Wednesday, February 28, 2018
How to Treat Mountain Bike Injuries By Scott Cotter
My friend Richard isn’t going to like this.
His story has been shared over campfires and piney IPAs, before and after races, or during hazy, caffeine-fueled drives to and from bike events.
Mostly by me.
Never mind that the facts have likely been muddled by time.
Richard’s tale starts at Landahl Park in Independence, Missouri, a quick hop from Kansas City. Out on his own, Richard decided to ride a line called the “Death Drop.” I mean, who am I to say, but maybe that should’ve been a clue (he gets major points for bravery).
OTB he went, snapping both of his arms like dry kindling. The story goes that Richard, with badly-twisted arms, kicked his bike into the woods, then stumbled his way into a nearby shooting range.
Here’s where it gets fuzzy. See, I like to think the intercom sputters to life as a delirious, candy-colored man in skin-tight clothes wanders out onto the range. “Hold your fire,” I imagine them squawking.
Next, Richard wakes, looking upward into a circle of guys as one pushes his way through shouting, “everyone back, I’m a dentist.”
Maybe none of that really happened. But it’s damn amusing. And were Richard not near a road and a place like the shooting range, we might still be hunting for him in those woods, arms twisted into origami.
With his arms all healed, Richard is now capable of clowning around as if nothing ever happened. The scars on his arms tell a different story. Photo credit: Howard Berkowitz
That’s the thing: being ready to deal with the unexpected. Because there are two types of mountain bikers: those who have crashed and gotten injured, and those who will.
As Carl Weil says, “there are old bikers and bold bikers, but no old, bold bikers.”
Carl is the director of the Wilderness Medicine Outfitters in Elizabeth, Colorado and has written multiple books on the subject of wilderness emergency care. He has covered a lot of miles – and rescues – of all types, and is emphatic: be prepared.
When you’re in a place like this, an accident can turn deadly because you’re a long way from help.
Both Carl and Dr. Greg Cummins, a mountain biker, internal medicine specialist, and former director of the Midwest Mountain Bike Patrol, agree. Get some decent first aid training and carry a first aid kit–especially if you’re in places that are hard to reach.
Carl suggests carrying, at a minimum, a triangle bandage, a SAM splint (or two), plastic covered gauze, triple antibiotic ointment, a Cinch-Tight compression bandage, gauze pads, roll of tape, CPR shield, and Micropur MP1 tablets for cleaning water when stuck and making wound irrigation with your hydration pack. “You don’t need a lot of things in your kit,” says Carl.
Here are some tips to help you deal with specific injuries when you’re far from home.
Broken Bones and Sprains
My friend Richard was lucky. He made it out quickly. Carl explains, “You have somewhere between five minutes and one hour where the pain is masked.”
That means work fast if you can… just don’t be carelessly fast.
Doing stuff like this can certainly cause bones to come apart. But really, small accidents can, too. Photo credit: Red Bull
Start with the ABCDE acronym, says Greg. Check the airway, make sure breathing is normal, test circulation at the extremities, look for dislocated bones or joints, and inspect the environment for clues about injuries. “If you wreck hard enough to break a bone,” Greg says, “there could be other issues, such as head or internal trauma.”
Stabilization is important. That SAM splint would be helpful in this situation because it’s moldable and stiff to provide support. Lacking that, Greg suggests using a tube and pump or stick to keep everything from moving. Not tight, just enough to keep it steady. That tube also makes a great, easy-to-rig arm sling, says Greg–good for supporting clavicle and shoulder injuries, common injuries for dirt nerds like us.
Just say no!
If dealing with a break, check for circulation. “If the arm is bent and the fingers are cold and blue, you’re going to need to manipulate it to get circulation going again,” explains Greg.
For sprains, treatment is much the same. You have to immobilize the limb to reduce the pain.
Lacerations
(Warning, grossness ahead.)
All of us have been cut, scraped up, or gouged while on the trail. That’s part of the game. And most of the time, lacerations are not that big of a deal.
Sometimes, though, they can be serious. Still, wound care is actually pretty straightforward. Controlling the bleeding is the key, says Greg. “Usually it’s more superficial and controllable with pressure,” he says.
And that Cinch Tight bandage Carl recommended? It’d come in handy now to help stop the bleeding. “Time lost is blood loss, which is life or death.” But don’t use tourniquets, adds Carl.
