What did you do today?

[vpt]

I finally made a flat top for my spare grille. Not real big but will do the job.

[Dan Dubeau]

Wife was is working nights all weekend so I had to vacate the house with the kids so she could sleep. We went to the Toronto sportsman show yesterday, but decided to stay home today and play outside. I lit up the big brush pile that's been sitting all winter waiting for me to burn it. Everytime I've had a chance, it's been too windy, but this morning we had zero wind. Not 20 minutes after I lit it up, did the wind pick up and start howling from the west.....Oh well, lot's of snow cover still, and I wasn't that worried about it going anywhere. While that was burning I took the kids on what will probably be the last snowmobile ride of the season around the property. We searched for Chaga (just found out about it at the sportsman show yesterday), and found a few. Then we parked the sled, and hit the woods on foot searching for shed's and other forest curiosities. There's a small spring fed creek that starts on our property. We walked it from the road up to the start, and the kids saw LOTS of fish, but I didn't see any.....(there were no fish ). To be a kid again for a day......

All winter long there's been a big rabbit taking up residence in the old chicken coups next to the house. I see him out in the yard almost every morning. Today we found what was left of him, just a couple small patches of fur, and some bloody snow next to the house...... Daughter was pretty sad (4) but my son (6) started explaining the circle of life to her, and how the food chain works lol.

All in all a good day outdoors. I tend to hibernate in the winter, not do much of anything and get a little cranky. Today broke the hibernation, and got me going again. Usually it's maple season that kicks it off, but I'm not taping this year due to zero time to boil, and I still have lots from last year.

[Tungsten dipper]

Dan,
That sounded like a great day! Those kids see everything! Wish I could watch and help with the maple season. One for my bucket list.

[tyrone shewlaces]

It ain't machining but it's for machining.
I picked up a little Taig CNC with servo drive a couple days ago and I found time to get it moving around a little with EMC today.
This is my first attempt with servo drive and I really, really like them. Much faster, smoother and quieter than steppers. Woohoo!

[PStechPaul]

Over the last few days we have been enjoying (finally) some really nice warm (and dry) weather, so I have been working on some outdoor projects. I have pruned back a lot of shrubs, mostly Forsythia and Rose of Sharon, and raked up several years worth of fallen leaves, branches, and other debris, exposing some of the remaining grass (a bit o'green for St. Patrick's Day!). I also moved a large rock out of the way along the lower service road, so that it hopefully will no longer impede my truck when backing up along a narrow section. Mr Tibbs enjoyed spending quality time outdoors.



I also did some work on my PWM Vernier project, which is essentially a solid-state Variac. It uses two sets of two back-to-back MOSFETs, driven alternately with a 20 kHz PWM signal. Here is the raw waveform (distorted due to sampling aliasing):



Details of PWM:


With some filtering:


Video showing adjustment:

http://enginuitysystems.com/pix/electronics/PWM_Vernier_5079.AVI

This design differs from a VFD in that it does not use a rectified DC bus link, but instead operates directly on the sinusoidal waveform. Thus it maintains the same wave shape and phase. The concept and circuitry are very simple - details provided if anyone is interested.

[Cenedd]

I did mange to crack a beer 20 minutes ago....Oh, this is a what did you do that was productive today thread, sorry, nothing.

You recycled some beer. Good for the environment that!

I also did some work on my PWM Vernier project, which is essentially a solid-state Variac. It uses two sets of two back-to-back MOSFETs, driven alternately with a 20 kHz PWM signal. Here is the raw waveform (distorted due to sampling aliasing):

Not going to claim I'd keep up with the intricate technical details but are we talking "vernier" as in a set of measuring calipers (or other measuring instrument)?

[markx]

I also did some work on my PWM Vernier project, which is essentially a solid-state Variac. It uses two sets of two back-to-back MOSFETs, driven alternately with a 20 kHz PWM signal. Here is the raw waveform (distorted due to sampling aliasing):


This design differs from a VFD in that it does not use a rectified DC bus link, but instead operates directly on the sinusoidal waveform. Thus it maintains the same wave shape and phase. The concept and circuitry are very simple - details provided if anyone is interested.

