Slope MOMs Racing - Lets get this going!

[smirkracing2024]

Guys, can we pencil in a date and a site for next month's race? I heard rumblings from Red that his arm might be twisted to join us next time if we hold it on Saturday. I'll propose the following:

• Date: Saturday 8/15
• Where: Thornton Beach again
  If we can scout out another site and confirm its suitability for racing, we can change this. I do think there is an advantage, especially for newbies, that we stick with a known site for the racing. Just my two cents.
• We should be able to schedule another event in September before the autumn winds put an end to most slope soaring in the Bay Area. Any opinions?

Ollie

P.S.: What say you, Red?

I have a conflict (wife has plans) on Sat, but Sunday the 16th is open.

If @Red can make a Saturday and agrees to this date, I will ask wife if her plans can be moved (penalties begin accruing as soon as the question is asked, regardless of the outcome, and no take-backs!).

Is it safe to say the likely window for high(er) winds will be say 2-4pm? I can't come for the entire day.

 

[gnichola]

I purchased 2 more airframes, one for me and one for another Santa Rosa local that wants to join us. The servos I used are not in stock, has anyone used the Emax ones? do they fit ok?

https://alofthobbies.com/products/emax-es3302-thin-servo-2-8kg-38-88-oz-in-10-sec-12-4-grams?variant=40017437261961

 

[zeo0nie1]

@Yotaman1985 can simply fabricate 50 slingshots in carbon fiber.

I kid, I kid.

I'll only be in the Bay Area half time going forward, so 8/15 and after is a "maybe" for me. I'll try.

 

[zeo0nie1]

Is it safe to say the likely window for high(er) winds will be say 2-4pm? I can't come for the entire day.

Typical week & day. Bad luck for wind last weekend, beautiful weather otherwise.

 

[OribaSJ88]

Saturday 8/15 at Thornton Beach sounds like a solid choice.

I would very much like to have the group visit some other slopes though. Just the experience of getting to fly different spots helps to keep things interesting. But I also am frustrated with the lack of actual flying sites we have in the bay area. We have lost some decent sites in the last 10 years and gained zero new ones. I'd like to see that trend reversed. I am actively on the hunt for old and forgotten sites as well as new possible sites. I have set out of some explorations to locate possible sites. (Maybe this should be a new topic as I have a few I want to do that will require some camping and exploring and maybe others are interested in that sort f thing too?)

For this season we will stick with the current plane, but lets keep our eyes out for what we might want to use for next season. If you all are OK, we can allow Rafael to make improvements to the Slingshot to address the weak spots. Seems like a lot of the carnage I saw this weekend was mostly fuselage at the wing mounting saddle. Is that correct?

(We resisted making any changes once we starting printing the airframes as to keep them all the same.)

I'm in violent agreement that there shouldn't be any changes to the airframe this season. We barely got things started! Next season is another story, but only if we have a good alternative. I'll keep advocating for a non 3D-printed design but will defer to what is feasible and what the community wants.

Well, regarding making changes to the airframe, you do know that it is already quite a departure from what I gave to Rafael, right? I think that train already left the station . If you guys want make changes that will improve the survivability, go for it. As I mentioned previously, the best thing, IMHO, would be to fiberglass the inside of the wing saddle area (the mid-fuse). More glass in the saddle area in contact with the wing and somewhat less around the circumference should work wonders. If done correctly, it should be strong enough for a removable wing. It has the added benefit of requiring no changes to the model and can be applied to any unassembled models. There are other areas which could benefit from some reinforcement but none as important as the saddle area. It will be a challenge to overcome the inherent brittleness of PETG without fiber reinforced composites.

 

[Wayne]

I was going to suggest we delay the start of the event a couple of hours?? Maybe closer to noon?

Mehrdad has placed an order for a Slingshot. I've seen several kits go out to other folks that we have yet to hear from. I'm pretty sure we will have 4 or 5 more pilots for the next race.

 

[OribaSJ88]

If I'm in town I'm in!

Let us know, Red. It would be nice to have you at the next event. Ollie

 

[OribaSJ88]

I was going to suggest we delay the start of the event a couple of hours?? Maybe closer to noon?

Mehrdad has placed an order for a Slingshot. I've seen several kits go out to other folks that we have yet to hear from. I'm pretty sure we will have 4 or 5 more pilots for the next race.

It's reasonable. We should check the forecast a couple days ahead. Had we flown on Saturday, we would have started earlier. As it was, we started just a bit after noon.

 

[Wayne]

Agreed - keeping the Slingshot for this season, no questions there. And again, if you need any parts to patch yours up, just let us know, you do not need to buy a full kit in most cases. If you want to add some thin fiberglass here and there to beef up the durability, go for it.

I'm thinking I might make a special prize for our winner.

 

[smirkracing2024]

I'm in violent agreement that there shouldn't be any changes to the airframe this season. We barely got things started! Next season is another story, but only if we have a good alternative. I'll keep advocating for a non 3D-printed design but will defer to what is feasible and what the community wants.

