Any crawler drivers on oople?

[Timee80]

Ive spent a bit of time looking at crawler vids on you tube recently and some look really good. Does anyone on here own one and crawl competetively? is there much interest or would you say its a dying side of rc?

[jimmy]

Hey mate, yes there's a few for sure but I'll let them confess. What sort of crawling are you looking at? I must say I like the scale stuff myself tho I've only got as far as buying my land rover shell so far

[Timee80]

the scale stuff looks good but i imagine you could easily spend a fortune on making it look "real". Its the 2.2 comp crawlers that im most attracted too. Ive been creating a shopping list and the cost is already crazy.
So far on the wish list:-
Axial xr10
2x brood 35t motors
Punk dig
Servos (my buggy stuff is too fast and too weak to be useful)
2x tekin fxr speedos
New radio gear with 3 position 3rd channel
HB sedona tyres

The list can easily go on. Ill be purchasing a lucky dip next week (youve got to be in it to win it!)

[terry.sc]

I own a few, been crawling since 2006 when you had to scratch build your own as there were no crawler kits, but been a couple of years since I crawled in competitions.
I have a
Clod based 2.2 http://www.tamiyaclub.com/showroom_model.asp?cid=77490&sid=297
Clod based Super http://www.tamiyaclub.com/showroom_model.asp?cid=77493&sid=297
and my competition Berg http://www.tamiyaclub.com/showroom_model.asp?id=297&cid=85784

There has never been too much interest in competition crawling in the UK, South Derbyshire model car club used to hold monthly competitions on their purpose built course which were quite popular but they have stopped now. Usually the competitions are small get togethers organised by the people competing, you can see what's currently happening here. (http://www.rccrawling.co.uk/default.aspx?g=topics&f=7)

Looking at your shopping list you have both a Punk dig and two FXRs when you only need one ESC. The dig is used with only one ESC, the dig disconnecting the power to whichever motor you want to brake. With a 3 channel radio and two ESCs you would be running both ESCs off the single throttle channel with both ESCs connected to the input on the dig unit, a bit like powering a motor by having two ESCs connected to it. If you want to use two ESCs then you will either need the Novak 'the Dig', a radio with sophisticated channel mixing or a 4 channel stick radio so you can control both throttles at the same time.

For a servo there's the old favourites the Hitec HS-7995TG or HS-7955TG, or their better modern versions the Hitec HS-7954SH or the HS-7950 which both can run direct from a 2S lipo. A cheaper alternative is the Savox SC-1256, I use a pair of these in my Super and they manage to steer the 4" wheels no problem. You will also need a separate BEC to power the servo, the Tekin can't give out enough power. If you are using high voltage servos like the 7950 and you are running 2S lipo you can run it direct from the battery, but otherwise I would recommend the Castle Creations CCBEC as the 10A output means the servo always has enough power to steer.


For more help www.rccrawler.com (http://www.rccrawler.com) is by far the biggest crawler site although it is a typically american site, and if you are into the competition side then www.rccrawling.co.uk (http://www.rccrawling.co.uk) will put you in contact with the competition organisers.

[Timee80]

Thanks for the very informative reply. i have been on both the sites mentioned and both are very useful. I have a dilemma though. Ive already got some electronics spare from racing buggies including a brushless esc. I know that running a shafty would be cheaper for me because i could stay brushless, but if i go down the moa route which alot say is more competitive, i would have to go back to brushed (which i dont really like the idea of TBH). Either way i want a kit to build as i enjoy building as much as racing (or in this case crawling)
I suppose the big question is, can a shafty compete with the moa boys??

[colmo]

For UK crawling, visit www.ukrcrc.com

MOA is generally more competitive than shaft due to belly clearance. A lot rests with the driver, though.

Its perfectly possible to do a brushless MOA - 2 x cheap Hobbywing speedos (the Justock or EZrun is fine) and sensored or sensorless motors to suit.

I'm a fan of outrunner brushless motors in shafties - the EZrun 25A + Turnigy 1000kv outrunner in my Losi cost me under £30 and has more than enough torque to lunch the drivetrain if the wheels jam. Alas, I'd be concerned their spinning cans (yup, that's right) would be vulnerable on the axle of a MOA.