This is the kind of wound that needs to be cleaned and covered before you start the trek out of the wilderness. Photo credit: Pixabay.com
Here’s where you can use those MP1 tablets for cleaning the wound, which will help reduce the possibility of infection. “Throw some of those MP1 tablets in your hydration pack and then irrigate the wound,” Carl suggests. Then get it covered, preferably with those bandages you are (hopefully) carrying.
If you lack bandages and need to control bleeding, “use a blood barrier of some sort, like your glove,” explained Greg. Simple compression can help. You can walk out of the woods holding steady pressure but, if you’re a long way out, it’s going to be one hell of a task. Tie a tube around the injury to hold that blood barrier in place. Just check to make sure there is blood flow to the rest of the limb periodically. “Feel below the cut to see if the skin is warm,” Greg says.
Dehydration
In the world of bad stuff that can happen far from home, this one is awful.
“Carry the right amount of water,” Greg says. It seems obvious, but a lot of people don’t.
Still, it can happen. If it does, quick re-hydration is key. But what if you find someone out in the woods who is disoriented and you’re not sure what happened? Here’s where checking the environment matters.
Does the person have water? Does it look like it has been used? Is his or her helmet cracked or dented? One thing you can do to check, says Carl, is the back of the hand test. Pinch the skin and see if it returns to normal quickly. If it doesn’t, or if it stays in a ridge, suspect dehydration (still check that helmet for cracks, scuffs, or dents). This has all the potential of being very serious.
A simple tablet from Katadyn and your water is safe. Photo credit: Katadyn
This is another good place to mention those Katadyn MP1 tablets Carl talked about. If you’re a long ways from the trailhead and it’s going to take time to get out, you’ll need more water to make it. And those tablets will make the water safer and won’t take up much room at all or be a weight penalty. In fact, eight tablets will treat two gallons of water and combined, they’re the size of two quarters. Rehydrate at a rate of one pint per 15 minutes, says Carl. “Any more than that and you could vomit,” he says.
As tempting as it might be when you feel like you’re painfully parched, do not touch this. Photo credit: Pixabay.com
It’s hard to put too fine a point on it. Dehydration is ugly–a potential killer, even. Remember, if you’re a long way from home, being prepared with enough water or a way to treat water if something bad happens could be a lifesaver.
Hypothermia/Hyperthermia
For overheating, picking up on early warning signs is important. Not sweating when you should and disorientation are the two most obvious. Acting quickly is important to turn this around or, like dehydration, it can get serious.
Exertion must stop. “Get in the shade, drink some water, hit vascular areas with cool water,” says Greg. “Or sit in a stream, making sure your groin is fully immersed in it.”
For hypothermia, disorientation is also an early sign. This is where a space blanket could help save body heat, says Greg. Again, work on those vascular areas to get them – in this case – warmed up: wrists, armpits, groin. When those fingers get (uncomfortably) cold, says Carl, you have between one and four hours before limb loss is a possibility.
Body temperature issues can sneak up on you quickly and leave you disoriented and in very real danger. Photo credit: Pixabay.com
“Avoidance is important here, again,” Greg says. “Don’t ride by yourself, or make sure someone knows where you are.”
Carl recommends heat packs for cold weather riding so you can break them open and use them on vascular areas. They are light and easy to use.
Snake Bites
“Don’t mess with snakes,” says Greg. “They don’t want to bite unless they feel really threatened. And sometimes, even a bite won’t transfer venom because of that.”
If you or someone you see gets bitten, do not cut across the bite area and try to suck the poison out. That’s a cute Hollywood trick. “The big issue with a snake bite is keeping calm,” Greg explains. “Identify the snake if you can, too,” which helps with treatment. “Do not,” adds Greg, “bring the snake or its head into the ER. The staff hates this, and it also exposes more people to a bite.”
Photo: Fatbike1
Look for two puncture holes, Greg adds. That’s a sign that the bite was from a pit viper, which is the venomous kind.
Unfortunately, walking a victim out can speed transfer of the venom, so it’s best to leave someone with the victim while you go get help or call it in.
Speaking of things that can bite you! This guy was wandering around on Gooseberry Mesa. Thing is, tarantulas are not aggressive and the bite typically isn’t bad unless you’re allergic. To prove that point, I let this guy crawl up onto my hand.
