Twitchity quad with power board - test build

[jhitesma]

I would have been extremely impressed if you were able to lawn dart the quad into that ground especially without breaking anything. That frame is probably begging for you to retire it and upgrade to the CF version with how much abuse you're giving it.

The ground is actually pretty soft right now. We've had more rain in the past month than we usually get in a year. The field was actually squishy as I walked across it - and that dirt the quad tried to lawn dart in we were sinking into standing on it.

And yes, it is begging to be upgraded and I was planning on doing so right after Christmas. But the hex is going to get priority now. Besides - I haven't actually managed to break the G10 yet despite giving it many many tries I'm not going to give up though. I'll keep trying until it does or until the CF frame upgrade finally bubbles to the top of the funding priority list. Though I will miss the flourscent pink and blue when that happens

Also: Lawn darting is a thing? I've done that twice already, but have to admit it was on a freshly plowed field . I'm asking, because I think I might be able to become an expert in that area.

EarHog on RCgroups in the Warp thread made a bit of a name for himself with that landing He didn't even have the benefit of a freshly plowed field - but I suspect his field is a bit softer than ours even after the rain we've had

He will break the frame sooner or later, so he has to switch to CF anyways ;-).

See, Balu has faith in me Seriously though I'm beginning to question if this setup has enough mass to actually break an arm. I've had some really hard hits at full throttle from pretty high up onto pavement and desert ground that's as hard as pavement but pointier....other than some scuffs on the ends of the arms so far no damage. I'm not a quitter though so I'll keep trying!


My goal with this build from before I started it has been to show that G10 is perfectly suitable for a 250 sized quad. At least for a budget priced acro trainer quad. And I think I've done a pretty good job of proving that theory correct so far. It really has stood up to a remarkable amount of abuse. It's not that much heavier than CF, and with careful building the overall quad can be just as light as a CF quad. It's also not as stiff and that limits the performance some. But for 18mm motors and a tight budget I would have no hesitation recommending it to someone as a learner acro quad. It will take a lot of hard crashes gracefully and is no slouch when it comes to performance even the flexing does prevent it from achieving what it could if it was CF.

The only real drawback is that G10 isn't really that much cheaper than CF so the savings aren't really enough for me to really get excited about it as a budget alternative. But then again on a quad where you're buying multiples of expensive bits like motors and ESC's every chance to save a few bucks can be the difference between quad or not quad for someone on a tight budget.

 

[cranialrectosis]

I like the G10 because you can paint it.

 

[jhitesma]

I like the G10 because you can paint it.

Yep, that is a big plus. I mean you can paint CF...but then you have to deal with Twitchity hunting you down like a dog for doing it

And this is still just 3mm G10 for the arms. If they were made from 5mm or maybe even 4mm I suspect they'd be stiff enough to eliminate the issue I've run into. (even though after todays experiment I suspect the main cause of the issue is vibration from the DYS motors and my FC mounting...I can still see the arms flex in some situations so stiffer arms would certainly be a benefit.)

But then you're back to the point of gaining weight and cost and defeating the benefit of G10.

Bottom line, I don't feel at all bad passing the original G10 arms/body to my co-worker as a first quad. I'll be surprised if he manages to break it and while not a warp it will still outperform a lot of the cheap 250 sized quads out there.

 

[Balu]

Good. Your coworker will really like the G10 frame. So if you don't think you can break it, you should start dismantling it.

 

[jhitesma]

No disassembly yet - I may not have made that quite clear I actually have enough bits to build two G10 frames at this point. I still have the original black G10 arms that I replaced with the painted natural G10 arms I'm currently using. I also have the original V1 PDB I had designed which works but isn't as nice as the V2 Twitchity re-worked which I'm currently running. And since I'm using the PDB I have a spare original bottom plate which I've used as a top plate when I ran the afromini since the cut-out low profile top I'm using now wouldn't have worked with the afromini. So I actually have enough parts (other than screws and nuts) for two G10 frames.

Now, I do plan on upgrading this one to CF - but I'm really not in a rush since I've only partly met my goal of finding a weakness in the G10 I've found a performance limit on it...but I've yet to actually break it Originally I thought I'd want to do the CF upgrade for durability reasons - but it's worked out that the G10 is great from that standpoint. It's just the arms being less stiff causing a performance ceiling that's pushing me towards the CF now.