That is a pretty interesting concept, with your kind approval I would like to extend my knowledge a bit on the internal makeup of that circuitry
Perhaps a hint on a generic schematic if you do not mind....

[Alistair Hosie]

Off topic

well tomorrow early get taken to the other side of the water by ambulance to hospital actually it takes 2 ambulances as they need to get two teams to get me out of the house, down my front steps then down our very steep drive one ambulance crew take me in an ambulance over on the ferry just down the drive from our house onto the main road etc. I can 't remember if I mentioned I was in the garden to the rear of our house when I slipped on the rear back grass
I stepped stupidly onto the top of two large plastic container square lids and slipped badly falling backwards no matter how much I tried to hang onto a large pile of wood and fell backwards and broke my right leg and also my ankle . It turns out from my x ray my Fibula back one is hanging off from my front bone so I am all plastered up to my knee and will need a scan again to see if I need an operation tomorrow . Am I not unlucky or what heh heh heh so no chance to get into my shop anyways. Alistair

[DennisCA]

Started working on a dead blow hammer, rough turned the parts:



I will cut an internal thread on the head, you can see that I cut a relief on the inside for helping with the threading. Then I will turn caps who will also be impact faces. I plan to TIG braze the face of one cap so it will be a non marring surface. I will cannibalize some shotgun shells for lead pellets to put inside.

[Black Forest]

Off topic

well tomorrow early get taken to the other side of the water by ambulance to hospital actually it takes 2 ambulances as they need to get two teams to get me out of the house, down my front steps then down our very steep drive one ambulance crew take me in an ambulance over on the ferry just down the drive from our house onto the main road etc. I can 't remember if I mentioned I was in the garden to the rear of our house when I slipped on the rear back grass
I stepped stupidly onto the top of two large plastic container square lids and slipped badly falling backwards no matter how much I tried to hang onto a large pile of wood and fell backwards and broke my right leg and also my ankle . It turns out from my x ray my Fibula back one is hanging off from my front bone so I am all plastered up to my knee and will need a scan again to see if I need an operation tomorrow . Am I not unlucky or what heh heh heh so no chance to get into my shop anyways. Alistair

Clumsy Bastard! We could put you back together again with lots of screws and bolts. A few plates and you are good.

[vpt]

Off topic

well tomorrow early get taken to the other side of the water by ambulance to hospital actually it takes 2 ambulances as they need to get two teams to get me out of the house, down my front steps then down our very steep drive one ambulance crew take me in an ambulance over on the ferry just down the drive from our house onto the main road etc. I can 't remember if I mentioned I was in the garden to the rear of our house when I slipped on the rear back grass
I stepped stupidly onto the top of two large plastic container square lids and slipped badly falling backwards no matter how much I tried to hang onto a large pile of wood and fell backwards and broke my right leg and also my ankle . It turns out from my x ray my Fibula back one is hanging off from my front bone so I am all plastered up to my knee and will need a scan again to see if I need an operation tomorrow . Am I not unlucky or what heh heh heh so no chance to get into my shop anyways. Alistair

Thats a funny way to ask for a vacation.

[Cenedd]

Clumsy Bastard! We could put you back together again with lots of screws and bolts. A few plates and you are good.

Leaded steel for easy machinability, right?!
Could be a good excuse to play with some titanium though: I need to Dear...it's to fix my leg!

[Black Forest]

Leaded steel for easy machinability, right?!
Could be a good excuse to play with some titanium though: I need to Dear...it's to fix my leg!

Naw...that cheap Scotsman will be OK with scrap metal. I have a few old bed frames we could use. He already is on Morphine so we don't have to worry about pain killers. Just drill and screw the old bastard back together again.

[MattiJ]

Naw...that cheap Scotsman will be OK with scrap metal. I have a few old bed frames we could use. He already is on Morphine so we don't have to worry about pain killers. Just drill and screw the old bastard back together again.

Do we fix the clumsy old bastard with metric or whithworth fasteners?
Or just self-tapping sheet metal screws?

[shampine1]

Scored clearance prices to expand my S&D drills form 1/16" to 1/32" steps, and knocked out a rack. Planning ahead for later acquisitions ;-)

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