http://www.hossmachine.info - Gosh, you've... really got some nice toys here. - Roy Batty -- http://www.g0704.com - http://www.bf20.com - http://www.g0602.com
yeah, it's definitely worth it. I have one of the little 4x6" bandsaws that harbor freight currently sells for around $230, and last week I cut some 3" round bar 304 stainless, not a problem.
I did try to cut some linear rail with it, and it didn't seem to want to even make a mark in it.
Ian
use an abrasive saw or a cutoff wheel in an angle grinder for hardened linear rails. once you get past the surface the stuff is easy to cut.
FS: Complete Z-Axis Assembly with THK RSR15WM slide, leadscrew, stepper mount. PM for more info.
Yeah I cut them with an abrasive chopsaw. I just wanted to see how the bandsaw would handle it.
Ian
I had a problem with the upper idler wheel on my 4x6, after 2 years of lots of use though.
The bushings they use just wore out and turned the hole in the wheel into cone shaped hole.
I bored both sides to fit some ball bearings so now it should last for several years, knock on wood.
Needed a piece of Oilite too for the spacer, whatever they had disintegrated.
Got my 4x6 at Tractor Supply.
Hoss
http://www.hossmachine.info - Gosh, you've... really got some nice toys here. - Roy Batty -- http://www.g0704.com - http://www.bf20.com - http://www.g0602.com
How many threads per inch do you have on the XYZ ballscrews?
http://www.hossmachine.info - Gosh, you've... really got some nice toys here. - Roy Batty -- http://www.g0704.com - http://www.bf20.com - http://www.g0602.com
Hoss-
Yet another electronics question. Why did you choose the Gecko G201X drivers in your 'best' package versus one of the keling drivers like the KL-8060?
Kevin
I didn't pick them, keling did, this is their package that I linked to on my site.
http://www.kelinginc.net/ThreeC6CNCPackage.html
Hoss
http://www.hossmachine.info - Gosh, you've... really got some nice toys here. - Roy Batty -- http://www.g0704.com - http://www.bf20.com - http://www.g0602.com
This is the package Scott and I put together and used on his, and one other, mill. John at Keling was kind enough to add it to their site so I, and others, could easily tell people where to get the electronics recommended for the conversion. The only reason we went with the Geckos is we had read and heard more about them than the Keling. Both brands obviously work really well.
EK
Gotcha. There isn't a huge price difference between the 2. Maybe $15 each or so which I guess adds up when you have to buy four of them. I have been using all Keling products on my X2 for years and have never had an issue. I wasn't sure if there was any benefit to the Geckos or not. If not, I will probably just get the Kelings and save $50. I think I am going to get the C32 also and use CAT5 cables to wire the drivers.
OK, last electronics question I swear. (2) 3 amp motors on the X and Y and a 4.5 amp motor on the Z for a total of 10.5 Amps. The power supply is rated at 12.5 amps. So this would probably be OK for 3 axis and even 4-axis if I am just replacing either the X or Y with the rotary axis but probably not enough to do true 4D, right? Not that I do true 4D now but if I plan on it, would a 20A power supply be a better choice?
Edited to add:
Here is what I am thinking
3 PCS KELING KL-8060 ($89.95 X 3 = 269.85)
1 PCS NEMA34 KL34H280-45-4A, HIGH TORQUE STEPPER MOTOR 640 oz-in for Z axis or KL-34H280-55-4A ($89.00)
2 PCS NEMA23 KL23H2100-30-4BM, dual shaft Motor 495 oz-in ($59.95 X 2 = $119.90)
1 PC C32 multifunction Breakout Board ($186.00)
3 PCS C34 RJ45 COnnector Board ($3.00 X 3 = $9.00)
1 PC 5V Power Supply for C32 Breakout Board ($9.99)
1 PCS KL-7220, 72VDC, 20A Power Supply ($189.00)
1 E-Stop Switch ($9.95)
3 PCS Limit Switche (3 X $3.29 = $9.87)
3 PCS Box Cable Connector (3 X : 3.99 = $11.97)
Total = $903.63
or alternatively swap out a C11 in place of the C32 and ditch the RJ45 adapters which would save $86 and make it 817.63. I don't think I gain anything with the C32 over the C11 other than the RJ45 connectors but I could be wrong. Now I'm thinking that the RJ45 connections aren't worth another $86.00
My understanding was you need a supply rated at 2/3 of the operating current of the motors since they are not all working at full current full time.
Make sure you factor in the Efficiency of the power supply. you might be cutting it way to close. Your not suppose to run the PSU loaded 100% all the time, you want a little head room, it will sure last longer.
Look at this: 73V 19.5AMP power supply. Bullet proof. Comes with a 5V 1 amp line as well. $225 I bought there 105V power supply and the quality is AMAZING.
http://www.antekinc.com/details.php?p=337
I have been thinking about the motor and power supply currents.
If the motor is rated as max. 5A per phase does it not take max. 10A if half stepping without torque compensation?
And if micro stepping then the motor takes max. 7.1A which is calculated from max{abs[5sin(x)]+abs[5cos(x)]}.
Or is the rating max. 5A for both windings? (why is the rating then 5A per phase?)
Some stepper controllers have a setting for halving the current if it is not moving for a fixed period of time (few seconds).
So if machining a 3D arc etc. the steppers can take over 21A for three steppers.
You guys are way over rating the current needed for the steppers.
The maxim value that a stepper can draw may be 3A but at any RPM over resonance it will draw less current, a lot less.
A 9A transformer supply can deliver 13A for 30% of the duty cycle with no problem. It is almost imposable for a stepper system to draw max current for any amount of time unless all the steppers are going the same speed. Most of the time the Z will be parked and drawing 60% less power.
You might want to see a 15A PS in real life and ask yourself if you want a 25 pound PS.
The ratings of the PS is for a 100% duty cycle so it is OK to run them that way. If you have a fan in the box you can run them even harder.
For two 3A and a 4.5A stepper a 7A or 8A coil PS is fine.
I like the Gecko's because the are made in the USA even the outputs are US products. All the Keling products are China made.