Very nice Build Thread and cool Project!
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Very nice Build Thread and cool Project!
Christmas- its time to hang up your stocking and disharge your Lipo's.
It's advised that Lipo and some other batteries are discharged if not in
use for a while. so with the winter holiday period approaching I chatted
to Adam about doing this.
I suggested we could run our batteries flat on one of our motors so we
tried this method-the battery easily run the unloaded motor for 8 minutes
and there was only a 0.3 drop in voltage after this so we connected the
turnigy charger and set it to discharge-this method was very slow but it
let us free to do other tasks.
We worked on the castor suspension first by cutting two angle brackets
to support the castor hinge at a higher level, I estimate 70% of the weight
of our Robot is at the front and the castors should make the front more
balanced and responsive to steering.
After welding the castors to thier base plates we looked to the scoop.
Originaly the return springs were set inside the scoop jaws but proved
unreliable and kept breaking so now the springs will be external and run along
the back -this will make them more vunerable to axes but it will be real bad luck
if we manged to lose all return capability.
Each modification comes with a consequence it seems, so the external springs
will lift the jaws off the Arena floor so we have made a beefy spike at the front
of the jaws as first inpact zone-to lift the enemy bot into the scoop-In Theory:-|.
We are hoping to sand down the bodywork in our next session and give it
a lovely two tone paint job.
Here's some pitures
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Careful there, for storage you're supposed to discharge LiPos down to around 40% capacity, not fully. Most chargers have a storage mode which gets the batteries to around 3.8V per cell for that.
Thank's for the heads up Cosmin-our intention was not to fully discharge the
batteries and Adam mentioned a similar % rate as yourself but for Lipo battery
novices like myself that storage mode is usefull info-I have only ever used gell
type batteries in the past which were heavy and quite short lived in a battle,
while comparing the two I was Amazed at the power of Lipos compared to Gells.
I was always taught to bring them down to around 25%, and definitely not over 60% when expected to be unused for more than 1-3 weeks.
I've never experienced LiPos degrading (capacity/ max voltage wise) when brought down to 25% for storage, but perhaps 40% also offers the same sort of protection, and a little quicker to bring them back to life too if they don't need to charge so much when brought back into use.
When I joined to help, I was quite eager to introduce Colin to the LiPos, as he has been out of the robot combat scene for most of the LiPo introduction and rise phase, I managed to impress even myself with the weight difference, as i'd never really used or even held the old style batteries before, so didn't realise how large and heavy they were in person.
Last update before Christmas and the new year...........
This week was designated as a painting weekend but I got slightly side
tracked and Adam was attending a Christmas do so I thought I would
tweak the mechanics of the jaws instead.
It had been bothering me that the winch jaw puller did not have a
clear path to the chains it pulled upon-namely its own drive motor
got in the way so despite it being a working system there's allways
room for improvement.
The original system was driven via a two sprocket chain to cut down
on the length of the single chain as detailed previousley and the winch
was set well back in the robot to pull the full length of chain.
I decided that if the winch was placed where the two sprocket roller
was I could negate the need for that roller sprocket and keep the chain
nice and short.
The covering polycarbonate lid didnt fit so I had to modify it and added
a curved plate to the front as a finishing touch.
Although the springs pull back the jaws after each bite, there is need of
a physical stop on the winch to stop it unwinding itself because it is also
powered return via the motor and has been troublesome.
At the moment I have put two short springs on top of the jaws-these need
rather too much energy to close the jaws so I think one much longer chest
expander spring at the side will work much better as in the previous jaws video
but not accross the front of the jaws.
I have added a long tooth to the middle of the jaws-made from 10mm steel
which sits on top of the spike and should help the enemy into the jaws.
Heres some pictures
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Merry Christmas
Holiday break over and we returned this Sunday to progress
with our heavyweight Robot-which Adam will detail shortly.
Over the Christmas break I was tempted to tweak a few outstanding
bits on the Robot and I had previousley described moving the winch
around for optimum operation.
My attempt at modifiying the position turned out to be a failure,-the
torque was much less and it still interfered with the drive motor, so it
was returned to the original position and a longer pull chain was fitted
which goes right round the drive motor and the end result is near perfect.
This Sunday was set aside for painting and electrical work so in preperation
I sanded down the Robot a little and used primer on any bare metal areas
and now for my input on the day!
