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Nick
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Beetleweight resource page

Beetleweight resource page





After I posted a few questions on the Delphi forums, I realised the amount of info on Beetleweights is, umm, light Rolling Eyes compared to other bot classes. Since beetleweights are becoming popular in NSW, I decided to share all my collected info in one spot. I figure that I will post a message for each major topic (ie Motors, Materials, builder's links ertc) and just edit them with more info as it comes to hand.

Feel very welcome to help me out...
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Post Wed Jul 20, 2005 12:20 am 
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Nick
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Drive motors:

Beetleweight builders often have problems finding suitable motors to power their wheels. Many of the choices are meant for Ants and are too wimpy, or more suitable for Hobbyweights and too heavy. You also need suitable gearing and that can be even harder to find. Below are some likely choices and my comments on them:

Maxon Motors
Why not start off with the Ferrari of small motors? The Maxon motors come in a huge variety of interchangeable options are are made like swiss watches. Hardly surprising, since they come from Sachseln, Switzerland.



These motors come in a range of sizes and have a matching range of planetary gearheads. The A-Max range is the most affordable and the ones to find on the surplus market. The common sizes are the 22mm and 32 diameter motors. The 32mm models will drive a 4 wheel bot via belts, as demonstrated in JR's Mini-Moo: http://www.teammadcow.com/mini_moo.htm The 22mm model is better suited for driving individual wheels. The gearboxes come in a huge range of reductions. Ratios around 17 & 19:1 seem popular, then the 60 to 80:1 gearing is sometimes used.


The US site is the best place to go for more info, just don't get lost in the catalogue! http://www.maxonmotorusa.com/

The Australian distributor isn't much interested in selling to hobbyists but if you want a standard model and know all the part numbers, they would be worth a try: http://www.mrutty.com.au/

You can get Maxons delivered next day in Sydney, if you don't mind paying RS Overcharge: http://www.rsaustralia.com/cgi-bin/bv/browse/Browse.jsp?catoid=-87821956&cacheID=auie

A 22mm maxon and 19:1 gearbox from RS will set you back about $250 Exclamation Needless to say, I want a set!

You can also get the 22mm / 19:1 Maxon from Acroname for $145 US: http://www.acroname.com/robotics/parts/R179-6V-ENC-MOTOR.html . Take off the encoder and its the same but cheaper than RSC Smile


"B series" Motors

Can't quite affors the Maxons? the next best could be the B series motors from the Robot Marketplace: http://www.robotcombat.com/marketplace_ant_motors.html





I am using these in my first beetleweight and they are clearly a low cost copy of the Maxon range. After importing a pair, you would be up for around $115 AUD including postage - still not cheap. Jim at the RMP has won events with these motors in Wallop http://www.robotcombat.com/wallop.html - I believe he uses the 12V 62:1 version, over-volted to 24V. I will have more to report on these when my set arrives. The RMP seems to be the only source of these motors at the moment.

UPDATE: I now have a set of the B16 motors and they definitely live up to the hype. The the only problem is that the motor's rated voltage is just 6V, so running them at 12V is significantly over-volting them and anything more is likely to blow the brushes. compared to the closest priced motors (the small Lynxmotions) the B16 motors are a little smaller, 14 grams lighter and twice as fast.

ESCAP motors

These are almost as high quality as the Maxons, but are hard to find at the moment. They are made by Portescap http://www.portescap.com/Sections/Products/products_main.asp?PC=10003000&CL=3&L1=10000000&L2=10001000&L3=10003000&L4=&L5=&L6=&IT=Descrip&lang=1

You can get some of the range locally at RS Components and I am researching other suppliers, so stay tuned. These occasionally turn up on US surplus sites.

Mounts for Escaps are available at CNCbotparts: http://www.cncbotparts.com/escap_mount.htm




Escap 27:1 and 81:1 motors are available from Sozbots



http://www.sozbots.com/

These are meant more for antweights but if you protect the fragile 2mm output shaft, then you will have a very smooth running motor which would probably over-volt well. They are good value for a Swiss-made motor


Jaycar electric screwdriver



http://www.jaycar.com.au/productView.asp?ID=TD2495&CATID=&keywords=screwdriver&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

I have always wanted to hack one of these cheap screwdrivers – they look like a great value if some way to attach a wheel can be found.

Lynxmotion

http://www.lynxmotion.com/Category.aspx?CategoryID=71


These guys have some very worthy looking planetary motors. They are often geared far too low but the 19 and 27:1 ratio models would be ideal. All the motors are standard sizes so you can replace them with faster, more powerful models. The smaller models look very comparable to the B series motors from RMP and at $9.15 US they are very cheap. I will definitely be getting some in the future. The description says the gears are all metal, but the photos make them look plastic…




http://www.lynxmotion.com/Product.aspx?productID=304&CategoryID=71


UPDATE: I have run the small Lynxmotion motors in Slash for several tests and while they are a bit slower than I wanted, they have excelent torque, pushing large objects (a vacuum cleaner) around the arena. The foam wheels have quite good grip too.

