Hi All,
So got my DIY efoil going and gave it a first test. All the motor ESC and things seems to work good. On an inflatable 145l board with NSP 2500 front wing and 80cm mast. I mounted the motor most of the way down so prop about 5cm clear of fueselage.
Have done about a dozen days tow foiling behind a boat and got quite confident. Can get straight on foil and starting to practice crossing the wake. The differnt tow line loads every time you turn made me think of going efoil.
So the problem is now I have gone from the thrust being a tow line at say hip height to a pusher prop at the bottom of the mast. The board just wanted to wheelie and I couldnt get enough weight forward to easily get it on foil. Normally stand where the foot straps would, Now ended up with feet infront of the straps and had to learn hard forward to keep the nose down. Eneded up with so much load on my front foot once on foil was really unstable. (I had this when I started with the tow foiling but moved mast back and balance is perfect. Currently hard back in the track)
Standing so far forward on the board just seems wrong. Should I move the motor up the mast so less leverage ? Should I cut the mast down to make shorter? Should the motor be angled up slightly ?
The best result I had was with the remote in the low setting. The thrust come on softer so gave me more chance to get on foil. Once on foil was fairly much full throttle most of the time.
Maybe just something I have to get used to. Cant move the mast back any more.
Any tips appreciated.
Cheers
Well front foil is really big for efoil so that might be part of the problem.
What prop are you using?
Yeah it is big, Im 100kg plus gear. It works well tow foiling. I do need to look at getting a smaller foil but thats another topic. Seems NSP not so popular these days so maybe need to go another route.
I was thinking about that. A smaller foil will be less drag which is below the thrust line so maybe only make it worse? Would have to be going faster to foil also so would need more thrust maybe? Maybe a whole heap of dynamics Im not thinkng about.
Not sure how big a difference moving it up the mast say 3" would make? I would have to cut new holes in the mast for the cables so trying to work out if its going to make any notable difference.
Cheers
Best way to get help here is to supply the readers with facts including photos.
The prop can make a big difference but still don’t know what you’re using.
Lots of people perhaps bigger than you EFoil on smaller foils - imo moving the motor up won’t solve anything.
Sorry forgot to add the prop details. Currently got the 162mm folding with the prop guard. Thought that might be a safe option.
Also got the 3 bladed white one from flipsky but not tried.
Yeah want to get a smaller foil. Just not sure what brand to commit to. Not sure what future there is in NSP.
Couple of pics attached.
Tow foiling with this setup balanced well. Feet where the foot straps bolt holes are (Not installed) and slightly more pressure on back foot.
Just the change from thrust going from above the center of mass to below has totally changed things. Maybe not surprising.
I might be able to get out again on the weekend and try again.
Actually another change is the weight of the motor and batteries, esc box which is all at the back. Maybe another 6-8 kgs right at the back.
Pitty I have run out of room on the mast track. Just feels like it needs to go back another couple of inches.
Cheers
It is normal that extra weight is needed on the front foot to leverage the motor thrust. Moving the motor higher on the mast will reduce this swing but then it is not an efoil anymore. I learned to foil on reduced throttle to counter this issue. Only use full throttle to lift off.
Might try to put some shims on the stab too.
Looking at the photos, it looks like the prop guard pointed downwards?
Choice of duct and prop are not good for full Efoil use.
Things you can try that don’t reguire moving the motor
Take the duct off
Buy a good three blade fixed prop (Flite)
Stay on your knees and try to foil, be patient during takeoff. Keep adding throttle slowly until you get enough board speed to just rise up out of the water with the board level. Once you can do that consistently and maintain level flight then progress to standing flight
If that is the case, there is something seriously wrong. After getting up on foil, you should be able to reduce throttle.
For me, I need about 2kW to get up on foil and about 1.2 kW after.
As the tilt you are having problems with is directly related to the amount of thrust, that is your problem right there.
I would try without the prop guard first and also consider getting a smaller foil.
Will take the guard off and try my 3 bladed prop next time for sure.
I did do a bit on my knees. Easier to get weight forward. Foiling on that setup has been fairly easy towing. Just the thrust from low down pitches it up so much. Think I need to try and get weight forward to allow for the extra motor and batteries.
That is with the joystick in Low mode. Not exactly sure what that does. Maybe just limits the power. Was a lot smoother and easier to get up. In medium had a lot of power and hard to control smooth. Slightest bit too much and just pitched up and really hard to get the nose back down without backing off.
Pitch up is directly related to the amount of thrust for sure. Tow foiling the balance is nice and easy.
How can you see how much power you are using. I dont seem to get any of that feedback. I have it connected in PPM mode not UART. maybe need UART for that? Do those Flipsky ESC have built in logging? I was trying to see but looks like only though bluetooth when phone is connected. Not so keen on taking my phone foiling.
