Show us what you are working on..

[Wayne]

I forgot to mention, should you ever need a boat prop, let me know, we can get any of the Graupner props, they offer a ton of different props.

 

[thenated0g]

@Wayne thanks. I will definately get some footage with a gopro

Martin's build has been really impressive so far. We are holding back on posting much until he is ready, but i have lots of pictures and thoughts so far. Having built my own 4 axis hot wire cutter from scratch, a 3 axis cnc machine, and a 3d printer, this is super super easy to put together. Very rigid and light. I wish i had something like this available when i was looking to get into hot wire cutting. I am going to make free plans/cutting files for a 71" pw51 plank as my way to learning the kit and DevWing Foam2. You could cut out 4 of them from one 2" 4x8 sheet of whilte foam from home depot, the $22 sheets. Needless to say i am having fun.

 

[Wayne]

This is the CNC foam cutting software I used long ago:

GMFC – Logiciel de découpe au fil chaud

I can not recommend it highly enough. Innovative methods that were ahead of everyone else. Developer (Gilles) was very active and was very responsive. I have not followed it for a number of years, but might be worth taking a look at it. The Kerf and Automatic heat compensation was one of the things that really made it stand out.

 

[Martin]

I know it is just checkbook modeling, but I’ve been assembling a Freewing F-14 from RC Castle. What I wanted to show was that despite my issues with FrSky when it comes to complex programing there really is no substitute for OpenTX. I have a lot of safety and lock out features that I just can’t seem to do very well with my Spektrum DX9!

Fans are Frankenstein rigs. Freewing housing with Neu 1410/2Y/SE (1850 KV) motors driving Jet Fan impellers! ESC are YEP 150 amp with Castle Creation cap packs. Far too many ESC are burned by the use of battery lead being more than 8 inches long (total). If adding any length the the battery side of the ESC please add these protection caps! Even though I'm only drawing 85amp it is the load on the protection circuit from the ripple current that fails the MOSFETS! We see far too many ESC burn when guys add these long battery leads!

All the best,
Konrad

Freewing F-14 Tomcat Twin 80mm EDF Kit Version With Full Servo

*** The optional Weapons Set Is Available Separately And Is Not Included. *** - High Performance & Super Scale Twin Electric Ducted Fan Jet.- Rigid Aluminum Wing Box Assembly For A Swept Wing Configaration.- Servoless Actuators To Sweep The Wing Duri

www.rc-castle.com

YEP ESC 150A (2~6S) SBEC Bürstenloser Geschwindigkeitsregler

Hobbyking YEP 150A (2 ~ 6S) SBEC Brushless Drehzahlregler

hobbyking.com

Cartloom | Admin | User Login

neumotors.cartloom.com

https://www.effluxrc.com/Jetfan-80-V2-V3-Rotor-System-JF-80-RTR.htm

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www.castlecreations.com

View attachment 3468

"Far too many ESC are burned by the use of battery lead being more than 8 inches long (total). If adding any length the the battery side of the ESC please add these protection caps! Even though I'm only drawing 85amp it is the load on the protection circuit from the ripple current that fails the MOSFETS! We see far too many ESC burn when guys add these long battery leads! "
I'm interested in this subject. maybe it should be another thread I don't know? Is this a common occurrance ? Do you use electrolytic caps at the esc to reduce the ripple current?
thanks
martin

 

[Konrad]

Far too common a problem! The ESC OEMs do add those caps in the design of the ESC to protect the MOSFETs. You can see them on most ESC. A lot goes into the sizing of these cap. The OEM doen't know what the end length (battery lead and ESC lead)will be. So often the size is dictated by what will fit in the shipping package. (Not my idea of proper engineering!) A big killer of ESC are cheap high impedence batteries.

Yes, most are electrolytic caps. The key is that the caps should be low ESR (Equivalent Series Resistance). This is to keep the heat build up in the caps low. Different brands will site different length as being safe. But the idea is the same, take the load off the protection diodes (or freewheeling circuits).

I think Castle Creation has a FAQ post addressing this issue/feature.

(I hope this doesn't get pulled for being off topic, whatever this topic is)

All the best,
Konrad

P.S.
I'm sorry I don't see a FAQ on CC's site for the Cap Pack and there use

 

[Martin]

I am using lower current systems. usually 40A and less but I'm not careful with the length of my battery leads. I use cheap chinese esc. I would be very surprised if these inexpensive esc are using low esr electrolytics. I would expect them to use the minimum required amount of filtering to save cost. With that said I've never lost an esc during flight. Maybe I've just been lucky. now I'm curious might take a few measurements.
martin

 

[Konrad]

You want to see a ripple voltage of less than 10% of the input voltage. low ESR are to extend the life of the cap. They do heat up! Its not a high or low current issue. It is the forward biasing of the protection circuits. (Yes, current is a large part of the equation) Too small a wire gage, long wire length, poor connectors, weak batteries and current all play into this issue.

