Lunchbox Front End Conversion

[aconsola 1]

I posted up my recent LB buildup on rc10talk, have a look:

http://www.rc10talk.com/viewtopic.php?f=32&t=10223

here is a teaser pic:

notice the full suspension compression and 0 toe-in, 0 camber

you can't resist clicking now

Mods, if such linking is frowned upon, let me know and I can stop being lazy and repost the entire thing here.

[TA-Mark 191]

I've done the same conversion with the CRP FX-10 double wishbones to my Lunchbox and Grasshopper. Cutting the upper links off the C-Hubs and mounting a ball screw in the top works better. Using a longer bottom eye on the damper and putting a 10 deg bend in the eye gets the damper out so it doesn't rub the chassis. I also centred the steering servo and used Tamiya Top Force turnbuckles so it's all adjustable (upper links and tie-rods).

I didn't need to cut the damper mount point on the arm. It lines up already.

There's no bumpsteer with this front end either... and no Caster angle. I heated my arms slightly and twisted them, now I have a left and a right arm with about 5 deg of Caster.

It hasn't made my Lunchbox handle any better. The front wheels are rarely touching the ground. It does however land from a wheelie better when you back off the power, it's predictable compared to the standard arms.

[mymonsterbeetleisbroken 16]

It's interesting how we all take a different approach to the same thing

Here's how I did mine:

I've got my shocks mounted to the top of the C hubs through the same bolt that holds the upper link arm. I decided to cut down and use the FX-10 chassis piece that the kit came with and use that to secure the upper arms to the pumpkin chassis.

I think it has made a difference to my truck, seems to under steer a little less, lands wheelies better and of course can now go backwards properly

[TA-Mark 191]

Doesn't your wheel rub on the damper with them mounted in the upper link position? With the wheel change they might not. I know the standard VLB wheels do.

I dragged my truck in and gave it a bath so you can see it. Was covered in so much mud you wouldn't have seen anything otherwise. Pics in my showroom of how I did it.

You should upgrade those tiny vintage 4mm ball screws on the steering links to 5mm ones. Stops them popping off with the weight of the big wheels. The 4mm ones are fine on a light Grasshopper. Re-re Lunchbox has the 5mm ball screws as standard.

Reversing is sooooo much better now too, forgot about that in the previous post.

[mymonsterbeetleisbroken 16]

The wheel clears the damper just fine, I guess thats thanks to the wider offset of the blackfoot wheels.

I probably should upgrade those steering links. I've just replaced them all as the old ones were worn out. My shelf queen metallic special has stronger linkage than my brushless runner

[bugjammer 2]

Top mod! - and I so love the axle stand

[Blacque Jacque 3]

I'll jump on that bandwagon - got a set of parts winging their way to me from Morongo Valley as we speak

TA-Mark, what did you mount the inboard end of the upper link to ?

[Leethal Driver 86]

Is that said FX-10 conversion kit CRP part number #1632?

I like the look of this mod, was surprised at how pants the front end is on a VLB esp when going backwards (not that I try to but always come in handy every now and then).

[Blacque Jacque 3]

Is that said FX-10 conversion kit CRP part number #1632?

Yup, if you check the TeamCRP website it mentions the kit being used on various Tamiya's

[RichieRich 355]

...such a lazy post. ;)

Nice mods. Now all you need is one of these bodies.

[TA-Mark 191]

TA-Mark, what did you mount the inboard end of the upper link to ?

Same place as aconsola. To the mounting block that fits to the bottom of the main chassis. 7mm in from the edge and centre of the 'flat' section. Hardened Tamiya hex ball screw with a flanged nut on the inside.

Is that said FX-10 conversion kit CRP part number #1632?

The set I bought was from TeamCRP on eBay and has only the dyed nylon parts. No mounting hardware. I used all Tamiya parts to mount it. Cut off the excess from screw pins. They could be TA01/02/DF01 parts, bits from my 'junk' tub.

Very easy mod to do it to a Lunchbox/Pumpkin compared to the Grasshopper/Hornet. Took me 2 days to get the Grasshopper one fitted up nicely and get working right. VLB took an hour if that.

[TA-Mark 191]

...such a lazy post. ;)

Nice mods. Now all you need is one of these bodies.

That's certainly different... I think I'll stick with my Truck body. Tempted to paint it bright yellow though.

[aconsola 1]

great to see some different installs with the same parts. I didn't even think to mount the shock on the c-carrier, or to lop the tabs off to mount the ball stud vertically, good stuff!

Soon I will finish up th rear of the truck. I already did the 3rd rear shock thing, next up will be the rear supports. Thanks TA-Mark for the pics in your showroom that show the rear braces. Do you have the tops bolted to a long screw through the upper shock mount/u--bracket, or are they mounted separately from the shock?

I hope to run this one in September at the Vintage Nationals race in CT. Ran it last year stock and got whooped by a bunch of blackfoot (blackfeet?) type trucks. This year I will be a little more race-prepped.

[aconsola 1]

...such a lazy post.

Nice mods. Now all you need is one of these bodies.

That's a Dahms, right?

