DF02 RTR - hop up help for newbie please

[Biggywiggy]

Hello everyone

Just bought a Gravel Hound XB for my son's 8th birthday. Didn't want kit as wanted to be able to play from day one, but I would like to ease him/us into the RC thing. I would really appreciate help with improving this vehicle. I'm thinking:

1) Oil dampers- Friction dampers with XB doh! what's the best oil filled/aluminum replacement part and the cheapest place to buy it in UK? (do I have to buy oil separately?). Also, when I was 9 my Bigwig had oil dampers...

2) Other parts they downgraded for XB

The steering linkage tie rod and the front turnbuckle shafts - do I buy part number 53788 and I'm up to a stock GH?

3) Ball bearing set for wheels (which ones? where from?)

4) To save on postage I'm happy to add a few extra "Essentials" to this order for upgrades over the next couple of years, e.g.

a) Sport tuned motor

Motor heat sink

c) anything else? (I've ordered a 3600mAh battery and 3A charger)

[XV Pilot]

Good choice - the DF02 is a lot of fun in stock form, and becomes even better with a few choice upgrades.

AFAIK the XB Gravel Hound does come with oil dampers, albeit rather inadequate black plastic ones that leave the rear of the car very under-damped, letting it bottom out easily over jumps. Ansmann alloy oil dampers work well on the DF02 however, 75mm for the front, 95mm for the rear. Modelsport stock them. When you order them, also order a bag of red Tamiya O-rings, as the Ansmann shaft seals aren't great. The rest of the shock is excellent though, and really good value.

The Tamiya turnbuckle set (53788) is a hop-up - even the kit DF02 comes with fixed-length plastic arms. It is a good hop-up though, and I would recommend it. Tony's Tamiya Parts on Ebay has them.

Bearings are a must throughout the car - I'd recommend rubber sealed ones for offroad use. RCBearings.co.uk is the place to go for these - they'll sell you a full set containing the correct sizes.

The stock silver can is fine for a beginner, but when upgrading I wouldn't go for a Tamiya Sport-tuned motor, as they are sealed, and for offroad use you'd want something rebuildable so you can take it apart and clean the muck out of it periodically. The Etronix Sport-tuned 27t motor is rebuildable, reliable, and more powerful than the Tamiya Sport-tuned. It can give the Tamiya Dirt-Tuned motor a run for its money at a fraction of the price. Modelsport stock them.

With a motor upgrade, the soft aluminium stock pinion will wear even quicker than usual. Go for a hardened steel RW Racing one instead. Modelsport sell them too.

Another part that would benefit from an upgrade is the long propshaft that runs down the centre of the buggy. The stock plastic item can warp under stress even with the stock silver can, and would really struggle with an upgraded motor. As the DF02 uses the same propshaft as the ubiquitous TT01, there are numerous different options available from different suppliers in either aluminium or carbon.

A motor heat sink is a good idea, but go for a low-profile one otherwise you may need to cut a hole in the bodyshell to clear it. You might also fit an alloy motor mount, as this also helps with motor heat dissipation. Fusion Hobbies stocks the GPM alloy mount, and most places will be able to supply the Tamiya one.

If you are upgrading to turnbuckles, you may also want to upgrade the rest of the steering assembly. You could go for the ballraced aluminium Tamiya steering rack, but it costs a lot. It is far better value to get the GPM aluminium steering rack from Fusion Hobbies, and replace the supplied nylon bushings with ballraces from RCBearings.co.uk. This approach costs less than half as much as the Tamiya parts, and is every bit as strong and smooth-running.

Depending on what terrain you plan on running on, you might want to consider alternative tyres. The kit tyres are fine for offroad use but wear out rapidly on tarmac. If the car is likely to see a fair bit of tarmac use, Ansmann make a suitable set of street tyres that last far longer. Modelsport stock them too.

Finally, the locations on the chassis tub where the lower suspension arms attach are not all that strong, and can let go in a big shunt. They can be made substantially stronger by turning the tub upside-down and filling the hollows under the attachment points with a tough epoxy glue.

