TBS Discovery alternative arm setup
- Thread starter RTRyder
- Start date
Zackthrills
Member
Ya I think he has a great idea and I hope that I can get my hands on some to try and test out or at least get the file for the maker bot so that way I can pay someone to make it
Yeah, so it appears!
So here's what I'm going to do. I only have enough materials on hand for another 2, maybe three sets at the moment, one of those is going on my other Discovery with Naza controller, another will find its way onto a set of F450 frame plates. Keep in mind other than some LOS limited test flights I haven't actually put this setup through any kind of thorough test, yet...
That will hopefully change this weekend, weather permitting. Even though I've been through a number of design changes to make everything as solid as possible there's always the chance that something still needs to be tweaked. I won't know for sure until I get to run a half dozen or so batteries on one and then give it a good close examination to see how the various bits hold up.
If everything is good I'll order in the materials to make a few more sets, it's mainly the aluminum tubing and nuts and bolts that I don't have enough of on hand. Once I have all that I'll make up a few sets for beta testing, based on the requests already made I'll parcel out however many I can make for the cost of materials plus shipping and see where it goes from there.
Ken
Ok, update time. I finally got the opportunity to field test the Disco with the new arms. BIG difference, as expected much more nimble and very smooth, it flew completely different than it did with the DJI girder arms, even had the opportunity for a bit of durability testing when it apparently threw a prop at approximately 150 feet over the woods at the edge of the field!
As you can see one motor has nothing left of the prop and that's how I found it on the ground, pieces not to be found anywhere nearby so I have to assume that was the cause of the crash as I can find nothing else wrong with the flight systems. Fortunately I always record the downlink video to a DVR cables off my goggles, without that the Disco might well still be sitting out in the woods. I was able to put the memory card in my laptop and fast forward to the last clear frame the pilot cam saw before it hit ground, that got me close enough that it only took another 30 minutes of searching to find the crash site. It came in hard, I thought the GoPro had been shed on the way down as I couldn't see it anywhere but then realized it was buried a couple inches down in the dirt where the was obvious sign of impact. When I played the video back there's about 6 minutes and 15 seconds of flight and crash followed by a little over 30 minutes of blackness while buried in the dirt.
A post crash analysis shows the arm mounting blocks and motor mounts absorbed the forces of impact, other than a slightly bent standoff there is zero damage to he Discovery frame plates. I completely disassembled the Disco, and found nothing other than the broken mounts, props and one motor that had the wires ripped out of the stator. The alloy tubes were not damaged either, a check with a straight edge shows them to be just as straight as when they were installed. Since the motor mounts proved to be less durable than desired I took the opportunity to rethink the design to make them stronger, the first batch of the new design are showing an increase of a least 3 to 4X the force needed to break them vs the old design. All new parts have been made and the Discovery is in the process of being reassembled, more flight testing to come.
If I can find the time to edit down the video I recorded on the flights before the crash occurred I'll post it up to Y/T.
Ken
As you can see one motor has nothing left of the prop and that's how I found it on the ground, pieces not to be found anywhere nearby so I have to assume that was the cause of the crash as I can find nothing else wrong with the flight systems. Fortunately I always record the downlink video to a DVR cables off my goggles, without that the Disco might well still be sitting out in the woods. I was able to put the memory card in my laptop and fast forward to the last clear frame the pilot cam saw before it hit ground, that got me close enough that it only took another 30 minutes of searching to find the crash site. It came in hard, I thought the GoPro had been shed on the way down as I couldn't see it anywhere but then realized it was buried a couple inches down in the dirt where the was obvious sign of impact. When I played the video back there's about 6 minutes and 15 seconds of flight and crash followed by a little over 30 minutes of blackness while buried in the dirt.
A post crash analysis shows the arm mounting blocks and motor mounts absorbed the forces of impact, other than a slightly bent standoff there is zero damage to he Discovery frame plates. I completely disassembled the Disco, and found nothing other than the broken mounts, props and one motor that had the wires ripped out of the stator. The alloy tubes were not damaged either, a check with a straight edge shows them to be just as straight as when they were installed. Since the motor mounts proved to be less durable than desired I took the opportunity to rethink the design to make them stronger, the first batch of the new design are showing an increase of a least 3 to 4X the force needed to break them vs the old design. All new parts have been made and the Discovery is in the process of being reassembled, more flight testing to come.
