cross brase and unfortunately the roommates truck is in the shop.

Thanks again for all the input. )

Jeffrey

[wriley]

This looks like a great build, thanks for sharing all the pictures.

[Turbo1zz]

This looks like a great build, thanks for sharing all the pictures.

Thank you, I have always been one to let photos fill in where my words fall short. The saying "A picture is worth a thousand words" has always rang true for me. )

After looking around for the best connection to use between the lead screws and steppers, I decided to hit up the local Grainger and picked up some Lovejoy Shaft couplers and spiders. I also picked up two sets of Abec7 bearings for the X axis. I didn't get nearly as much done this evening.. actually, I got nothing done this evening but I am plugging away at figuring out my alternatives to VCarve since dropping 600 on a software program is not in the budget any time soon. I have Mastercam X2 and Surfcam Velocity but getting them to do what VCarve does is not a task for the faint at heart. Any ideas on what is out there that can do what VCarve does for maybe not so many clams? I need to pick up some more dowel nuts and another section of angle stock and I should be able to get the machine all together. I'm getting super excited seeing everything come together. Can't wait to flip that router on and watch it carve away.

[Turbo1zz]

One step forward.. Two steps back. I am having to rethink my router mount. I have no idea how Grunblau was able to use the draw latches but I made attempt to use them on my router but the wood split no matter what screws I use. I am thinking of using HDPE for the mounts instead. This will give me a super strong mount that will definitely last a lot longer than the MDF would have. I may just give in and get a motor mount from K2CNC isntead. That way I will have a mount that will move on to the next machine and be done with it.

I made the mistake of going to Rockler for a forstner bit with too much free time to walk around. I ended up with a couple T tracks with hold downs that I plan to put on the CNC. I will have to beef up the table now seeing as I will be cutting out slots to fit the tracks. I might just lay another sheet on over the table but then I lose three quarters of an inch of my clearance. I am just over four inches of clearance between the table and gantry and want to lose as little space as possible.

I got all the drive parts together and now just need to figure out how I am going to attach the AB nuts to the moving bits. I have the X Axis figured out but the Z and Y axis are going to be interesting. I have a sneaky suspicion that I am going to have to rebuild the the whole Y,Z assembly again but we'll see. Grr.

[ger21]

When screwing into the edge of MDF, pre drilling to the correct size is mandatory, and you can NOT overtighten the screws. Another option is to use machine screws into the mdf. Drill and tap the mdf, then coat the threads with thin cyanoacrylate glue.