Lynxmotion have very strange international shipping policies; they only use expensive UPS shipping and that will easily double the cost of the parts. I recommend giving these guys a miss in favour of the RMP.


Motors with spur gear reduction




These are a cheap but fragile option. The gears never seem to hold up and stories of gears stripping during the first match are common. I will find links to the best options.

Hacked Servos
This could be a topic all by itself - hacking a servo is common in antweights, but the bigger servos have plenty of power for a beetle and can be fairly cheap. The main problem with servos is the plastic reduction spur gears and the weak output shaft. If you have exposed wheels, one hit from a spinner will surely break them!

One of the best places for servos and cool accessories is Servo City http://www.servocity.com/ . They have an amazing range of servos and accessories to make them more useful.

Acroname have a range of wheels for servos http://www.acroname.com/robotics/parts/c_Locomotion.html They look to be very light, but fragile too - definitely for use inboard!

One of the main problems with modified servos is that they are SLOW! The link mentioned in the next post is about the best description of speeding up a servo on the web.
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Last edited by Nick on Sun Oct 02, 2005 10:04 am; edited 2 times in total

Post Wed Jul 20, 2005 2:12 am 
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Ali



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http://www.teamkiss.com/antweight.html
Some good servo hacking guides and tips
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Post Wed Jul 20, 2005 2:16 am 
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Glen
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and www.lynxmotion.com has an absolutely gargantuan range of drives which are really popular along with their wheels.

http://www.lynxmotion.com/Category.aspx?CategoryID=50

also a little tip with those foam wheels from dubro and dave brown (lite flite), if you rub a bit of hot glue around the edges its supposed to give you a tad more traction, and also makes a great repair method if chunks start coming off them.

and some more beetle first hand advice. DO NOT attempt to use the VCR drive belts from dick smith as a weapon belt. they are extremely stretchy and weak and will just snap with no warning. not to mention they are much too narrow. O-rings are a better alternative.

the p9004 motor from dick smith is also a great little powerhouse for $4 or so. ive run it at 7.2v - 18v and just havent broken it. its used in about 3 different spinner versions and axe bot (lots of loading and stalling). without doubt the best CHEAP motor you can get for the purpose. not to mention dse have a belt set that presses straight on.

the AA 700mah Nicads from jaycar are also a good option. from the packs andrew and angus' have shown us they are the same cells that come with those 6v race packs at tandy. they last a long time powering a p9004 (more than enough for a match) and also are good for 10 amps instantaneous and at least 3 amps conservatively.

cybot drives - cheap, available, low power. slow turning at 110rpm but have really low power usage and its easy to change the wheels as the normal ones are just solid rubber = heavyness. just make sure to change the wires on the motors as one is a tiny piece and the other is just a strand of wire with no insulation (uses a piece of heatshrink instead wierdly).

and lastly dont overlook the humble set of lego gears, the wider ones. i use a set of 2:1 lego gears in the axe bot and with a 2/3 drill motor at 18v and a 270 degree swing time of about 1 frame of video they are still fine and dandy.

\ transmission over!
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Post Wed Jul 20, 2005 6:19 pm 
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Nick
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Drive Motor controllers

All these controllers are available from the RMP http://www.robotcombat.com/marketplace_ant_esc.html and from the manufacturer’s sites. There is an excellent feature comparison here: http://www.robot-power.com/products/compare-ants.html


SOZ MX controller



http://www.robotcombat.com/images/store_scorpion_conn.jpg

A good controller but lower powered than the Scorpion. It also has less protection against shorts and high current.


Barello 150 controller



http://www.barello.net/ANT/index.htm

This one is lower powered but is quite cheap and has a decent 15 amp weapon control channel. It comes in a version without the weapon control for an even lower price. This would be a good controller if you were going to use a separate brushless weapon controller.

One of the bad points of the Barello and the SOZ controllers is that they cannot be improved by adding a heatsink to the driver chips, like the Scorpion can.

Scorpion HX



http://www.robot-power.com/products/scorpion_info.html

This controller is probably the best of the bunch, with smarter electronics and slightly higher power ratings. The Robot Power guys give large discounts for multiple purchases, which makes the Scorpions cheaper than the rest if you are buying in bulk. It’s slightly larger and heavier than the others but the difference won’t be noticed. I really like the extra indicator LEDs and the improved current limiting.

UPDATE: I have now installed a scorpion in Slash and they are extremely easy to work with. he set up is a no-brainer and the status LEDs make the controller functions easy to check.

The only thing you need to be careful with is the small terminal block. The block accepts up to 16g wire and because the entry holes are so close, I recommend tinning your wires so they will not fray and short out to an adjacent terminal.

I can highly recommend this controller!