If I can find the time to edit down the video I recorded on the flights before the crash occurred I'll post it up to Y/T.
Ken
I didn't even try the GoPro to see if it still worked until today, turns out it works fine. I finished the rebuild about 11:15 PM last night, went to the field this AM and got 5 flights in on the rebuilt Discovery mainly doing PID tuning. Quite windy from the time I got there to the time I left but did manage to give the Discovery a good workout, I'll post video later.
Ken
Zackthrills
Member
Awsome ken I look forward to seeing what you got. I do shot of high altitude flying and enjoy.
This is one of the last flights I did yesterday, I pruned some of the dead air off the beginning and end but otherwise is as-recorded. In the rebuild process I swapped out the DJI motors for a set of iPower 2217 and the generic ESCs for a set of all nFET HK Blue series 30 amp with SimonK firmware. Part of what I wanted to accomplish yesterday was to get the Multiwii PIDs dialed in for the new motor/ESC combo but with the wind blowing as it was all I could do was get close, too hard to tell what oscillation is caused by PID settings and what is from the wind pushing it around in FF. Have to wait for a calmer day to get it dialed in better but overall it's almost back to the level of stability it had pre-crashwith the DJI motors. Definitely will outfly my Naza powered Disco with the stock DJI arms...
Ken
Ken
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Testing and redesign done...
With 7 inch tubes they're about an inch longer than stock DJI arms, I can make them any length within reason by just cutting longer or shorter tubes. For larger motors I have a scaled up motor mount that can take 36mm already done and can make virtually any size as long as I have the necessary dimensions...
Can do different colors too, I like the dayglow orange on some parts as it makes it easier to spot in the grass or woods if it happens to have an unintentional landing, DAMHIK...
The landing gear not only holds it up off the ground, it offers a handy place to mount a second battery or the main battery if you want to use the internal bay for electronics and smaller batts for the FPV gear...
Basic black with landing gear, $85 US for the full set, custom lengths and colors $100 US for the full set.
Ken
With 7 inch tubes they're about an inch longer than stock DJI arms, I can make them any length within reason by just cutting longer or shorter tubes. For larger motors I have a scaled up motor mount that can take 36mm already done and can make virtually any size as long as I have the necessary dimensions...
Can do different colors too, I like the dayglow orange on some parts as it makes it easier to spot in the grass or woods if it happens to have an unintentional landing, DAMHIK...
The landing gear not only holds it up off the ground, it offers a handy place to mount a second battery or the main battery if you want to use the internal bay for electronics and smaller batts for the FPV gear...
Basic black with landing gear, $85 US for the full set, custom lengths and colors $100 US for the full set.
Ken
SMP
Member
Hi Ken,
Wondered if we might be able to do two sets in black - Running Tiger 2814/750s w 10" Graupners on stock arms for the 1st set and looking to run the same Tigers w 14" (and 12") props. Not sure how much further out that arm set would need to be. Love what you've got going with the landing gear and battery bay. Brilliant mate!!
Just drop me a line at your convenience to steven@sequinminer.com and we'll sort out the details??
Wondered if we might be able to do two sets in black - Running Tiger 2814/750s w 10" Graupners on stock arms for the 1st set and looking to run the same Tigers w 14" (and 12") props. Not sure how much further out that arm set would need to be. Love what you've got going with the landing gear and battery bay. Brilliant mate!!
Just drop me a line at your convenience to steven@sequinminer.com and we'll sort out the details??
This project kind of fell by the wayside due to dealing with some family issues that kept me otherwise occupied, I've recently started back to working on it now that things are resolved on the home front. I did a complete rework of every part and have now been flying a pair of Discovery fully kitted with 16mm C/F tube arms, inboard ESCs, and better landing gear plus underslung battery carrier. The big bird has 320mm long arms and currently uses 12 inch props spun by 390kv motors, getting a solid 20 minutes of FPV flight on 6S 4000 packs...
The little Disco has more or less standard length arms but with the exception of a slightly smaller motor mount everything else is the same as the big bird. Both are using Naza Lite flight controllers and the little one flys far better than the same setup with DJI girder arms and a bunch of wires and ESCs hanging out in the breeze, this is before I got it fully built...
On both of these, all parts are done in ABS, I'm currently assembling one more using a Paris Sirius Air flight controller and all parts done in PLA, otherwise exactly the same as the small Disco now flying with the Naza.
