MB diff

[Headcase]

Hey chaps.

Does the MB have a limited slip diff?

Can it be turned into a solid axle?

Would a lack of slip be a good thing?

Thanks! []

[Shodog]

Are you talking about the Monster Beetle? It doesn't come stock witha ball diff. Thorp and Robinson made a ball differential but they can be pricy as Tamiyabeaterfleet has found.

http://www.tamiyaclub.com/forum/topic.asp?TOPIC_ID=8548

You could use a subaru brat solid drive gear. two problems with this is that they are probably rarer to find than a Thorp diff and with the solid axle an torque from the motor would make it almost impossible to turn.

Jim

[Headcase]

Thanks, Shodog.

I don't have buckets of money, so i better be happy with what i've got!

I don't suppose anyone knows the highest turn motor i can fit into the Monster Beetle and still keep the front wheels on the road?

[mymonsterbeetleisbroken]

not sure what the highest turn motor you can use is, but more powerful motors put a lot of strain on the diff and can cause it to seperate[8)]

only saying this from my past experience[]

i run a locked diff in my MB, it makes it slide about a lot but helps it to handle well in long grass, but i wouldnt recommend it on tarmac unless you like dohnuts[]

i find it still steers fine with a locked diff, in fact it turns really sharply if you speed up fast when turning as it brings the back around, it takes a lot a prctice but looks well cool[8D]

[Headcase]

Hey MMBIB.

Which diff do you have fitted?

Is there an off-the-shelf replacement that's stronger than the standard one?

Rick

[mud4fun]

Don't try running a hot motor in a stock blackfoot or monster beetle as the gearbox just isn't up to it. I tried a Kyosho meyhem truck motor in my blackfoot and the gearbox simply 'slipped' all the time due to increased torque. Locking the rear diff is only useful for severe off road terrain, on 'high traction' surfaces locked rear ends cause poor steering and potentially spin outs on cornering - I know as I have a very powerful SRB chassis that likes to do 180 degrees on every bend of our circuit!!!

[petercabrio]

What is the maximum size motor to use with a stock monster beetle diff without it needing constant attention? i have a esc capable of 13 turns

I have seen motors like Mtroniks Vision Modified 17x2. what does the x2 mean?

Also what about batterys, i have seen lots about sanyo being the best but surely if a battery is rated to 3000mA this is the same for all makes. Is it just the smallest difference that only hardcore racers can notice

these seem reasonable for 3000mA from folley models on ebay

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...egory=1200&rd=1

peter

[DJTheo]

quote:What is the maximum size motor to use with a stock monster beetle diff without it needing constant attention? i have a esc capable of 13 turns

id="quote">id="quote">

I wouldnt go lower then 17 turns on MB, it already may be too powerfull though, better a more turns large can 550 type motor, which has less RPM and more torque.

quote:I have seen motors like Mtroniks Vision Modified 17x2. what does the x2 mean?

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id="quote">id="quote">

x2 means doulbe turns, a thinner wire is wounded double (parallel) instead of using a thicker single wire, this way you can get a bigger crossection of wire in the armature.

quote:Also what about batterys, i have seen lots about sanyo being the best but surely if a battery is rated to 3000mA this is the same for all makes. Is it just the smallest difference that only hardcore racers can notice

these seem reasonable for 3000mA from folley models on ebay

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...egory=1200&rd=1

---

id="quote">id="quote">

Sorry but only the nominal capacitance is similar, but not the resistance, discharging curve, how well the cells are matched, even how the capacity is measured (like some cheap stereos stating 500W PMPO which is equivalent to something like 5W RMS at 1% distortion), but also the GP cells you found are not bad.

Cheers

[petercabrio]

thanks theo

that helps a lot

peter

[mymonsterbeetleisbroken]

hi headcase,

i made up the locked diff by putting a nut and bolt through it![]

[mud4fun]

I agree with DJTheo and I would go further and advise against anything less than 22turn. The MB/BF gearcase is a poor design which Tamiya rectified with the later super and king blackfoot designs.

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I also found that double and triple turn motors produced less torque which is not ideal for your MB as it is relatively heavy compared to touring cars which most racing motors are designed for. The large tyres also require more initial torque to turn them and the MB is not low geared so low torque motors will struggle.

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The rear driveshafts on the MB/BF are also prone to wear badly and are difficult to source so again more power will only aggrevate the problem.

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I have a blackfoot and I have gone down this road already......[] In the end I fitted a cheap futaba ESC and a £29.99 stock motor (22t I think) and it works well enough.

[petercabrio]

I have just bought a 20 turn motor and fitted it into my monster beetle and now

my monster beetle is broken

the counter gear that is driven by the motor (53 tooth?) and has blackfoot on it, its plastic and has a 17 tooth smaller gear aswell, has pulled a tooth off the 17 tooth part.

1) can i get a stronger one that fits the king blackfoot / blackfoot extreme?

2) is the monster beetle one better than the blackfoot?

3) i also have a frog 49 tooth gear that has a brass smaller gear, can this be used with a larger spur gear or is this going to make the problem worse?

4)my pinion gear is 10 tooth, is this correct?

sorry for so many questions but im stuck - well just spinning actually

peter