DO YOU NEED MORE
An exhaust or expansion box especially designed to enhance the Solo and Hirth 210cc engine. Replace your box exhaust and "possibly" your prop and see the enhanced power. See Price List
There are other options to consider:
1/ Reduction ratio correct?
2/ Increase internal compression, modifications to barrel
3/ Porting and bead blasting of outlet and inlet ports.
POINTS 1,2 AND 3 ABOVE ARE ALL DESCRIBED
IN DEPTH IN OUR E-BOOK WHICH IS AVAILABLE ON CD.
Our new tuned pipes designed with our
NEW high torque
After viewing my notes on "Do you actually need more thrust" ----"And the amount of thrust depends on------" and you still think you should be getting airborne sooner bear the following in mind
Our tuned pipes or expansion boxes where originally designed specifically for the Solo and Hirth 210cc paramotor engines, however may be used on a variety of other engines.
THERE`S NO NEED ANY MORE TO GO TO EXTREMES,
IN ORDER TO OBTAIN EXTRA THRUST!
Our expansion boxes or tuned pipes have been specifically manufactured for the standard 210cc engine. They are supplied with or without a stainless steel mounting bracket an d four mounting pillars which will allow the exhaust and bracket to attach directly onto the engine. Where the exhaust mounts onto the engine, the cap screws on the exhaust are spring loaded to absorb all vibration.
Exhausts are supplied chromed (additional extra of anadising silencer box) Click here to go to price list. A paramotor may ideally be horse power driven, torque driven or a compromise between the two. With the former, lower reduction ratios may be used (as low as 1,8:1) with longer, lesser pitched props. There is obviously now less interference from the associated turning effects resulting from torque based designs.
With the latter a coarser pitched prop is utilized with a higher reduction ratio (up to 2,78:1 and a prop diameter up to 130cm`s and the prop pitch up to 34degrees).
An easy way of envisaging torque is to picture a block and tackle and not the vast weights it is capable of lifting through a similar pulley system. Another example would be the motorcycle`s power band which is also referred to as the Torque band. Now with ether of these set ups one may increase the horse power, obviously depending on the prop size, pitch, reduction ratio etc, from around 15-18horse power with a standard box type exhaust (which is usually sold standard with the engine) to around 32 HP. This amount of extra energy is now sufficient to fly tandem with (obviously depending on the passenger weight and the presence of a head wind which reduced the ground run and thus facilitates easier take offs).--- this along with Thrust Vs horse power is discussed in depth in my book (An insight into powerd paragliding)
So you are probably saying to your self "Can I simply take off my old box exhaust and replace it with one of these "power converters"? Well in most circumstances with the 210cc Solo and Hirth varieties (which are probably the most common paramotor engine world wide) the answer would be Yes. If one wanted to go one step further and maximize your thrust you could optimize the prop length and pitch in accordance with your existing reduction ratio.
Another way of increasing the thrust from your motor
1. Increasing the internal compression
This procedure will certainly increase the internal compression, however may result in slightly higher internal thermal activity. If you are concerned fit a heat guage. We however have never had any problems.
2. Modifying the inlet port.
2. Modifying the overall shape. the slight upwards bulge may be flattened, thus allowing slightly more fuel consumption, however the overall set up becomes more efficient.
3. Modifying the outlet port
4. Increasing the length of your prop.
For those flying at altitude one of the
most efficient props are those with high aspect ratios (ie long and
thin), along the same lines that fixed wing sail planes are built, with
the least resistance and drag). Hand in hand with this one usually increases
the torque. This is undertaken by increasing the reduction ratio, from
eg from 2,5 to 2,74 or even higher to 2,84. Either a larger large pulley
is made or else the same small pulley is machined down. This will now
entail a new belt if not enough tension is available through the off
A variable three blade prop may also help (in the reduction ratio is fairly high and a tuned pipe is used). These blades which are thin enough to reduce drag, with solid ends that may be trimmed down, to fit your existing cage, may result in the pitch being fined in order to pick up the RPM. I dont believe though that the CORRECT two blade prop for the set up required will ever result in less thrust from a multi blade.
Make sure however that the prop stays within the power band (2400-2800RPM)
This may necesitate a new cage to accommodate a longer prop. (Contact us to make up a new cage to accommodate your prop.)
When modifying the internal compression of the engine by reducing the barrel size one may however find the revs increase slightly. Make sure the prop is still within its power band and the engine does not over rev. If travelling to altitude though with a prop designed for sea level, this will however be ideal as the engine loses power at higher altitudes. What is needed is to pick up the engine revolutions. Using a variable pitched prop is a good idea as one now may easily decide on the props required revs.
Make use of our Tuned Pipe
THE BLADE RESULT IN A SIGNIFICANT
Although certain pilots will argue this point with me and insist that experiments have been undertaken to prove this point, I certainly do not believe that it is possible. Engine and hence prop RPM is a direct result of drag. This drag results from blade span and chord, ie aspect ratio, in the same manner glider drag is created. (High performance aerofoils such as competition wings and conventional gliders have long thin wings with the associated low drag). There is no way on earth a few hundred RPM will be attained from simply polishing the blade. If it has shown on the scale then I can only surmise that the scale and instruments need recallibrating. To further investigate this point I approached a well known propeller manufacturer George Killey in South Africa, and received the same response. PH him if you wish on (031- 7763915!). My assumption on this point stems from the number of horrifically mended props I have witnessed over the years. I have seen props mended with body filler, fibre glass, putty with some of them not even sanded flat. They seemed to fly exactly the same as they did prior to mending with virtually the same thrust. For those of you that are unaware, a few hundred RPM on the prop corresponds to a significant reduction in drag, which will only be attained by changing the prop its self.
1. Purchase a wing that will not need upgrading within a year or so. There are incredibly cheap paragliders on the market, that are immaculate. These however are great to learn on, however are slow and unresponsive (remember you fly as fast as you wing under normal flight conditions). On the other end of the scale there are the imported gliders which are great, neatly finished off with all the trimmings etc, however up to triple the price of locally manufactured gliders. In fact in many cases the locally manufactured gliders contain a fabric which is far superior to overseas designs. (Our local material is now being exported for use in other countries). Most of our local designs are direct copies anyway of overseas designs, at a fraction of the cost.
2. Your wing should be the right size
for the extra weight, resulting from the back pack. There certainly
is a trade off between a too large wing (much drag) and too small (big
sink rate), I personally prefer slightly larger
3. If at a later stage you will be thinking of adding advertising to your wing, in order to subsidize your flying, then from the outset obtain one where future writing will be visible (white glider)
When choosing a canopy for powered paragliding there are a few criteria that are useful to bear in mind.
4.LENGTH BEFORE HAVING
We have for a while now been exporting a glider called a “PROFILE” This is an incredibly safe glider which has 12A`s been awarded by the Acpul testing facility. During testing the glider is deliberately put into various situations and depending how easily it recovers back to stable flight patterns and how much pilot input is required, will determine what rating it is given. Any rating of an A means it recovers easily with minimum pilot input. It also means that theoretically it should be allowed to fly in most countries. Shortly we will also be launching another glider. This will also be rated as a beginner / intermediate wing and will be perfect for all motorised pilots entering the sport. Looking at the glider specs provided one will find a wing called the “XTC”. Although this wing has never been sent for official testing it has been used for all new students entering powered paragliding. It is made standard with trim tabs which allow the wing to be slowed or speeded up while in flight depending on various applications and speed bar attachments which facilitate the “speeding up” of the wing should for example one require more speed. It`s weight of 31,5 square metres makes it ideal for powered application. I have also flown this wing during our central African expedition with never any concern for it`s behaviour in turbulence. It is classified as an intermediate wing, which means it is faster than a beginners glider and will thus respond slightly differently and quicker, however I believe there is no compromise in safety with new pilots entering motorized paragliding.
The glider you choose should be based on safety first. Different wings have different safety ratings. When beginning off, purchase a glider that is relatively safe, however make sure you will not out grow it within a year or two else you will be buying another. Secondly ensure the wing is the correct size for the extra weight you will be carrying with regard to the motor unit. Many schools are putting new students on incredibly small wings(and yes I am aware of the extra drag caused by the larger wings), however smaller wings usually have a higher sink rate even though they are flying faster with more airspeed. Lets presume the student has a wing that suits his all up weight inc. the back pack. If he or I suppose she!, now flies this minus the extra weight, the wing will have a lighter wing loading. This has a number of influences. A lighter wing means a poorer glide ratio( (distance traveled vertically in relation to horizontally) and a better sink rate (the actual time spent in the air). The implications here are that your forward speed will be less and if for example a head wind picks up you will battle to penetrate. (Your mate will also travel further than you, partially due to your increased co-eficient of drag). A lower wing loading also makes you more susceptible to more wing collapses in turbulence . . So my thoughts are-- Obtain a wing for powered paragliding. If you now wish to use it for normal flight, take care and choose the conditions. Else obtain two.
1. Usually these are 100cc, 210cc and 312 cc engines. The former is heavier than the 210cc, a higher revving engine and thus slightly louder. It employs a different reduction ratio to optimize peak rpm. The 210cc is probably the most common set up world wide and here a number of options are available. Different size props, normal exhausts and tuned or expansion boxes which deliver more horse power and different reduction ratios. The prop is not bolted directly onto the crank shaft of the engine, but instead onto another pulley which links to the crank shaft via a belt. This ensures that the prop will turn at optimal speed. Heavier pilots and especially those flying at altitude should consider a set up containing a tuned exhaust. There is however a bone of contention linked to this statement. Pilots up to 85 kg`s should be able to fly a standard 210cc paramotor without a tuned exhaust, providing the correct prop and pulley ratio has been used. (Initially to facilitate becoming airborne without undertaking a marathon, limit take off`s to headwind conditions. This will ensure adequate airflow over your wind (which is essential for flight) while at the same time reducing your ground run speed.
2. In order to maximize the power and thrust output from your unit there are a number of procedures available. These include reducing the barrel or head distance, porting the inlet and outlets and modifying your existing pulley ratios. In order to facilitate easier starting a decompression valve may be fitted, or the exhaust port may be enlarged. TAKE CARE, some procedures may effect the thrust output and compensatory mechanisms then undertaken to increase the horse power again.
3. The 312 cc is a much more powerful engine and great for tandem flying. (Tandem flying may also be undertaken with a conventional 210cc, depending on pilot weight and take off altitude). The 312cc is however much heavier and far more expensive.
These do have associated uses, such as inflating the canopy first and then only when one is ready for take, starting the engine. Terminating the engine in the air and then flying as one would in conventional paragliding has it`s advantages, however the carburetor may need re-priming if the engine has been off for an extended period of time.
Normally with the engine on idle, you can still hear your flight instruments quite sufficiently. (Just give it rev. every now and again, else the plug may oil up and then it cuts out just when the accelerator is squeezed). Just remember with electric starts there is the associated weight of the starter unit and a small 12V battery.
Is it crutial to torque the head cap screws etc on the Solo and Hirth 210cc when replacing them??
I can only talk from experience and the
problems we have encountered over the years. Out of every engine we
have ever taken apart, and this involves every new engine we have built
as we fit a decompression valve in the head, we have NEVER torqued any
head bolts or ANY other. (Incidentally nor do many of the agents!).
By Cracking the caps tight an almost identical pressure
may be attained amongst the various bolts and cap screws around the
head etc. We have also NEVER had any engine related problems associated
with lack of
IS IT DIFFICULT
TO BUILD YOUR OWN PARAMOTOR?
You may decide to what extent to become involved in building or assembling your own portable flying machine. There are obviously certain items such as the wing or canopy that for safety reasons it is recommended to purchase one from a reputed dealer. (Refer to canopies). Other items worth purchasing include---
Propeller. (Should you wish to build your own we will supply you a CD with step by step instructions)
Tuned exhaust. (Only if you require one for additional power. Refer to Do you need more thrust
Harness. Most sail makers or businesses with industrial sewing machines will accommodate you in this regard, however for the effort it probably is worth while obtaining one from us. (Refer to price list)
Other minor items worthwhile obtaining which certainly will make life easier inc:
Skytribe mounting plate
HOW DO YOU GO
ABOUT BUILDING THIS?
1. If you have access to a lathe or know someone with one, simply down load the plans from our CD, print each individual component out and have them made. When time and finances permit, simply assemble them.
2. If not take the individual plans to an engineer and obtain a price. Shop around as prices will vary greatly. Any individual components may be ordered directly from us. Then simply follow our assembly instructions.
Also Skytribe's video now available on CD
WHAT CAN GO
WRONG BUILDING YOUR OWN?
- You havnt secured all items properly and something falls off. (Thus avoid flying near people and houses till it has been thoughly tested)
- Your centre of gravity is slightly too high or too low. I believe, and this is simply a personal view based on years of flying various home made paramotors, that this is not as crucial as many people seem to think. Unlike conventional aviation where thrust and drag line are almost within the same plane, here the thrust line hangs under the drag line, and power equates to lift. If one is hanging below the thrust line of the prop, you may take longer to become airborne as the thrust will be pushing you downwards. If the thrust is too low down you will find that as power is applied there is a tendency for you to become more supine (layed back)
Remember the engine is simply to get one into the air. Your forward speed is determined primarily by the inherent speed of the canopy you are flying.
- The bearings that the cam shaft rotates on does not fit tightly inside the large pullet, and instead of the inside of the bearing rotating with the cam shaft attached, the entire bearing rotates. (A manufacturing fault)
- Your machine does not provide the required thrust. (Refer to do you need more thrust. You have used the incorrect reduction ratio/ prop or exhaust. Launching with reduced thrust is easily overcome by modifying this or by taking off into a head wind, thereby reducing your ground run and with the wind blowing towards one, airspeed has already built up over the wing and one does not have to run more than a step. (In other words fly initially when conditions are conducive to reverse or back starts)
The prop is not directly responsible for inflating the canopy.The weight of the outfit is only felt prior to take off on the ground. Thereafter all weight is taken up by the wing.
The accelerator is held usually in the hand. Squeeze to ascend, release to descend.
Take off distance - sometimes not even one step. This depends whether wind is present or not.
It is possible to fly a paramotor safely without completing a paragliding course first. Should you require a license you will have to complete a paragliding course first (25 flights & around R2500), then complete a conversion course onto a paramotor.
You may easily launch yourself with no help required. Flying time depends on the amount of accelerator used. Typically on 6 l one may aquire 2 hours of air time.
Very little maintenance is needed on our two stroke engines. Should anything be required spares are freely available.
Tandem flying usually requires extra horse power and a larger canopy (around 40 square meters)
Squeezing the accelerator does not speed up the forward speed.
Back starts should usually be done for controllability. If the kill switch breaks in mid-air it is still possible to terminate the engine in other ways.
Repairs and maintenance of your prop may usually be undertaken at home.
New props range from R750 up. Reserve chutes may be attached to our designs.
IS IT ESSENTIAL FOR AIRCRAFT ALUMINIUM TO BE USED ON PARAMOTOR FRAMES.
PARAMOTOR FRAMES. No. We believe this is a completely outdated marketing tool that in many instances without the correct temper and grade has led to many accidents. (from the alloy shattering under stress).On foot launched versions very little weight bearing strength is needed allowing the frame to be made out of thin walled (1,6mm) by 16 or 19 mm tubing. On trike versions the undercarriage may be increased in strength. In over 10 years of frames we have never had a frame disintegrate, shatter or welds break and we have been using normal, off the shelf industrial aluminium.
THE TURNING EFFECTS CRUTIAL TO EFFECTIVE FLYING??
It certainly will help in take off and comfort while in flight. Once your take off technique has developed sufficiently you will be able to accommodate these unfortunate turning effects that arise from the rotating prop.
A. Gyroscopic precession.
Try spinning a bicycle wheel and turn it 90 degrees. A twisting motion will be experienced. Prrecession is the term applied to the resultant action of a spinning object, such as a propeller when a force is applied to the edge. The resultant action will be 90 degrees ahead of the applied force, in the direction of the spinning gyro
B. Asymmetric blade thrust
Depending on the direction of prop rotation, one of your blades will have a higher angle of attack that the other. This will result in one thus having a higher angle of attack and effectively develop more 'thrust', causing a YAW effect.
B. Torque reaction.
Very simply this effect has the ability to rotate or "ROLL' the engine set up in the opposite direction from prop rotation.
Methods of eliminating these effects.
Cross over straps
More on these turning effects and how to mimimize them refer to "An insight into powered paragliding" see 'books and videos'
IS THERE A RISK
USING SECOND HAND PARAGLIDERS?
Providing the glider has been checked
out previously, there should be no problem. You should not expect to
pay more that around R3000- R 5000 for one such wing. (considering a
new wing is between R8500- R10500) These are the equivalent of a DHV
1 and 2 wings. Fabric age is measured using a porosity tester and on
many beginner wings, these may still be safely flown with fairly low
MAY LINES BE
TIED BACK TOGETHER AFTER BEING CAUGHT UP IN THE PROP?
We have most certainly done this for quite some time now. (as long as the wings are non high performance). Ensure the broken line is the same length as the corresponding line on the opposite side. If line is missing simply splice in a piece of spare paraglider line while ensuring 'stop knots' are placed to prevent slippage of line.
100C AND 210CC
BALANCING BE UNDERTAKEN AT HOME?
Most definitely. With a simple balancing tool, props may be finely balanced back to the original. Whether prop balancing on paramotors has any long term detrimental effect is certainly a debatable topic. In the short term I however do not think the effects are much at all. One will simply feel more vibration.
CAN ONE FLY TWO
Even on a standard Solo engine with a tuned exhaust we fly tandem. Take into account pilot and passenger weight and the altitude one is flying at. You will also need a larger canopy to accommodate the increased weight. Adapter bars will also be needed that allow the passenger to attach himself. The passenger is simply attached in front of the pilot in his own harness. Taking off from a slope into a headwind will certainly provide an easier take off. When launching tandem a reverse take off is feasable.
HOW DO I SUBSIDISE
Have someone else pay for your entire set up. Alternatively place your own promotional logo or name on the wing and it becomes a form of advertising. This form of aerial promotion due to the uniqueness and slow form of flight is without doubt one of the most effective that is available. Depending on the paraglider fabric used a number of methods are available for applying the material.
DO SYNTHETIC OILS
HAVE TO BE USED ON HIRTH, SOLO
No, we have compared engines run on synthetic oils Vs engines that have run on normal two stroke and found very little variation in any engine or piston wear. I believe this is a fallacy that is completely misunderstood. Many engines such as the Solo and Hirth are used in industrial purposes and hence are run at maximum RPM for prolonged periods, the need for reducing carbon build up is thus quite essential. The recommended oils even in this case by the manufacturers are usually along the lines of Castrol super chain saw oil (and not the exhorbitant conventional fully synthetic oils) The reasoning behind this is since their engines are running close to their maximum for extended periods, carbon build up around the exhaust port eventually scores the piston. Eventually the exhaust bleed hole (half way down the barrell) blocks up with carbon and simply makes pull starting more difficult(even when a decompression valve is present). We usually drill this out to 5mm and replace the grub screw with a 6mm one. That solves the starting problem without effecting the top end power.
WHAT HAPPENS IF
THE ENGINE STOPS IN THE AIR?
Again what makes this one of the safest form of aviation available is firstly the slow forward speeds (around 30-40 Km ph), and secondly the fact that it really is no big problem if the engine dies. You simply glide down as one would in conventional paragliding or parachuting.
PRIMING SOME CARBURETS / WALBRO
Tillotsom Carb - Customising
SIDE BAR CONFIGURATION and harness attachment
Above are some pics of how the harness goes together. You will have to nock the nylon end pieces onto the end of the side bards then pop rivvot it in place. Then weld the square tubing to the frame and drill a hole straight through everything to hold it in place.
The sides of the nylon block have been chamfer to allow them to move inwards and outwards a bit. If you use a square tube bigger than the block then this will allow them to swivel even more else cut the side out as shown.
The positioning of the side bars on the side of the frame is quite important for the comfort of the harness.
The clip in buckles on the main hanging straps can move. It’s a bit of a tight squeeze getting them on and off! When you have found the correct place replace them with the metal ones provided. As you clip in further down the ppg will sit more back and visa versa.
HELPFUL TIPS - Adding an electric start to your ppg
I would first establish if the problem is with the starter motor or its bendix, or with the battery.
For a slightly more robust battery, get the one with the "X" in the model number, for example instead of a YT4L-BS, get the YTX4L-BS.
Also check that all the connectors and lugs are making solid contact and that none are heating up too much when used. I use an infra-red digital camera to film the heavy-duty wires while I crank the engine for 5 seconds with the spark- plug disconnected. A hot spot shows up very sharply. Most cheap digital cameras have an IR filter which is quick and easy to remove, then IR shows up very bright. To check, film a IR remote control's IR LED while pressing the Volume-Up button. It should show up as a bright strobing light.
Otherwise just clean up all the lugs and wet down with WD40 or something to protect them for a few days.
If you fit a new battery and it’s freshly charged, and the cables are good, and it still does not turn the motor over properly, then perhaps you have too much compression (by-pass hole blocked?).
If it turns the starter motor rapidly but the bendix does not engage, then check the spring-tension on the bendix, and lubricate the shaft that the bendix operates on (or strip it down and clean & lube both the shaft and the female side).
If the starter bendix was "serviced" by the owner, check if it was assembled correctly. I’ve seen a few arrive her as "faulty" when they were just not assembled correctly.
PS. I use one of those smart multi-stage chargers to keep these batteries in tip-top condition. You can leave it connected for months if you want, for long storage of a paramotor or just the battery. I supplied the electric starter motors with a cheaper constant voltage charger, but always advised the customer to purchase a decent multi0stage charge.
Pull Start - Solo 210cc -
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