I have performed all these upgrades to my DF02, and it runs like a dream. Let me know if you'd like any pictures, or if you have any queries!

Edited September 14, 2012 by XV Pilot

[Biggywiggy]

Fantastic advice, thank you so much. I'm going to place an order for a heap of this stuff. A few follow ups if you don't mind:

1) Which hardened steel RW Racing pinion gear would you recommend? there are 78 different ones! I guess this is all about gearing, but your recommendation, and ideally a part number would be awesome

2) Will the Etronix Sport-tuned 27t motor be OK on the standard ESC?

3) Pics of you DF02 would be great

4) Exactly where and which epoxy glue? (pic?)

5) Any other special tools, greases, oils I should buy to keep this thing running?

Edited September 15, 2012 by Biggywiggy

[XV Pilot]

Glad to help!

As for pinions, with a stock spur the DF02 takes 0.6 mod pinions with 16, 17, 18 or 19 teeth. The kit comes with a 19-tooth pinion as standard, so I would assume that the RTR does likewise. You might want to start your youngster off with a 19-tooth pinion, and then reduce the number of teeth as he gets better at handling the car, since fewer teeth = taller gearing = higher top speed. If you plan on going racing, you might want to get all four sizes, as different track layouts call for different gear ratios. However for general bashing use, I find that the 17-tooth pinion gives satisfying performance on a 27t motor without stressing it or the ESC. Here is a link to the pinions you'll need: http://www.modelspor...ibuteID[41]=647

The Etronix Sport-tuned 27t will be a good match for the stock ESC. The stock ESC is able to easily handle any 27-turn 540-size brushed motor.

Here are some pics of my DF02, wearing a Rising Storm bodyshell and FTX Vantage wheels and tyres:

In the photo below, you can see the Ansmann alloy shocks and Tamiya turnbuckles. I also added some blue anodised wheel nuts, but they are for looks alone and were more of an indulgence than anything else.

As in the first photo, but from a different angle:

In the photo below, you can see the GPM aluminium steering upgrade fitted with ballraces in place of the supplied white nylon bushings. It is a significant improvement over the stock arrangement:

This is what I meant when I referred to a low-profile heatsink. You can also see the blue alloy motor mount. The car has a Reedy MVP motor fitted in this shot, as the last people I raced with were sticklers for ROAR legality:

The areas that would benefit from epoxy reinforcement will be easy enough to spot once you have the car in front of you. Just flip the chassis upside-down and remove the bumpers by undoing the screws indicated with the blue arrows in the picture below. You will then see hollows in the areas indicated by the red arrows:

To reinforce my chassis I used Pratley Steel Epoxy, which I then painted black once it had fully set. To help it get into all the corners, I warmed the chassis gently with a hair dryer during application, as this temporarily thins the glue and makes it flow more easily. It also speeds drying time. The reinforced chassis looks like this: (This is my spare chassis tub.)

As for special tools, I do all my Tamiya maintenance with a good-quality Stanley crosshead screwdriver and Allen key set, along with the little box spanner that comes with the car. Occasionally a pair of long-nosed pliers comes in handy too.

Regarding lubricants, Tamiya AW grease is very good, although there are numerous other greases on the market that work just as well, and many people swear by good old Vaseline for model car use.

If you are going to go for the Ansmann alloy shocks, and want to upgrade the shaft seals using Tamiya O-rings, you'll need to refill the shocks with oil after doing so. I use Associated shock oil, 15wt as the holes in the Ansmann pistons are quite small.

Hope this helps! Let me know if you have any other queries.

Edited September 16, 2012 by XV Pilot

[Biggywiggy]

Thanks again XV Pilot,

I really couldn't have hoped for such great advice.

I bought a load of Parts:

* GPM: Aluminium front and rear shocks, front and rear Alu shock towers, Alu steering assembly, Alu tie rods, Alu main shaft, Motor heat sink clamp

* Boom racing rubber sealed ball bearing set (12 5*11*4mm, 4 8*12*3.5mm)

I think I got carried away given my son hasn't even opened the box yet! (remind myself its a present for him on his 8th Birthday...)

My plan is to fit one or two bits with him each week to get us both into RC together.