For sure keen to get a smaller foil. Just need to decide if I stick with NSP or switch to another brand. NSP seem a bit out of date maybe ?
Cheers
The white aluminum prop from Flipsky is too big so not worth trying as is.
There are lots of topics here on how to do what you want but you seem reluctant to use the search tool.
If you prop that motor correctly and use good technique you should be able to takeoff.
Using that large a foil will not be enjoyable.
Commonly used foil setups are well documented here and have even been suggested in your other topics
It really shouldn’t matter, once you are up on foil you should be able to reduce thrust.
I assume your complete setup just has too much drag.
When I was still using the Flipsky VX3, it was displaying power on the remote. Need to connect UART for that, yes.
I suspect your huge wing is the problem. I am having the same problem on a slingshot infinity 84 (2066cm2). I just took an efoil lesson in Hawaii and that setup was a heavy beast of a board, full efoil battery, and 1500cm2 wing. I’m told that’s the size wing they put on for beginners 200lbs and greater. After doing some reading (everyone - feel free to correct me) if you have that huge wing and have just enough speed to fly, once you fly, the water friction is gone and the lift of the massive wing remains with the same power output… and you start to accelerate and feel out of control. I am going to try a negative 1 degree shim on my rear stab (testing tomorrow) to see if this helps at all. But I suspect 1500cm2 is what I should be riding. I’m going to see if a friend will loan me his foil setup to give it a shot. FYI… For the efoil lesson, I would pin the throttle, move the gear up to 7, stand up, increase the gear to 8, and then shift my weight to fly. I never had to let off on the throttle at all and never felt like I accelerated once off the water and certainly never out of control. (The gears on my VX5 remote are just like the L, M, H on your VX3 remote - they limit power output - they are not true gears in the sense of bike gears). I didn’t find it possible to let off throttle on the VX3, too twitchy. But the VX 5 trigger has more travel so I may try feathering it back once flying if the shim experiment is a fail. Or if my buddy lets me borrow and I find that the 1500cm2 is the fix.
That is a really big wing. I use a 1200cm2 and I am 95kg.
I have also a 1400cm2 wing and I find it more difficult than the 1200. That surprised me. I plan on getting a 1000cm2 for the coming season.
I have a similar setup with a large 1957sqcm front wing, 118l board with 82cm mast (motor also 5cm from foil. Im 80Kg (180lbs) I stand about 15cm (6") further forward when efoiling vs tow or winging.
I suspect you are trying to foil too fast for your setup. With this configuration, most of my efoiling is at a leisurely 18-25kph (11-15mph). Anything above 35kph (21mph) requires more front foot weight than I can provide.
Hi All. Thanks for all the helpful comments. I have not had a chance to look at or test any changes since first test. Some things I think have become obvious.
Yes the foil is big and I want to get a smaller one. I am going to get some lessions from a recommended teacher and try some different setups as may end up changing brands so hopefully only have to do that once in the forseable future. That aside the foil I have works great tow foiling. 15kph is about the sweet spot for it.
Yes I will remove the prop guard. I put it on for first test. Letting the throttle go is a natural thing so not worried about hitting the prop.
I totally over looked the weight added to the back with motor batteries etc.
The thrust comes on too strong and pitches the front up instantly. Then have trouble keeping the nose down. I have found a sensitivity setting in the remote. I think some ESC setup changes may help this also this. That is why the slowest speed worked best for me. Ill try and smooth out the mid and high setting so can accelerate slower and smoother.
Agua4fun that is really intersting you have to stand so much further fowrard. I was not expecting this so started in the normal spot hence half the struggles. Was nervious about standing too far forward. Ended up with most of the pressure on my front foot hence half the problems. I went through this exact balance issue when learning to tow foil so know how it feels.
Hopefully can get out again in the next few days for another test.
Cheers
agua4fun, that’s good to hear. My technique is likely a factor :).
Curious, what board do you use? I tried a North Seek 140L and even with the foil all the way back in the foil box, it mostly just plowed water. My inflatable 135 has a smaller and flatter bottom and flies no problem (although my control is crap)
I was able to try my buddies Armstrong S1 1550 setup today. Much less front foot pressure needed but I still have my front foot forward of the deck pad to hold it down. I’m going to make sure my pod is not angled. I might also try shimming the stab a bit. Not sure. Unable to try shimming my slingshot setup as the stab bolts are seized. Now I want to try a 1200 front wing
have you tried to shim your tail to change the pitch? I was having similar issue but printed a shim to pitch tail down and that helped keep nose down and reduce front foot pressure
I only have a 1 and 2 deg shim so been using the 1 deg one. Didnt think about 3d printing one. Maybe can make a 0 deg or -1 deg shim.
Cheers
Mark