I'm cheap. Really really cheap. I kind of chuckle when I hear Josh or Chad say they're cheap because compared to me they're almost spendthrifts. But I'm also stupid cheap to the point I'll do things that cost more because I did them so cheap. I try to learn from my mistakes though and like to help others keep from repeating my mistakes. So I try to share a lot as a way to help others be cheap without making the mistakes I make.
Just as a taste of my cheapness...my first article on FT was about making a replacement button to fix my $20 battery charger: http://flitetest.com/articles/charger-button-repair
What I left out of that article is I also fixed a missing rubber foot on it with just a drop of hot glue
Growing up I always dreamed of flying RC planes. I built a number of balsa and tissue planes but couldn't afford RC gear so I was stuck with rubber power...and none of them got more than a half dozen or so flights because I got tired of spending more time repairing them than "flying" them. Then a few years ago I found out just how affordable the hobby had gotten and picked myself up a micro heli. I had fun with it but quickly learned that my house was too small to have much fun flying in and it was rare for me to find a day with light enough winds I could fly it outside. Thankfully just as I started to loose interest due to that I found Flite Test about the same time they first released their swappable nutball plan. Since then I've been having a blast building and flying cheap foam planes.
But I've really wanted a quad. Before I built my first foamie, before I bought that first heli...I wanted a quad. I did pick up a Syma X1 last year for about $50 and had a lot of fun with it - but it's just too small and too limited. I really want a "real" quad with a controller I can hack and parts I can easily and cheaply replace when they break. I just couldn't justify more than $100 in my budget and couldn't find a way to make one happen for that little. Now a few years later I have more parts on hand, more experience, and I think I can finally pull it off.
I should be working on it right now...but I feel like sharing more than building at this moment and I feel bad about hijacking a number of other threads talking about my in-progress project.
If I'm done I plan on writing up an article for the main site whether I'm successful or not. But for now I figured I should start this thread to share my progress and give others a chance to give me any advice (not that I'm likely to follow it even if I do appreciate it!)
I started the week before Halloween. After a stressful Saturday I did some browsing on Hobby King and started building an order. I had missed out on my second chance at grabbing a KK2.0 board that week when they were already back ordered again by the time I saw the e-mail announcing they were available. So I started reading up on the MultiWii. I had never had much interest in the MW since I hadn't heard much about it and the idea of taking parts from Wii controllers just seemed like it would cost more and give worse results than just buying a KK board. But as I read up on the MW I quickly learned that most of the MW boards have advanced to better sensors and don't actually use Wii parts anymore. But I also learned that the whole thing is based off Arduino and I just happened to have an unused Arduino Mega sitting within reach on my desk and a couple of wii controllers that haven't been used in months and I started thinking.
So I wired up the arduino and my Wii Motion Plus, loaded the MultiWii firmware...and within an hour had what seemed to be a functional (though not flight ready) flight controller sitting on my desk.
http://www.youtube.com/watch?v=v4I_DGs7rSk
Cutting the cost of a flight controller out of my order suddenly made it very viable to pull off a <$100 quad based on the FT RotorBones Knuckles with Blue Wonders......
I bit the bullet and ordered:
4 - 1300kv 24g motors $32.38
4 - 10A multistar ESC's $24.96 (These may have been a mistake...we'll see...10A is cutting it kind of close and it turns out that while they are supposedly flashable with SimonK they don't have pads to make it easy. I've read mixed reviews about their suitability for quads but the price was hard to pass up and if it comes down to it I'll break out my SMT iron and a magnifier and reflash them or use them for something else at some point.)
1 - XT60 to 4x3.5mm bullet breakout cable $2.94 (this WAS a mistake, the HK website listed the 10A multistars as having 3.5mm bullet connectors but they actually have 2mm. But the breakout cables with 2mm bullets only have JST connectors and since I plan on using my 1500 or 2200mah packs which have XT60's on them those don't help me much...so I'm going to end up doing my own thing instead, will save this for a bigger quad project in the future.)
2 - Sets of 8045 quad props $5.18 (I know I'll break props...probably should have ordered more than 2 sets...and really kicking myself for ordered both sets the same color...guess what I'm going to order this weekend )
1 - 8ch 9x RX $8.99 (I had planned on using one of my existing RX's...but my order came in low enough I was able to splurge..good thing too because the next day I lost one of my RX's and no longer had a spare!)
