ptwizz

Wasn't expecting that - well played sir.

Very kind of your hairdresser to let you use their car, @PatPux.

I was able to transport my Bailey in a Triumph Spitfire. The prop and cage were removed and stowed in the small space behind the front seats. The rest of the paramotor sat in the passenger seat, with seat belt. The wing, helmet etc. went in the boot. I have also transported the motor in an estate car, when it was only necessary to remove the upper cage quarters and rotate the prop to the horizontal position. There is no reason to dismantle the cage or remove the prop if you don't need to. Every time the parts are dismantled, there is more wear in the various fixings and more chance of something getting damaged.

Yes, you are correct. But... just resting the plug on the head might be producing a spark somewhere other than the plug gap. You really need the plug held firmly against the head (so the movement of turning the engine doesn't bounce it off at the moment when the spark should happen). The HT lead and plug cap should be away from the head - a tiny puncture in the rubber can allow the HT charge to spark from the lead to the head, often where you can't see it. Personally, I simply hold the plug in place with my hand. Yes, I've had a few minor shocks from doing this, but at low speed the HT output is low and the shock is no more than a sudden tingle.

The item in your link is indeed intended for routing the reserve bridle to your frame / harness. The exact routing of the bridle is critical. When you throw a reserve, it opens very quickly (as you'd hope!) and the bridle is suddenly jerked into a straight line from its attachment at your harness to the direction of the reserve. If the bridle passes under your arm, or under one of your hang points, it is likely to cause you to spin over and become disorientated, if not cause bodily harm. Your paramotor handbook should have details of reserve mounting. If not, contact the manufacturer and ask.

A couple of things spring to mind: 1) are you proposing to pack your engine in component form - and if so do you have assurances from any airline and airport security that they will not reject it? You have already shown that their judgement is entirely subjective and there is no reason to suspect they'd be any more tolerant to dismantled engine components. 2) repeated dismantling and reassembly of the engine and carb is likely to cause damage to seals, wear in threads, leaks at metal to metal interfaces, dirt ingress, lost parts etc. It would be worth contacting the local paramotorists at you destination and trying to borrow a motor, possibly on a reciprocal agreement basis.

Darius, it's not CNC. It's a manual milling machine with a manual rotary table. I have fitted a set of digital readouts to the three primary axes of the machine, but these are simply an easier-to-use version of the dials on the handwheels. For complex parts like the rockers, my drawings have several sheets. The first one or two sheets simply define the part and tolerances. Other sheets show the angles to set the part for particular operations, the linear distance to move the cutter at that angle, etc. When I design parts, I have to think of how I will make them, how I will hold the part to the machine at each stage, how I will cut a particular face with the tools I have in my workshop, etc. It makes sense to record all this information at the same time as I record the design of the part itself.

If I were a patient man, I wouldn't have bought the Russian cylinder heads in the first place. As the project progresses, I am leaning more towards the idea of making my own heads. I'll probably get it running with these heads first.

Now looking more like a rocker. I am carrying out each machining operation on all 14 rockers, so I won't know if any of them are any good until I've finished all of them.

Still not much to see. Here is the beginnings of a rocker. You can see how little is left from the 3" diameter billet. At the risk of repeating myself, I'd like to tell the story of the duck carving man: I was at a local village fete some years ago, where there was a stall selling assorted carved wooden ducks. Behind the stall sat a man on a stool, beside him a pile of logs, each about a foot to 18" long and maybe 4" diameter. As I watched, he picked up a log and began carving it with a small knife. After about 20 minutes, he had produced another duck, which was waxed and added to the display on the stall. As he picked up another log, I asked him "Do you have a design in mind when you start, or just make it up as you go along?" He replied "I just pick up a log and cut off all the bits that don't look like a duck". Since that day, I have described my approach to machined parts in the same way. Pick up a billet of Aluminium 2014A-T6 and cut off all the bits that don't look like a rocker. I have been telling this story for years. Recently I overheard someone who I have never met telling the story to another.

A rigid tank should be vented to allow vapour to escape and to allow air to enter as fuel is consumed by the engine. If your tank swells, the vent is blocked. As Simon says, fuel bags are not intended to be used alone. They are part of a fuel cell system, which has a bag inside a rigid structure. In the event of a crash, the bag can deform as the structure collapses, reducing the chance of fuel leakage.