I'm thinking next week (once he's actually opened it...) I'll make another purchase of:

* The Pinion gears you mention, an alloy motor mount (GPM or Tamiya), the Etronix motor (don't plan to fit these for a while until he's used to the stock car)

* Epoxy

* I might even get some alternative "Truggy" wheels

Which brings me onto a few more questions:

Pinions - I'm a little confused about the gearing. I read that DF02 standard is 70T spur and 19T pinion (FDR of 9.58:1, which I'm interpreting as 9.6 turns of the motor to one turn of the wheels). 70T with 16T gives an FDR of 11.38:1, so higher acceleration and lower top speed. Switching to a 16T has been recommended to balance larger truggy wheels. Have I got this wrong? you mentioned "You might want to start your youngster off with a 19-tooth pinion, and then reduce the number of teeth as he gets better at handling the car, since fewer teeth = taller gearing = higher top speed". Also do I need to use threadlock to keep the pinion screwed on? Anywhere else that needs threadlock?

Epoxy - Would I need two of the 40ml of the Pratley epoxy (http://www.creatrix....w&product_id=10)? Would a couple of these cheaper ones from Amazon do? (http://www.amazon.co...xgy_auto_text_B )

Truggy Wheels and Tyres - Dirt Hawg 2 truck tyres (2.2 inch mounting diameter) with HPI Split 5 truck wheels (2.2 inch, 12mm hex). Can you see any problems with this set up? will I need to glue the tyres?

Thank you

Edited September 16, 2012 by Biggywiggy

[XV Pilot]

Hello again!

Firstly, sorry about the confusion regarding the pinions. You are quite right - I had it backwards. Smaller pinion = fewer teeth = more acceleration and less top end. So starting with a smaller pinion and working up to a larger one would be a good idea - basically the opposite to what I said earlier. Talk about brain fade...

You're quite right about needing to put on a smaller pinion to compensate for larger wheels. I'm afraid I can't comment on the suitability of the HPI wheels or Dirt Hawg tyres you mention having never tried them, but yes, gluing the tyres is recommended. However if you are going to get alternative wheel sets for the car, you may want to consider getting a few different sets of standard 4WD buggy size wheels/tyres with different types of tread for different conditions. Then you can swap them around without having to swap pinions, and you won't be placing any extra stress on the axles or drivetrain.

A drop of threadlock on the pinion grub screw wouldn't go amiss. Be sure to use low grip threadlock though, as the strong stuff can make the pinion impossible to remove - the Allen key just rounds out the socket in the grub screw and you end up having to drill it out, usually damaging the pinion in the process. I can't think of anywhere else that would benefit from threadlock on the stock parts, apart from possibly the screws that secure the motor to the motor mount. When you fit the GPM parts though, all metal-to-metal fixings should be threadlocked.

As for the GPM parts, that's quite an order you have there! You may want to reconsider the aluminium shock towers though. They undoubtedly look nice, and are undoubtedly stronger than their plastic counterparts, but ultimately that is their downfall. If a car with the standard springy plastic shock towers is involved in a shunt, the towers bend, and usually spring back to shape with no harm done. If it is a major shunt, the plastic towers may snap, but that isn't such an issue as they are quick and cheap to replace. However if a car with aluminium shock towers is involved in a shunt, the impact forces are transferred through the stiff aluminium towers to the relatively weak and brittle plastic diff housings, and if they crack, they are more of a hassle to replace. Plus, in a major shunt the aluminium towers themselves may get tweaked. They don't spring back to shape, and are a right pain to straighten out again. In short, aluminium shock towers are great for DF02 shelf queens, but runners are usually better off with plastic ones. The same argument applies to lower suspension arms BTW.

If you are able to review your GPM order, you may also want to think hard about the aluminium tie rods. In your original posting, you mentioned Tamiya part no. 53788. This pack contains hardened steel turnbuckle tie rods, upper suspension arms and an adjustable link to run from the servo saver to the steering rack. It costs about twice as much as the GPM ones, but the rods are far stronger, and instead of just three rods, you get all 7.