1 - MultiWii Bluetooth module $7.49 (this was a bit of a risk since I wasn't sure if it would work with my homebrewed controller...but I didn't see any reason it shouldn't and it was cheap enough to risk. Not to mention the idea of being able to program the controller from my phone was one of the things that REALLY impressed me about the MultiWii. Turns out it was worth the risk as it took me all of 5 minutes to set it up and it seems to work great!)
Even with shipping my order was under budget enough I was able to toss in a few spare props for some of my other planes and still keep the total under $95. Woo Hoo!
Of course then I realized I forgot wires to connect my RX to the controller. And I forgot prop adapters. And I started reading more about the MultiWii.....
So before my parts even arrived I had ordered off ebay:
1 - BMP085 baro sensor breakout board - $2.95 shipped (Still waiting on delivery, by mail from Hong Kong...I'm not holding my breath.)
1 - HMC5883L 3 axis magnetometer compass - $2.31 shipped (Still waiting as well...but like the baro I'm not in a hurry since it's not needed and is just for me to experiment with after I have this thing flying.)
1 - Arduino Pro Mini - $4.98 shipped (Figured for <$5 it would be nice to have on hand because I don't really want to devote my mega to this...though the more I read about MultiWii the more I start to think about picking up another Mega and sticking with the Mega since it can also run MegaPirateNG and ArduPilot giving me even more options down the road. But the Pro Mini will be nice to keep the weight as low as possible on the knuckle quad I figure and the price is right.)
I also ordered some male/male 10cm servo extensions. Though I messed up and misread the first listing I bought and didn't realized that unlike most sellers their price was per cable and not per pack of 10 So I ended up odering another pack of 10 from a second seller. ($5.80 for the 2 cables...$4.15 for the pack of 10 - still smacking myself over that especially since the seller I bought the 2 cables from signed me up on their spam list )
And I ended up placing one more HK order from their US warehouse for:
4 - 3mm prop adapter $4.72
2 - 10pc 2mm bullet connectors $4.86
As of this morning USPS was saying that order wouldn't be here until Tuesday so I wrote off my chances of building a quad this weekend....but while working on building a play house for my daughter this morning the mailman showed up and had 2 packages for me! My 10 pack of servo extensions came in and so did my HK order! Woo Hoo! I've got all the parts I need to build this thing!
So next trip to the hardware store for bits for the playhouse I also picked up a 100 pack of 6-32 bolts and nuts (none of the hardware stores in town had nylocs in any size small enough so I'm going to have to bust out the loctite for now ) I alrady picked up a few 1/2" square dowels on an earlier trip to the store. (Nuts, bolts and washers were about $10 for 100 which should be enough for a few quads...the dowels were about $1.20 each and I used 1 and a half to cut my frame.)
I'd love to take advantage of the ongoing 15% off FT sale...but well...this playhouse project is seriously depleting my hobby fund (but it's worth it because she's already having a blast with it even though it's just a frame at this point) and with all the other parts on hand I don't want to wait for shipping.
So last night I cut up some dowels and printed out the knuckle parts plans and this evening I started cutting them out...more on that in a moment.
When my first HK order came in earlier this week I promptly hooked up the BT module and as I already mentioned within 5 minutes I had it working wonderfully! So I went ahead and gutted my motion plus with the 2 servo connectors that had come in hooked up two more channels on my breadboarded controller:
Seems to be working great! I still don't have yaw hooked up so I can't actually arm it yet...but on both my phone and the PC based config app things seem to be responding correctly!
With all of my parts on hand I laid everything out to get a feel for it all:
Like I said I'm kicking myself for only ordering one color of prop...I do have some CW rotation 8045 props on hand of the same design so I may put one of those on for now and fly it plus style until I can get some other props...
Now the real reason I'm writing this up instead of building right now...I needed to take a break from making my knuckles.
I started by using some spray tack adhesive (the same Krylon spray I use to stick plans to redi-boad when building FT foamies) to attach the printed plans to a piece of ply I had laying around from when I made my own firewalls before getting hooked on the FT Firewalls. I hate this ply...it's the standard Monogram Revel ply from Michaels and it's horrible. Impossible to get clean cuts because it flakes so bad. Even when I cut it while sandwiched between other bits of wood or drill it on top of some scrap wood it splinters like crazy. But it's what I have on hand and it should be ok for now.