[Timee80]

do you need to use a 3s lipo to get enough wheel speed with that motor? I never realised you could get away with a small esc like that in a crawler without making it give up the magic smoke. Always assumed it consumed alot of amps because of the torque needed.

What do you guys think of the venom creeper? Reviews ive read all seem positive

[colmo]

I'd maybe get a 1600kv-2000kv motor as it is quite slow on the worm-drive of the Losi. I stuck with 2s for simplicity - I got a tiny 2200mah pack to mount on the rear axle, haven't got round to doing that yet.

Crawlers don't consume much power, run time on a small pack is 20-30mins+ - amps can spike with an outrunner, but those Hobbywings have very good peak amp ratings.

The Venom Creeper suffers poor support in UK, though you break stuff less often with crawlers than in racing - the diff lock feature is unique afaik. Most competitive MOA is Axial XR10, and shaft, Losi Comp Crawler. Berg and G-made have some nice options, but you have to import, and there are some crazy torsion chassis out there too.

For fun, the Axial Wraith looks great, and who knows, may be competitive too! Its not really a 2.2 comp crawler though.

[terry.sc]

do you need to use a 3s lipo to get enough wheel speed with that motor? I never realised you could get away with a small esc like that in a crawler without making it give up the magic smoke. Always assumed it consumed alot of amps because of the torque needed.

What do you guys think of the venom creeper? Reviews ive read all seem positive
Unless you are running the Losi comp crawler if you are running a 35T motor you should have enough wheel speed for most situations with a 2S pack unless you intend to launch it up a slope. The torque is generated by the motor wind and gearing, not through the current draw. My Berg runs happily on 2/3A cells from 1/18th scale cars.

Realistically, if you want to use your racing brushless ESC if it doesn't have a decent drag brake option you are limited to something with worm drive axles such as the Losi comp crawler, without a strong drag brake everything else will roll backwards when you let off the power which will cost you points in a competition. If you are using anything but a Losi comp crawler then you want a motor around 1000kv, ideally an outrunner, to generate enough torque to give you slow speed control. I've never run brushless in a crawler, it's so much easier to get smooth low end throttle control and powerful braking with a brushed system. Brushed in a crawler is virtually zero maintenance, the low speed and current draw means the brushes and comm only need the occasional check and you might want to clean them up once every few months rather than every week in a buggy or tourer.

The Venom is currently being sold off cheap by CML, it's not the best choice as by the time you've added the remote diff lock kit and dig kit you have spent more than an Axial cost, but the biggest downside is when you break it (and you will break it) there are no readily available spares and the only hop ups for it are made by Venom. The Creeper is a nice kit, but the remote diff locks are more of a gimmick as you will have them permanently locked when crawling.

Whether a shafty can compete with a MOA is entirely down to the driver, MOAs have some advantages such as lower centre of gravity the shafties also have advantages such as axles locked together so no clod stall and worm drive axles mean guaranteed no roll back when stopping on climbs. The top drivers use MOA, but all those same drivers with shafties would beat everyone else running MOA. It's more important you get in lots of practice so you know how your truck reacts in any situation than what drive system it uses.

[Timee80]

if i want an moa, it seems pretty much obvious id be looking at an xr10. If i go shaft driven and want to build it myself, what are my options?. Weve dismissed the creeper and the only other kit that comes to mind is the ax10. Is this now too old to compete? Or is it still capable in the right hands? There seems to be lots of different rtr's available but i have never like this idea with anything i have previously bought

[Timee80]

just looked at some 1000kv outrunner motors and they all seem to be sensorless. Is sensorless ok in a shaft driven crawler then?

[colmo]

The Losi Comp Crawler is competitive out of the box - key features are the dig (Night Crawler doesn't have this) and worm driven axles. My crawler has the night Crawler transmission, but its not used in competition (no competitive scene in Ireland, alas). A consequence of this is a huge turning circle!

It can be converted to MOA using a kit from Eritrex.

Outrunners have more poles and more inertial spinning mass than inrunners, so do not cog easily. The only time it does in mine is when wheels are bogged, which is a good thing! They also weigh far less (60-70g), helping with CoG. You'll need to use the supplied motor bracket to make it fit the mount intended for an inrunner.