I'm not ready to give up trying to break it yet And I'm not sure my co-worker would appreciate the hot pink either - I think he'll like the black arms more

 

[jhitesma]

Well I had a feeling Balu was hinting at something. Didn't have to contact Twitchity to find out who to thank this time







Seriously guys, you're all amazing and I don't know how to thank you enough! But if we make it to FT and so do you I'd suggest watching out for my wife. She's starting to get upset that her gifts for me this year are being upstaged

I see Twitchity drilled this one for both 18mm and 22mm motors...so I can keep flying on my 1806's while I save up for even more nice motors

Just not sure what's up with the screw sizes on this...there were 8 of one length and 4 a little longer...not sure why the 4 are a little longer. But I was pretty rushed over lunch so I may have missed something obvious on my quick test assembly.

Note - the CF is less than 10g lighter than the CF..but it's MUCH stiffer. And the weight difference may be even less once I add the PDB to this. Also this is now using aluminum instead of SS for the screws so that may have affected the weight a little as well. Didn't have time over lunch for a full comparison

CF doesn't give a huge weight advantage over CF for the same size material...but it is a lot stiffer and stronger.

 

[Twitchity]

It was hard for me not to say anything after I saw what Balu said. I remember you contacted me about the CF frame, but wanted arms that would work with 1806 motors, but still be able to upgrade to 2204's later.

This is just the standard version of the frame, but those 16mm long bolts will come into play later when you decide on getting an FPV pod. You already have too many FPV crafts right now, so you just need a tough acro monster Take a look at the mounting location for the FPV pod on my quad, this is where the four 16mm long bolts will go.

Once your wife has some time to cool down and not kill any of us, we'll get you an FPV pod

 

[cranialrectosis]

It was tough keeping my mouth shut the last few days.

Happy Buildmass Jhitesma.

 

[Balu]

After you mentioned you'd really like to upgrade to CF but had to save for it, deciding on this was easy. You can imagine my surprise when Twitchity mentioned that he had just sent the hex as gift from Cranialrectosis. Fools seldom differ, I guess

Perhaps I can calm your wife down with some German chocolate if I really make it to FF?

 

[jhitesma]

I figured the taller bolts were for something like that, just wasn't sure which holes they were supposed to go in to match up. Makes sense why no top cap either (not that I've been using mine since I need some taller spacers for it to clear the nano/speksat the way I currently have them setup.)

And yes I really need to spend more time in the goggles with the FPV rigs I currently have. Just so hard for me to find a spotter to fly with. But once I pass the original G10 frame down to my co-worker I suspect it will be easier to get him out to fly more

@Balu - That would calm her down immediately

Guess I need to pick up some purple paracord to match these bolts now ... pink may clash a bit

Still think I'm going to take the G10 version out for a few more flights though...really honestly shocked I haven't broken anything on it yet, need to give it one more day and a few more props before the upgrade.

 

[cranialrectosis]

Still think I'm going to take the G10 version out for a few more flights though...really honestly shocked I haven't broken anything on it yet, need to give it one more day and a few more props before the upgrade.

Go 4S! That should fix it.

 

[Niall762]

4S might get it a bit muddy...Do this! http://youtu.be/oR3q4hlmoEo

 

[jhitesma]

Don't think I'll be going 4s or above....with all these frames piling up and needing parts I don't need to be buying more batteries just yet...and I really need some more 1.0/1.3 3s packs as 1 of my 2 nano-techs lost a cell after just a handful of flights and my 2 Turnigy packs don't quite have the C rating to do this little guy justice. Maybe some day I'll step up to 4s but I've got a ways to go.

Besides it's the frame I'm looking to torture test not the motors/esc's

Speaking of the frame...I said I was going to fly the G10 one more time didn't I? Well, it was a bit windy at lunch today so plans changed:


Well, that and today is my co-workers last day in the office for the year and I really wanted to give him a frame before he took his vacation in case he got himself a TX for Christmas and decided he wanted to build the quad up before he got back. So I had to get the arms, top plate and SS screws/nuts off for him

Hopefully tonight I'll be able to transfer everything over to the CF frame. No fancy sleeving just yet though...haven't had time to pick up any new colors of paracord and I don't think the pink I have goes very well with this purple. Part of me wants to just sleeve it all in black and give in to the "all black" trend since it's a CF frame....meh...we'll see. For now I just want to get things transferred over so I can get it flying before my friend with the warp goes back to school so he can experience it

 

[Twitchity]

Hmm... you can use purple paracord for the wires I suppose... Once you start dying the guts of the paracord and wrapping various items then we'll have a problem! Tell your co-worker to join us of the forums (if he isn't already) and post his build.