As noted above, the majority of the day was spent purchasing and applying the first layer of paint, with some electrical work later on.
We started off by buying the paint, whilst possibly not the cheapest option, we decided to go to B&Q as they have a wide range of colours, and an on-site mixing suite for anything not in a tin already. We decided on a color, waited on it mixing, then set off back. As soon as we got back, we wasted no time and started applying the first coat. It's now pretty much a solid red everywhere, an image of which is below, later on we'll get some black for the chassis pieces, to add some contrast. It didn't take us very long to get a coat on the bot, although we expect we'll need to go over it again and touch up areas covering up brighter colors, or just missed spots. We also may need to do some extra work to cover up a few logos and text on the components we used, as certain hosts may not approve of a 'Calor Gas' logo visible behind the paint, so that might need grinding off or more layers coating over.
Afterwards, we got on with the electric work. We're still having very little luck with the speed controller, so as a work around, we've put together a simple relay system that'll allow us to get the bot moving, and test what we need to with it. It isn't the ideal solution, but it gets us to where we want to be with the progress of the bot, and will get the bot as a whole into a working order, and certainly allow us to do some needed human related tests to figure out who is going to be the driver of the bot, and may also be fine for competitive use should we not resolve aforementioned issues with the speed controller.
Colin & I would much appreciate any input on getting a speed controller working, or repaired, or even anyone local to pop by one day and offer advice or even repair in person.
Some images for today,
1) Some colour comparing at the local B&Q
2) The first layer of paint is on!
Attachment 7580Attachment 7579
Sunday update-After last weeks painting session I thought I would
take a few pictures while the Robot was on it's wheels and I'm very pleased
with the look considering it's very much an undercoat and the final coat will
be applied a week before our first event to allow time to dry.
Adam was unavailable this week so I set to on my own.
I picked up a seedling planter from a rubbish pile and thought it may be quite
effective set into the air intake vents/wheel gaurds on either side of the Robot-
so I cut it to shape with the grinder and inserted a piece at one side, I may
run with the idea, but the other side would have to be a half section due to
removable link being located at that side.
I told Adam I would check out the temporary relay system to see how it coped
with with driving the motors at 24 volts via 2 gell batteries (static test).
This worked really well and even when the wheel was suddenly reversed there
was no arc on the relay and the chain did not break-so we may be able to have a
run around with this set up if we conciousley be kind to the circuit and don't suddenly
reverse the Robot like in the static test.
We are still unsure what to do about a permament speed controller after getting
our fingers burnt with the last one and it may be the batteries we have may not
suit all speed controller types-it would be a shame to spoil all the good work by
not having a control system as least as good as the competition has.
After testing the relay I worked on the external return spring for the jaws
and although this meant grinding off a little paint to weld, it was interesting to
see how well it scrubbed back and I was pleased that it was almost like grinding
on old bodywork.
Lastly I painted over any bare metal with a primer.
Attachment 7597Attachment 7598Attachment 7599Attachment 7600Attachment 7601
We have stuck with the agricultural/industrial paint scheme and overhall look and
I think the Robot woulden't look out of place in a country agriculture showroom
even if it leaves you perplexed about it's application
Wintery weather Today but the build must go on- unfortunatley due
to the bad weather Adam was unavailable this week.
I had planned to use most of today on the electrical side of things
but due to me working on my own I thought I would do outstanding
fabrication first.
Early last week I ordered a couple of things of e bay and they arrived
in time for this weekends build.
I bought 2 cheap speed controllers at £8 each -they are rated at 7-16 volts
and 300 amps and I bought 2 weightlifting bars to complete the fabrication
of the jaws.
Fitting of the weights bar to the front of the jaws was quite straight
forward, it just needed slight shaping and welding in place.
I then needed to cut a false tooth out of a car disc brake which I had used
on previous occassions for various things and I welded that to the bar.
Now I turned my attention to the never ending saga of the electrics
and namely the speed controller-I could be green with envy at other roboteers
who say " controller arrived and five minutes later it was running around "-
this hasn't been my experience-the Ragebridge blew with a massive spark
as soon as it was plugged in, so before we commit to another I'm doing some
experiments.
So my thoughts were-how would a £8 speed controller designed for small RC
cope with driving a heavyweight ?.
Bearing in mind my motors are 24 volt and the max current of the speed controller
is 16 volt I wasn't expecting great performance.
