Can the CH3-R kit be a template for building a larger hexapod? What would change if I decided to make my own brackets and use larger servo gearboxes to build a hex twice the size or four times the size of the kit? Can the existing programming be used? I would think the programs would all apply except for the speed. As the much larger servo/geraboxes are substantially slower, the programs would need to be changed to reflect that. Or are there a lot of other issues involved I am not aware of?
The IK math is metric and there is limit of 255mm on the length of the leg segments. That’s the only limitation that I know of.
What is IK math?
as far as making the chassis bigger or even smaller it shouldnt effect the motion to much. maybe a few tweeks in the program to expand the extra movement within the walk, but is not crittical.
has a whole i would have thought that “up sizing” the joint, brackets and servos wouldnt course massive problems for the overall algurithum of a gait!
i could be wrong…
… i say try it as you will only learn my making mistakes!
a guess you plan on using the BotBoard and SS32? shouldnt pose a problem but like i said… Try it! We all look forward to seeing it!
Yes I plan on using a Bot Board and the SSC-32. If the model is proportionately larger, shouldn’t all the angles be identical. The overall distance a leg travels would be the further, but if a CH3-R leg movement is 10 mm, and the scale is 1:2, wouldn’t the larger model throw the foot 20 mm? It may take four times as long due to the decrease in servo speeds. But it should mimic the actions of the smaller hex (in my mind anyway).
Yes if the bot is exactly proportionally upsized the math should work.
i would guess that the angles would remain the same.
i replicated a hex and made the chassis smaller which ment i needed to change the hip angle…
HipH_AngleDef con 64 ;90° (90/360*256)
HipH_AngleMin con 21 ;30°
HipH_AngleMax con 107 ;150°
HipH_PulseMin con 910
HipH_PulseMax con 2090
HipV_AngleDef con 64 ;90° (90/360*256)
HipV_AngleMin con 25 ;35°
HipV_AngleMax con 103 ;145°
HipV_PulseMin con 960
HipV_PulseMax con 2040
------------------------------------------------------------- these are only an example!!!
think of it this way. you are only using the CH3-R as a prototype for your project, so aslong as you try to keep all the “up-sized” proportions the same then you should have no probs. the larger model leg throw should be double as you say but only aslong as you make all the components 1:2 scale.
im with you mate i can only invision it in my mind so i guess its all down to just seeing if it works!
good luck.
I have the brackets in stock now, if’n you don’t want to build them from scratch.
lynxmotion.com/Product.aspx? … egoryID=87
lynxmotion.com/Product.aspx? … egoryID=87
lynxmotion.com/Product.aspx? … egoryID=87
lynxmotion.com/Product.aspx? … egoryID=87
Actually, the actual angles shouldn’t matter at all. Just determine the angles, and enter the data in the program. That assumes, of course, that the limits of the R/C servos aren’t exceed.
Alan KM6VV
Is that from servo horn center to servo horn center?
8-Dale
Yes
Excellent. Now I can make sure my leg designs don’t exceed the limits. 
8-Dale
This is great. Loading up the shopping cart and pressing a button is so much easier than making a scale drawing, taking it to the waterjet guy, picking it up three days later, putting it on the bending brake and hoping you line it up perfectly…
Cheaper too!