Had both out at the field yesterday and got a few decent test flights in before passing rain showers put an end to the flying for the day. The big Disco narrowly avoided a major crash when one of the ESCs literally burnt up as it was making a low and slow turn in preparation for landing. Amazing how much smoke burning SMD components and shrink wrap can produce
#3 motor stopped spinning and it fell maybe 10 feet with no damage other than the burnt ESC and a little bit of charring under the deck, I've got a spare set of ESCs still in the packaging that I'll be swapping over to before the weekend. I also managed to stuff the smaller Disco from a much higher altitude when I mistakenly put a discharged battery on and then took off for what I thought was going to be a 10 to 12 minute flight which in reality lasted about 3 minutes before there wasn't enough juice left to keep it in the air. Total damage was a couple broken landing legs and props and one cracked motor mount, not bad for a quick uncontrolled descent from 50 feet or more! So I'm happy that the new designs and parts are proving to be quite durable, more so than the old designs.
I'll be posting some video taken with the new frame setups as soon as I get a spare few minutes to upload it.
Ken
The little Disco has more or less standard length arms but with the exception of a slightly smaller motor mount everything else is the same as the big bird. Both are using Naza Lite flight controllers and the little one flys far better than the same setup with DJI girder arms and a bunch of wires and ESCs hanging out in the breeze, this is before I got it fully built...
On both of these, all parts are done in ABS, I'm currently assembling one more using a Paris Sirius Air flight controller and all parts done in PLA, otherwise exactly the same as the small Disco now flying with the Naza.
Had both out at the field yesterday and got a few decent test flights in before passing rain showers put an end to the flying for the day. The big Disco narrowly avoided a major crash when one of the ESCs literally burnt up as it was making a low and slow turn in preparation for landing. Amazing how much smoke burning SMD components and shrink wrap can produce
#3 motor stopped spinning and it fell maybe 10 feet with no damage other than the burnt ESC and a little bit of charring under the deck, I've got a spare set of ESCs still in the packaging that I'll be swapping over to before the weekend. I also managed to stuff the smaller Disco from a much higher altitude when I mistakenly put a discharged battery on and then took off for what I thought was going to be a 10 to 12 minute flight which in reality lasted about 3 minutes before there wasn't enough juice left to keep it in the air. Total damage was a couple broken landing legs and props and one cracked motor mount, not bad for a quick uncontrolled descent from 50 feet or more! So I'm happy that the new designs and parts are proving to be quite durable, more so than the old designs.
I'll be posting some video taken with the new frame setups as soon as I get a spare few minutes to upload it.
Ken
While not a Disco frame, I did a proof of concept Y6 design for a client and the coax motor mounts would be easy to adapt to one of the frames I have setup with tube arms. Not sure where all the extra bits of wire and 4 more ESCs would go but it certainly is possible to build an X8 Disco although I think the Y6 is more useful...
Ken
Great stuff Ken, thanks for the reply.
I like what you've done with the inboard esc mounting and the esc tube mount on the y6!
These upgrades turns all those cheap/readily available dji style frame plates into really flexible machines!
are you using f550 frame plates on the y6?
anychance of sharing the STLs? I'd love to print a set.. Or are you looking to sell them commercially?
I like what you've done with the inboard esc mounting and the esc tube mount on the y6!
These upgrades turns all those cheap/readily available dji style frame plates into really flexible machines!
are you using f550 frame plates on the y6?
anychance of sharing the STLs? I'd love to print a set.. Or are you looking to sell them commercially?
The Y6 is a full 3D printed frame with the exception of the alloy arm tubes, the center plates JUST barely fit on my 8 x 8 build platform. Some of the stuff I can give out the STL files for, although there's quite a bit I can't because it was done for paying customers and while I retain the design files they have the rights to reproduce them. I can make a set or two for my own use in that case but not give out the files.
I was thinking of doing the Discovery parts commercially, not sure if it's worth the time and investment to do it properly meaning setting up an LLC and getting product liability insurance plus the headaches of mass producing the parts along with shipping, support, etc, etc...
If I weren't so well paid at my day job it would be an easier decision, but as long as I'm doing what I do now and making the kind of $ that I do, I don't need to sell parts to supplement my income, my wife would only find more ways to spend it anyway...
Ken