Strive to Survive
“You can always go around if you’re not macho,” Carl laughs. He’s right. You don’t need to prove anything to anyone. But look, this sport is not without danger, even if you never act crazy. Regardless of what kind of rider you are, what kind of first aid kit you have, and how much training you’ve received, accidents happen.
This kind of joy can turn into something altogether different if you’re not prepared. Photo credit: Pixabay.com
And if you’re a long way from anywhere–say, on the Monarch Crest Trail in Salida, Colorado, where changing weather, difficult conditions, and elevation will all play a part in what it takes for you to get off the mountain–you’ll need to be ready. The best thing you can do for yourself, your riding partners, and random strangers out on the trail, is to be prepared. Go ahead and leave the weight weenie at home. In his or her place, take a kit with the items Carl outlines. That’s the kind of gear that can help you through a lot of different problems without weighing you down. And, Greg adds, carry a light wind/rain jacket when you’re going remote. It could save your life during unplanned overnights in remote areas.
Now, go have fun out there. Safely.
Please note: While Carl Weil and Dr. Greg Cummins provided information for this story, they also both assert that this isn’t intended to be medical advice or help you handle medical emergencies like a pro. Get some first aid training, carry what you need, and seek the attention of a trained professional in case of an injury.
BUILDING A PORTABLE SOLAR POWERED SPOT WELDER: CHARGING SUPERCAPACITORS
Before Lunar New Year, I had ordered two 3000 F, 2.7 V supercapacitors from China for about $4 each. I don’t actually remember why, but they arrived (unexpectedly) just before the holiday.
Supercapacitors (often called ultracapacitors) fill a niche somewhere between rechargeable lithium cells and ordinary capacitors. Ordinary capacitors have a low energy density, but a high power density: they can store and release energy very quickly. Lithium cells store a lot of energy, but charge and discharge at a comparatively low rate. By weight, supercapacitors store on the order of ten times less energy than lithium cells, and can deliver something like ten times lower power than capacitors.
Overall they’re an odd technology. Despite enthusiastic news coverage, they are a poor replacement for batteries or capacitors, but their long lifespan and moderate energy and power density make them suitable for some neat applications in their own right. Notably, they’re used in energy harvesting, regenerative braking, to extend the life of or replace automotive lead-acid batteries, and to retain data in some types of memory. You’re not likely to power your laptop with supercapacitors.
Anyway, I had a week-long holiday, and two large capacitors of dubious origin. Sometimes we live in the best of all possible worlds.
Each capacitor is allegedly capable of storing about eleven kilojoules, and delivering that energy at a frankly alarming rate. Exactly what rate is unclear, as I don’t have any documentation for the internal resistance, thermal tolerance, or even the polarity.
Further complicating matters is that all my suppliers are closed for the next two weeks or so. Whatever I was going to build, the first challenge was that it had to be built from the parts on hand. Second, most hospitals are running at reduced capacity right now – so even more than usual, it had to be reasonably safe.
For that and other reasons, directed energy weapons were out of the question. (Use science for peace please!) I did really need a spot welder though, and there was no shortage of examples of people who had built their own from supercapacitors, typically in the 500 F range.
However, I’m using six times that capacity, and I didn’t feel the safety precautions used in these builds (most often none) scaled particularly well. My concerns were in two main areas: a safe and efficient charging method, and preventing unintentional discharge.
The latter was simple to fix. As the supercapacitors were roughly the shape of a large battery, I put a collar around one electrode as a spacer. The tape is not structural, it’s just to hold the plastic in place for a photo and while inserting the capacitor.
Then I made a large version of an AA battery holder out of a weatherproof plastic box and some 0.7 mm thick copper plates I had left over from other projects. Later on, I’ll drill holes in these plates and attach thick copper wires with bolts. I may also pack the empty space inside the enclosure with something fireproof, like packed sand.
The capacitor fit firmly in place and I wasn’t able to dislodge it by shaking the case vigorously. The next challenge was to determine capacitor polarity so I could clearly mark it on the case. Out of habit, I pulled out a multimeter and measured the voltage across the terminals, without realizing that probably wouldn’t work.
Unfortunately, it did work. Someone has decided to ship the supercapacitor containing significant charge (about one volt). They were pretty well packed when I received them, but I still can’t imagine any reason they would ship them bearing charge. If any of our readers can think of one, please let us know in the comments!
