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That second video is very impressive Ayrton.
Is the handle being wider at one end the reason for the squint sprocket? If so, try putting a spacer (a couple of washers or a piece of material with a suitably sized hole in it) between the sprocket and the narrower part of the handle to fill up the space. This should make your sprocket straighter and hopefully reduce the chance of the chain jamming and/or coming off.
I'd suggest you try taking some links out of that chain before anything else. It seems to 'droop' when it's sat in place. Fine for bikes but all the chains we have (hydras and SMIDSY's drive) have chain tensioners and guides.
A chain tensioner is either an idler sprocket which you fix onto an adjustable arm to push the chain tight or you can use a piece of HDPE/nylon 6 bolted to an angle where you can move the HDPE up and down.
The chain doesn't need to be mega tight but does need to avoid the amount of slack you can see in the video whilst it operates.
Guides on the sprocket may also help. Nothing special but you can cut a piece of 3mm ali and bolt it to the sprocket on a spacer which will help the chain 'feed' onto it.
Your chain is way, way too loose!
You can try a spring loaded chain tensioner. Im using this kind of setup in my buggy, and its the best choice, in my opinion.
Something like this:
http://t1.gstatic.com/images?q=tbn:x...9Large.jpg&t=1
i think it is the handle making the procket out of place, but i cant seem to get it go straight if i add washers to it. going to take a better look at it tommorow.
also whats the best way to remove links from a chain?
A chain breaker and master link (?) to push out the pins and then reattach it.
I would still go with a tensioner because it's easier and probably faster to adjust tension.
Edit: if there are two bolts connecting the handle and sprocket, try different amounts of washers on each or cut some stand offs from some tube that can fit over the bolt flat at one the sprocket end and handle shaped at the other.
thanks,Quote:
Originally Posted by daliad100
the problem with a tensioner might be that the chain seems to be tighter at certian points because of the sprocket. i think il sort it out and see what its like.
If the chain is tight at some points and loose at others, it sounds like your sprocket is not concentric. In other words, the hole in the middle of the sprocket that the shaft goes through is off-centre. The best solution without re-making/re-drilling/re-whatever the sprocket would be the spring-loaded tensioner idea mentioned above. That way, the tensioner can move to take into account a variation between slackness and tightness while still keeping the chain tensioned.
i will probably fit a sprung chain tensioner to stop the chain coming off.
also i doubt i will get much work done within the next 2 weeks or so because iv started sixth form and its going to be caotic for a while.
oh and i sent my receiver/transmitter away for repairs and i havnt even received an email from them yet, odd perhaps they will repair it before emailing me
little update.
i just got the reciever back, it workes perfically.
also the one wheel seems to be wobbling, going to take it off and see if its the motor or the wheel.
Just a little update,
i havnt been able to keep to schedual(money rather tight atm) hoping to get the rest of the metal for the frame/armour within 2-3 weeks.
untill then il spend some time tidying up the robot and its wiring(almost cut half the wires in half during a test). :rofl:
Its been a while since i have updated the thread.
So far there has been little change to the robot. Im really unhappy about how its turned out, the axe doesnt work verry well and it has no armour at all at the moment. Im contemplating scrapping the whole thing and building a new one from scratch.
Im going to talk to my brother about it, but i think its the best option. I doubt the design will change much if i rebuild it, but im hoping to build it more to what i want and not be limited by the awfull materials i have.
would that mean you would sell the parts of your old feather?
I doubt it. if i recreate it it will either using most of the same parts im afraid. I just dont have the money right now to change my design compltely.Quote:
Originally Posted by harry hills
ok, cheers
Decided to build the robot again. Its taken way too long to get this far.
Im planning on stripping it down and rebuilding it properly this time. Going to be using the drill batteries that i got from the motors however. I cant afford to buy new ones.
As for parts all i need are new batteries for the axe and materials for the chassis, then im nearly done.
I should have £80 next week, so im definatly getting this finished around christmas.
Still havnt thought of a name for the robot yet...
Sorted out the batteries and just got what i need to build the rest of the robot. Should be finished soon.
Cardboard mockup done just so i can see if the design will work. Il post pictures tommorow, but its a fairly simple rectangle shape. Dont want to complicate things on my first build.