Well, regarding making changes to the airframe, you do know that it is already quite a departure from what I gave to Rafael, right? I think that train already left the station . If you guys want make changes that will improve the survivability, go for it. As I mentioned previously, the best thing, IMHO, would be to fiberglass the inside of the wing saddle area (the mid-fuse). More glass in the saddle area in contact with the wing and somewhat less around the circumference should work wonders. If done correctly, it should be strong enough for a removable wing. It has the added benefit of requiring no changes to the model and can be applied to any unassembled models. There are other areas which could benefit from some reinforcement but none as important as the saddle area. It will be a challenge to overcome the inherent brittleness of PETG without fiber reinforced composites.

I have never worked with fiberglass or carbon fiber cloth. The one time I tried to repair some carbon fiber landing gear, I wrapped kevlar thread around the broken part and soaked it in CA. To avoid getting CA on my hands, I wore nitrile gloves (which I normally don't do - I just keep debonder handy). The CA got onto, and perhaps INTO the nitrile gloves, which then bonded to my skin. Then, the gloves started burning (or so my nerve endings told me). While the gloves were not actually on fire, they sure as heck were extremely hot (as in, burning hot). It felt like what I imagine napalm would feel like - a gel stuck to my skin on fire. It was a horrible experience and I've not tried anything like that since.

What that illustrious background in fiberglass and CF cloth, here's my noob question: would it help to just wrap the outside of the fuselage with 2-3oz fiberglass cloth+epoxy? That seems do-able even for people whose planes are fully assembled.

 

[zeo0nie1]

Konrad mentioned that the heat from curing CA deformed PETG on his wing.

hmm, maybe I'll run some carbon tow or cap strips along the fuselage with epoxy.

 

[OribaSJ88]

Konrad mentioned that the heat from curing CA deformed PETG on his wing.

hmm, maybe I'll run some carbon tow or cap strips along the fuselage with epoxy.

I don't recommend CA, but it's less of an issue on the fuse because it's thicker. Use some longish cure epoxy, the thinner the better. It has gotten obscenely expensive. I use so little these days that I simply use thick 30 minute epoxy and 3/4" fiberglass woven tape. Wet the tape fully with epoxy on a scrap surface and then apply to the area you want reinforced. If possible, I cover it with a piece of tape which is later removed. It leaves a surface that requires minimum sanding.

 

[Wayne]

Konrad used 1.4oz fiberglass on his wing. He suggests 1.4 to 2 oz cloth and 30 min epoxy or thin CA and a sanding block. If you saw his wing you will understand the potential of this, he had the nicest wing there, but he also had something like 12 hours invested. Konrad's first attempt was 1/2oz glass and thin CA, but the CA shrank enough to pucker his wing. (I'd probably try the epoxy instead of the CA.)

 

[Red]

Let us know, Red. It would be nice to have you at the next event. Ollie

Ryan as well.

 

[Red]

Konrad used 1.4oz fiberglass on his wing. He suggests 1.4 to 2 oz cloth and 30 min epoxy or thin CA and a sanding block. If you saw his wing you will understand the potential of this, he had the nicest wing there, but he also had something like 12 hours invested. Konrad's first attempt was 1/2oz glass and thin CA, but the CA shrank enough to pucker his wing. (I'd probably try the epoxy instead of the CA.)

He used glass on the outside of the wing?

 

[Wayne]

Yes, maybe a little cheaty, but we are racing for fun here. Can't argue with wanting a more durable plane.

 

[Red]

Yes, maybe a little cheaty, but we are racing for fun here. Can't argue with wanting a more durable plane.

Yeah I'm gonna call foul on that lmao

 

[zeo0nie1]

so nice with decent wind.

 

[Wayne]

Someone was asking about servos - We just got more of the Orbits in. Should be up soon.

 

[smirkracing2024]

Someone was asking about servos - We just got more of the Orbits in. Should be up soon.

I don’t know how other servos fit but the Orbits fit perfectly down to the mm. Very convenient and secure.

Two tips:

1. In order to get the servo extension to fit inside the wing for the aileron servos, I had to cut off the large plastic housing that normally holds the two servo plugs together. I glued the two servo plugs together with E6000, and once dry, everything it fit perfectly. This is the lazy man’s alternative to soldering directly as shown in the build thread. I am pretty sure it is just as secure, given how protected the wiring is.

2. I wrapped all my servos in tape and then glued them into the pockets. I am very glad I did this because they are very easily removable. As it happens, I need to yank all four of my servos. For the two aileron servos, I want to put in a slight amount of mechanical differential, so I need access to the control horns. For the flap servos, I need to reset them completely so that the neutral position (i.e. when the flaps are parallel to the wing root) is at negative 100%, not 0% (i.e. center) which is what I mistakenly did initially. Anyway, having the servos glued with E6000 makes this very easy.