Forza 2.5

[MartinH]

Thx chaps

I'm now moving on to the cockpit layout and some "intelligent" reinforcement around the cockpit opening. There's loads of space so lots of options...

I've got a theory that the weakness in open cockpit fuses comes from the opening splaying open during heavy landings. The fuse can easily distort into an oval cross-section shape, allowing the thing to split around the cockpit lip. My idea is to brace across the opening and prevent the splaying from occuring. Maybe even adding a bulkhead to hold the tube shape?

In my head this seems like a good idea but what do you engineers out there think?

Martin

 

[Wayne]

Yes, we almost always put in some sort of a shelf in there glued to both sides to keep that from happening. With an electric this is a bit harder as you need space for the battery.

 

[MartinH]

I think it's doable, allowing for battery removal plus motor/esc removal without major surgery.

Just playing with some ply scraps to see what can be done. Maybe esc on the shelf and Rx below? The shelf extends beyond the opening to add extra strength.

Martin

 

[MartinH]

More progress on the E-Forza fuse.

3mm ply shelf ready to install in the fuse or should i use it as a template for a 3mm grp one?

RX and esc wiring is under the shelf, esc on top with velcro.

4S 1800mAh lipo sits back against the spar and a velcro tab stops it from moving around.

The canopy still fits !!!

The RX antennas will have to go on the outside of the fuse

Martin

 

[MartinH]

She's almost ready to fly...

Just doing some final tweaks and balancing before the first flight.

Balanced at 99mm CG, she needs 39g of weight in the tail, which is quite a lot to lose in a small space in the fin

That means that realistically speaking, my ~1kw setup will be about the max that you can put into the E Forza, unless you make a custom split lipo and push it all the way back under the wing joiner. Sadly, the 4S 1800 packs are about 1mm too fat to go under the joiner.

Space wise there's loaaaads in the nose, so I managed to eaily install the ply shelf and some rear motor supports too.

Martin

 

[Hill Hobbit]

Super tidy Martin, very nice!

 

[MartinH]

Thanks Jonty, I've done a few now and it's getting easier each time

 

[MartinH]

She flies...

Today was the day for a quick test flight of the E Forza and i'm really happy with the way she flies. Just like the glider version but goes vertical too

The goal was to extend the flying envelope to include days when the conditions are a bit marginal and allow me to only take 1 or 2 models to the slope or field. She's a high perfomance model and for me, an anaemic climb rate was never going to be good enough. She needs to be able to do unlimited vertical to perform at her best. I'm pleased to say that all of these goals have been met with a good margin to spare

The pre-flight static motor test only gave 850W with the 14x9 on 4S, so I think I'll probably go up a size to give a bit more oomph. Other than that, we're ready for the season

Martin

 

[Wayne]

She looks great!

 

[MartinH]

She looks great!

Thanks chaps, I’m really pleased with how she’s turned out. I’m off to the slopes in a week or so and will hopefully get some more flights and some video.

I’ve also made a tweak to the elevator linkage on both fuselages to give more down throw - now at 21 degrees max down and 10.5 degrees up on the TX. This allows for around 17 degrees of elevator down comp for braking plus a few extra degrees of down when bringing her in to land. Normal flight is + and - 10 degrees as before. In mm this equates to 5.5mm up and 11mm down for the travel limits set on the TX.

Martin

 

[MartinH]

Hi all,

More flights today and a little bit of drama...

Powering up the motor after a fast dive over the field, the motor was just juddering as though something was jammed. Luckily, I still had enough speed and height to perform a go-around and landed safely. Phew...

It turns out that the GM slim prop on the aeronaut Z spinner is sooo snug with the fuselage that when I powered up, one blade went under the canopy, preventing the motor from starting. Not an issue with the model itself, but not something that I've seen before as I usually use the std Aeronaut blades and spinner which don't sit so snug.

No damage but i'll need to put a piece of tape along the canopy-to-fuselage join to stop it happening again.

Other notes: The wind was blowing slightly across the field and a bit bumpy (still only 10 mph) and she didn't want to track very nicely. I may be talking nonsense (probably) but the tail boom length is very short compared with most other gliders that I see out there. Could this be a factor? Incidentally a longer tail boom would definitely help with more powerful motor setups to get the balance right.

Some photos of the prop issue:

Cheers, Martin

 

[Wayne]

I have seen that before. I suggest a bit of tape on the canopy to fuse joint where the blade makes contact.

 

[MartinH]

Forza Electric final thoughts for anyone who's still reading

I've been flying my E forza a lot over the last week, as it's been sunny and almost dead calm at the field.

Flight perfomace is good, maintaining the overall excellence and fun factor of the glider version.

She's very heavy though at nearly 2500g or 87 oz, which is 270g (10oz) heavier than the glider setup . Maybe go for a lighter layup if you only fly from the flat...

I'm off to France for some slope soaring in a few days, so will see how she goes with slope assistance...

Martin

See weight tables below:

 

[Tmcfarland]

Forza Electric final thoughts for anyone who's still reading

I've been flying my E forza a lot over the last week, as it's been sunny and almost dead calm at the field.

Flight perfomace is good, maintaining the overall excellence and fun factor of the glider version.

She's very heavy though at nearly 2500g or 87 oz, which is 270g (10oz) heavier than the glider setup . Maybe go for a lighter layup if you only fly from the flat...

I'm off to France for some slope soaring in a few days, so will see how she goes with slope assistance...

Martin

See weight tables below:

View attachment 25512

View attachment 25511

That is heavy but looks like it’s designed to fly fast so maybe its good.

 

[Wayne]

Yeah, not to worried about her taking the weight, but landings will be a little on the brisk side.

 

[MartinH]

Yeah, I need to get to the gym to build up my launching muscles LOL

We’ve got a slope that is quite gentle and never really generates huge lift, even in strong winds. It’s a huge space though and the thermals in summer just keep rolling in from the fields below. Perfect for doing some fast aerobatics with the E Forza, I reckon.

Here’s my Forza glider at that slope last summer - i can’t wait to get back there.

Martin

 

[Wayne]

I call that a slermal site. Part slope, part thermal. I actually like that kind of site a lot! The elevation on the hill gives you tons of flying space. Should be a blast!

 

[Doc James Hammond]

Glad you are having fun with your Forzas (Forzeri?) Martin.

That site is gorgeous - England's green and pleasant land, as someone once said. I miss it.

Looking forward to more pics from Le France.

Cheers,

Doc.

 

[MartinH]

Yes, my favourite slermalling site can be a bit scary with a pure glider when the thermals suddenly run out ...

Some of my models that I fly there:

- The king of the slermal - 2.5m NAN Orion aerobatic/F5J-ish model with 800W geared motor and only 1700g
- Micromax - not cheap but it's a truly amazing glider
- Multiplex LS3 - 40 years old now and still flies great
- Royal model Minimoa - now sold but looked amazing in the air with those gull wings

Damn, I wanna go flying now but gotta get back to work

Martin

 

[Yotaman1985]

Looks like a fantastic spot Martin. I completely agree, my Micromax is one of my favorites but they are on the pricey side for sure.

My E-Forza fuselage made it state side so I just need to make some time to go pick it up and then Ill be starting my build. Apprciate all the info youve shared on yours as I will be referencing and reviewing it for mine. Anything you would change if you were to build it again?