I tried running it at 12 volts on a gell battery to begin with and it worked well
(wheels off ground ) and then I tried our 14.5 volt lipo battery and it was slightly
better going forward and backwards no problem.
Whether or not the ESC will blow when the Robot is on the ground remains
to be seen-I have heard that the ampage rating is not the true rating ?-
What I do know is that I can wire them up and why the Ragebridge blew
is still a mystery (possible overvolts) but Adam thinks not.
Attachment 7621Attachment 7622Attachment 7623Attachment 7624Attachment 7625Attachment 7626
Very inventive use of bar bell matey ... THE WHOLE PROJECT LOOKS FUN !!!
Unfortunately this weekend proved to be extremely icy here in Wakefield, and I was unable to safely leave home and walk up to Wakefield Westgate rail station, so had to give it a miss. Have to consider not breaking any bones!
Under load, i'm not sure how those ESCs will perform, or if they do perform as anticipated, how their lifespan will be. The current will only increase under load, up until they (if) they stall, where the current will be at its highest. They only way to find out realistically is to try it though. However for £8 its a bit of a cheaper loss if they do not work, or lifespan is poor.
Assuming those are the ESCs you sent me (here) - they should easily perform at full load (320A is quite a lot). Although two fully charged LiPos will be over voltage. (nearing 30V)
I do doubt that is going to get to 320A though. It's an incredibly small device with a small fan. I'm not sure how realistic the 320 amp max, that is a heck of a lot of heat in need of dissipation.
Do you recall it getting heated during off ground testing?
According to the BBC, the weather will be much milder this week. So i'm hoping that next weekend I can get there and test out these little ESCs. Even if they don't prove viable for movement, they may still be of use to help control the weapons motor, as that'll be very short bursts compared.
I have to say, it certainly has been fun getting to this point. Despite our issues and distance between myself and Colin sometimes causing issue. We've certainly used a lot of varying parts in some inventive ways. How it'll all hold up in battle, will certainly be interesting! Thankfully the majority of its structural components are fairly cheap to re-acquire for replacements!Quote:
Originally Posted by katch
I was watching those on eBay too. Regarding overheating I'd take some tips from overcooking computers. I'd firstly lift the heatsink and put in some thermal compound as at that price be surprised they use any. It may be possible to replace heatsink completely with a better on or perhaps even a liquid cooled solution. Such a bargain item though. If they work I'll be getting some too, at least for my feathers.
Cheers for the advice. We'll keep you updated with our adventures with it, i'm sure.
I probably have some thermal paste lying around from last time I upgraded my PC. They're very small units, so i'm not sure how much area i have to deal with for attaching heatsinks and how effective it'd be with that small area outputting up to 320A worth of heat. If we space things about wisely internally, we might end up with a bit of excess space to play about with some oversized heatsinks. If we can figure out between us all how to make these viable units, they'd be a very cheap alternative, if they can be made to not set themselves on fire faster than Diotoirs fur at high amps, if they do to begin with..
considering fans are don't last long in combat robots i would say a liquid solution would fair even worseQuote:
Originally Posted by Deathly Hallows
Yeah. I don't think liquid cooling is in anyway a workable solution. One good hit would probably dislodge all the plumbing and spill all over every possible electric circuit knowing my luck!
Is that really 16AWG wire on those ESCs? Since it says they are for 540 motors. I doubt they will manage more than 50A.
The Fans on those small speed controllers come on as soon as they are
plugged into the battery-I'm not sure if we will put the two lipos in series
and hope it survives that voltage Adam, not after the Ragebridge blew
which was rated at 35 volt max and these are only 16 volt max-despite
us not knowing the true cause of a spark typical of touching the positive
and negative wires together of a 30 + volt battery.
What was interesting is that there was a no real spark when the lipo
was connected.
It's Sunday! Which means another day of progress, and the most surprising part. Nothing got in the way of me heading up to Colin today!
Today was spent on the electrical side of things. Colin has bought a new ESC, a Cytron MDDS60. This has a max concurrent amp rating of 60 per channel, which is still plenty for us. It also has a wider voltage tolerance, both lower and higher sides.
We firstly started by trying once more to breath life into the Ragebridge, again without success. So we quickly swapped to the Cytron and didn't waste further time with the other for now.
