Monday, 27 August 2018

Back to the Blidgeport CNC conversion - fitting the X axis drive compts

After 3 months of the new job, I've been getting workshop fever. I've not had the mental bandwidth to deal with all the changes going on in my working / living away life to have productive / workshop thoughts. But I'm now bored shitless from a workshop point of view and things are about to warm up in the workshop, at least at the weekends when I'm back home.

I'm not certain how to proceed with the ATC (Shiz toolchanger) for the moment, so perhaps I should focus on the CNC conversion for now. I was proceeding nicely on that project when I was offered the ATC, at which point work came to a halt. Shortly afterwards I started the new job 200 miles away. Hmm.

Here's where I left it last time. I'd fitted the bracket, motor, tensioner, pulleys etc for the Y axis and pulled the handwheel off the end of the X axis ballscrew, ready to fit the X axis parts. 



Here's the clearance between the motor and the table / DRO scale. Seems I made a reasonable job of measuring and modelling it up way back when I designed the components.



Front view:



The coolant drain hose connection will even go back on, once I've finished fettling the rest of the parts.



Here are the main components for the X axis drive. Taper lock pulley and grub screws, key, 
M12 fine nut and various washers not shown.


I need a spacer between the back of the taper lock element and the thrust bearing. It's a simple 16mm bore, 25mm long jobby. I have a handy piece of mystery loominum that will work here. I like using boring tools for both internal and external machining. Saves changing tools over - just run the spindle in reverse and use the tool behind the axis. I'm facing it off here:



Quick skim of the OD for cosmetic purposes mainly:


Job done:



Motor in place, tensioner fitted (moves in a slot to tension the belt):



There we are. Mustn't forget to tighten the grub screws in the Taper Lock pulley at some point. And here's the Y axis I fitted previously:



Next - do some more tuning with the DMM Technology software, then perhaps consider tackling the Z axis parts.

Sunday, 26 August 2018

Raspberry Pi 3? Smart connected home?

Smart plugs:

I'm away from the workshop during the week right now, so can't get up to much.

Fof the last 6 months or so I've been using a "smart plug" to control my 3000VA / 110VAC isolation transformer in the workshop. I use this to power the various tools I bought in Canada that require 110VAC, such as the Bridgeport power feed, belt sander, band saw etc.

Although the transformer has been approved (ie UK made and has proper CE marking), I know from experience that it gets pretty hot if you forget to switch it off at the end of the day and come back to it next day. So regardless of the (low) risk of fire, it must be using a fair bit of power on standby - several tens of Watts I'd guess.

I like TP Link, so that's what I bought. The TP Link HS110 may cost a little more than some of the generic Chinese ones but at least I have some confidence in the quality and safety of the design and manufacture.

These "smart plugs" can be remotely turned on and off from anywhere on the internet, as they are Wifi-enabled and come with a simple app that allows you to both turn them on and off remotely AND see what their status is currently. They are a piece of wind to set up. You can even schedule times when they should be turned on and /or off, so I have mine programmed to turn off at 11pm every night. Of course, it will do that even if it wasn't turned on in the first place. That's a simple failsafe solution to the problem caused by that stupid fat git who sometimes manages to sneak into the workshop when I'm not looking.

And if you have coughed up a few quid extra for the slightly snazzier version (ie the HS110 rather than the slightly more basic HS100), you'd also have a measure of the instantaneous and cumulative energy consumption. Not strictly necessary but possibly interesting(?). Depends how much you get out I suppose.

Home Assistant - HASS.IO:

You can string loads of "smart" (ie Wifi connected) devices together using various "hubs" such as Google Assistant, Apple Homekit etc. But there are also some simpler(?), less proprietary (open source) options such as Home Assistant that can run on devices such as a Raspberry Pi or an iOS device etc. It's all there on Github, just waiting to be used.

The website is where you go to download images for the likes of RPi.

I've got several RPi's - versions 1, 2 and (as of today) 3. The latest version (3) differs from the previous versions in having Wifi and Bluetooth, as well as faster processor, video and memory of course. I'm far from expert / experienced in their use as I find Arduino much easier to understand than the Python or Linux that the RPi expects. Arduino is pretty much C which I have had some (minimal) exposure of.

Various videos outline the procedure to get Home Assistant (HASS.IO) installed on a RPi, along with a few sensible add-ons. Although you can add a display (or connect to any HDMI dispay), keyboard, mouse etc and end up with a perfectly usable desktop PC, obviously I don't want to have to go to that bother. So HA allows you to control the RPi through a browser.

Overview of how to install stuff from DrZz.



A more software-orientated intro from BRUH Automation, who clearly knows what he is talking about:



Your actual Raspberry Pi:

Got one of these delivered at work today. The price is pretty much fixed whether you buy from RS, Farnell, CPC or whatever - but at around £30 you can't complain. I have several 8GB MicroSD cards and of course I just noticed that lthough you can run it on 8GB, you soon run out of space. Which is why they recommend 32GB. Hmm. Ah well, I'll see how I get on with the 8GB for now.




Here's a RPi 2 and an RPi 3. The main visual difference is the metal can containing the Wifi / BT device (and the Broadcom SOC has also developed a metal shield). Beyond that there's little physical difference, which is handy as it allows me to reuse the nice case I bought for the RPi 2. When I say "little physical difference", in fact the power and ACT LEDs have been moved to make way for the Wifi / BT module. So they don't line up with the light pipes in the case...


Wow, this is funny. Looking at this photo you'd think the boards had been folded. It's just a trick of the light:



This is what you are supposed to see - red power light on and green light flashing / mostly on. 




Here's a comparison of the 2 models.

So first, download the appropriate image for your RPi. And install Etcher to create a bootable image for the MicroSD card.

Obviously this is where things ground to an almost complete halt, being out of range of a mobile phone signal (can't use my 4G hotspot) and the B&B bandwidth being not far from dialup speed. And of course I can't see my iPhone pictures because they haven't uploaded themselves to the (i)Cloud and thence downloaded themselves onto the laptop.

I resumed the next day but came up against a brick wall when trying to get the thing to boot. Then I went back and spotted the following detail:



Ah. That explains why it wouldn't boot up off either of my MicroSD cards. The red LED would do an 8 flash fault code and although that doubtless indicates a precise fault condition, the RPi troubleshooting pages didn't go into that level of detail.

So this is what you need to do - install Hassbian ie a Pi image with Hass....



...on Github:


So - start again. this time with a degree of success. Whew!


That'll do for now. Perhaps I may go back to it and do something with it at some point.

Chinesium Leeb (rebound) hardness tester

Another mouse accident: I bought one of these  portable Leeb hardness testers  from AliExpress. Arrived fairly promptly but of course TNT ...