 

[jhitesma]

I was planning on purple...but then if we ever meet up we may not be able to tell our quads apart Thinking I have to do something a bit different just to be unique.

I'll try talking him into joining us here again...but he's not much of a forum person, tends to be more of a lurker when he does check them out

 

[jhitesma]

Well, I couldn't leave the quad without a frame...so last night after my daughter was down I put it back together. It's not "Done" as I do want to clean it up a bit more...but it's ready to fly.

Right after assembly I discovered something that wasn't an issue with the G10 frame, but could be disastrous with a conductive CF frame. When I soldered the battery wires solder wicked up the wires and made them stiff right where they leave the PDB. There's only 3mm of clearance and these wires are almost 3mm thick so things are tight here. You can see where the insulation is getting pinched as a result of all of this. With the G10 frame no big deal, but on a CF frame this could short out my battery. It's something to watch for when building this frame, might be better to put the wires on the other way but I liked the clean look of them coming out of the inside rather than hanging off the bottom. For now I added some extra electrical tape on the top plate of the frame in this area for additional insulation:


I then started putting things together...only to realize I hadn't finished the CF and the edges while not as sharp as most CF frames were still sharp enough to worry me. So it all had to come apart again and get sanded. That actually went really quick. There's a lot less to sand than in a H frame and this CF sanded fairly easily with 400 grit. After about 20 minutes I had nice smooth edges on all my pieces:


Twitchity dyed the nylon FC mounts purple to match the PDB and hardware, it's hard to see in the photos but he nailed it on the color - the Nylon matches the PDB almost perfectly. You can also see here that I bought some longer screws to mount the FC with so I could put O-rings on both sides. I had to rush to get to the hardware store before they closed and it turned out they don't have nylon metric screws But I did get a dozen o-rings (they're SAE but close enough in size for this purpose) and some black metric 3m x 10mm screws. It turns out though these are too long and leave the FC too loose. So I ended up just going with one O-ring per corner for now as the nylon screws were too short to fit two O-rings.


I'm mounting the KISS ESC's on thick double sided foam tape...but still wanted more protection against shorts on the CF frame. I didn't have enough of the right size shrink wrap to do all four arms so for now I'm just using some electrical tape on the top.


Closer view of the electrical tape.


And another angle. You can see I still have the original DST on the ESC's - it will be coming off shortly.


When I got to the ESC that I think is the one that let out a little puff of smoke when first powered up I found what looked like a small burn hole in the tape!


After removing the tape and looking under a magnifier I don't see any obvious damage, and it's been flying great. But that's one of the FET drivers (the square bit) right where it happened. I'm wondering if the issue Cranial had with the KISS could be due to tape melting and allowing things to short. I double checked that the tape isn't conductive...but maybe it picked up a little something off the build bench and caused a tiny short. I could see something really small shorting out and causing the tape to melt which on my G10 frame was no big deal but on a CF frame may have allowed things to short out and keep getting worse. Since the KISS are made in europe and sold in europe they have to use lead free solder (RoHS compliant - you've probably seen that on electronics)...now most of the issues with lead free solder have been solved but I still hear complaints about it causing microscopic filaments called whiskers that sometimes "grow" after the soldering is done: http://en.wikipedia.org/wiki/Whisker_(metallurgy). Pure speculation here...but maybe what's causing failure on the KISSes is whiskers forming on the fets or fet drivers - too small to see unaided but big enough to cause a small short. In a situation like mine no big deal - the whisker burns, the tape melts a little and lets out a puff of smoke and since there's nothing else to conduct a short it's all good. But...if you are on a conductive arm and that tape burns through - things get ugly. Even with insulation on the arm that could burn through as well (I've had heat shrink fail on an CF arm even though the arm was sanded - when the shrink shrank it stretched too much at the edges and tore.) I may switch to using some of my silicone self fusing repair tape as an insulation method as I trust it to not burn more than electrical tape and this apparently easily burned DST.


But...I carried on and kept putting things together. Just about ready to wrap my ESC's, you can see bits of silicone tape I cut laying there waiting. If you look carefully you can also see the bit of the frame by the battery cables where I wrapped it with electrical tape for insulation - but when I clean this build up I may swap that for some black silicone tape as well.


