Just want to ask the community if anyone from the build it your self backers has a successful build?
I’m sure we would all like to know how you achieved it and what and how you resolved the issues.
From reading the posts there seems to be a number of issues all over the place from parts fitting to broken servos.
Perhaps we can have a list of issues people have had and open an opportunity for the builders/users to resolve them one by one.
How about a trouble shooting section broken down to four distinct areas: Body issues, Servos issues, electronics issues, power source issues.
Mine is up and working. http://www.youtube.com/watch?v=KhcNxiPwj_g
Only “issue” was not high enough amp batteries. Got the powerex (amazon) batteries and that with the 1.7 firmware solved everything. Oh and had to order the batteries 2x as I forgot to use 5 and only got a 4 pack the first time. I still get some shaking on one or two of the servo’s (not sure my charger is up to the high miliamp batteries and will amazon a new one (man projects are money pits).
wait… ok now that I think about it…
Body issues (build):
On the build… I did not know about “flip” the piece over if the screw did not fit (makes sense in hindsight with using a laser cutter as the laser is refracted by the acrylic and would have a slightly larger hole on the backside). IMHO (though I have not done it) the drop of superglue in the hole before and after screwing it in sounds genius. I went to the local hobby shop (insert local name brand here) and got some super duper small nuts and bolts instead of the screws.
Servo:
sigh, I join the stripped gear club last night, probably bad calibration on my part and I noticed that the servo mount to the acrylic is one that the screws lifted on. I might tear apart and do the nut/bolt on all those joins. Maybe the additional torque on the servo as it was at an odd angle (screws came out) made it strip the gears?
Power:
I found a 5volt 5amp power supply at my local “good army” and tested with multi meter for proper voltage and amperage (got lucky this one floats between 4.99 and 5.01 volts) need to wire that up as a tether cable while I test new movements.
Electronic:
The 1.7 firmware is a must, I had the “spastic colon” mode aka curl aka seizure bot movements until that build. I run mac and windows and did not have problem with the pomoco on windows but did on mac until the 1.0 release of that. Much like any software/firmware latest greatest is the best bet.
I have not tried the bluetooth module yet. 
I did not order it but it came with it, thanks! 
This is my first hexabot build project hardware and what internet research I did before throwing my money to back the kickstarter I could see this was an entry level project. For the price the quality and build experience is more than what I “backed” (paid) for. Not trying to kiss ass or excuse some of the speed bumps in the process, just saying for getting a first production product this thing rocks.
Mine’s working. She does all the Pomoco moves just fine. Running the 1.7 firmware.
My issues are with bluetooth and the PING sensor. I can’t get bluetooth working even after changing the baud rate. And Hexy won’t power up with the PING sensor plugged in.
Once I get over those two hurdles, Hexy will be fully functional.
Edit got the PING sensor working. I was just plugging the wires in wrong. All that’s left is bluetooth.
I’ve got a fully functioning green Hexy- at least functioning enough to make me ready to tackle the next challenges. Ready to try authoring some new poises and gaits. All in all, I’m super impressed with this kit. Went together like a charm with lots of clever bits that seemed to solve themselves. Built it with my 8yr old son, who was just thrilled by the whole thing.
Awesome job, Arcbotics!
john
.
Excelent to see some working builds.
I asked that we start this stream because I’m having a number of issues.
Servo Issues
I had the dead or broken servo issue, ended up replacing them myself because I was in a shop and found compatable units there also if I broke them on install then Arcbotics shouldn’t have to replace them.
Body Issues
I found that the pivots at the body (horizontal leg pivot) are too inprecise and the servo housing is hitting the triangle shaped piece of the upper body and stopping the leg from fully moving. Have not resolved that yet.
Program Issues
In-spite of installing 1.7 and using the new PoMoCo the legs go all over the place. Zero.py sets sll the legs into zero position and I have done a calibration for zero, but reset.py curls some of the legs up and others down. Even with no description or example of what to expect I’m pretty sure that it is wrong. I have not gotten much past that.
Power Issues
It may be that all the problems with the program are attributed to inadequate power.
I have to find an alternate power source I expect but I don’t want to burn the circuit board out with a bad choice, I’m waiting to see what the users can recomend. There seems to be some headway here but nothing specific about providing power on the two power inputs and what is the best voltage or amperage to use.
Bugger- spoke too soon. I’ve now got three servos with spun out top idler gears, as others have also reported. All failed in exactly the same way, one right after another within the space of half an hour. Are we over torque-ing these things somehow during assembly? I don’t have the highest expectations that these servos will ever be completely bomb-proof, but I’ve run out of spares…
What’s the best solution for replacing these? Is there a source for replacement gears? Or a higher-spec servo to try instead?
john
.
We haven’t found a higher-spec’d servo that comes even comparably close to the price. If it wasn’t for these servos, Hexy would be more like $600-700.
One thing that helps keep the servos from over-torquing is doing the offsets in PoMoCo, see ‘Calibrating offests’:
github.com/ArcBotics/Hexy/wiki/PoMoCo
This makes sure all the legs are lined up properly, and you don’t have Hexy resting on one leg anymore than another. Imagine how you would feel if you were balancing on say, on foot’s heel all day.
We are, however, looking to get replacement gears for the servos. The included screwdriver with Hexy is already the correct size to take the servos apart. We talked to the manufacturer, and they do sell them, we’re just trying to find a price to order a couple thousand to sell in the store. I can imagine we’d be able to sell 10 packs in the store for $5 or so. We’d probably even start including them in future kits.
I have few servos not working and do want to replace them, when do you think the servos will be ready to sales in store?
Thanks!
Mine has 6 servos not working right now within 10 days after unboxed…
one of the legs pointing to sky forever like this…
I think it is impressive that you were able to find servos that worked at all in this price range- I was never able to figure out how to get any of my hexapod designs under that $6-700 price point. You were able to source carbon fiber gears at half the price. I don’t mind swapping in fresh gears every now and again when you’re able to get the supply chain worked out. I suppose we’ve figured out what Hexy’s “Achilles Heel” is now, right?
One thing to consider might be to up the spec for only the servos that take the most stress, leaving the rest at the more economical lower spec. I assume, for example, that the hip servos take less stress than those in the thigh. By swapping the thigh servos alone out for a metal geared replacement in the ~$10 range you might only increase the price of the kit ~$50 or so.
You’ve probably tried every possible servo under the sun at this point- would you be willing to share your experiences? What’s the “cadillac” servo for Hexy if price were not a consideration? And what is the absolute lowest end you would ever consider if price alone were the consideration?
john
.
Thinking about this further (coffee beginning to kick in…) why not design just the servo you want and have it manufactured to your spec? I don’t know how many Hexy kits there are in the wild now (are you over 1k kits sold yet? must be close to that at least by now…) but maybe there’s evidence of enough demand to interest a manufacturing partner in Asia. Failing that, maybe there’s another Kickstarter project out there… “a cheap but durable servo for building legged robots.”
edit: Come to think of it, why not simply source replacement gears that are metal? Maybe it is cheaper to field-upgrade failed servos?
john
.
The ‘cadallaic’ servos that a lot of high-end hexapod kits are the dynamixil series. Those start at $50/piece, though.
The reason we don’t get a custom servo manufactured is because even at 20k+ servos ordered, we’re still not anything close to the quantity where people would take us seriously enough to produce a comparable custom OEM servo.
We’re trying to find an appropriate metal gear servo that doesn’t trash the price, but that process is taking quite some time. In the mean time, it looks like replacement gears are a viable option. I just got word back from the servo manufacturer that I can get them cheap enough to sell 10 packs for $5 in the store.
Mine is working fine, three servos broke, but ArcBotics has sent me replacements, now I’m waiting for servos to arrive.
I had issues with PoMoCo, but the new version is working fine. Also had troubles with powering Hexy, but I solved using proper batteries.