Just remembered i still need batteries for the axe. i may have to get those for xmas :D
We took apart the model so we cant get pictures of that. We have started building the frame. Turns out we need a lot more box section than i anticipated.
Should have the bottom section of the frame finished next week.
Just finished a quick CAD of the robot. its probably going to look nothing like that once we are done, im planning on making the front end more slanted.
Will try finish off the bottom of the chassis today and may start adding the mounts.
http://i639.photobucket.com/albums/u...re/robot-1.png
Turns out the steel i bought is too thin to weld (6mm) so il have to get some pop rivets, so that will set this back a couple of days. Going to get some thicker stuff next time.
it shouldn't be, my feather is 3mm mild steel :)
^ what he said, I assume you've only got an extremely cheap Arc welder if 6mm is too thin?!
A cheap arc welder can't make 6mm steel feel to thin.
On the other hand, it's 20 years ago I welded something with a Buzz Box.
I Prefer TIG, and with my second hand Clarke, 6mm Steel is too thick for 1 bead.
3mm in 1 go is the max.
sorry i meant 0.6mm :oops:
yeah, that would be useless as armour, 3mm seems pretty soild
The cheapest I've used are hopeless at low amps, even then 6mm is fine but 3-4mm touch and go. But now we know it's 0.6mm that makes much more sense!
0.6mm, that's next to impossible to weld with good results, unless you have top of the bill welding tools.
I would glue it with TEC7
Im just going to use it for the bottom of the robot i think, so i can reduce some weight for thicker armor elsewhere. Thankfully i didnt buy much of it.Quote:
Originally Posted by harry hills
.6mm steel =5mm HDPE
5 mm HDPE stops some respectable attacks.
0.6mm Steel will be dented and ripped just by looking sternly to it.
Havnt updated this in a while. The robot has once again gone on hold, due to the price of building it. Its a shame as i already have most of it and have probably spent £250 building it already, but other things seem to come first.
Hopefully it will be done by the end of summer, but i very much doubt it :(
noticed that i forgot to post pics of the new chassis, il try get them up soon.
i spent £250 on an Antweight
a good one though
i regret spending that much on it but i know it is awesome.
if money is tight try using micro switches or relays for drive.
you could even get supermassive servos
lf you stretch the belt enough you won't need extra sprockets
i plan to build my first fw soon but am summing up what i think i should use from build diarys
axes look cool and quite easy for beginners
good luck though
PS 6mm polycarb is cheap as hell on eBay A3 size for under £10
that will take a few hits
We have almost everything needed component wise,apart from batteries as the ones i bought are far from ideal. The problem with money is buying the material to make the chassis from. It really wont cost much more than £50 to get completely finished, but at the moment its money i cant spend.
Pictures of the chassis as it is now. Started doing a complete rebuild, but i was stupid and spent £50 on sheet metal that was too thin :oops:
http://i639.photobucket.com/albums/u.../Photo0223.jpg
i think il just give in and make the frame out of box section and then put some hdpe or similar as armor. This has been going on way too long for my liking and i would really like to get into an event this year.
good start look nice and solid
what thickness did you go for now
What you can see on there at the moment is 0.6mm hdpe, but thats coming off because its obviously too thin. Going to be replacing it with i think 12mm hdpe, maybe thicker if i i think the weight will allow.Quote:
Originally Posted by archie2000
Looks a bit shiney for HDPE, is it not 0.6mm steel?
Looks like it's been welded to the steel box-section as well. Never knew you could do that with HDPE :rofl:
On a more serious note, was the £50 of too-thin sheet metal bought from B&Q? If so, don't bother buying any metals from there. All the sheets they sell are too thin for the majority of roboteers' needs and the prices are just ridiculous. Either go on a scrounging mission around local recycling centres or scrapyards, or check through eBay.
The sheet on there at the moment is steel, i havnt ordered the HDPE yet. Its hardly welded on there anyway, the welder just melted through it even at the lowest setting...Quote:
Originally Posted by Anttazz
Im going to finish making the frame out of box section first, then see what sort of weight il have left to play with. its probably not going to be finished till the end of summer though.
Yea, i was amazed at the prices there, it cost me about £50 for two 500x500 sheets and the box section was quite expensive too.Quote:
Originally Posted by k_c_r