1:6 crawler Ford superduty build

[Fly In My Soup]

Build update

 

 

 

 

wheels @ 00:20

- Axles @ 00:40

- Chassis rails @ 01:13

- Body mock up @ 01:47

[Fly In My Soup]

Hope you like the soundtrack 

[Fly In My Soup]

Made more progress tonight.

 

I'll just post a pic tonight and a full slideshow tomorrow, may be a while longer with another update after that, I'm hung up waiting for parts!!

 

[Fly In My Soup]

Quick question for all you crawler Boffs......

 

Axle mounted servo or hung upside down on a plate etc etc?

Edited January 12, 2018 by Fly In My Soup

[Fly In My Soup]

Build update

 

Here's the spec so far;

- T6 5mm aluminium plasma cut chassis rails
- Xtraspeed full alloy axles
- Alloy shock hoops
- Epic beadlocks with face/back alloy beadlocks ( colour coded to body )
- Austar 125mm tyres

- Custom links 

 

More to do !!

 

Updates to follow in due course......

 

 

Edited January 13, 2018 by Fly In My Soup

[luckland]

On 1/13/2018 at 08:21, Fly In My Soup said:

Quick question for all you crawler Boffs......

 

Axle mounted servo or hung upside down on a plate etc etc?

 

Personally I wouldn't put the servo on the axle because a real 1:1 truck does not have one there. But it is all up to which direction you are going to. I used to believe the servo-on-axle crawler performed better but probably that is no longer the case, judging from successes achieved by SCX10 II and TRX4.

 

The links look nice. You might want to start thinking about the skid plate now.

[OllieNZ]

On 12/01/2018 at 23:21, Fly In My Soup said:

Quick question for all you crawler Boffs......

 

Axle mounted servo or hung upside down on a plate etc etc?

Depends on how 'scale' you want it to look and your choice of front suspension setup. If you use a 3 or parallel 4 link with panhard you can use either but if you go with a triangulated 4 you need to put the servo on the axle other wise the steering will be all over the shop as the suspension articulates

5 hours ago, luckland said:

 

Personally I wouldn't put the servo on the axle because a real 1:1 truck does not have one there. But it is all up to which direction you are going to. I used to believe the servo-on-axle crawler performed better but probably that is no longer the case, judging from successes achieved by SCX10 II and TRX4.

 

The links look nice. You might want to start thinking about the skid plate now.

On 1:1 trucks it's a bit different, most stock vehicles with a live front axle run either leaf springs or radius arms and are legally required to have a mechanical link between the steering wheel and the wheels so that in the event of power loss the vehicle is still steerable. Stock setups are full of compromise and cost is also a major design influence.

One of the first things they do on a competition offroader(rules permitting) is ditch the stock mechanical steering in favour of a fully hydraulic setup which uses a double ended hydraulic ram attached to the axle to steer the wheels(equivalent to servo on axle). This allows for a triangulated 4 link to be run on the front(which offers many handling benefits), eliminates bump steer and helps steer 40"+ tyres at low speeds.

[Fly In My Soup]

On 15/01/2018 at 08:23, OllieNZ said:

Depends on how 'scale' you want it to look and your choice of front suspension setup. If you use a 3 or parallel 4 link with panhard you can use either but if you go with a triangulated 4 you need to put the servo on the axle other wise the steering will be all over the shop as the suspension articulates

 

Thanks for this info.....really appreciate it.

 

Did some research after the headstart you gave me...trawling these nerdy crawler forums and whatnot

 

Most info is based on scx10, trx4 platforms and as this is custom built, coupled with my serious lack of crawler knowledge.....I'm flying blind in many ways...although hirokis build pics are helping a LOT!!

 

So i think I'll attempt for a 3 link and panhard bar......

 

I've mocked up some bits etc etc and loosely bolted everything in, first thin I noticed is the steering tie bar is on huge pivot balls, meaning there's loads on roll play on the bar itself (not the axle) when its steered.

 

Second order of business is to mount the servo lower, so the angle of the steering link and panhard bar will be roughly 40-50°....I'm attempting to get them parallel......

 

Lots of trial and error for me at the moment, measuring, swearing, dissemble /assemble

 

Still....all part of the fun!

 

Here's a quick update pic 

I've rearranged the links as I'd unwittingly reverse triangulated them (schoolboy error it seems) 

 

(Some links are loose underneath in this pic)

 

I'm also still waiting on parts like shocks etc, so making do with these for mockup at moment

 

WiP is an accurate description right now !

[OllieNZ]

I don't have much RC experience but a bit with the full sized stuff

When designing a 3 link you need to make the panhard and steering rods indentical in length and parallel with each other. What you won't often hear is that you also need to make them as long as possible and as close to parallel with the ground as you can get them. Doing this will offer the best handling characteristics. You can bend the rods to provide clearance if necessary, all that matters is the imaginary straight line between the rod ends.

[Fly In My Soup]

1 minute ago, OllieNZ said:

When designing a 3 link you need to make the panhard and steering rods indentical in length and parallel with each other.

 

10 hours ago, Fly In My Soup said:

Second order of business is to mount the servo lower, so the angle of the steering link and panhard bar will be roughly 40-50°....I'm attempting to get them parallel.....

 

Yeah I realised that from hirokis build!

 

 

 

[OllieNZ]

3 hours ago, Fly In My Soup said:

 

 

Yeah I realised that from hirokis build!

 

 

 

His links could still be more parallel to the ground. I've also noticed you have your servo mounted pretty centrally, I'd move it as far to one side as you can to make the steering link as long as you can get it.

[Fly In My Soup]

42 minutes ago, OllieNZ said:

His links could still be more parallel to the ground. I've also noticed you have your servo mounted pretty centrally, I'd move it as far to one side as you can to make the steering link as long as you can get it.