I’ve been building robots for two years now, always wheeled robots, so this project gave me a chance to try out legged robots 
Overall, I’m extremely happy about my hexapod; considering the low price, it’s probably the best I could get 
Wow, there’s been a lot of activity during my absence!
Good to see improvements of Servotor32 + PoMoCo - I got mine to work as well;
but I just broke 2 servos while testing the “Move Forward” and “Move Backward” moves 
I read in a previous post that Arcbotics is sending them replacement servos? Can someone shed some details as to how that happened?
Got mine finished working via bluetooth from linux too:
youtu.be/FkfdVXA3MKE
Joe: Where and how do we go about purchasing these metal gear sets for the meanwhile?
No metal gears yet that fit Hexy. We’re looking at trying to find a supplier again, but last time we did this we didn’t have much luck.
As far as replacement gears, we have them quoted and should have them in stock in 1-2 weeks (presuming the Chinese manufacturers keep to their timelines, don’t hold your breath). We’re currently expecting them to sell for $5 per pack of 10 sets of gears.
[quote=“roboalchemist”]No metal gears yet that fit Hexy. We’re looking at trying to find a supplier again, but last time we did this we didn’t have much luck.
As far as replacement gears, we have them quoted and should have them in stock in 1-2 weeks (presuming the Chinese manufacturers keep to their timelines, don’t hold your breath). We’re currently expecting them to sell for $5 per pack of 10 sets of gears.[/quote]
Why don’t you come up with a clutch system to go between the servo and the horns (or replace the horns with a clutch) that disengages when there is too much torque, that way the give point would be the clutch and not the gears in the servos. Then you can just reset the clutch when this happens.
[quote=“neogeek”]Mine is up and working. http://www.youtube.com/watch?v=KhcNxiPwj_g
Only “issue” was not high enough amp batteries. Got the powerex (amazon) batteries and that with the 1.7 firmware solved everything. Oh and had to order the batteries 2x as I forgot to use 5 and only got a 4 pack the first time. I still get some shaking on one or two of the servo’s (not sure my charger is up to the high miliamp batteries and will amazon a new one (man projects are money pits).
wait… ok now that I think about it…
Body issues (build):
On the build… I did not know about “flip” the piece over if the screw did not fit (makes sense in hindsight with using a laser cutter as the laser is refracted by the acrylic and would have a slightly larger hole on the backside). IMHO (though I have not done it) the drop of superglue in the hole before and after screwing it in sounds genius. I went to the local hobby shop (insert local name brand here) and got some super duper small nuts and bolts instead of the screws.
Servo:
sigh, I join the stripped gear club last night, probably bad calibration on my part and I noticed that the servo mount to the acrylic is one that the screws lifted on. I might tear apart and do the nut/bolt on all those joins. Maybe the additional torque on the servo as it was at an odd angle (screws came out) made it strip the gears?
Power:
I found a 5volt 5amp power supply at my local “good army” and tested with multi meter for proper voltage and amperage (got lucky this one floats between 4.99 and 5.01 volts) need to wire that up as a tether cable while I test new movements.
Electronic:
The 1.7 firmware is a must, I had the “spastic colon” mode aka curl aka seizure bot movements until that build. I run mac and windows and did not have problem with the pomoco on windows but did on mac until the 1.0 release of that. Much like any software/firmware latest greatest is the best bet.
I have not tried the bluetooth module yet. I did not order it but it came with it, thanks!
This is my first hexabot build project hardware and what internet research I did before throwing my money to back the kickstarter I could see this was an entry level project. For the price the quality and build experience is more than what I “backed” (paid) for. Not trying to kiss ass or excuse some of the speed bumps in the process, just saying for getting a first production product this thing rocks.[/quote]
I have the blue Hexy too and the same leg shakes, are there others with the same leg that shakes if so it must be in the firmware that is causing this shake!
So what should a Hexy look like when it is “resting?” Should the legs be flat on the ground or slightly bent? Wish I could find a picture.
Leg standing vertical perpendicular to the ground, with feet flat on the ground.