What tool to use for CNC mill or router?

Excellent three part series of articles talking about the right tools required along with many side articles providing more details.

How Can I Figure Out What Tool to Use On My CNC Mill Or Router? (Part 1 – Holes)

How Can I Figure Out What Tool to Use On My CNC Mill Or Router? (Part 2: 2D Profiling)

How Can I Figure Out What Tool to Use on My CNC Mill Or Router? (Part 3: Pocketing)

 

 

 

Strength degradation in webbing and cord with introduction of knot

I’ve always used webbing for setting up top rope anchors, but recently I’ve investigated using cord instead of webbing. For one thing, knots are easier to undo in cord then in webbing after being loaded. But is there any difference in strength between knots in cord and knots in webbing?

Interesting to see that a knot (Bowline of figure 8) will introduce a weakening to 73% of cord tensile strength.

Maybe more interesting is that in webbing, a water (overhand) knot degrades the strength much more then a figure 8 knot. Water (overhand) Knot gives a 57% of webbing tensile strength, while a figure 8 gives similar to a cord figure 8, at 71% of webbing tensile strength.

http://www.bethandevans.com/load.htm

 

Find and change quality setting on image files

The webserver I was working on was running out of space only to find people had been uploading anywhere from 3Mb to 9MB jpeg images. Nobody needs that kind of image size and quality on the wordpress site.

Put together a script to for find and re-encode jpeg images over a certain size, to a lower quality setting.

find . -type f -size +1000k -name “*.jpg” -exec mogrify -quality 50 {} \;

CrashPlan stuck at analyzing

I had this problem before where CrashPlan (the backup service) software will seem to be stuck “analyzing” data over and over without actually backing it up.

The last time that happened I had found no way around it except to re-start the entire backup. And since it takes months to transfer 1.8TB of data, it wasn’t a decision I tool lightly. I had searched all over the web and tried everything I could find, but to no avail.

This time I did some more digging again, and found a solution that worked.

CrashPlan for me runs as a docker container under UnRAID and UnRAID is a virtual machine in my ESXi homelab. I had 4GB allocated to UnRAID to do what it needed to do. The memory usage (at least as reported by unRaid) was about 60-80% so I dind’t htink I was running out of memory, but seeing as no other solution was working this time either I made 2 changes.

  • Increase the amount of ram that CrashPlan can use (as per this article)
  • Gave UnRAID 4GB more ram for a total of 8GB.

Between those 2 tweaks, the next time the CrashPlan app started, it wet straight to actually transferring files instead of “analyzing” them.

ESXi and PCI passthrough

So the troubles seemed to be over with the ESXi server crashing when I was starting VMs that used PCI devices which had been passed through, but I was wrong.
The Win10 VM that had the GPU passed through is now once again either locking up the computer (ESXi locks up) or I get a PSOD (purple screen of death).

I read about others reporting similar issues and I updated the ESXi install to the latest build of version 6.0.0, but the problem persisted.
For reference, this is a listing of all the ESXi versions and updates and links to how to apply them (source).
One thing I just tried is disabling Interrupt Remapping (source) to see if it had any effect. It had no effect.
Removed and added the GPU device from the list of passed through devices.

VP multi-rotor: development testing

I figured I should put together a list of what the development tests I want to do before setting out to actually build a prototype of a VP quad. The temptation is high to just build something, but I know I will learn a lot more by doing some testing ahead of time in a controlled environment.

Would like to build 2 test stands. One based on Trex450 heli parts and another based on Trex500 heli parts. Both are available in belt drive or torque tube, both are available from HobbyKing and hence are quite inexpensive.
The rigs need to be modular enough to test both belt and torque tube designs.

What I would like to test:

– How much power can be handeled by either torque tube and belt drive

– Failure mechanism at high power. (what fails first?)

– How much does the boom flex (carbon vs aluminum) as this may impact the effectiveness of the torque tube?

– Ability to test out different blades (length, profiles) at different angles of attack, and record thrust vs RPM vs angle of attack.

 

What I will need:

– some sort of I/O card for data acquisition so I can record in real time things like RPM, blade angle, voltage, current, thrust, displacement/bending of booms,… (add more)
Preferably a USB solution so I can use a laptop to do the data recording on Labview?

– a test rig that can accommodate the data acquisition parameters. Also needs to be  inside a lexan or mesh enclosure so failure testing doesn’t hurt me.

 

Rig Design:

I will start with a heli body, since i will be using all the gearing inside the heli body and stick a motor in side
Figure out the gearing first.

Resurrecting my old Amiga 4000 (currently not working)

Got my old Amiga 4000 out of storage at my parent’s place and decided to relive the glory days.
I still remember the great times I had with all the amigas I had owned. Starting with an Amoga 1000, then an Amiga 500, then an Amiga 2000 and finally an Amiga 4000. A few years after getting the A4000, I even remember dropping another $1000 on a Cyberstorm MKII 68060/50 Mhz accelerator card.
It must have been nearly 20 years since I powered up this machine.

Continue reading

The onset of a cold?

It’s been a while since I remember having a nasty cold and I’ve been attributing this to my supplements of Vitamin D. Same goes for the rest of my family which also takes Vitamin D supplements.
Recently there has been some cold virus going around where people have been quite ill and I thought I was spared. Maybe not?

I woke up this morning with a bit of a sore throat and the feeling in my breathing that I get just before I come down with a cold. It’s a feeling in my lungs that I can’t really explain. When I breathe in the air passing into my lungs feels different just before the onset of a cold.
A few days ago (on friday) I was out to a concert which ran until 2am so I didn’t get to sleep till near 3am. The next morning I got up around 8am so only 5hrs of sleep.
For the next few nights (saturday, sunday and monday night) I felt really tired in the evenings. So tired in fact that I went to sleep around 8pm or 9pm each night. During the day I was fine and alert. I had a thought that maybe I was fighting something, but not having had any other symptoms, I didn’t quite know what to make of it. I thought I was just recuperating from sleep loss on friday night.
Other then the subtle sore throat and feeling in my lungs, I feel a little tired today with a very mild headache. More like just some pressure then an ache.
I haven’t stopped my daily Vitamin D supplements (5000IU) but I will continue to document how this cold progresses.

Saturday: Tired in the evening; went to sleep at 8pm
Sunday: Tired in the late afternoon/evening: went to sleep around 9pm
Monday: Tired in the afternoon even after my 2pm tea. Tired through the late afternoon and evening; went to sleep at 9pm
Tuesday: Woke up with a slight sore throat and the feeling I get in my lungs before the onset of a cold; also a little tired with a very mild headache.

RemoteFX for RDP-finally working

There’s still a bit of testing to be done, but I may have gotten where I’ve been wanting to get for a while now in terms of virtualizing an remote desktop. That is the ability to use the GPU to render remote desktop sessions. By default this setting is turned off in Windows, and for the longest time I thought I had do crazy things like install VMWare Horison, or Xen Desktop (XDH) or even windows server to enable RemoteFX (which is the windows version of the GPU accelerated desktop delivery).

All along, it was just a few setting away in regular windows itself to enable RemoteFX.
http://blog.tedd.no/2011/04/28/optimizing-rdp-for-casual-use-windows-7-sp1-remotefx/

Now running and playing on a remote desktop served by a virtual machine with a quadro 6000 gpu (well actually a modded gtx480 since it’s way cheaper then a real quadro 6000) in full HD.

Some testing is in order.
Bring on the heavy GPU use software!

What works so far:
– Full screen, full HD (1920×1080 video playback)

 

What doesn’t work so far: