thrust figures

[bernoulli]

I'm sure this has been answered before, but I can't find it quickly: When someone says their Paramotor is good for, say, 100kg thrust, does this mean it'll propel a person FULLY laden at 100kg - comfortably, or does it mean just the person WITHOUT all the kit ?

Thanks

[nigel_d.]

Thrust is the amount of force a motor presses against you with. So a 50kg thrust motor might be ok for an all up weight of up to say 120 kg.

Nige

[dmwood]

I'm sure this has been answered before, but I can't find it quickly: When someone says their Paramotor is good for, say, 100kg thrust, does this mean it'll propel a person FULLY laden at 100kg - comfortably, or does it mean just the person WITHOUT all the kit ?

Thanks

Unfortunately it means neither. It is purely a measurement of generated forward thrust when air is pushed in the direction opposite. That's all. It has no bearing at all on your weight, all up or otherwise.

It does however have a direct bearing on how much weight you can actually fly with. The more thrust the unit has the more forward momentum is created for a given mass, and so the more weight can be carried in flight, (as more lift will be generated by the wing).

I hope this helps.. however I am sure you will read all sorts of wierd and wonderfull explanations after this post.. so the best bet is to read up on it yourself as much as you can and dont rely on other peoples interpretations (including mine) as they may not create the full picture, or even worse provide information which is completely incorrect.

[nigel_d.]

Also to add to the picture an average weight flier might need 30kg thrust to maintain level flight so more than this you climb and less means your going down.

Nige

[pete_b]

Well I did a powered nil wind one step take off in Spain, Simonini evo. Not that thats any help but it frightened the shit out of me at the time.

Pete

[enzo200500]

How was that achieved pete?

[pete_b]

How was that achieved pete?

Hitting full power by mistake

[enzo200500]

Ooops!!

[pete_b]

Ooops!!

Nearly opps in my pants at the time

[bernoulli]

Back to the thread. So when looking for suitable Paramotors, do you measure your stand alone self when considering thrust, or do you include everything you are taking airborne before considering thrust?

Finally for someone like moi - 75Kg what sort of thrust figure would suit me, please?

[aquatix]

Hi Bernoulli - I think it would help your understanding if you studied some of the principles of flight, as the forces involved are all inter-related (lift, drag, weight etc) to give a forward and vertical component. Without power a paraglider will simply glide forward at around 25-30km/h and descend around 1.2 - 1.8m/s. Adding the extra force of thrust from the motor changes the resultant to allow level flight or an upward angle (climb rate).

For most people using the correct size wing in neutral trim, around 30kg of thrust from the motor is required to maintain level flight (more needed in fast trim or for smaller wings with higher loading).

At your 75kg body weight, a Bailey V5 producing 60kg thrust is more than adequate - and you have a very wide choice of machines offering similar or more power. I recently flew a V5 (at over 100kg naked) but found the climb rate too slow for my liking. I think it is always best to have extra power available even if you hardly ever use it (which can give better economy and a less stressed engine).

Of the 2-strokes, you could comfortably fly a Polini (less power but nice & light) or something with a Moster, F200, Simonini or Corsair engine for all the power you could ever need (around 75kg thrust) and the latter 3 all have electric start options (for about a 3kg extra weight penalty.

I would suggest that thrust is less important at your weight than actual paramotor weight, harness comfort, hangpoint choice etc.

[outkast]

Hi Bernoulli - I think it would help your understanding if you studied some of the principles of flight, as the forces involved are all inter-related (lift, drag, weight etc) to give a forward and vertical component. Without power a paraglider will simply glide forward at around 25-30km/h and descend around 1.2 - 1.8m/s. Adding the extra force of thrust from the motor changes the resultant to allow level flight or an upward angle (climb rate).

For most people using the correct size wing in neutral trim, around 30kg of thrust from the motor is required to maintain level flight (more needed in fast trim or for smaller wings with higher loading).