CHARGE!
In any case, now that I could store and connect things to the capacitor more or less safely, it was time to build a charger. Certainly, there are many examples on YouTube of people manually connecting and disconnecting a lithium cell and current limiting resistor to the battery while also holding a multimeter in place, or connecting a large variable-voltage power supply with current limiting function. There are also voltage limiting and cell balancing supercapacitor protection boards that are a very reasonable option, but my suppliers don’t carry them and are closed for the next 2 weeks.
Directly using a battery was out of the question. A current limiting resistor wastes a lot of power, and human error can lead to overcharging the capacitor or polarity errors, reducing its lifespan (and possibly mine as well). The fail state of large capacitors seems to vary between ‘large firecracker’ and ‘small hand grenade’, both of which I prefer less. A high current benchtop power supply wouldn’t be great either, because it requires a wall outlet, and I was hoping to make this a mobile unit.
I had a few DC – DC buck converters lying around that were rated to 5 A of current. These are fairly efficient, around 85%, and can output down to 0.8 V with a DC input between around 5-32 V. My intended power supplies for this are a bunch of lithium batteries at different voltages, a 40 W 18 V solar panel, and possibly other things like old laptop power supplies.
I tore apart one of the broken DC – DC converters to see what chip it used. It was an XL4005E1 (PDF). The datasheet said that it has a ‘maximum duty cycle of 100%’ (hilarious for reasons we’ll discuss later) and had an active high enable pin. This seemed like a good way to limit the output current of the power supply to within a safe current using pulse width modulation.
While a 555 timer would have been sufficient, I used an ESP8266 because I plan to expand functionality later. The capacitor charge rate slows as it charges, so the ideal PWM duty cycle depends on the present charge level. Later on, I want to use the onboard analog to digital converter on the ESP8266 to optimize the charge rate, display charge state using an LED or screen, and turn off the circuit automatically to save power when charged. For now, the only goal was to find a reasonable duty cycle to charge the supercapacitor to over 2 V for testing. To this end I set the output to 2.5 V and connected the PWM output from the ESP8266 to the XL4005E1 enable pin. The PWM output was determined by the following simple program on the ESP8266:
1
2
| pwm.setup(1, 1000, 650)pwm.start(1) |
Unfortunately, this didn’t work at all. The XL4005E1 always stayed on, and thankfully it shut down before any combustion occurred. Tying the enable pin to ground or VCC also had no effect – I suspect a counterfeit chip. Ironically, the datasheet was still exactly correct to say it has a ‘maximum 100% duty cycle’, it just turns out this is also the minimum duty cycle!
I looked around for something that could switch enough current to be a useful alternative. I found a stack of LED dimmers that someone had asked me to buy for them, and never picked up. They were super cheap, and I’m happy I kept them now. Inside I recognized a 9 V voltage regulator, a 555 timer, and an IRF530N power MOSFET (PDF) with heatsink.
I couldn’t help but think that if I just removed the 9 V voltage regulator, I could use the dimmer directly to control the output current of the power supply. However, that would mean no automated control later, and a dial without any particularly useful markings.
I desoldered the MOSFET, and used the 3.3 V output to drive the gate. The datasheet suggested this probably wouldn’t work, and frankly I shouldn’t have bothered. What did eventually work was connecting the input of the DC-DC regulator — it will always be 7.4-18V for my use cases — to the MOSFET gate via a 2N2222 transistor. The base of the transistor is connected to the ESP8266 PWM output. The PWM output allows the transistor to switch the DC-DC regulator input, driving the power MOSFET effectively.
I had found earlier that the DC-DC converter shut down if you draw more than 8 A. Through trial and error, I found a 40% duty cycle worked acceptably well while safely accounting for vendor optimism. The downside is that with a fixed duty cycle, the charge rate drops to nearly nothing when the capacitor hits about 2.15 V. My goal for testing was to charge it to 2 V, so this was acceptable for now. For convenience, I attached a small LCD voltmeter to monitor charge, and called it good enough for now.