With the plans glued on I grabbed my center punch and started marking the holes:
Then got out my 9/16" brad point drill (I LOVE brad point drills - so nice for drilling accurately!):
And drilling on top of some scrap to minimize (but due to the lousy ply not eliminate) tear out I proceeded to make all the holes in my knuckles:
With all the holes cut it was time to separate the knuckles...but how? I have a nice old 1940's Delta bandsaw that a friend gave me for free because it was a rusty mess on the of his house. I disassembled it, cleaned it, rebuilt it and it works...but I haven't found a new tension spring for it and as a result it tends to break blades and I'm out of silver solder to repair the blades right now. Plus it's not the best for straight accurate cuts. My table saw is overkill and has way too big of a kerf. My xacto razor saw has a nice thin (.015") kerf and would do it...but it's time to replace that blade as it has almost no teeth left so it would take forever to use it.
I decided to do it the hard way. And this is one of those points where I effectively spend more to do something the cheap way. $12 to order a set of knuckles from FT would be a lot cheaper than the time I'm spending cutting these by hand with this method (WAY cheaper if I was to charge myself the hourly rate I charge clients when doing my day job!) I got out a steel straight edge, some clamps, and one of my utility knives along with some new blades:
A half hour later I had them cut out enough to test how accurate they are:
Looks pretty good! All of the bolts went it with almost no resistance except for the last two which needed just a bit of twisting from my fingers to get them through one or two tight spots.
And now is when I really wish my bandsaw had a blade in it (And no I can't just buy one locally...can't even get one on-line easily as not many people stock the length of blade needed for a 70 year old 10" bandsaw. Buying slightly oversized blades, cutting them and re-welding them is the only way I've found. Did I mention I'm "stupid cheap"? ) The bandsaw would let me quickly and easily finish these last four cuts in a few seconds.
Instead I just spent about 40 minutes typing this up while giving myself a break before making the last four cuts by tediously going over the line over and over again with my utility knife.
Oh well...here goes. Doubt I'll have any more updates tonight. Once these are cut I'll be drilling my frame and assembling it but my wife is due home from work in half an hour and I'll have to cook dinner so I doubt I'll have time to get any photos before we crash out for the night!
Tomorrow priority #1 is getting the floor and walls finished on my daughters playhouse...but my wife has the day off so I should have time for both that and getting more done on this quad!
Would love to get it in the air tomorrow but I don't think that's realistic at this point. Once the frame is built I still have to figure out what I'm going to do for the center (I'm out of ply and the knuckles center is nice but overkill for what I'm doing), get the motors mounted, solder bullets onto the motors, wire up the ESC's, finish cleaning up the connection between the WMP and the Arduino, make a power loom, mount it all.....
To be honest I'll be happy if I can power it up without props by mid-week so stay tuned!
Just as a taste of my cheapness...my first article on FT was about making a replacement button to fix my $20 battery charger: http://flitetest.com/articles/charger-button-repair
What I left out of that article is I also fixed a missing rubber foot on it with just a drop of hot glue
Growing up I always dreamed of flying RC planes. I built a number of balsa and tissue planes but couldn't afford RC gear so I was stuck with rubber power...and none of them got more than a half dozen or so flights because I got tired of spending more time repairing them than "flying" them. Then a few years ago I found out just how affordable the hobby had gotten and picked myself up a micro heli. I had fun with it but quickly learned that my house was too small to have much fun flying in and it was rare for me to find a day with light enough winds I could fly it outside. Thankfully just as I started to loose interest due to that I found Flite Test about the same time they first released their swappable nutball plan. Since then I've been having a blast building and flying cheap foam planes.
But I've really wanted a quad. Before I built my first foamie, before I bought that first heli...I wanted a quad. I did pick up a Syma X1 last year for about $50 and had a lot of fun with it - but it's just too small and too limited. I really want a "real" quad with a controller I can hack and parts I can easily and cheaply replace when they break. I just couldn't justify more than $100 in my budget and couldn't find a way to make one happen for that little. Now a few years later I have more parts on hand, more experience, and I think I can finally pull it off.
I should be working on it right now...but I feel like sharing more than building at this moment and I feel bad about hijacking a number of other threads talking about my in-progress project.
If I'm done I plan on writing up an article for the main site whether I'm successful or not. But for now I figured I should start this thread to share my progress and give others a chance to give me any advice (not that I'm likely to follow it even if I do appreciate it!)
I started the week before Halloween. After a stressful Saturday I did some browsing on Hobby King and started building an order. I had missed out on my second chance at grabbing a KK2.0 board that week when they were already back ordered again by the time I saw the e-mail announcing they were available. So I started reading up on the MultiWii. I had never had much interest in the MW since I hadn't heard much about it and the idea of taking parts from Wii controllers just seemed like it would cost more and give worse results than just buying a KK board. But as I read up on the MW I quickly learned that most of the MW boards have advanced to better sensors and don't actually use Wii parts anymore. But I also learned that the whole thing is based off Arduino and I just happened to have an unused Arduino Mega sitting within reach on my desk and a couple of wii controllers that haven't been used in months and I started thinking.