At your 75kg body weight, a Bailey V5 producing 60kg thrust is more than adequate - and you have a very wide choice of machines offering similar or more power. I recently flew a V5 (at over 100kg naked) but found the climb rate too slow for my liking. I think it is always best to have extra power available even if you hardly ever use it (which can give better economy and a less stressed engine).

Of the 2-strokes, you could comfortably fly a Polini (less power but nice & light) or something with a Moster, F200, Simonini or Corsair engine for all the power you could ever need (around 75kg thrust) and the latter 3 all have electric start options (for about a 3kg extra weight penalty.

I would suggest that thrust is less important at your weight than actual paramotor weight, harness comfort, hangpoint choice etc.

you flew the bailey naked? bet that was boody cold

Bernoulli, I am tad heavyer than you and fly a Kobra with the polini thor motor, at full fast trim on my 23 metre revo 2 I still had enough thrust to climb quite nicely albeit on nearly full throttle, so I would say any motor with the polini, mated with the correct size wing of course , would be adequate for you.

[s1buell_wl]

I'm 80k and fly the miniplane

1. Small cage

2. Helix Top 80 Carbon Fiber Propeller (130cm)

3. Gearbox is a 19/73 ratio

With out gas I'm around 21k and 105k thrust apprx. That's about 47k of thrust with no issue.

I like to keep it light. I fly a 29 Nuc and maybe a 26 speedster soon

I fly in mainly shorts and T. I'm not sure if I need more power but I agree with the guys it's always nice to have if you need or if your going to do a one step full power launch..... hehheheh.

But if you do this type of launch you need the washable harness option.

Update from site website

static thrust kg

115

47k

125

52k

T

[pete_b]

I'm 80k and fly the miniplane

1. Small cage

2. Helix Top 80 Carbon Fiber Propeller (130cm)

3. Gearbox is a 19/73 ratio

With out gas I'm around 21k and 105k thrust apprx. That's about 47k of thrust with no issue.

I like to keep it light. I fly a 29 Nuc and maybe a 26 speedster soon

I fly in mainly shorts and T. I'm not sure if I need more power but I agree with the guys it's always nice to have if you need or if your going to do a one step full power launch..... hehheheh.

But if you do this type of launch you need the washable harness option.

Update from site website

static thrust kg

115

47k

125

52k

T

How did you get a 130 prop in a small cage?

or dont you ever do forwards as the prop would cut your lines

[s1buell_wl]

T

How did you get a 130 prop in a small cage?

or dont you ever do forwards as the prop would cut your lines

It's no issue but I do forward launches almost always or if doing front launches I take a few steps back and commit 110%

Once the glider is up at 60deg or more apply generous amounts of throttle.

But its not that bad. I can take pictures if you like.

I was just looking the 125 says 52k of thrust so I must be over that with the helix. It does not take me much to get off the ground.

T

[t_andrews]

Dmwood nailed it.

Thrust is just thrust.

Knowing how much you need:

1) skill level

2) load

3) wing size

4) wheels or not

Par example;

I know a pilot who could launch at 110kg all up on a sky 26 with a pittance of 27kg thrust.

He didn't have a high skill level as he was new, but he was fit and could run for 100m full bore.

Since he needed to run so much to get airborne, he didn't fly much, and had a pretty bad taste from his gear making his life so hard and failed launches so common.

If he had wheels, he may still be flying it. (motor)

If he had a larger wing he may still be flying it.

If he weighed a lot less he may be....

you get the idea.

The amount you need depends more on wing loading as that takes wing size and all up weight into account.

You can fly with much less then you need to launch quickly and therefor safely, rather then running 100m and fatiguing on your face. So, your call in the end how much you need.

I like lots.

edit:

One board member compiled a survey:

http://paramotorsurvey.cloudstrategies.co.uk/

Another compiled some results links:

viewtopic.php?f=4&t=5111&p=33555

None of them speak to wing loading in relation to thrust.

That's a pilot decision.

[bernoulli]

Thanks for your time guys. Much clearer - don't fancy running 100m for a launch Enough to put anyone off.