Here's a close up of the KISS mounting. Electrical tape over the arm, DST, then KISS.


I then gave the KISS a wrap of silicone tape for protection. It's not quite as clean looking as heat shrink but I love the utility of it and I think it gives a bit more protection. The tape stretches to about twice it's original length. I found that cut in half lengthwise 3" pieces worked well - but 2" full width pieces use less material and look cleaner since it uses fewer wraps. And as expensive as this tape is using as little as possible is nice. The "clear" is a bit milky for my taste but lets me see those pretty blue LED's on the KISS. This "tape" is really neat stuff for those who've never used it. It's not sticky and leaves no residue. It only sticks to itself - but once it does it fuses and can't be undone. So it makes a very nice insulative cocoon that seems a bit sturdier than heat shrink and can be applied at the end since it doesn't have to slide over. I like it even though it's not quite as pretty.


All done and it came in under 195g before props!


Final weight with props...208g....11g less than my friends warp. Not too bad. But...he has SS2204's (it's also 10g less than my orignal build of this frame.)


Can't wait to fly it. Gave it a quick bench test last night and it seems like the high throttle oscillations I was having are gone. But we'll have to get it in the air to say for sure.

 

[Twitchity]

Your quad should come in within a few grams of your friends Warp once you get some 2204's on there. Mine without props came in at 210g.

The way I got around the battery wires getting compressed by the top frame was to strip off more silicone from the wire than needed, feeding it through the hole, and then bend the remaining silicone insulated part of the wire flat against the frame. Use some cutters to remove the excess wire sticking through the hole and then solder it in place. It's still a tight fit, but the wires aren't being compressed by any means.

Your sat receiver placement had me confused and I thought you installed the 16mm bolts in the wrong holes Are you going to run the signal wires under the frame?

 

[jhitesma]

Your quad should come in within a few grams of your friends Warp once you get some 2204's on there. Mine without props came in at 210g.

Yeah I expect it will be very close. Just no clue when I'll have the budget to step up to 2204's. Not in a big rush either as these have plenty of power for now and with the KISS they're finally behaving well. It will happen eventually...but is a very low priority to upgrade to 2204's. (Unless I can get a major price break buying 10 at a time since I need them for the hex as well...)

The way I got around the battery wires getting compressed by the top frame was to strip off more silicone from the wire than needed, feeding it through the hole, and then bend the remaining silicone insulated part of the wire flat against the frame. Use some cutters to remove the excess wire sticking through the hole and then solder it in place. It's still a tight fit, but the wires aren't being compressed by any means.

Yeah there are a couple of ways to solve it. Being more careful with the soldering and having the wires bent before soldering would help as well. Was just something I wanted to point out for others who may build one of these to watch for on their own builds.

Your sat receiver placement had me confused and I thought you installed the 16mm bolts in the wrong holes Are you going to run the signal wires under the frame?

I checked those 16mm bolts about 15 times as I kept getting mixed up as to where they should go I may move the sat a bit still...then I'd be able to put the "hat" on...but I'd have to dye my own spacers for that or live with ugly white ones...so I'll probably just stick with it all exposed for now. I'm not really worried about damage as it seems most crashes that area just doesn't get much if any of an impact.

I may move the wires under the frame when I do a final cleanup. I'm kind of torn...going under the frame seems messy in it's own way since the wire has to go to one side and having two wires on one side and one on the other sets off my OCD I also don't much like the idea of running the signal wire right next to power wires. So I'm not sure just what I'll do yet. All I know for sure is next I'm flying it (Almost lunch time!)

 

[jhitesma]

Maiden went well:

Still a bit of oscillation at higher RPM's. Could be vibration from my less than new props, or the DYS motors, or the FC mounting, or I may just have my P too high still.

The extra stiffness is apparent, but it's not a huge change. More a matter of giving me more confidence than anything. Need to get failsafe working and get out where I have more room to really feel the difference.

Have the next two days off though so I should have some time to get up to the big field and do a bit of tuning and see how it does. Still have quite a few spare FC props and a few sets of HQ's. Going to have to stock up again soon though!

