Thread: Diy Brushless Spindle
-
20-06-2012 #111
Jonathan, have you ever had any problems with cell balance using a LiPo?
I'm just wondering how actually using a multicell pack without balancing it works out longer term, as my current project needs a 2cell pack, and I'm trying to decide if I really need to include a balancer circuit.
-
20-06-2012 #112
-
21-06-2012 #113
It's one of these things that gets mentioned alot, but not sure how much difference it's going to make in practice. I'm probably going to at least add the circuitry to the PCB as I've spare ADC pins on the uC anyway, and might built a couple prototypes with and without the extra components just to see what happens. I'm aiming for longetivity, so it may be a case of every little bit helps!
-
11-09-2012 #114That battery is rated for 60A constant, or 90A for 10 seconds which is plenty. Since my PSU has variable voltage output and current limiting I can set it to just below the fully charged voltage of the battery (i.e. <22.2*4.2) and it will never overcharge the battery, which is very important since overcharging a lipo battery is a good way to start a fire. So whatever PSU you get if you decide to use in combination with a battery will need to have good stable voltage regulation below 25.2V. Two computer ATX PSUs in series is nice and cheap and will give very close to 24V, however it is CRITICAL to ensure they are electrically isolated before putting them in series. The battery would never fully charge, but that's a good thing if anything as it increases it's life expectancy. You could get the battery first, use it to power the motor to measure the current then buy a PSU to suit.
Anyway, I've gone ahead and ordered two ATX supplies with 12V 30A outputs, and looking forward to making a 24V supply with them for a spindle PS. I will isolate the negative buss from the case, and I know about setting up the switch line and adding a starting load resistor on the 5V lines to keep the supplies running.
I build and fly R/C planes, so I'm familiar with the rest of the motor side components. I have two 5055 1500W rated motors -- one 400 kV and one 540 (I believe) -- both have 8mm shaft dia. I have an 8mm ER-11 collet spindle, and collets.
ps. I also wanted to post a possible correction to the above -- I think the bolded text above should read "(i.e. <6*4.2)"
Thanks for your PSU info!Last edited by vtcnc; 12-09-2012 at 03:11 PM.
-
11-09-2012 #115
(deleted and prior post corrected)
Last edited by vtcnc; 12-09-2012 at 03:13 PM.
-
10-10-2012 #116
Made some progress on this after concentrating on helis for the last goodness knows how long. The amount I've spent on helis recently I probably could have built a reallt top notch router by now.....oh well still having fun with the helis so not too worried :D
Anyway....below is the progress I've made with the spindle housing, will dig out the bits from the box in the cupboard tonight and see if I can put it together tonight (minus the bellville washers as I've forgotten to order them!!)
-
10-10-2012 #117
-
11-10-2012 #118
Brilliant work :)
What is your PSU?
-
11-10-2012 #119I'm waiting on getting some Bellville washers then I can finish it off :)
-
11-10-2012 #120
Thread Information
Users Browsing this Thread
There are currently 3 users browsing this thread. (0 members and 3 guests)
Similar Threads
-
Denford router - Brushed router too brushless spindle - Help and advice please
By Tom B in forum Brushless Spindles & MotorsReplies: 4Last Post: 16-05-2016, 09:13 AM -
All-In-One Brushless Servo System
By Gytis in forum Stepper & Servo MotorsReplies: 0Last Post: 22-12-2015, 10:21 PM -
DIY Brushless spindle
By booski in forum Brushless Spindles & MotorsReplies: 2Last Post: 30-10-2013, 09:36 AM -
Using RC Brushless motors as spindle
By Jonathan in forum Brushless Spindles & MotorsReplies: 30Last Post: 20-12-2012, 08:51 PM -
Mach 3 control of DC Brushless motor?
By templecorran in forum Artsoft Mach (3 & 4)Replies: 15Last Post: 18-11-2010, 04:20 PM
Bookmarks