The airbox, like the exhaust, is a functional part of the 2 stroke engine. Changing the airbox volume or the length of the induction tract will change the engines performance. The rubber itself is less critical. Provided it is a reasonably smooth bore and is soft enough to allow movement between the carb and the airbox, it will do the job. Measure the dimensions (inside diameter) and search e.g. "30mm carb rubber". Scooter spares suppliers are a likely source.

Steve, you're absolutely right about the relative risks. The pilot of a light aircraft with 3 passengers on board would take a similar view of a rogue paramotorist. I am working on the basis that one who goes flying without training has very little appreciation of the risk to themselves, just like the guy on the ground with the control box. While the errant paramotorist may experience a sudden increase in that appreciation when they cross the path of the light aircraft, it's too late. My point is that we, as unregulated users of airspace, should be careful when throwing stones in our glass house.

Some of the issues with rogue paramotorists have come about because individuals have bought kit from ebay and gone flying with no training. I am aware of a couple of individuals near where I work who did exactly that, their only guide being youtube videos. I agree that the scales are different (quadcopter from <£100, paramotor kit from ebay <£1000) but the principles are the same.

There are individuals who 'hate' paramotors, just because one irresponsible individual behaves badly. It has become far too common in recent years to take the lazy approach and simply ban the thing which is abused, rather than deal with the abusers. Unmanned aircraft, whether they are 'drones' with some level of autonomy or simple R/C fixed wing aircraft, have been around for longer than paramotors. The new element is abuse by a small number of individuals. That is the element which needs to be addressed.

Just to be clear: Carabiners are used to attach the harness to the wing, maillons to attach the harness to the reserve bridle.

Somewhere between this account and the paranoid ranting of the Daily Mail, lies the truth about the risks posed by drones.

I am referring to the connection between the reserve bridle and the harness. This connection is made under the Velcro flaps. Quote "The carabiners are whats supplied when new". Supplied with the paramotor or the reserve?

I have a Bailey 175, which I believe has a very similar frame to the V3. I have my reserve front mounted with two maillons to the harness, either side of the buckle. I have the right hand side maillon tight (the side where the bridle runs up under the velcro) and the left side just finger tight so I can detach it easily to get into and out of the harness. This could be made easier with a small carabiner. It serves only to hold the weight of the reserve container and hold it in place during deployment. Note: the reserve bridle should be connected to the harness with maillons, not carabiners. The potential shock loads are high and would require big carabiners.

Apologies for the radio silence on this project. My time outside work has been divided between motorcycles and the pursuit of NPPL(M). While I haven't made much headway with machining parts recently, I have obtained a starter ring gear and starter motor which will be suitable for the radial. When I have made all the major assemblies (i.e. finished the valve gear, made the supercharger and the oil tank) I would like to make a time lapse video, starting with the crankshaft mounted in a bearing and rotating slowly (driven by a small motor), then adding parts so that it is clear how everything works.

"I have a paramotor which can drop an overheating lithium battery with several megajoules of stored energy onto the innocent bystanders below - I'd like a quote for third party insurance please." "HA!"

I'm not sure that the perceived reliability of electric machines will survive the level of battery development required. The battery is an energy store, like a fuel tank. In the IC engines fuel tank, we keep petrol, which is about 1/16 of the weight of the fuel/air mix which is burnt to produce power. The battery contains all of the fuel for an electric motor. In this way, it is more akin to the fuel tank of a rocket motor, with the potential to release all its energy in an uncontrolled manner. As the energy density of batteries increases, so will the potential for catastrophic failure and the requirement for mechanisms to prevent that failure. These mechanisms will be required to 'fail safe', will add complexity and will inevitably impact reliability. Edit: I've just had a look at the Revolt kickstart appeal. There are some truly outrageous claims on there and with 15 days to go, they've only convinced 100 punters and raised 25% of their target.

1) The wing should have come with a manual. The manual will give guidance relating to contamination of the wing. Failing that, contact Ozone directly. 2) A leaking fuel tank is a bad thing. Dribbling fuel on your wing is an inconvenience and may be expensive. Dribbling fuel on your hot exhaust if you've crashed is a greater concern. Even if you have to replace your tank to fix the problem, it is cheaper than a wing or a fire. Edit: I would worry less about the effects of petrol than the effects of the ethanol. It attacks most materials.

It's well worth having a free flying harness for these occasions. I bought one off ebay which I use only for ground handling. With the light harness, I can practice launches with minimal effort until I am happy that my technique is correct, then strap on the motor and fly.

http://www.fresh-breeze.de/fileadmin/user_upload/Markus/Downloads/solo_manual.pdf Any good?