After a short time wiring things up, we had no luck once again, although a quick switch over of the receiever - ESC wires produced results! We've finally managed to get an ESC to fire up, and fully control the motors from the transmitter. We started on the safe side, using some old SLA batteries. The Cytron is significantly larger than the Ragebridge, so if we stick with it, we may need to juggle things around internally, but we'll find a way to fit it in there.
We then decided to move outside, when the weather finally allowed us to do so during a fairly dismal day in Yorkshire. To have a test run outdoors and with an actual floor to see how it performed.
Unfortunately we ran into a few issues here, and the robot was seemingly underpowered. So we switched the SLAs to the LiPos. Even with a single LiPo at around 15V, the robot was showing more life than the 2 SLAs at about 24V were doing. So we placed both of the LiPos in, however this is where the improvement was somewhat limited. It was struggling to move around in a meaningful manner.
We'll spend the coming week and next sunday trying to pinpoint that, if it was a matter of finding traction, not enough current, voltage, if the ESC isn't providing the needed power, or if it is a fault somewhere with the wiring or bot elsewhere. We're confident we can overcome this, and already have a few ideas for things to test and tweak over the coming week.
We also mentioned possibly using the small ESC Colin noted a few posts ago to build a feather or beetleweight with, a potential future project. Whether it'll be a new design, or just a mini version of our current build, who knows!
A few images
1) The ESC almost wired up, and just needs a final connection for a complete circuit. The wooden board here was just used to secure the ESC to, so we didn't accidentally knock it flying.
2) The bot prepped for its first outdoor adventure.
Attachment 7657Attachment 7658
What lipo did you use was it Charged. ?
I used different receiver inputs off my dx6i to you looking at picture and the speed / response varied for me when I changed them
We used 2x4500s (4s) zippy lipos in series, they wern't fully charged I think
Adam said they were around 50%-giving us around 15 volts each so
a total of 30 volts.
What was your optimum set up for the Radio control Katch giving
you the best results?.
I used Dx6i with Receiver ar610 I think ..
Left stick Forward back - Speed / ( Receiver throttle)
Right stock Left right mix - Combines motors tank steer ( Receiver Aylerones )
After my first install ( more luck thank judgement) I trialled out the other channels and I didn't get full throttle... but I've never read the manual for dx6i so I could have potential fixed it I just played to see if there was a better combination. Just a suggestion as possible contributor..
I'm testing mine with 12v x 2 and 12v x 3 24v/36v - 200 kilos this weekend. ( bot & 100kg ) so we'll see what happens or breaks. :rofl:
Only things that affect yours differently to mine that I can see...... may be useful or you can just ignore me :)
- Chain friction - dry chain is up to 6 - 9% power loss on motorcycles, Using motul wet road lube is by far the best, almost no fling or mess.. so on smaller power sources is a huge power drain. They over heat and snap or get a lot stiffer a they warm up, they also stretch super quick when dry as in 1 inch in a single short ride. Always spray the inside of a chain so centrifugal force push it into the chain where it needs lubing. If I need a chin drive i'll be using 428 O-ring - no stretch no maintenance in comparison. Grease is retained inside the chain so almost never stretch how we use it. Not much heavier.
- Batteries can produce volts with low amps its like a tidal wave - it can read 15v and have 1 amp behind it. You need a lot more than 1 amp ..I've had plenty of arguments with workshop customers, where they claim a battery is NOT at fault as its 6 months old, but we have load tested it and showing 13.5v but fails loads test, barely enough power to light a bulb.
I would try it fully charged
- Your wiring is half the thickness of mine. reduce draw ? not sure .. I have ZERO bullet connectors all big red things
- Your motors are they used ? 24v ? MY used ones are notably slower than my new ones.. worn brushes or bearings
- Gearing combinations, I don't work stuff out I learn and play with trial an error, but...
I see you used a DID motorcycle chain etc - not sure where but... for reference and guiding you.. you can offer it up against your sprockets..
Example Aprilia rs50 - 12 52mm - 47 225mm ratio is 3.92 for a 12bhp motorcycle that weighs around 100 kilos.
So your 24v motors are being expected to work just as hard ( with internal gearbox ) without the benefit of a gearbox, but move the same weight.
Dropping to 10 tooth front -47 Rear is 4.70 - significant acceleration benefits and much faster movement since we operate at sub 10 mph I would go to 8 tooth front if I could.
food for thought.........