What you quoted is my idea of low current. As you can see I added the caps to a brand that is historically known to burn spontaneously (YEP). Again this is more often than not as a result of guys adding length to their leads.

 

[Martin]

yeah I'll take a look at the voltage at the esc input. Usually the current travels through about 8" to 12" of wire, a frsky I/V meter and 3 xt60 connectors to get from batt to esc. I might be surprised. I'll let you know what I find.
martin

 

[Konrad]

I use an oscilloscope. Your meter will need to be able to filter out the DC offset and not report an RMS value, but rather peak to peak. Many modern ESC will give you the ripple current. The good ones will want to help you protect them.

 

[Martin]

I've got an old hitachi scope that I use on ocassion. that should show me what I'm after.
thanks
martin

 

[thenated0g]

Pretty productive weekend. Took friday off and checked out a sloping spot on the north shore. I remember AMA guys telling me about it years ago but never made the trip. Wind were estimated to be 15mph but at the top it was 24mph gusting to 28. About a 10-20minute walk past the parking area. Really great to find a local spot after years of driving around. This is about a 25 minute drive for me.

Google maps link: https://goo.gl/maps/P3HrvWr8QS7vHanw9

Also made a lot of progress in learning how to use DevWing Foam 2 and the WindyHill CNC

WindyHillHobbies – German Engineering. Made in the USA.

windyhillhobbies.com

 

[bracesport]

@thenated0g - awesome stuff - flying and geekery!

 

[Hank GB Z]

@thenated0g,


I like the cnc foam cutter. How much was the Dev Wing software?


Hank

 

[thenated0g]

125 Euros, think thats $140? And i also picked up the DevCNC to use as my CAM for another 60 euros. AFter fighting with other software for 2 years i am so glad i got them.

 

[Wayne]

Nate watched the videos over the weekend. Good job on both! I might have to come fly your new slope. Looks really nice! How is the landing area?

 

[thenated0g]

The top of the ridge is about 2 or 3 Road lanes wide so you gotta dip back into the back side. I did it a couple times right and once had a fun "hope theres no snakes" walk down the grassy hill lol. It was the first time i have been in that crazy of wind and the gusting. LIke my plane was jumping and when you hit a higher lift zone, even fully ballasted up, it would climb 30 ft in a second it seemed like. I had also forgot that i had set my rates to full 100% and that combined with the wind made it a little tense for the first flight i posted above.

Im going to find a day when 10mph is predicted and see what it is at the top, maybe even go when it says 5mph. That way i can than say if its this online it will be that at the top. Worth it for the views even if you didnt get to fly.


I was flying in the blue area and the arrow represents the wind direction (southwest?). The red arrow represents another flying direction that gets funneled up a bowl kind of valley, but it was at little bit more of a climb and i didnt have time to check it out. Heres a picture of the hill as well.

 

[thenated0g]

Oh yeah, here is the wind site i use: https://www.windfinder.com/forecast/clear-lake_kono-tayee-point

 

[Wayne]

If your flight was in the heavy winds this weekend, then I think you have a good site there! My little local site is not flyable when the winds pickup to that level. Well, you can fly, but it is not at all enjoyable as it gets really bumpy and becomes very hard to land as the winds are very turbulent down low and now clean zones. I need to dust off some of my flying wings for my local hill.

From the video it looks like your site will be a great site for Slermal flying too. (Slope Thermal) and that can be very rewarding too. Those days were you have to watch what the birds are doing to try and find some lift. Lots of fun. I really have not found a good Slermal site up this way, think you just did. Makes me want to fly big planes there. Should be able to drop down low, burns off some energy, then come up the hill and land near the top..? May not be a good option when the wind is really howling.

I like it.

 

[JiminWA]

Understood. Those spec's at Motion Sickness make me sick, like Type "B", Type "C". That tells me nothing! I'd like to see at least some idea as to the flang mount. An upside of calling out the model you can see what they fit. Doing some research you can find if they are stong enough for the weight. Strut geometetry, strut size and wheels are usually a seperate spec'd (item) from the retract unit itself.

I know this was an old one. However there is a list of what type of retract’s “B” etc. means. I just went through an agonizingly long search to find all metal retracts for my FMS PC 21. Some search I did kicked me back to this post. My apologies for cleaning out my email trash otherwise I would give you the link to the type specification chart. I found XRP CNC out of Hong Kong that makes most of them for all your favorite flavor manufacturers. I paid the same price for a complete set as you would pay for just the nose strut from another well known horizonal raper of modelers.

 

[thenated0g]