 

Lol, I'm in the process of shifting the servo as we speak after I realised it wouldn't work where it now is.....

 

Also, I think hirokis build is top notch, I'm certainly not going to differ too much from his 'master build'..... as I'm finding out first hand the difference between saying something and doing it......is a world apart!

 

I also think he / I am constrained in some ways ......if I mount the servo any lower than he has.... to try get the links more parallel to the axle...the servo will be visible, in which case I might as well throw it on the axle.

 

I'll continue with the trial and error etc etc

 

Cheers for the advice though Ollie, it is appreciated

[OllieNZ]

What you're going though is no different to the full sized stuff and there's ways around these issues. Instead of lowering the servo you could use an offset or bent servo horn (dropped pitman arm).

Another option that is often used in conjunction with a dropped pitman arm is known as high steer. Instead of the steering rod attachment on the knuckle being roughly inline with the middle of the knuckle it's raised higher so it's inline or above the top of the knuckle.

 

But then again with an RC you don't really have to worry about the handling quirks that can cause so much grief in a full sized vehicle, if it wanders or the steering feels a bit vague it's not gonna make you poop your pants when it decides to tramline at 70 going down the motorway (don't ask) or the death wobble sets in under brakes.

[Fly In My Soup]

Thanks again Ollie!!!!! You're a star!

 

That good advice...I'll give it a go later and post the results

 

26 minutes ago, OllieNZ said:

But then again with an RC you don't really have to worry about the handling quirks that can cause so much grief in a full sized vehicle, if it wanders or the steering feels a bit vague it's not gonna make you poop your pants when it decides to tramline at 70 going down the motorway (don't ask) or the death wobble sets in under brakes.

 

Lol, thats too funny

[Fly In My Soup]

Well, the shocks, motor and some other bits turned up today.

 

 

 

So, you can see here, I've moved the servo as far right as it will go, and with the actual shocks its meant to have now fitted, its ride height is more pleasing....its a bit lower so the steering link can be at a lower angle.

 

 

 

I'm going to move the link so it bolts to the knuckle itself, why they put it on the tie rod I'll never know....then after that, I can setup the panhard bar! Hopefully!

 

[Fly In My Soup]

 

Below is pre compression

Here's with compression

 

@OllieNZ. I took your advice and moved the link end to the knuckle and raised it.....in the hopes of decreasing the angle of said link...

 

Now I can concentrate on the rear, I'm on attempt 3 of the leaf springs Lola

 

 

 

[luckland]

Ollie NZ is quite right. You want to make a nice parallel with those two links in the front.

You might also want a servo with a good torque. It is going to be a very heavy chassis, so I would say 20kg at least. And you will need an external BEC too. The BEC in the ESC is never enough for a rig of this weight. You will change the servo horn to an aluminum one, won't you?

[Fly In My Soup]

2 hours ago, luckland said:

Ollie NZ is quite right. You want to make a nice parallel with those two links in the front.

You might also want a servo with a good torque. It is going to be a very heavy chassis, so I would say 20kg at least. And you will need an external BEC too. The BEC in the ESC is never enough for a rig of this weight. You will change the servo horn to an aluminum one, won't you?

 

This qz505 is rated for 7kg in 0.05 sec... So thou may be right with it not being powerful enough....time will tell.

 

If it is, I'll just go grab a cheapie sp one like the one you had, as you can get them for £20, I've previously used one in a kyosho ARC for steering.

 

On the ESC/bec note.....I'm not sure what I'll be running yet so I'll have a think first

[OllieNZ]

Shocks look nice :). Good job with the steering link, what are you doing panhard wise?

The TG1501 seems to be a good budget servo option, mine is certainly working well on my Mauler which is pretty hefty and running 140mm tyres..

 

Also found an offset aluminium servo horn that may be of use.

Servo Horn

 

Edited January 18, 2018 by OllieNZ

[yoodoo]

Hey FIMS , what do you think about those shocks? I bought some a month or so back and found the pipes are popping off all the time.I have tried to tighten them up all ways but to no avail.

J

[Fly In My Soup]

20 minutes ago, yoodoo said:

Hey FIMS , what do you think about those shocks? I bought some a month or so back and found the pipes are popping off all the time.I have tried to tighten them up all ways but to no avail.

J

 

They're budget shocks! Nuff said

 

I did find a way to prevent that happening, squeeze tiny blob of superglue on a piece of card, then use the end of a zip tie to pick up the tiniest amount of glue......then 'paint' a very small amount around the outer circumference of the end of the r.pipe.(.NOT the inside of the rubber pipe end, the outer) 

 

Push on,jobs a good un!

 

I have to really pull to remove them once I did this

Edited January 18, 2018 by Fly In My Soup

[Fly In My Soup]

Here's a small update!

 

Including me attempting to build leaf springs!

 

Took three prototypes before I settled on an actual working design....based on the Hotchkiss style semi elliptical setup

 

Getting closer to finishing, although I'm held up waiting for parts again!

 

Enjoy homies!

 

 

 

[Fly In My Soup]

Had some fun completing the rear leaf springs!! 

 

Rear suspension completed, support link added, driveshafts and transfer case due soon...

 

 

Will get more better pics of the setup etc when other parts are fitted, but you do get a good view at 45+ seconds in

Edited January 20, 2018 by Fly In My Soup

[Fly In My Soup]

Small update...

 

Fitted transfer case and 2x200mm steel driveshafts....boy, they are weighty!

 

They are an upgrade originally designed for a tamiya 1/14 Hercules truck

 

Transfer case mounted as high as possible

Will do a larger update next week

 

 

 

[yoodoo]

Why are you mounting the case high?

J