We tested it with all the dip switches set to 0. Which is mixed RC input mode, with exponential & MCU modes disabled.
I wonder if it'll get better performance on independent mode instead of mixed.
When I purchased the batteries, I did test that they were able to draw their maximum currents. Which is 202A (45C, 4500mAh, 45 x 4.5). Using a load tester, i achieved satisfactory amounts near to that, however I no longer have the tester to measure an exact output amperage to retest with now.
The main issues I see are the size of wheels, the tyre compound and the gear-ratio. The tyres look very hard and plastic-y, so they probably won't offer much grip. May be worth running a layer of bike tyre around them to improve grip. The wheels are also very close together, which will make turning difficult. The gear ratio from the motor doesn't look that large for the size of wheel so torque may also be an issue.
Obviously changing the gear ratio would be extensive work so maybe try screwing some bike tyre onto the wheels first to see if that improves things. Halfords often have old tyres in the back from bike services that can be obtained for free.
You have hit the nail on the head Jamie-very perseptive analysis from
just a set of pictures.
We do have wheel spin and one factor is probably the hard rubber on
the wheels and also the tread.
Another factor is that the Robot is very front heavy and thus the
weight over the back wheels is too light.
The sprocket ratio is around 4 to 1 and altering this is possible
but as you deduce -not an easy task.
The distance between the wheels will have to remain-it would be easier
to cut off the front jaws and have a lightweight heavy than to alter the
wheel spacing.
Conclusion-Fixable
Yeah. That is definitely an issue we had on sunday. It was slipping on the surface we used, although we weren't able to fully decide if it was due to the wet and slippery surface, or an issue a little bit more sinister at the time. But in hindsight, Jamie is probably correct.
Weight wise, we are already probably within 5-15kg of the limit, so we can't do too much extra, unless we take stuff off. I wonder if we could weld a slab of something between the wheels, to weigh them down a little and give them extra traction.
If I recall correctly, the current wheels are wheel barrow wheels, the type that don't have air in them.
Another week into 2018, another weekend of building!
Before today however, Colin had spent some time with an angle grinder, retreading the tyres. They almost look like they could have always had that tread!
We started today by weighing everything, as for the past few Sundays both myself & Colin have starting voicing concerns over the overall weight of everything, so we brought out the scales, piled everything onto it, and we are up to within 5kg of the weight limit at this point.
Next, we discussed our options for the concerns raised during the motor testing last weekend, which were somewhat disappointing. Two options were discussed, we can either get some extra sprockets in the mix, and increase the ratio from 4:1 to 8:1. There is a potential issue here though, as there isn't enough space at both sides needed for this, the right hand side would fit correctly, but the left would go over to where the jaw control sprocket, chain/belt and motor is. Whilst there is space in other places to do the same but in a different place, so it might end up a bit of a jigsaw puzzle inside. Another option, is using friction drive. There is just enough room on both side to do this, without having to jiggle things about or place things in mismatched locations at each side, we reckon. Later this week, Colin is expecting a large box of sprockets, bushes and other similar items. So next Sunday we'll take a look in there and see if there is anything in there to sway our decision.
A large portion of the day was also spent drilling out holes in the scoop and jaws, after realising we may need to add extra weight as part of the drive changes, even if we don't end up going that way, the less weight will perhaps afford us more armour in areas where needed. The holes have been drilled strategically, in places where it won't cause weaknesses, such as in the jaws themselves, which will usually be within the scoop anyway.
We ended the day by testing out the motors, but removing the ESC from the equation. The roughly 50% charge LiPos were quick to spin up the wheels, although they still skidded on their new treads. The first thing we'll do next week is probably repeat the test with the ESC, and slowly increase the speed to see if we get any better control, and if with a controlled acceleration the new treads will prevent major slips. What we find in Colins box of stuff and how that test goes will take us in the future direction for the bots drive.
Some images from today;
1) The new tread on the tyres
2 & 3) The cut holes in the jaws
4) The holes on the outside of the jaw
Attachment 7672Attachment 7674Attachment 7675Attachment 7671
BRRRRR-it's been a raw day with a freezing wind but the build continues.
First task was to test the drive system via the speed controller to see
if the wheel spin problem is better with a gradual power increase,
So we set too wiring up the motors and the speed controller and the
radio control-this seemed to take quite a while, I think mainly because
the wiring circuit is not so much plug and play its more screw,zip ties
and gaffa tape-but we are working on the correct wires and connections
for this and the final version should take 5 or 10 minytes tops to
connect.