 

[jhitesma]

Hope you've all had as merry of a Christmas as I have! I may have decimated my hobby budget treating my daughter - but seeing her so happy and thankful today (I'd like her to be a bit more thankful...but we're working on that) brings me more joy than my hobbies so I have no regrets about it

My wife was afraid that the gifts this community has bestowed upon me would eclipse what she got me. And while there's no discounting that the gifts I've been given by the community are amazing and more than I feel I deserve she had nothing to worry about. She got me something that's been on my list for several years and I didn't think I'd actually get since it was more than I was expecting her to spend on me. Supposedly she found a sale but I'm not sure I believe her:



I don't drink coffee all THAT often...but when I do I'm kind of picky about the coffee and the way I make it (I actually roast my own beans - which probably won't shock those who know me). I've been wanting a siphon brewer since I first learned about them about 5 years ago so I'm super happy to finally have one. And while it may be too windy to fly today a few cups of great coffee were just what I needed to keep up with my daughter and the brew was better than I expected

(Please excuse the mug...I haven't got a FT mug yet...though I do have my $10 gift certificate from the FliteFest kickstarter and I see the mugs are $10....Hmm...I could use some more firewalls and servo horns as well....)


But she also didn't leave my hobby wishlist untouched:



Note the new 25"x36" cutting mat on my table (big enough to work on a full sheet of DTFB at once!) and the new DuBro balancer sitting on it I've been using a HK magnetic balancer but it's too small to check the props in all orientations so I haven't really been able to balance my prop hubs, and it's a pain to use and I don't trust that it's shaft is really all that accurate. I had requested the topflite magnetic balancer last year but I've heard a lot of good things about this DuBro and my LHS carries it while they don't carry the topflite - so I modified my list to allow for either. Pretty happy with it so far. First impression wasn't very good though. The machining on the threads of the vertical shafts and the nuts is really bad and I almost had to get out some taps and dies to get it assembled. Once assembled though I'm quite happy with it. It seems to be as low or lower friction as the magnetic balancer I've been using and has plenty of room for my props to fully rotate so I can finally balance the hubs as well. Found that props I had balanced on the magnetic still looked good on blade balance with this - but once I turned them with the blades up/down they almost all needed a bit of hub adjustment. I've never noticed a big difference from balancing the blades on my props in the past - but have never been able to do the hubs as well. So I'm curious to see if I notice a difference and if it helps with the higher RPM oscilations I'm getting on this build. (though more TPA may still be the best answer there...or just better motors.)


Side Note - My LHS who I had been developing a better opinion of due to their prices becoming more reasonable on many things (proto-x and proto-x parts they carry at the same prices as on-line retailers - effectively cheaper since there's no shipping. And no waiting since they're local.) But apparently when my wife and daughter went in to shop for me the owner asked what I was into, when they said I build my own quads he supposedly replied "We don't really support the local multirotor community because they don't support us since we don't stock the stuff they need".

Now I'm not business expert but it seems kind of silly to me to expect the local community to support you when you openly admit you don't stock anything they need! They pretty much only carry Horizon/Great Planes/DuBro and I suspect their vendor agreements prevent them from carrying stuff from other sources since the last time I was in there someone came in with a quad looking for 8" props. They went through every vendor they had and couldn't find any reverse rotation 8" props available and told him to try on-line (At least they suggested Altitude and HeadsUp or ordering "a case" from China since they won't be carrying any.) Their bread and butter business is cars/trucks and they have a small corner of plane stuff mostly geared towards the large fuel planes the local club flies on their nice paved runway, along with the usual Horizon stuff. Almost every time I'm in there there's someone looking for scratch building or multi stuff and leaving empty handed - and I often leave empty handed since they don't have what I need and don't seem interested in even looking for it (like when he all but laughed at me when I asked for reverse thread 3m nyloc nuts even though supposedly they're used on the axles of one of the buggy lines they carry.)

I'd love to support them more...but the way they seem to actively discourage guys like me from doing business with them sure makes it hard. Just found out last month that Hobby Lobby is building a store in town, fingers crossed they'll have better stock of some of the things I sometimes need on short notice and don't want to mail order. I'd rather give the little local guy my business...but if he doesn't want it, well, why should I go out of my way.

Bah, rant over. Back to the happy stuff! Girls will be waking up from their nap soon and I've still got some 8" props to balance for the knuckle. Even if I can't fly today I want to be ready for tomorrow in case the winds ease up

Gotta go clean up a few of my old rockets too, Santa left some rocket motors in my daughters stocking and she's super excited about flying them