Another Buy Or Build Thread

[wizard]

Thanks, Fretman_2. Some of my photos are OK. I just enjoy shooting almost as much as being a machinist / application engineer at work. I have to have creative outlets. These two, work & photography, seem to give it all to me.

Something tells me you wont have many problems no matter which way you go with your machine.

As a side note, working in automation means having constant contact with tool and die shops and of course tool and die makers. One places i worked one of the tool and die makers spent all his free time making a large format view camera. Literally worked on the camera piece by piece, we both ended up working someplace else and i always wondered if he finished the camera but it did bring new meaning to the phrase hand crafted. The guy wasn't messing around either, using good quality steels and other materials. I guess one passion feeds another. This was all well before digital hit the scene too

[fretman_2]

The last line below would describe my machine...LOL. It won't hit 1,000ipm rapids, but cuts things and does it accurately.

There is a very small minority of people that don't understand electrical systems and probably never will. Most people can grasp the concepts fairly quickly. Considering what you have posted so far i don't see you having a problem. More so for machines this size the engineering is pretty much a done deal, that is a perfectly serviceable machine can be had using commonly recommended solutions. Serviceable might not be optimal or high performance but few of the low end machines out there would ever be considered a high performance machine.

[ynnek]

Design question here. Is there any downside, other that costs to this configuration? I an sure to gain rigidity, but at what cost to performance, if any? Instead of say 25mm profile rails, I was looking at doing this with either 15mm or 20mm rails. A boxed way configuration. Possibly a similar design on the Z

[ger21]

There's really no upside. All your doing is compensating for weak sides. You'd be far better off using a single 20mm rail, and doubling the side thickness.
Fwiw, there's zero benefit to ever using 25mm rails on a DIY machine. 20mm rails can handle thousands of pounds of force.

[wizard]

There's really no upside. All your doing is compensating for weak sides. You'd be far better off using a single 20mm rail, and doubling the side thickness.
Fwiw, there's zero benefit to ever using 25mm rails on a DIY machine. 20mm rails can handle thousands of pounds of force.

ger21 is of course right here. On the X more than one rail per side would be a waste in my opinion

I highly recommend downloading some of the design guidelines and catalogs form the various rail manufactures. This material will greatly help with understanding which orientation best resists the forces being applied. No low cost DIY machine is going to be perfect, but you can arrange the components for the least cost and highest performance possible.

By the way sometimes people get lucky and score used or even new linear rails, on E-Bay or wherever, that are rather large for the machine they are building. This is great for them in that it is one costs they don't have to deal with. However it isn't at all likely that they gain anything from those rail, they may even loose a bit. In the end using 25 mm and large linear rails just leads to having to make a bigger and heavier machine.

[ynnek]

I appreciate the comments Ger & Wizard. Again. I am torn as whether to build or buy. I have most of what I need. As far as rails go, I have two sticks, 96" long, of 25mm round rail & bearings. I have considered chopping it up & building the x & y. I have a spindle, vfd, nema 34 steppers, drivers, & an available PC at home. But duty calls 60 - 70 hours a week. Kinda tough getting a build in between work & hone do list. I am so confused. I am very close to pulling the trigger on the FLA Saturn 4x4. Again, thanks, guys, for the input.

[ynnek]

Well, good news and bad news on my front. Good news is I am moving forward with a cnc router build. Bad news is I had some financial setbacks, new roof among other things, so I will not be doing a heavy duty, 4 x 4 machine. I am gonna compromise and do something smaller. There will still be costs but much less. So to start with, I found an antique, metal teachers desk at the local Goodwill, for $25. 36 x 60. I will build directly on top of it, using mostly what I already have. 25mm supported rails, i will buy new bearings for. I may do some supported , gusseted, over hang on the 36 inch side, which would allow this to be a 24 x 48 inch working area. Biggest problem will be the motion components. I have R&P, if I build directly on the table top, I have nothing to mount the racks on, which would lead to cost in purchasing lead screws / ball screws. Maybe a fixed gantry machine, then I could drive the table from the center. 3060 beam for the gantry. Maybe I can get this built, use it to generate funds to build or buy a better machine. Suggestions would be much appreciated, and much needed.

