Tuesday, 10 December 2013

More CNC parts coming

I know it's been a while since my last update, I have been quite busy moving out of my parents house.

I have just bought 6 of these and 1 of these packs.

I'm pretty sure that the current motors on my CNC's are NEMA 17's but even if they are not I can buy or make some kind of alternate mounting plate or just use them for a 3D printer if I can't make it fit.

In other news having moved out I don't have anywhere to put my HF antenna but soon I should be able to get my 2m rig online from inside so I won't have to go out to my car to talk to someone.


Friday, 6 September 2013

DC Spindle motors... Woo

I finally tidied up my electronics desk so I could see how I would need to drive the original spindle motors.

Short version:

They are DC motors that seem to be able to go fairly fast at 30V.

Long version:

This is the assembly for the mill option on the converted lathe I had to throw away.
On the top you can see the the speed controller with a switch and a pot to vary the speed.
This is the bit I really wanted to look at as it would be the part to simulate.

After I got a few screws undone it came apart fairly easily.

From there it was a fairly simple process to unscrew the ground cable and take the plastic backing off. From there I could see the conductor side of the PCB.
From there looking at the board it looked like there was a diode either as a reverse polarity protection or as a half wave rectifier. Working on the theory of it being a half wave setup I decided to hook it up to my power supply and see if it would turn or at least produce some kind of cogging effect. When I connected it up and slowly ramped up the supply voltage/current I was rewarded with rotation. Upon experimentation I found it to start spinning with about 0.55A and to just keep turning over at 0.50A.
It's not very obvious but the motor is spinning slowly in this photo. I ramped the voltage all the way up to the maximum that the power supply will provide at about 29.7V which rewarded me with a nice whooshing noise from the air getting blown out of the motor. It looked like it was going pretty fast so I was glad there was a limit to stop me from going any further without having to bolt the thing down. Now I just need to confirm the voltage/current capacity of the PWM supply of the BeBoPr so I know if I need to build a buffer amplifier. The buffer should be able to be a fairly simple design with just a power transistor (probably some kind of FET) attached to a relatively small heatsink.

Being able to easily use these motors and spindles means that I can shave a fair bit of the potential cost of this project and I can focus on more important things like how to get the rotational speed of the spindle when it uses a plastic belt and a DC motor to drive it. I'm thinking some kind of back EMF based system. However the lighting conditions probably won't change too much so some kind of light based system could also be used. This is particularly true of the lathe which has all of the mechanism inside the headstock and is fairly well sealed to light.


Tuesday, 3 September 2013

Bearings for the Heisler

I got the bearings for the bogies on the Heisler at work the other day. I might need to stop getting stuff delivered here, some people are starting to look funny at me.
And here's a comparison to the axles that we've bought. There's a bit of material to take off so I'm glad for the CNC's to run automatically.
Hopefully I can get the G-Code written by the end of the week and start machining this weekend.

On the BeBoPr front; I have got the bridges and the components to assemble them. However when I look at the Element 14 webpage I see that I need to call to get the availability for the BeBoPr's themselves. I called and they'll be in the UK around the 16th so I should see them near the end of September. At the rate these are going I might have the new hardware running by early next year.


Wednesday, 14 August 2013

Boat work - Centerboard

So on Sunday I got a chance to do some work on our little Vagabond. The other weekend we pulled it off the trailer and pulled the centerboard out so we could put anew rope on it and thin it down so it doesn't jam in the casing as much. This is what it looked like after about half an hour of hand sanding with 80 grit paper:
I don't have the patience to take all the paint off by hand so I got the electric sander out. This is what it looked like after half an hour of sanding with the orbital sander:
After that I took a break and helped my brother make a prototype pipe organ pipe out of scrap MDF we had lying around. If you want some more info on that let me know and I'll take some photos and do a writeup of that.

Once we got the pipe finished and working I went back to sanding and I got another 15 minutes into it so the centerboard looked like this:
That was all good. What wasn't so good was that the sander looked like this:

For reference it's supposed to look like this:
So it looks like I owe Dad a new orbital sander...

Thursday, 8 August 2013

Beaglebone Progress... Or lack thereof

So I finally got my Beaglebone Blacks out last night to try and get started on the CNC controllers and what did I find? I found they need micro SD cards to store all their info on and don't come with them... So today at work I'm going to order some from Dick Smith and at least one mini HDMI to HDMI adapter so I can plug them into a monitor...

Edit: I have just ordered an adapter and 3 x micro SD cards, one for my phone. I should have them within the week now

Tuesday, 30 July 2013

Progress on the CNC's

Today I finally bit the bullet and ordered 2 Beaglebone Blacks and 2 BeBoPr capes so I can do some more work on the refit of my CNC Lathe and Mill. The BeBoPr Capes are not avaliable until the 15th of august however so I won't be able to do anything with those for a while.

Stay tuned for some initial insights when I get the Beaglebones.


Wednesday, 24 July 2013

New Toy

This arrived while I was at work today.
However to be able to use it I needed to do some cleaning up...
I can't see much room for any test equipment in there can you?
This might be a little better:
Now I can get some real work done with my op amps...


Friday, 19 July 2013

New Gear

I have just ordered a new lab power supply from ebay. It should be arriving between next tuesday and the tuesday after. So Look forward to some work with op-amps after that.


Monday, 15 July 2013

Oil Burner Atomiser

Due to some offcuts of 12mm square bar from the frames of our Heisler loco becoming avaliable I'm going to make some small test runs of making some atomizers for it.

I can't find any open source CAM software for outputting to a lathe so I'm going to be writing the G-Code by hand in gedit. I'm getting the design from here which I've found to be a very good resource for info in the shay and heisler locomotives. I am making some changes to simplify construction with the avaliable tools (rounding to the nearest metric drill size).

I can post up some CAD files of the proposed design and the G-Code if anyone is interested.


Saturday, 18 May 2013

Getting back into elecctionics finally :D

Last night I finally got some time to get some prototyping done. I figured that I should start with a regulator circuit so that I have smooth power for using with op-amps. I will build a more efficient and permanent supply when I need it a bit more but using what was on hand I have a half reasonable output from this hobby train controller that was sitting in the garage.

Just about to start work on the triangle wave generator from this page.

Stay tuned.

EDIT: Just finished compiling LFS on my server so I should have more time to work on this.

Thursday, 9 May 2013

Finally back to this blog...

I know it's been a while since I've posted but after just finishing my voyage on STS Young Endeavor and now I have some more drive to get some cool stuff done. I've almost finished compiling LFS on my server so soon I'll have some more free time to work on stuff and I've just ordered an AVR programmer and some op-amps from adafruit.com so when they arrive I'll be atarting to get some projects happening.

Stay posted

Sunday, 20 January 2013

Busy time at AJ 2013

While I was having an amazing time at the 23rd Australian Scout Jamboree I had a chance to get my Amateur Radio licence. This means that soon there should be another pile of radio related posts coming soon.