Anyroad we tried the Robot with the RC gear and although it managed
to bust the door again the performance was sluggish and some wheel spin
still occured so reluctantly we need to modify the gear ratio.
After removing the speed controller we began work on a idler sprocket with
a 2 to 1 ratio, this was in the form of a stub axle type shaft supporting
a couple of sprockets on a brass bush-fabrication went really well until
I realised that the axle shaft had been made too short and didn't allow
for the second smaller sprocket-this was a real set back but after I had
taken Adam to the bus stop I was able to rectify the mistake and I'm
just awaiting sprocket size confirmation to finish the lathe work.
Furthermore to Colins post, I have a few images, and a little extra to add. First thing tomorrow, I will go to a local to me dealer of transmission materials which myself & Colin have used a few times now, Calda-Morley. Due to their fast turn around, we should have the new sprockets for next Sunday easily. Then I can pass on the information of the bore size to Colin as noted in previous post so the shaft can be adjusted if and as required. I've also got some different fuses to the currently installed ones too, as our newer ESC tops out at 60A per channel with a higher margin for short bursts of time, so we're going to replace the current motor fuses to ones of that value, as the motors we use shouldn't top 60A even for a burst. We still have another fuse between the batteries and {the rest of the electrics}, this is currently 200A, inline with the batteries maximum draw of 202A - despite all of the electrical components not drawing anywhere near 200A combined, I thought it'd still be better to give the option to draw more, up to the battery maximum rather than risk fusing what is essentially our master fuse for the entire bot.
Some images from today.
Securing our Zippy batteries with some Zippy ties!
Attachment 7708
For the second consecutive weekend, we managed to break the workshop door.
Attachment 7709
This week we worked on the sprockets to increase the ratio for
the drive from 4 to 1 to 8 to 1 overall.
I had been working on the problem in my mind all week and with a
couple of failed practical experiments with bearings I had settled
on a wheelbarrow style bush/spindle support system.
Adam had ordered 2 new sprockets from calda morley with a bore
size of 12mm but when we looked at the sprockets they were much
smaller than the 12mm required so they needed work first off.
Earlier in the morning before this I had turned down the spindle to
support the 2 sprockets one of which I bought online and welded on
this onto the spindle.
One of the sprockets that Adam had brought was drilled out to fit the
spindle too and we had our 2 to 1 ratio-giving us 8 to 1 overall.
We had made one support bracket last week which needed slight modification
by means of a bush and housing welding to it and a second smaller version
bracket was made with bush/housing for the other side also.
This all seemed good and with the sprocket between the brackets it
seemed to line up well with the wheel and the motor sprockets.
There was a slight stiffness on the spindle in the bush but I narrowed this down
to the end cap of the spindle and I gave this a skim on the lathe after taking
Adam to the bus stop and it was a lot better.
I should be able to fit the chains beofre Adam comes over again and we can
see what difference these changes make.
Some images to followup Colin's post yesterday evening, and even a gif this week!
Firstly, the lathe - Colin has spent a lot of time at the wheel of this over the past week, turning the poles for the new gearing stuff. Here one of the poles can be seen, after been turned somewhat already.
Attachment 7731
Secondly, the completed reduction sprockets on their central mount.
Attachment 7730
Thirdly, a quick gif which demonstrates the level of reduction from chain movements.
http://imghst.co/82/1.gif
IT'S ALIVE-ALIVE I TELL YOU!-A very good day on the Robot today, after realising
that the overall gearing to the drive from the motor was wrong at 4:1 we decided
to go for 8:1 and finished one of the reducer sprockets last week.
We usually have a four hour build session on a Sunday 12-4pm but to be sure of
getting any where near being able to test a new ratio set up I put some hours in
on Saturday and Sunday morning too.
On Saturday I turned down a length of bar using a old lawnmower cylinder
blade as the spindle to set the double sprockets on.
I then welded on the sprockets and added the end cap-I was very pleased with
the sprocket alignment, it was straight and true, two bushes were then set into
old sprockets as housings and they were welded to two brackets to support the
spindle / sprocket set up.
When Adam arrived with the half links he ordered on Sunday we were
able to fit the chains to both sets of reducer sprockets and it was time to test.