Admittedly, after a few unplanned revisions to the circuit this became a bit of a kludge of parts. If I had to redo this, I might keep the power MOSFET controlled by a BJT, but replace the ESP8266 with an 8-bit Atmel MCU. It would be smaller, more power efficient, a little cheaper, and I used to love programming those chips in ASM. Another big advantage of that approach is I can use pulse sequencing to add multiple power supplies in parallel, whereas that might not be practical on the ESP8266. Normally this would be unsafe – among other things one power supply failing means things get out of hand rather quickly for the others. However, if each power supply is connected to the supercapacitor via its own power MOSFET, and a microcontroller manages them so that only one is on at a time, it should be fine and offer a faster charge rate at an acceptable cost.
The next steps are to build electrodes and a high-current switch, then try welding different materials. I also want to optimize the charging circuit. I think this has been enough for one day, so stay tuned for sparks coming up soon.
Tuesday, February 27, 2018
Sunday, February 25, 2018
Saturday, February 24, 2018
MT Adventures: West Yellowstone powder get away
MT Adventures: West Yellowstone powder get away: Leah skiing good powder. Leah and I were able to get away for a few days of skiing on President's day weekend. With all manner of ...
Friday, February 23, 2018
Tuesday, February 20, 2018
How to Build Your Own Tiny Off-grid Cabin Today
The tiny house movement is not just a fad.
It is quickly growing in popularity due to cheaper living costs, less environmental impact, and a simpler lifestyle.
A large proportion of tiny homes owners don’t want to be grid-tied and so off-grid tiny homes are also growing in popularity.
There are so many different options when it comes to living in a tiny home, from buying an old horse box to convert, to building your own log cabin.
Today, we’re going to take a look at the process of building a tiny off-grid log cabin.
There are 5 vital steps in the process of building any home. They are:
- Planning and Designing
- Foundations
- Raising the Walls
- Floor and Roof
- Installing Windows and Doors
Planning and Designing
There are loads of log cabin floor plans available online. You might be lucky enough to come across one that suits your needs.
If not though, you’ll need to spend time planning and designing the perfect tiny home for you.
The most important design consideration for tiny homes is making sure everything has a multi-purpose use.
For example, your sofa area may pull out into a bed, and your side cupboards might pull out into a dining table.
Getting your design right in the beginning stages is crucial.
If you start altering your plans mid-way through the build, it’s likely to add big costs to your project.
Foundations
Even tiny homes need foundations.
They might not need to be as substantial as a regular brick and mortar house, but you still need them.
Most tiny homes only need shallow foundations such as raft, strip or pad foundations.
The one you choose will depend on your sites soil and rock type as well as your budget.
All of the above foundation’s types are relatively easy to do, even for the novice builder.
Raising the Walls
During your planning process you should have chosen what types of logs you’ll use for your build.
Typically for Tiny cabins, this is a soft wood; spruce or pine.
Typically for Tiny cabins, this is a soft wood; spruce or pine.
To start your tiny home log cabin, you’ll need to create your base with four ‘sill’ logs.
These will be your four best, straight and longest logs.
These will be your four best, straight and longest logs.
The simplest method, which doesn’t require any expertise or cutting of the logs, is the Butt and Pass method.
This method requires a lot of brute strength, as you’ll just drive large pieces of rebar through the logs to pin them together stacking them onto each other.
Floor and Roof
To install your floor, you’ll need to insert floor joists into the bottom sill logs.
You should space these evenly, and you can then lay planks of wood on top to create your floor.
Roofing your log cabin is actually a lot simpler than it looks.
You’ll need to build up two gables (triangular shaped) walls, and lay two purlin logs (mid-way up the gable wall on either side) and one ridge log (at the very top of the wall), to connect the two gable walls.
You’ll then need to install roof joists in the same manner in which you laid your floor joists.
Lastly, you can lay your finishing roof material; wood shingles, roofing felt, metal sheeting etc.
Remember to lay insulation in the floor and the roof; these are the largest areas in which you’re likely to lose heat.
Installing Windows and Doors
To install your doors and windows, you’ll need to remove the lumber.
To do this you can use a chainsaw, and support the opening with a lintel log and tacking cleats.
Then install the frames of your windows and doors, and then the windows and doors themselves.
You may choose to do this step as you are raising your walls.
The easiest way to do this is to make the cut when you reach the height of the top of the window.
Finally
If you’ve been dreaming of living a more minimalistic lifestyle, and getting off the grid, it is entirely possible to do.
Thousands of people are making this move every year, and the tiny house community is only going to grow.
Stop waiting and go do it!