Regarding the epoxy, you shouldn't need two packs - one pack contains more than enough material to fill the hollows. I know the Pratley epoxy is very good, but I have not used the V-tech stuff so cannot comment on its quality. My guess is that it would be fine though - as long as the glue is as strong or stronger than the plastic tub moulding, it'll do the job. You might also want to get the epoxy sooner rather than later, and add the reinforcement before the car is taken for its first run. Maybe even do it before giving the car to your son, as I am sure he will be very excited to receive it, and will probably want to start using it right away.

Do keep us posted with your progress!

Edited September 16, 2012 by XV Pilot

[Biggywiggy]

So much fun!

Took my son and his new toy out in standard trim on Saturday morning on a gravel athletics track, grass banks and a ramp I made by cutting down a grocery box ("Epic fun" apparently).

My boy and I then added the ball raced wheel bearings (8x), and the motor heat sink, and went back for an afternoon run. Definitely ran better with the new bearings, and the heatsiink was hot to touch after second battery we ran.

cleaned car

Major hassle with the next upgrades we put on, the GPM Alu front and rear shocks. They came with the wrong bolts (technically machine screws), different length and pitch to the Tamiya parts. Managed to bodge them on by mixing washers and borrowing the bolts from the GPM steering assembly. An ebay order of M3x16mm stainless panheads and M3 washers should set things right.

The new shocks did really helped with the ride when we went out Sunday - especially from more ride height from the longer shocks and switching to inner most hole. Need to soften the rear for next run as it kicked hard on bumps.

Cleaned car again. Wet grass then mole hill, then wet grass, then mole hill! he was having too much fun for me to stop him, but car doubled in weight with mud!

Also ordered:

epoxy

Tamiya metal motor mount

The Etronix Sport-tuned 27t motor (we'll add this once he's got the car under control)

Ansmann Racing RW .6 Module Pinion Gear

Edited September 23, 2012 by Biggywiggy

[XV Pilot]

Glad to hear you are enjoying the model!

As for the bearings, you'll find your pack came with 12 small bearings and 4 big ones. 8 of the small ones go in the wheel hubs as you already know. 2 more small ones go on the shaft that holds the drive cup at the front of the propshaft, and the remaining 2 go on the shaft that holds the rear drive cup and spur gear. The 4 large ones go on the differentials.

Did your car come with a manual? If so, that should show how to fit them. If not, manuals are available on Tamiyaclub.com, or let us know and we can talk you through it.

Good luck!

[Biggywiggy]

My boy is really starting to get the hang of the car (nice figure 8s etc.), so I'm starting to think of putting in the Etronix Sport-tuned 27t motor. I'd realy appreciate some tips on wiring up the motor

I've taken a photo to illustrate the questions I have

http://www.msuk-forum.co.uk/gallery/image/18233-/

* Do I solder the the wires to the two copper tabs at one end? (pic shows the red wire tucked under one of these)

* Not the two with fine wires attached I assume (motor is resting on these)

* These tabs have a slot and a hole in. Do I ignore these and just solder flat to the top of the tabs?

* Do I need to use flux as well as solder wire?

* Do I need to remove the little white thing that is wedged behind one of the copper tabs against a green cylinder? (under the tab that i haven't put the wire under)

* Red wire on the right if looking end on with tabs facing at the top? (as shown in the pic, just solder it flat on the top instead of underneath as shown)

Edited October 15, 2012 by Biggywiggy

[XV Pilot]

Okay, let's see.

Yes, you do solder the wires to the copper tabs.

It is easier to solder them to the tabs not already occupied by the capacitors (the things with the fine wires).

The slot and hole are for push-on clip connectors. Ignore these and solder straight to the topof the tabs.

If you use resin-cored solder, you won't need additional flux.

I don't know what that white thing is. I have several of these motors in my various buggies, and none of them have a white thing. My guess is that it is a stray piece of packaging material. Go ahead and remove it.

If you look at the motor end-on, the black bit in the middle between the copper parts has a little + symbol on one side. Solder the red wire to the copper tab closest to the + symbol.

Hope this helps!

[Biggywiggy]

Thanks again!

