DT-01 front double wishbone conversion

[bsy2010 218]

Well it's a nice solution.

Are you able to check if the DT03 lower arms are able to in any way fit the standard front end, if say, instead if the U pin, 2 correct diameter straight pins into the standard DT01 lower arm pivot mounting positions. Do you think that would work?

And if this is asking too much then please ignore this request, but could you take some pictures of the DT03 and DT01 lower arms together, with a couple of rulers on the table for dimensional correlation?

It's been a while since I worked on the Mad Bull (and drove it), so I can't remember all the details.

But here's the original setup (with some spacers to reduce slop)

As you can see, the standard arms are very close together, probably the front would be too narrow with the DT-03 arms. Also, the angle would be a bit weird

[Lawsy 27]

I've done exactly that. I used professional grade, glue filled 2 layer heat shrink. After 20 packs there's still barely any slop.

You won't happen to have a chance to pull a DT03 arm out and lay it over the original, in a similar shot to the above? Seeing them in proportion in the same image would give me enough to go on. Funny angle aside, it would still be 100x better than the camber loving setup that comes as standard...

[Nobbi1977 1793]

I've done exactly that. I used professional grade, glue filled 2 layer heat shrink. After 20 packs there's still barely any slop.

You won't happen to have a chance to pull a DT03 arm out and lay it over the original, in a similar shot to the above? Seeing them in proportion in the same image would give me enough to go on. Funny angle aside, it would still be 100x better than the camber loving setup that comes as standard...

I have a set of spare DT-02/3 arms so I will try and remember to pull a DT-02 out this weekend and take a shot

[Lawsy 27]

Did you meant pull a DT01 out and take a shot with the DT03 arms?
That would be very helpful. As soon as getting additional DT03 parts are involved

(over just the lower suspension arms), the cost skyrockets and it becomes completely unfeasible.
However, if there is a chance they could work with a bit of tinkering, it becomes feasible again.

[Nobbi1977 1793]

Did you meant pull a DT01 out and take a shot with the DT03 arms?

That would be very helpful. As soon as getting additional DT03 parts are involved

(over just the lower suspension arms), the cost skyrockets and it becomes completely unfeasible.

However, if there is a chance they could work with a bit of tinkering, it becomes feasible again.

Yes sorry DT01. I hope they do not do a DT-04 for a long time, I am running out of room

[bsy2010 218]

You won't happen to have a chance to pull a DT03 arm out and lay it over the original, in a similar shot to the above?

Sorry, I don't have the original arms anymore

[Nobbi1977 1793]

they are a long way short.You would need to 12mm hex hubs to push it out a little

[Nitomor 2122]

Interesting pic, so with DT02 arms, potentially you could fit WT01 uprights, hubs and hexes?

[Lawsy 27]

That's really great nobbi, thank you for these images. I think a crankshaft shaped adaptor of some kind (each side, and then fixed together somehow to prevent rotation around the existing pivots) would be fairly easy to make with some threaded rod and aluminium sheet, allowing the DT03 arms to fit without modifying the DT01 front end (or at least, not so much that it isn't reversible).

I already run 12mm hex up front on Traxxis carriers, so my Fighter Buggy has, I would guess, 4mm of additional track - but this really depends on the offset of the wheels.

[Nobbi1977 1793]

Interesting pic, so with DT02 arms, potentially you could fit WT01 uprights, hubs and hexes?

Looks like it. With long axles you could sort the track out fine.

The problem is going to be reduced ride height. Hex hubs sit higher above the lower arm so you would need them at an angle to get the height.

[Lawsy 27]

Nobbi1977, on 01 Feb 2016 - 5:36 PM, said:

Looks like it. With long axles you could sort the track out fine.

The problem is going to be reduced ride height. Hex hubs sit higher above the lower arm so you would need them at an angle to get the height.

I don't understand how hex hubs reduce ride height. Or is that a unique carrier design for the WT01 where the axle is not centered in the carrier, but offset?

[Nobbi1977 1793]

The hub and axel on a DT01 / hornet etc sits right on the lower arm. On a hex hub the axle sits half way between the top and bottom arms.

[Lawsy 27]

The hub and axle

...

Ok I think I get what you mean now by thinking through a more "normal" hex conversion. The vertical height increase of the axle is due to the C hub. Since most C hubs are taller than what is moulded to the lower swing arms on the basic models, the axle centre must be higher (because the axle carrier is vertically centred on the C hub's vertical axis, and the bottom of the C hub is pinned to the lower arm).

I think that's what you were getting at.

I in my case, my DT01 is able to use either standard axle carriers or the modified Traxxis carriers in the stock C hub, so this doesn't apply. I wasn't thinking "generally" enough, if that makes sense.

But I think we're on the same page now

[manny 83]

I'm a little late to the party but I was inspired by the solutions on this thread (especially the one by TA Mark)  and I designed some arms that I had 3d printed.  They're basically a copy of the original arm with a hole at the outboard end for a DT-02 knuckle assembly.   I don't know how durable they are, but others have used this same material for suspension arms. 