What I have:
25mm rail & bearings - enough for the entire build ( though I will buy new bearings )
R&P - Though I may not use it. If I do I will purchase Pro pinion drives from CNCRP
Power supplies - qty of 3
Nema34 Stepper motors - qty of 6, more than I need
Stepper Drives, CW-250 - Qty of 5
Cable chain
Air cooled spindle - ER-25
Hitachi VFD
Computer
220 Service in garage

What I need
BOB
Electrical enclosure
Gantry beam - 3060 x 36inch long
machine framing, probably steel, but I may go with extrusion
All other plates needed steel or aluminum, not sure yet as I have to start my design process all over again
Proximity switches
Dust collector & dust shoe
Fasteners, more if I go the extrusion route
Welder If I go the steel route



Picking up the desk today. I will pull the drawers & install the electrics directly in the cavities.

[ynnek]

Picked up the desk, Heavy as hell. Pulled out the drawers, One compartment for the drives & power supplies, & one for the PC. I think this just will work.Not what I originally wanted to do. But it will be fun.

[ynnek]

I will be starting a build thread once I get started. I was cleaning the bearings & assessing my components. The Z will be built using SBR20 rails & bearings, I will cut the long lengths of SBR25 in two to build the X & Y. As I am designing this on the metal desk, I may be able to squeeze out 32 x 48 cut area, with about 6 inches of Z clearance.


Happy Super Bowl Sunday to everyone.!!!!!!!!!!!!!!!!!11

[ynnek]

So I have 6 step motors, I will only use 4, unless I do a rotary axis.
3 are this made in china model 85BYGH450B-06D-42J
Step Angle - 1.8+/-5%
Insulation Resistant - 500V DC 100MΩ Min
Insulation Strength - 50Hz 1Minute 500V Min
Ambient Temperature - -20~+50 degree
Temperature Rise - 80 Max.
Radial Play - 0.02mm Max.
End Play - 0.1-0.3mm
Model: 85BYGH450A-06
Motor dimension: 85*85*75mm
Current/phase: 4.0A
Voltage/phase: 2.0V
Inductance/phase: 2.3+/-20%mH
Resistance/phase: 0.5+/-10%ohm
Holding torque: 3.5 N. M
Shaft diameter: 13 mm
Shaft lenght: 31.50mm
Leading wires: 4 leading wires
Weight: 2.1KG

One is a smaller version of the one above, though it has no numbers. How do I determine the specs for this motor?

Two are Danaher model CTM31NLF45KAA00

The drivers I have are CW-250

Question for all of the motors, is how do I determine which wire connects to tjhe appropriate terminal on the driver.?

They Are all 4 wire motors

[Biggs427]

If the color coding on your steppers is standard, here it is:

[ynnek]

If the color coding on your steppers is standard, here it is:

Go figure, the made in china ones are Yell Green Red Blue. I will check the other two when I get home from work. Thanks for the info. I already save this graphic.

[ynnek]

So, from what I have been reading, I should probably go with UCxx motion control ove Mach3. So I take it this will also be the better option as opposed to Mach4? So which board should I get? I really want precision, which I know will be a direct result of the build. Anyway, I am still in the design stages & pricing stage, but inching closer every day. Build thread to come soon.

[ger21]

If your going with UCCNC, get the UC300ETH. The extra $40 gives you a LOT more flexibility and options.

[ynnek]

If your going with UCCNC, get the UC300ETH. The extra $40 gives you a LOT more flexibility and options.

I have not decided as of yet to go with UCCNC, but from reading your posts, Ger, I am heavily leaning that way. I may even migrate my router at work to that also. C32BOB driving DC Servos

[ynnek]

Still in the design process. Though I did not want to use the round rail, it is available & it was free. The rail on the Z axis is SBR20. The x & z axis will utilize SBR25
Here is a link tho the Fusion360 model of the Z axis. Critiques are expected & welcomed.

http://a360.co/2lACmNb