After a temporary wiring job we set the Robot on the patio and gave it a whirl-
needles to say we were more than pleased and I said to Adam "This is the champagne"
moment.
Attachment 7760Attachment 7762Attachment 7761
1 lawnmomer blade used for metal
2 the reducer sprockets
3 Adam adjusting the motor wires
And a little extra from me!
Also covered today, we replaced the blown out banana / bullet connectors from the old ESC blowout. This allowed us today for the first time in a while, not to resort to using bonding tape around one of the connections, and will help largely with a proper and stable electric circuit over bumps, as its possible this was a contributer to some of the problems.
But the moment we've all been waiting for, include myself and Colin. The robot alive, and moving in a manner we were both happy with!
https://www.youtube.com/watch?v=uaLGbQkiMxg
At this point, we're both confident we're on the right track, and the only real challenge left we hope, will be working out the weapon and its motor, with the added sprockets for the 8:1 ratio limiting space internally a little. I'm sure we'll manage to find a way though.
Well done lads.. I Did a test on mine today too must be the day for it
In Readiness for this weeks Robot build I ordered a couple of clamps on e bay
and they arrived just in time for use this Sunday.
Unfortunately due to the bad weather, Adam was unable to come through this
weekend but hopes to make next Sunday.
During the week I had time to weld in place the retro fit sprocket to the winch
and managed once again to get it spot on straight.
Today I worked on the Jaws and a possible way to drive the winch sprocket
through the narrowed gap created by the drive reducer sprockets.
It turned out that there was just enough space at the side of the reducer strut to
run a line of chain up to the front mounted motor drive.
To make this idea work meant moving the winch drive motor to a more internal
position and thats where the clamps came in to support the motor.
Upon fitting the chain in place it looked like needing another half chain link, so
rather than settle for that I decided to enlarge the adjustment slots on the winch
so the chain could be easily adjusted.
Lastly-I noticed one of the drive reducer sprockets chains was slightly tight so
I slackened off the drive motor and added a metal shim under the clamp to lift
the motor and so give a little slack in the chain.
There are still the jaws to re fit but thats just a ten minute job and theres no
reason to think they wont work as well as before.
Next week we will probably concentrate on the electrics and get them to
competition standard.
Heres some photos showing the clamp and the chain from the winch up to
the winch drive motor.
Attachment 7799Attachment 7800Attachment 7801
Todays build session was set aside for the electrical but unfortunatley
Adam was unavailable this week and a last minute change of plan was
needed.
I had noticed that the rear of the Robot was a little untidy and this was
clearly evident in the first video or the Robot moving around, so todays
plan was to tidy up the rear and discover if the cavity there would house
the switch gear for the jaws.
On inspection there was quite a lot of room in the gap and also there's a
convenient channel in the metal structure to run the wiring loom into.
The Rear of the Robot is probably the strongest part of the Bot-designed to
take the flip of a full pessure heavyweight flipper and also be resistant to
spinners-there may be shock issues with putting the electrics in there but
there is also plenty of room for foam padding.
I then welded the top of the rear of the Robot with some 3mm steel and
the lower (access) door was bolted on
Attachment 7829Attachment 7830Attachment 7831
Picture 1-plate to cover gap
2 The rear cavity with a sample switch to show space
3 top view or Robot with plated piece showing
Those fuse switches easily flip off, I would imagine a hit from anything would cause them to switch off... Would advise on replacing them with something more oh what's the word... It clicks and stays switched...
Thank's Nat
The switches are just to show the area of space and will not be used in
the Robot.
When Adam returns I will talk to him about speed controllers and types
of switches.
We only need a simple on off really because the jaws need to close as fast as
possible and then we need a powered return so I'm looking at 80 amp
speed controlllers on Ranglebox but they have sold out-any suggestions
welcome.
Have a look at
https://nutsandbots.co.uk/product/fe...-dual-channel/
https://nutsandbots.co.uk/product/fe...ingle-channel/
Should be fine as it looks like you are running on scooter motors
The turnigy TZ85A are sold out from all suppliers, and according to hobbyking, will be back in stock in 3-4 weeks time now.
The ranglebox ones are the same but programmed to run as brushed motor drivers.
Shakey ones are lower amperage but as shakey says shoudl; work if using the right motors.
Otherwise there may be some avaiilable soon.
Hobbyking ones will need to be programmed yourself or by a fellow competitor. not sure what other options are available.