[GregM 1109]

Those arms look lovely! Do you happen to have a link to Shapeways or others, please? Just in case I'd like to get my own pair of arms...

 

cheers, GregM

[manny 83]

Thanks for the kind words GregM.  It was a fun side project and I'm pretty satisfied with the way they turned out.

I did use Shapeways to produce them and I can make them available.   I'm thinking about shrinking the screw screw and suspension pin holes and have the end user ream them out to the required 3mm diameter since 3d printed holes never seem to be just right.   FYI the Dt-01 I have the arms installed in is a shelf queen with the clear gearbox, so It's never been driven  let alone tested for durability.   Also, I've yet to verify the upper link geometry; I just screwed it into a convenient hole in the chassis.  

[GregM 1109]

Hi manny, any news on the availability of your custom DT-01 front arms? I haven't found them on Shapeways yet.

Cheers, GregM

 

EDIT: I just found bsy2010's double wishbone conversion being discussed with some more pics on another forum:

https://www.rc-modellbau-portal.de/index.php?threads/kleine-umbauten-an-einem-tamiya-mad-bull-dt-01-58205.400/

Google translated:

https://translate.google.com/translate?hl=de&sl=de&tl=en&u=https%3A%2F%2Fwww.rc-modellbau-portal.de%2Findex.php%3Fthreads%2Fkleine-umbauten-an-einem-tamiya-mad-bull-dt-01-58205.400%2F

 

I wonder how this changes the front track width.

 

EDIT2: I managed to find Wolfgang's DT-01 conversion and edited the links of my first post in this thread.

[TurnipJF 9192]

On 07/09/2016 at 0:46 AM, manny said:

I'm a little late to the party but I was inspired by the solutions on this thread (especially the one by TA Mark)  and I designed some arms that I had 3d printed.  They're basically a copy of the original arm with a hole at the outboard end for a DT-02 knuckle assembly.   I don't know how durable they are, but others have used this same material for suspension arms. 

That looks like an interesting model with some cool parts. I like the transparent dampers for example. Any chance of some more pictures showing mote of the model?

[manny 83]

This modified car is my second Mad Fighter.  Other than the front suspension and  clear gearbox & shocks (which I thought looked cool but relegated the car to being a shelf queen) It's pretty stock.  I may get around to driving it someday but most of my free RC time is spent working on my Frog.    

[Darat76 265]

at least you'd know if your gearbox is wearing out... and if your pinion is in alignment with the spur....

[manny 83]

LOL  This gearbox is pretty tough and almost foolproof at the same time!  I think the clear gearbox was for hobby shop owners to display the car with.  I know the clear gearbox came with the first production run of Mad Fighter and also had colored gears....I'm keeping an eye out for those.

 

 

 

[GregM 1109]

So it happens that I got a pair of manny's 3d printed DT-01 arms in the mail, and guys, I'll be your guinea pig for testing them on my Mad Bull.

First of all, let's take a closer look and cut the parts from the sprue.

This is the first time I'm holding 3d printed/sintered nylon in my hands. That stuff feels funny with it rather rough surface. When trying to bend the arms, they are really strong but retain some flexibility. I have some ideas about how to prevent the plastic pegs getting worn out in the chassis' plastic suspension arm mount over time. Until then, I need to dig into my boxes and spares, to get the Mad Bull out as well as the other needed parts (DT-02/03 c-hubs, kingpins, tie rods, ball mounts...).

Stay tuned!

[GregM 1109]

So it was time to mount the c-hubs.

I used DT-02 c-hubs, 0.2 mm washers and screw pins. The hole for the screw pin was widened to 3.2 mm diameter with a cordless drill, although a simple manual pin vise would be fine, too. The outer diameter of the screw pins is roughly 3 mm, so you can try a 3 mm or 3.1 mm drill bit, too. The washers are optional, I'm just following Pintopowers advice for reducing wear on the plastic parts.

From what I can see when comparing to the stock suspension arms, the track width reduction is negligibile. I decided to put heat shrink tubing on the pegs (not pictured), to allow smoother movement and reduce wear on chassis and pegs.

The lower damper mount hole is slightly widened to allow a 3mm tapping screw going through. Caution, don't drill the hole where the screw needs to tap into. Instead of a kingpin screw, I used a brass tube, and placed a washer under the screw head to distribute the pressure.

This leaves me with determining how and where to mount the upper link to clear the damper. I like manny's decision with re-using the bumper mounting screw holes. Eventually, I'll need to adjust the steering links, too.

[GregM 1109]

This is how I attached the upper link. As you can see, the angle is far from being parallel to the lower arm, but OK for what I'm aiming for. I had to use hex nuts as spacers. Once I'm done, I'll cut down the screws to the necessary length and use locknuts on the ends.

Another closeup on how extreme the link gets articulated. Since the long bolt goes all the way down to where the bumper attaches, there's a lot "meaty" plastic in that section to hold everything securely in place.

Suspension uncompressed.

Suspension compressed. There's some negative camber gain, but that's not worrying me too much.

[Nobbi1977 1793]

Very cool. I might have to invest