The Hobbywings have immediate forward/reverse modes and 100% drag brakes (not used with worm axles), so ticks all the boxes for a crawler ESC - the Justock is very cheap from Giantcod (who also do inrunners), is 45A compared to my 25A (I don't see it for the £15 delivered I got it for anymore!) and is versatile enough to be used in something else if you decide to move to a different powerplant. Only downside is its not waterproof.

My intended layout for the Losi is battery on rear axle, esc on rear plate, rx on front plate and servo in normal position on front axle. Some try to get all the electrics on the axles, which a bit harder to do. Wheels weights then to be added to taste.

A popular radio for crawler is the DX3E as its cheap and has a 3 position (for the dig) 3rd channel.

[mrspeedy]

If you enjoy the building and modifying then the way to go is with the Axial AX10 IMHO. They're pretty tame out of the box but can be easily and cheaply modifed with home made custom chassis and links to really improve clearance and climbing ability.

They'll run quite happily on a brushed 55t motor and a 1300mah 2 cell lipo will give at least 30mins run time.

A few of us in the South West use these with the Landy shell, you get awesome climbing and reasonable scale appearance at the same time :thumbsup:

http://img263.imageshack.us/img263/2366/042sw.jpg

http://img824.imageshack.us/img824/1262/044es.jpg

And a wee vid - http://www.youtube.com/user/metalmickey0#p/u/12/BkZW_3aa7D0

[Timee80]

After much research and listening to you guys i think the crawler that best fits the bill will be a losi comp crawler. I know i dont get to build it myself but performance per £ it seems the best shafty available. Its competetive out of thebox and i can use my brushless esc, and a spare low pro to power the dig, buy a cheap outrunner, and use a 1700mah 18th scale lipo pack i already have. I dont have a dx3e but i do have spektrum receivers so should be cheap to sort out.
Are HB sedonas a good allround tyre for most uk driving ?
Which 2000kv outrunner size do i need?. Ive looked and some seem to be really tiny and others are huge
PS Ive spent some time on rccrawler.com and know the worm drive needs some bedding in and looking after

[terry.sc]

Whether a crawler comes ready built or as a kit is kind of irrelevant as you'll be stripping it down at some point to upgrade it and effectively create your own, all that's left on mine that's original are the axles.:lol:

The Losi Comp Crawler is a different beast to most crawlers, the extremely high gearing means most are using normal 17.5T or 21.5T brushless motors rather than crawler specific outrunners. Just make sure that whatever ESC you use you turn off the brakes to help the motor as the worm axles will hold it themselves.

For tyres the Sedonas in white compound are very good, in fact too grippy at times as they can make it difficult to turn with the dig when the tyres won't let the wheels spin. Some like the extra grip, others prefer Sedonas on the front with something less grippy on the rear. HB white compound Rovers are almost as grippy but less likely to bind up the transmission as the tyres will slip under heavy loads. It's all down to personal choice. The foams that come with the tyres are pretty good as well, with a lot of tyres the foams are only worth binning but the HB foams are pretty well matched to the tyres and still work well with heavily weighted wheels, although like the choice of tyres the choice of foams and wheel weighting is down to personal preference and can only be worked out by experimenting yourself.

[colmo]

The Losi Comp Crawler is a different beast to most crawlers, the extremely high gearing means most are using normal 17.5T or 21.5T brushless motors rather than crawler specific outrunners.

It looks like I was nearly right with my estimate of a 1600kv-2000kv motor - 17.5T is around 2200kv, 21.5T is 1800kv. If you match kv, does the small size and extra torque of the outrunner pay off, or is the inrunner the safer option as it draws less amps at peak? I've yet to experiment with gearing up the 1000kv I have, as it has so much spare torque.

[terry.sc]

The gearing on the LCC is so low the extra torque of an outrunner isn't needed and the preferred option is a sensored normal motor due to the much better low speed precision that a sensored system gives you.

If you are running a cheap sensorless ESC then the outrunner is preferred as the extra torque hides the cogging that a sensorless system has at low speeds and when starting.