So I wired up the arduino and my Wii Motion Plus, loaded the MultiWii firmware...and within an hour had what seemed to be a functional (though not flight ready) flight controller sitting on my desk.
http://www.youtube.com/watch?v=v4I_DGs7rSk
Cutting the cost of a flight controller out of my order suddenly made it very viable to pull off a <$100 quad based on the FT RotorBones Knuckles with Blue Wonders......
I bit the bullet and ordered:
4 - 1300kv 24g motors $32.38
4 - 10A multistar ESC's $24.96 (These may have been a mistake...we'll see...10A is cutting it kind of close and it turns out that while they are supposedly flashable with SimonK they don't have pads to make it easy. I've read mixed reviews about their suitability for quads but the price was hard to pass up and if it comes down to it I'll break out my SMT iron and a magnifier and reflash them or use them for something else at some point.)
1 - XT60 to 4x3.5mm bullet breakout cable $2.94 (this WAS a mistake, the HK website listed the 10A multistars as having 3.5mm bullet connectors but they actually have 2mm. But the breakout cables with 2mm bullets only have JST connectors and since I plan on using my 1500 or 2200mah packs which have XT60's on them those don't help me much...so I'm going to end up doing my own thing instead, will save this for a bigger quad project in the future.)
2 - Sets of 8045 quad props $5.18 (I know I'll break props...probably should have ordered more than 2 sets...and really kicking myself for ordered both sets the same color...guess what I'm going to order this weekend )
1 - 8ch 9x RX $8.99 (I had planned on using one of my existing RX's...but my order came in low enough I was able to splurge..good thing too because the next day I lost one of my RX's and no longer had a spare!)
1 - MultiWii Bluetooth module $7.49 (this was a bit of a risk since I wasn't sure if it would work with my homebrewed controller...but I didn't see any reason it shouldn't and it was cheap enough to risk. Not to mention the idea of being able to program the controller from my phone was one of the things that REALLY impressed me about the MultiWii. Turns out it was worth the risk as it took me all of 5 minutes to set it up and it seems to work great!)
Even with shipping my order was under budget enough I was able to toss in a few spare props for some of my other planes and still keep the total under $95. Woo Hoo!
Of course then I realized I forgot wires to connect my RX to the controller. And I forgot prop adapters. And I started reading more about the MultiWii.....
So before my parts even arrived I had ordered off ebay:
1 - BMP085 baro sensor breakout board - $2.95 shipped (Still waiting on delivery, by mail from Hong Kong...I'm not holding my breath.)
1 - HMC5883L 3 axis magnetometer compass - $2.31 shipped (Still waiting as well...but like the baro I'm not in a hurry since it's not needed and is just for me to experiment with after I have this thing flying.)
1 - Arduino Pro Mini - $4.98 shipped (Figured for <$5 it would be nice to have on hand because I don't really want to devote my mega to this...though the more I read about MultiWii the more I start to think about picking up another Mega and sticking with the Mega since it can also run MegaPirateNG and ArduPilot giving me even more options down the road. But the Pro Mini will be nice to keep the weight as low as possible on the knuckle quad I figure and the price is right.)
I also ordered some male/male 10cm servo extensions. Though I messed up and misread the first listing I bought and didn't realized that unlike most sellers their price was per cable and not per pack of 10 So I ended up odering another pack of 10 from a second seller. ($5.80 for the 2 cables...$4.15 for the pack of 10 - still smacking myself over that especially since the seller I bought the 2 cables from signed me up on their spam list )
And I ended up placing one more HK order from their US warehouse for:
4 - 3mm prop adapter $4.72
2 - 10pc 2mm bullet connectors $4.86
As of this morning USPS was saying that order wouldn't be here until Tuesday so I wrote off my chances of building a quad this weekend....but while working on building a play house for my daughter this morning the mailman showed up and had 2 packages for me! My 10 pack of servo extensions came in and so did my HK order! Woo Hoo! I've got all the parts I need to build this thing!
So next trip to the hardware store for bits for the playhouse I also picked up a 100 pack of 6-32 bolts and nuts (none of the hardware stores in town had nylocs in any size small enough so I'm going to have to bust out the loctite for now ) I alrady picked up a few 1/2" square dowels on an earlier trip to the store. (Nuts, bolts and washers were about $10 for 100 which should be enough for a few quads...the dowels were about $1.20 each and I used 1 and a half to cut my frame.)