Servo switches
With all the choices above why bother? The size and weight will be greater than the other controllers and the cost difference is not all that large either.
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Post Sat Jul 23, 2005 3:11 am 
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timmeh
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Was thinking of building an antweight but if people are building beetles then might build a beetle instead so theres more of them.

How many people have one?
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Post Tue Sep 01, 2009 10:07 pm 
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dyrodium
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I have countless bits. Made a few, but they're not really worth their cost, especially if there isn't any comps going for them... throw in all the lipo, brushless stuff and fancy drive motors/esc and you might well make a feather weight XD
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Post Tue Sep 01, 2009 10:37 pm 
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timmeh
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Hence i was going to build a us 454g ant cos i can get bits for like $50.

In the beginning i just wanted a pocket robot really for taking with me for fun.
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Post Tue Sep 01, 2009 11:08 pm 
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Rotwang
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Totally missed this thread till now.

Anyhow, just thinking about the little soccer bot comp Moth and Daniel have been trying to get of the ground.

Seems to me that one way of getting some XP in the1˝ kg class in Vic is to start with a soccer bot.

I found a box of bits a few weeks ago, early beetle parts that with current esc batteries and radio are now usable.
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Post Wed Sep 02, 2009 9:02 am 
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seanet1310



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im thinking of entering techfest mike posted about a few months ago.
as i also have to make a 1kg sumo bot about the same size next year thought beetle hardware would be a good idea.
Anyone had any experience with Maxon Motors ?
or any more experence with Beetle B62 or other motor in that range other then posted here?
same as the banebot 24mm Planetary Gearmotor or banebot 28mm.
and the lynxmotion mentioned previous here.

Any possible motors i missed that could be of use?

Thanks anyone. any coments on any would be great.

Also Gary i may not have been paying as much attention as i should have.
For the soccer any idea what sizes they where thinking for the soccer bots?
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Post Wed Sep 02, 2009 8:57 pm 
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dyrodium
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I have maxons, they're nice, but too fragile really for long term use, certainly not in the robots we make. They're very efficient though.
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Post Wed Sep 02, 2009 9:38 pm 
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Rotwang
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The little soccer bots were mostly hacked RX cars or trucks. No hard weight limit as I recall.

http://www.allsuburbs.com/robots/botbash/mini-bash/mini-bash.html


Various posts buried on this forum, search botbash.


http://www.allsuburbs.com/robots/botbash/mini-bash/bashminispecs.html


Just looked through Moths rules. 3KG max

As far as cheap drive components we experimented with cordless screwdrivers { Rotorblade} but gave up on them.

Only worthwhile if you wont really small wheels.

Ended up with a selection of RC cars and trucks mostly second hand.

Trick is to find tank steered ones as in more than one of the same so as to have spare parts without having to buy them new.

Off to the tip shop, flee market and school fete. Smile
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Post Thu Sep 03, 2009 8:11 am 
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seanet1310



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quote:
Originally posted by Nick:
Drive motors:


"B series" Motors

Can't quite affors the Maxons? the next best could be the B series motors from the Robot Marketplace: http://www.robotcombat.com/marketplace_ant_motors.html





I am using these in my first beetleweight and they are clearly a low cost copy of the Maxon range. After importing a pair, you would be up for around $115 AUD including postage - still not cheap. Jim at the RMP has won events with these motors in Wallop http://www.robotcombat.com/wallop.html - I believe he uses the 12V 62:1 version, over-volted to 24V. I will have more to report on these when my set arrives. The RMP seems to be the only source of these motors at the moment.

UPDATE: I now have a set of the B16 motors and they definitely live up to the hype. The the only problem is that the motor's rated voltage is just 6V, so running them at 12V is significantly over-volting them and anything more is likely to blow the brushes. compared to the closest priced motors (the small Lynxmotions) the B16 motors are a little smaller, 14 grams lighter and twice as fast.



i just got a large range of B seris motors the B16's motor has a white end cap and states 6v on it.
B62,B104,B231 all have black end caps and state 12v on them.
replacement motor has black end cap and states 12v.

just coundt quite justify anything more expensive
i have 4 spare motors so plan to subject one or 2 to large over volts see what hapens
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Post Mon Oct 05, 2009 5:03 pm 
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Philip
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What armour thickness is required on a beetle to survive a full on attack by the nastiest beetle spinner? I am thinking of stainless steel.

What battery capacity would suit a powerful pusher?

Do any QLDers plan on building a beetle?
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Post Mon Nov 29, 2010 8:22 pm 
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Bort
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This is what I love about the 'new' classes, is that a lot of this is still being figured out.

I use 1000mah batteries but could definitely go lower.

As for what armour is required. I think you've seen the nastiest spinners on the weekend, but perhaps no match was quite long enough to demonstrate their capability.
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Post Mon Nov 29, 2010 8:38 pm 
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