So far we've fitted:

• Ball bearings in wheels (x8)
  
• Front & rear shocks
  
• Shock socks
  
• Foam tyre inserts (what a pain!)
  
• Front alloy Shock tower (platic one bent in a crash)
  
• The Epoxy
  
• motor heat sink
  

Next up the remainder of the bits I bought (think it makes sense to do most of this together)

• Rear shock tower
  
• Modified motor
  
• steel pinion
  
• Aluminium drive shaft
  
• Tamiya motor mount
  

I might also change the other bearings in the drive train for the remaining ones from the set I bought although I'm not sure there is much difference. Also contemplating getting some molybdenum grease rather than use the Tamiya anti wear grease (that looks a bit like Vaseline) that came with the car for the bevel gear bits.

Edited October 16, 2012 by Biggywiggy

[XV Pilot]

Sounds like your DF02 is coming along very nicely indeed. Any chance of a photo or two?

[Biggywiggy]

I'll grab a few snaps and post em up (needs a clean first...)

[Biggywiggy]

http://www.msuk-forum.co.uk/gallery/image/18282-/

http://www.msuk-forum.co.uk/gallery/image/18283-/

http://www.msuk-forum.co.uk/gallery/image/18284-/

http://www.msuk-forum.co.uk/gallery/image/18285-/

Needs a proper clean now

I'll do the alloy tie rods, steering mechanism and all those motor/drive mods while I'm at it

[XV Pilot]

Looks like it is coming on well! I like your shock socks. Where did they come from? It would be nice to see how it looks with all your hop-ups installed!

[Biggywiggy]

Thanks. Shock socks were from ebay

http://www.ebay.co.uk/itm/280969062345?var=580136917531&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Car is getting a full tear down and hop up today / tomorrow

[Biggywiggy]

Took a while

http://www.msuk-forum.co.uk/gallery/image/18382-/

But here it is

http://www.msuk-forum.co.uk/gallery/image/18379-/

http://www.msuk-forum.co.uk/gallery/image/18380-/

http://www.msuk-forum.co.uk/gallery/image/18381-/

Fully tweaked:

• Ball bearings throughout
  
• Front alloy Shock tower
  
• Rear shock tower
  
• Front & rear Aluminium shocks
  
• Shock socks
  
• Foam tyre inserts
  
• Epoxy reinforced suspension mounts
  
• Etronix 27T sport tuned modified motor
  
• Tamiya motor mount
  
• Alloy motor heat sink
  
• Hardened steel pinion gear
  
• Aluminium drive shaft
  
• Alloy tie rods
  
• Aluminium steering mechanism
  

[XV Pilot]

That looks very neat. Glad you got the motor leads sorted. Do you have any further plans for it, or are you happy with where it is now?

[Biggywiggy]

No further plans other than going and driving it! New motor definitely seems much faster, although It's only been bench tested so far. Thanks again for the advice on wiring the motor - nearly had a disaster when a big blob of solder rolled off the copper tab and into the motor! but eventually got it out (phew).

I'm actually thinking about getting this:

http://www.modelsport.co.uk/kyosho-dbx-ve-2.0/rc-car-categories/24/9900/990010&ChassisID=941

(with 3s lipo)

or a second hand one of these:

http://www.modelsport.co.uk/traxxas-slash-4x4/rc-car-categories/60/9900/990010&ChassisID=662

[chewbacca]

Have enjoyed this thread, very informative especially as I have a Plasma Edge on my wish list (DF-02 Chassis)! Quick question for you XV, would the aforementioned Ansmann shocks fit my DT-02 Chassis?

[XV Pilot]

Hi!

Glad the thread was useful. Yes, the Ansmann shocks are a good fit for the DT02 chassis. I have a set on mine:

[NuttyProfessor]

Sick mate!

[chewbacca]

Cheers XV, you've made my life that bit easier! And I have to agree with The Professor, that is one sick ride. Gives me something to aim for.

[NuttyProfessor]

Id love those rims but in 1:8 size.

[mxfun]

Just read through this thread ,great stuff ,father and son spending time together and having fun also building a buggy