I'd love to take advantage of the ongoing 15% off FT sale...but well...this playhouse project is seriously depleting my hobby fund (but it's worth it because she's already having a blast with it even though it's just a frame at this point) and with all the other parts on hand I don't want to wait for shipping.
So last night I cut up some dowels and printed out the knuckle parts plans and this evening I started cutting them out...more on that in a moment.
When my first HK order came in earlier this week I promptly hooked up the BT module and as I already mentioned within 5 minutes I had it working wonderfully! So I went ahead and gutted my motion plus with the 2 servo connectors that had come in hooked up two more channels on my breadboarded controller:
Seems to be working great! I still don't have yaw hooked up so I can't actually arm it yet...but on both my phone and the PC based config app things seem to be responding correctly!
With all of my parts on hand I laid everything out to get a feel for it all:
Like I said I'm kicking myself for only ordering one color of prop...I do have some CW rotation 8045 props on hand of the same design so I may put one of those on for now and fly it plus style until I can get some other props...
Now the real reason I'm writing this up instead of building right now...I needed to take a break from making my knuckles.
I started by using some spray tack adhesive (the same Krylon spray I use to stick plans to redi-boad when building FT foamies) to attach the printed plans to a piece of ply I had laying around from when I made my own firewalls before getting hooked on the FT Firewalls. I hate this ply...it's the standard Monogram Revel ply from Michaels and it's horrible. Impossible to get clean cuts because it flakes so bad. Even when I cut it while sandwiched between other bits of wood or drill it on top of some scrap wood it splinters like crazy. But it's what I have on hand and it should be ok for now.
With the plans glued on I grabbed my center punch and started marking the holes:
Then got out my 9/16" brad point drill (I LOVE brad point drills - so nice for drilling accurately!):
And drilling on top of some scrap to minimize (but due to the lousy ply not eliminate) tear out I proceeded to make all the holes in my knuckles:
With all the holes cut it was time to separate the knuckles...but how? I have a nice old 1940's Delta bandsaw that a friend gave me for free because it was a rusty mess on the of his house. I disassembled it, cleaned it, rebuilt it and it works...but I haven't found a new tension spring for it and as a result it tends to break blades and I'm out of silver solder to repair the blades right now. Plus it's not the best for straight accurate cuts. My table saw is overkill and has way too big of a kerf. My xacto razor saw has a nice thin (.015") kerf and would do it...but it's time to replace that blade as it has almost no teeth left so it would take forever to use it.
I decided to do it the hard way. And this is one of those points where I effectively spend more to do something the cheap way. $12 to order a set of knuckles from FT would be a lot cheaper than the time I'm spending cutting these by hand with this method (WAY cheaper if I was to charge myself the hourly rate I charge clients when doing my day job!) I got out a steel straight edge, some clamps, and one of my utility knives along with some new blades:
A half hour later I had them cut out enough to test how accurate they are:
Looks pretty good! All of the bolts went it with almost no resistance except for the last two which needed just a bit of twisting from my fingers to get them through one or two tight spots.
And now is when I really wish my bandsaw had a blade in it (And no I can't just buy one locally...can't even get one on-line easily as not many people stock the length of blade needed for a 70 year old 10" bandsaw. Buying slightly oversized blades, cutting them and re-welding them is the only way I've found. Did I mention I'm "stupid cheap"? ) The bandsaw would let me quickly and easily finish these last four cuts in a few seconds.
Instead I just spent about 40 minutes typing this up while giving myself a break before making the last four cuts by tediously going over the line over and over again with my utility knife.
Oh well...here goes. Doubt I'll have any more updates tonight. Once these are cut I'll be drilling my frame and assembling it but my wife is due home from work in half an hour and I'll have to cook dinner so I doubt I'll have time to get any photos before we crash out for the night!
Tomorrow priority #1 is getting the floor and walls finished on my daughters playhouse...but my wife has the day off so I should have time for both that and getting more done on this quad!
Would love to get it in the air tomorrow but I don't think that's realistic at this point. Once the frame is built I still have to figure out what I'm going to do for the center (I'm out of ply and the knuckles center is nice but overkill for what I'm doing), get the motors mounted, solder bullets onto the motors, wire up the ESC's, finish cleaning up the connection between the WMP and the Arduino, make a power loom, mount it all.....
To be honest I'll be happy if I can power it up without props by mid-week so stay tuned!
Last edited: