Anatomy Atlas Part 5 – Skull Base

Skull base is really more interesting than the shell that covers our bulbous brain lobes. This is where our brain stem resides, the evolutionarily oldest structures in our central nervous system that could be called “brain”. That means that here are the exits of most of the brain nerves and, of course, the spinal cord. Here also enter and exit all the blood vessels supplying the brain with oxygen.

Skull base

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Profesor Kos has put a great emphasis on the fact that here is the position of the brain stem, because any damage to the brainstem is most likely to be lethal. And what he constantly warned about was the danger of hemorrhaging in this region, which can occur after even superficially mild concussion. He mentioned the absurdity of movies and media in general portraying  hitting someone in the head as a routine way to knock someone out. But it is extremely dangerous, especially hits delivered on the top of the head.  A hit on the top of the head transfers most of the force right down to the base of the skull and if it causes there a damage to even a small blood vessel, it can mean game ever.

Poor Man’s Belt Grinder – Mark 2

As I was saying last time, I have given my belt grinder a complete overhaul.

Since now I knew that I can do it and it will work, I was not so stingy about spending money so I bought for about 50€ a few beech wood profiles 50×50 and 50×30 mm, some new ball bearings and a few other thing.

First thing I have done after that was to remove the belt support and compeltely dismantle the idler wheels. I have rebuild them. Instead of using threaded rods throughout I used about 100 mm length of a 10 mm rod on which I cut thread on the ends – on one side just about 1 cm each side . This has provided better fit with the inner opening of the ball bearings. I also shortened the inner spacer between the  ball bearings so that I can sink in the nuts inside so it and the rod are flush with the wheel edge.

This has allowed me to to fix the wheels on the future idler on only one side, so I fixed them perpendicular to 50×30 profile and after that I got distracted.

Latch

©Charly, all rights reserved. Click for full size.

The distraction was the spanning wheel, which I did not intend to rebuild. But changing belts was a bit awkward – I had to pull on the lever with left hand and change the belt with the right hand. And I got an idea on how to improve that. So I have built out of plywood a gravity latch that falls into position when the lever is pulled beyond certain point. That frees both hands to put on the belt comfortably and without hassle. When the belt is on I lift the latch, the spring spans the arm and after I let go the latch end lays on the top of the spanning arm without restraining it.

Idler

©Charly, all rights reserved. Click for full size.

With that done I returned to the idler. Whilst I did spend some money on good materials, I did not spend too much time with planning except in my head. So I was still working by mostly piling stuff on other stuff making it up as I go along. I did not bother with precision too much and relied heavily on epoxy to fill any gaps and I added dovels and sometimes screws for strength

The only thing that I actually have spent some time to make precise was the parallelity of the wheels.

On the idler I prepared two screws with wing nuts for fixing the platen, and on the other side are two screws for fixing the support table (not seen here, but the positions are the pale circles in the lower half).

With that done I have cut two platens out of an old U profile that was rusting in my garden for years. Here is the final setup with all threee options visible. Left is setting for 20 cm hardbelt, middle 12 cm hardbelt, 10 cm slackbelt and right is 24 cm slackbelt.

Belt support options

©Charly, all rights reserved. Click for full size.

After this was done and tested – which I have done by truing the platens by alternating them as support/workpiece against each other on the grinder – I gave the whole thing a new coat of paint. The machine blue and the detacheable idler arm pale grey.

Belt grinder

©Charly, all rights reserved. Click for full size.

Belt grinder

©Charly, all rights reserved. Click for full size.

It is Amazing how a simple paint can improve the looks of things, isn’t it? I am glad to say that it all works as intended.

Next step is to make second detacheable arm with changeable wheels of different diameters, for hollow grind an fullers.

Jack’s Walk

©voyager, all rights reserved

It’s another beautiful day here and I’m enjoying the freedom of being outside without being all bundled up. For the past few days Jack and I have been walking in a new area because our usual forest path hasn’t been cleared yet of several large fallen trees. Jack thinks this new route is pretty swell. It runs close to the river and he’s been able to frolic in the water every day. I don’t think the route is swell and it’s not because of the wet dog. It’s because of all the dead trees. Several years ago my area was hard hit by the emerald ash borer beetle. (Agrilus planipennis) It destroyed every tree in the park that connects with this path and many more were cut down in neighbouring areas to help to help prevent the spread. What was once a lush green park with mature trees is now riddled with decaying stumps and fallen branches. Our winters have become so warm that these critters can now survive this far north. One more victim of climate change.

Off For The Day.

Yeah, it’s that time again. For once, we were scheduled for a decent time, and I took advantage to sleep in, heading out now. If all goes well, we’ll be back very late; if things don’t go well, I’m sure you’ll all hear about it. (I developed a…complication yesterday.)

Anyroad, I leave you all in the more than capable hands of Voyager & Charly. Have a good Monday, everyone.

The Beautiful Town Idstein – Part 2 – Rathaus

Rathaus has of course nothing to do with rats, unless you mean politicians. Which would be insulting to rats, I guess. Rathaus is from german words for a counsel (Rat) and  a house (Haus) and means town hall.

The building is nothing extraordinary in the context of the town, but to the right side of it is a beautiful gate to the castle. Unfortunately you can only imagine the gate, because it was being  repaired at the time of our visit so I could not take good pictures of it . And I did not have time to spend with the various plaques around the staircase either.

Idstein Town Hall

Idstein Town Hall

Idstein Town Hall

©Charly, all rights reserved. Click for full size.

 

 

Scandinavian Letters: Äng.

Äng.

Äng is meadow in Swedish. The sunset picture is a variant version of a picture from the Laajalahti Nature Preserve I’ve used before and sent to this blog. While there are trees in the picture, there’s open land that is used for as a cow pasture there, in order to restore traditional seashore meadowland.

The night time picture is from summer 2017. I was walking home from my cousin’s wedding and decided to take some night photos.

Ä is used in at least Finnish, Swedish, Estonian and German. In different languages, different pronunciations are used, but it’s generally a wovel pronounced in the frontal part of the mouth. In Finnish and Swedish it’s the second to last letter in the alphabet.

Click for full size!

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