Boner

Ok so for the 3rd or 4th or whatever time I'm going to try and keep a thread updated with progress etc etc.

Well boner is in a fairly battered state after the yeovil event last year. I wasn't able to make the champs as I was working offshore at the time however this year I will be there and have some upgrades to make to boner.

First out are the drill motors. They have worked well for me but on more than one occasion the plastic casings for the gearboxes split open. So it's time to go for some gimsons. I didn't want to get the plastic versions as I just didn't feel great about how rugged they were hence waiting for a metal version. Bought two 24v 36:1 ratio motors and gearboxes. To these I am using the 124mm banebots wheels. Same as the ones I previously used. However this time instead of the green ones which are far too soft and now looking worse for wear, I have gone for the orange wheels. They definitely feel far more up to the job although the green ones did last for two competitions. To mate the two I have gone for the hex hub from banebots with a 1/2 inch bore. Now this doesn't match completely with the 12mm shaft of the gimson motor (around 0.7mm larger in diameter) however with the grub screw and a bit of key stock holding the wheel in place I can't see it being an issue. It's also nice to move away from the thread and reverse screw that was such a pain when it came undone. The shaft currently sticks out beyond the end of the gearbox however I am just going to cut off the excess. I don't fancy using the thread on the end due to the large bending moment around it plus it wouldn't fit into the space reserved for the wheels in boner.

The drum is staying the same. Think it's done at least 6 competitions if not more now and is still in good enough condition to warrant use.

I'm going to ditch the electronize in favour of the hacked botbitz controllers hacked by me as I have the programming kit to do so and it isn't a difficult job. The electronize will likely find themselves in the for sale section before long.

I'm going to ditch the castle creations brushless esc in favour of an unhacked turnigy 85a esc. Basically one that I haven't hacked. I've burned out two of the large castle creations controllers in the past and they aren't cheap to replace or fix!

Battery wise I may stick with the large 5s pack I have or go up to a 6s pack or 2x 3s packs for that bit extra oomph from the brushless but time and money will tell.

Few pics below of the bot as it currently is and the new parts.

http://i.imgur.com/yRUpETe.jpg

http://i.imgur.com/njJrU9F.jpg

http://i.imgur.com/EXmagri.jpg

This will likely be the last outing for boner as it currently is. I'd like to redesign the chassis completely, keeping what's good about it and designing out the flaws.

Looking forward to follow this re-build. :D

Exciting stuff! I'm looking forward to this build. Lots of quality parts

I'm really looking forward to following this, I'm really like how compact and rugged it all is.

Wow around 50 views and a few interested responses in only a couple hours. Didn't think this would be that interesting. Decided to start the dismantling process tonight so here's a few more pictures.

A few bolts out and it's off with the outsides
http://i.imgur.com/yYiaK7Z.jpg

Most of the weight of the machine is on the outside. The inner chassis currently only weighs around 4kg give or take
http://i.imgur.com/ZE6ZMaP.jpg

Titanium base and battery compartment
http://i.imgur.com/g2NYHWl.jpg

Taking out a motor
http://i.imgur.com/6vOcSci.jpg

Motors out and just the electronize to go
http://i.imgur.com/X6AYrPJ.jpg

It's always interesting to see people who know what they are doing do things.
Boner is looking cool, I think it will probably do very well in competition.

It's always interesting to see people who know what they are doing do things.
Agreed! :rofl:

So at this point are you going to rebuild the chassis or just give it a spruce up? It looks like it needs a ruddy good clean ;)

Agreed, this will be interesting! I didn't have the guts to face it at Yeovil last year. Our robot has improved greatly, but this will be improving in line with it, so I'm still fearful!

The draw for the champs is going to be... fun?

My chassis always end up dirty. It's probably because i spray WD40 onto the disc shaft and bearings. Gives it a noticeable extra few hundred rpm.

Ahh that explains it, I thought the grubbiness looked familiar

Do you use brushless stuff to power the drum?

Yep, the last picture shows an outrunner mated to a timing belt wheel.

It's a scorpion 4035 series motor that I use. More than enough power from it although I'm not using it to it's limits hence I want to up the lipo cell count

Is there enough space to go to 8S or 10S to really get the drum going? But at that speed you would probably loose engagement; you know it better than I.
We did the same trick for Binky with the Banebots hubs and the GR02's. Its nice to know we are thinking along the lines of an Ex champ

I've not found that boner has an issue with being too slow as it is. It's done severe damage to a number of machines over the years so I don't see much point in increasing the speed. I like that it flips other machines on a regular basis.

I could go to 8s or 10s but the problem is that I don't want to drop below the 3Ah mark which makes the packs a bit on the large side.

I did a bit of testing yesterday with the wheels/hubs on whilst running in the motors and whilst there was a slight wobble it was nothing to get worried about so I think I'll just keep with it.

Down the line I could look at boring out a custom hub to 12mm when I get access to my lathe again.

8-10s seems a bit overkill anyway. There are plenty of effective spinners, brushed and brushless that run on 4-6s. The only 10S I know of it LS4 and they run a huge reduction and rarely go above half throttle, the power is mostly there to get their 6.5kg spinning element moving!

We are using 10S on Binky... its really quite scary.

What are the side walls made of,. they look like 20mm Nylon, with your Ti baseplates and motor mounts

Ah, a reminder to get the hubs finished...

It's meant to be 20mm however when I bought it it was 22mm thick nylon. 4mm hardox bum and 2mm titanium top and bottom

Ok quick update. I have since writing the above posts decided to run boner on 10s. Mainly for one reason. I was taking a look at hobby king and stumbled over these batteries

http://www.hobbyking.com/buddy.asp?code ... 27C3E15B91

Now granted the specs may be inflated but boner only ever drew the big current for a split second before settling down to a few amps on the drum. So two of these in series should do the business. If anyone happens to buy via this link you will get the same packs cheaper too.

Still in two minds about the brushless esc. I may go for an el cheapo option or stick with the castle creations and get the blown one repaired.

El cheapo all the way! Plus then you can seriously over spec at little cost.

http://www.hobbyking.com/hobbyking/stor ... ouse_.html

Was keeping that Jem to myself. Bargain!

No good i'm afraid, 7s max

Sorry you did say you wanted to upgrade to 10s.

Yup, 7s seems to be the limit for el cheapo controllers. I'm treating these batteries as an experiment. They should give a better performance than the hyperion I was using previously purely on the greater voltage but i'll need to see how they handle the power demands. I'm not overly sure on the figures they quote for discharge but time will tell.

Gonna bring both along to the champs so I can run in a few combinations should it be required.

I thought the drum was already running at a good RPM. Seems to have good bite, can throw and keeps on hitting. Why so keen for the voltage upgrade?

Well it's a motor that's rated for 10s as is the esc so I wanna see how the two of them run on 10s. Plus the lipo were cheap and we shall see if they give the performance they promise. A fair few good reviews of them but time will tell.

Also got my eye on another motor but again time and bank account will tell. It's something very special though 8)

Can I ask what motor & esc you are looking at?

I am still a little confused when it comes to Brushless motors. Simply going bigger doesn't always mean more watts or torque.

For example: an sensored In runner I am looking at is 2650KV but is 4S max, where as a HK40 is 800Kv but can go to 10S. Both ultimately end up with about the same speed; 28'860 and 29600 rpm. But the HK40 is 120g heavier, so which way round is better? Can anyone shed some light?

Currently I use a scorpion 4035 motor. These come in a number of KV ratings and tbh I can't remember which I have in boner as it's rubbed off. This motor is an outrunner, ie the magnets in the outer can rotate along with the shaft whilst the copper coils in the center remain static.

Inrunners as the name suggests rotate internally with the magnets sitting in the center of the motor.

For a given voltage generally an outrunner will spin slower than an inrunner. You will also get more torque from an outrunner than an inrunner (generally). These both mean that an outrunner is usually better for combat robots as they require less gearing to get a useful rpm range for a disc or drum.

The power of the motor will be given in the specification. The 4035s give around the 4 to 5hp range (same as a big magmotor!) and peak even higher.

The controller i'm using atm is a Castle Creations Phoenix Ice 2 160HV ESC. A very nice controller that has a data logging feature that means that i can download the data from the controller after the fight and see the current draw, voltage, temperature and rpm of the motor during the fight.

Out runner it is then! We need more torque than speed most of the time.

Though I spotted a machine with HK40's for drive which was interesting. Will took them at an event in germany I think?

Update time!

Photos to follow but thought I would post a few updates. Things are certainly getting interesting.

The off center issue with the hex hubs on the gimson shafts was really bugging me so I looked at my options. Best option was to shim the inside annulus between the shaft and hub. Bought some 0.3mm copper sheet off ebay. A few reasons I went for it, it was cheap as chips, it was available in the rough thickness I required (would have preferred 0.35mm but beggars can't be choosers) and being copper it was easy as hell to bend into shape with my hands and squeeze into position. Seems to have worked well and reduced the wobble a good deal. Also got some keystock off ebay to properly secure the hubs to the shafts. Again was only a couple quid.

Lipo batteries arrived the other day. I will have to do a few modifications to make to the battery box I had previously but it's very doable and they fit in nicely. Might have to skim a bit of material off the hardox bum to get an extra hundred grams or so but it shouldn't be tricky.

Going to do the programming on the turnigy 85a controllers this weekend so fingers crossed there.

Biggest and baddest news is the new motor I'm planning on putting on the drum, a scorpion 4530-540 LE. If you do a search on this motor you will see it peaks at 11KW power. Although that is likely on 12s. Either way i'm going to be running some serious power behind the drum on boner 8)

And when they say the might Motor they reacted with Awe!

Awwwwwww...

I said Awe. A.W.E.

Oooooooooo...

Thats better.

[Name the film!]

Photo time.

http://i.imgur.com/p8iUG3s.jpg

Copper shim placement

http://i.imgur.com/ldZiLk7.jpg

Keyway and copper in place

http://i.imgur.com/oYmZtBh.jpg

Reprogramming turnigy 85a controllers

http://i.imgur.com/u7YcqJj.jpg

3 programmed controllers

If anyone is thinking of using the banebots hubs with the gimsons I would heavily recommend shimming with copper or something similar as it completely removes the wobble on the wheel.

Got 540 out of the basement and I'll need to give it a clean down before working out how best to mount either a brushless or speed 900 motor to the beater for the whiteboards.

Small update but it put a big smile on my face.

Just arrived, a scorpion 4530 motor. 11KW peak of power in a package not much bigger than my last 4035 motor. I also was running the last motor at only half it's rated voltage so not only will boner have twice the power from the upped voltage, it's going to be a more powerful motor. The drum should now be spinning at around the 8000rpm mark give or take.

http://i.imgur.com/S87DtdV.jpg

Back down to my parents place in Edinburgh today to do some work in their garage whilst i'm still getting my own workshop in order in Aberdeen.

With the increase in weight going to the larger motor and needing a small lipo pack for the drive as the converted turnigy can only handle 6s I needed to find a good few hundred grams of weight. The ideal place to find this was the 22mm nylon bulkheads. Each one weighed around 300g a piece and didn't provide much in the way of structural support. So I decided to replace these with 2mm titanium welded to the base. This makes a whole lot more space internally and saves around 400g in weight. Got the gimsons mounted and the shafts shortened. They give me more space than the old drill motor gearboxes.

http://i.imgur.com/eXBTg2i.jpg

http://i.imgur.com/tBmtzDn.jpg

The new motor fits in nicely and those observant will also notice I put the timing pulley on the lathe and took the teeth off it to act as a clutch. Should hopefully help reduce the stress on the motor and esc.

Got my replacement castle creations on the way back from the states as well after burning it out in yeovil last year.

Quick update.

Got a bunch of bits and pieces arrived,

- 6mm gold connectors for brushless motors
- A bunch of EC5 connectors to redo the wiring in boner
- Two new Nimh transmitter batteries as the old ones were nicads around the 600mah mark (new ones are 2400mah) and I had to keep charging between fights previously
- A mini lipo, 6s 1300mah for the drive motors

is 1300mah enough for GR-02s?
what nominal voltage have you gone for on the gimsons?

The gimsons are 24v. Yes it should be but I wouldn't advise it if you haven't used lipos and understand them.

Post 10 000 in this part of the forum!!

Back from a week long training course in London with work to spend the final 3 and a half days before heading south again for the featherweight champs.

Jobs still to do on boner,

- Thread axle for drum at ends
- Make nuts for axle threads
- Redrill new hole for the changed position of the weapon batteries/titanium battery holder
- Make a box or bracket to mount the drive batteries
- Make a mount for the weapon motor
- Mount the castle creations esc
- Wire it all up
- Test

Gonna be a long few days ahead of me!