I think it will be a bit tough to find. I'd love to have HPI re-release the vw bus body now that they have that new mini platform for the scale bodies. I had one years ago and it fit great.

[TA-Mark 191]

Soon I will finish up th rear of the truck. I already did the 3rd rear shock thing, next up will be the rear supports. Thanks TA-Mark for the pics in your showroom that show the rear braces. Do you have the tops bolted to a long screw through the upper shock mount/u--bracket, or are they mounted separately from the shock?

Yeap. Nut either side of the ball eye. The front mounts to the strongest part of the swing shaft blocks. Machine screw with a nut on the inside.

I hope to run this one in September at the Vintage Nationals race in CT. Ran it last year stock and got whooped by a bunch of blackfoot (blackfeet?) type trucks. This year I will be a little more race-prepped.

Mine will keep up with a nitro Savage IF I can keep it rubber side down and remember to ease in the throttle so it doesn't wheelstand uncontrollably. Standing backflip if you thump it from nothing to full. Love my Castle MambaMax systems! Make 'Em Cry!

Blackfeet. Hahahahaha

I also have 300g of lead weights inside the rear of the tub right where the swing shaft blocks mount to the tub. This truck needs extra weight over the rear to make the suspension work. The extra weight doesn't affect the powerful motor/esc combo. If I run Li-Po in it (280g pack) I add another lead weight in the battery tray, don't use it if I'm on a 530g Ni-MH pack. To see if the rear of your truck has enough weight in the actual sprung part of the chassis drop it from about 1 foot up and if the rear bounces add more weight.

I have added weight to rear end of my Grasshopper too. The spare wheel that sits on the rear rollcage is not there for show. It is filled with lead weights to make the rear suspension work.

1:1 Tyre wheel lead weights and old lead head roofing nails (nail removed) hammered to the right shape.

My springs are short, I don't have as much pre-tension pulled up on them as you would think. Short springs keeps the weight low in the chassis so it's not so top heavy in a corner. Front springs made of thicker material and stronger than the rear springs. The 5th damper has the same weight spring as the front with quite a bit of pre-tension pulled up on it to take the shock of the Mamba kicking in.

I have foam inserts in the wheels and material tape stuck to the inside of the tyres to stop them from ballooning so badly and the tyre bouncing.

Need to get some video footage of it running my backyard track. So much fun to drive and really keeps you on your toes.

[Blacque Jacque 3]

My FX10 kit arrived today - WOOHOO!!

Quick question for TA-Mark, how did you put that 10° bend in the rod end ?

[TA-Mark 191]

Put a screw in the threaded part so it doesn't bend there. 2 pairs of pliers, grab each end, and hold it over the soldering iron and bend. The bottom eye is from a DF01.

[Blacque Jacque 3]

Yup, Manta Ray ends, used a 100w anglepoise lamp, didn't have a soldering iron to hand.

[TA-Mark 191]

Did you centre the servo? Check pic #6 in my showroom entry. Steers equal left and right then and removes the touch of bumpsteer that remains. It took a creative reshape of one of the plastic servo stays and drill 2 new holes in the chassis.

Try to keep the upper link arms and the steering link arms all parallel to the lower arm.

[Blacque Jacque 3]

I centred the servo when I built it, the FX10 parts need longer tie rods anyway and I may need to put a kink in them to clear the bottom of the shock (I'm using the kit saver for now, don't have a Tamiya High Torque or Kimbrough to hand).

I'm still experimenting with the length of the upper link and the inboard mounting position, trying to get a nice balance between parallel motion & +ve or -ve camber at extremes of travel. I'll mount a ball end horizontally on the front of the C hub like Aconsola's version, rather than drilling as you have done.

[TA-Mark 191]

I did mine this way to help reduce as much unsprung weight as possible. Yes, you will need 2 of the long steering links from a re-re shafts bag (should be already 1 on there unless it's a vintage).

You should be able to slide the servo toward the rear on the servo stays just slightly which will make the links clear the damper. The longer servo horn will give more steering throw too. You can remove a small amount of material from the c-hub to increase steering lock. I removed about 0.5mm on the backside.

[Blacque Jacque 3]

Not a vintage, it's a bitsa, I can't honestly remember if I had the shafts bag or not, I'll have a dig in my box of general spares, failing that, I have plenty of studding.

I think the servo is already pushed back as far as it will go.

I'm not too bothered about getting more steering, it will only make it easier to roll.

[bfst24 2]

Not a vintage, it's a bitsa, I can't honestly remember if I had the shafts bag or not, I'll have a dig in my box of general spares, failing that, I have plenty of studding.

I think the servo is already pushed back as far as it will go.

I'm not too bothered about getting more steering, it will only make it easier to roll.

would love to see some build pics if poss.

ive just ordered my fx10 kit from mongo valley

[bfst24 2]

also what size front shocks are you using ?75mm?

[Blacque Jacque 3]

I'm using short CVA's built to 80mm (Monster Beetle size) but with DF01 rods ends & spring seats (Manta Ray) .

Mine rides level or very slightly nose up, 75mm shocks would work well & give it more aggressive stance.

The original build for the Munchkin is here.

Mark's showroom entry.

I will add some pics of the conversion later.