ThunderDragonCy

Crowd sourcing - Let's design the ultimate DT02 / DT03 rear upright?

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Next project! The massive bulky rear uprights on my dt03 offend me! They are huge to clear the plastic dogbones and with metal driveshafts in they actually foul the lower arms preventing full droop. Aluminium ones are rare and cost a fortune so I thought I would model up some slim uprights myself and get them from shapeways. 

Seeing as I am on this though, I can do pretty much anything I like so would it be good to add a degree of toe angle maybe? There's already some toe in on the car, but I remember the @super gripper write up bemoaning the lack if toe adjustment. I figure with a 1 deg pair you could either add or subtract some toe in depending on how that affects the car (I have no idea what the effect is by the way!)

Would you want more camber link holes? If so, what configuration? 

Any other features I should add?

Let's design the ultimate DT02/3 rear upright!!

 

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Nothing useful to add other than I’d have some once the benefits were known. 

Why not do both or more? Standard, 1deg, 2 deg etc all with the added clearance, or does that start getting expensive?

Could some sort of insert not be worked that gave + in one way and if flipped/rotated gave - or back to standard?

I do recall reading that toe-out = bad = unstable though or was out never a consideration and you are just thinking toe-in?

Wish I understood all this better 🙄

Edited. 

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OK, had go and knocked this first version up. Based on the TRF201 rear upright with the ball end screwed vertically into the top (which also makes doing the toe in much much easier)

Rear Upright Left 1 deg toe V1 Front ISO

 

Rear Upright Left 1 deg toe V1 Rear ISO

I left a bit of a shroud behind the bearings to keep the support from the king pin area and to protect the bearings a little. As you can see it tapers in from the lower pivot which is the opposite of the DT03 original. The top mounting of the top arm along the centreline of the part also has the added bonus of moving the turnbuckle away from the shock springs which is get very very close to on the stock configuration. See as it's there I added position options for the top link but I don't know why you'd want to tweak that. Can anyone enlighten me? 

What do you think?

 

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Far to clever 😂

So if I understand that right. We’d use the original lower arm and the upper arm would be?

Sorry if that’s really obvious. 😳  Possibly making myself sound stupid now!

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19 minutes ago, Man1c M0nk3y said:

Far to clever 😂

So if I understand that right. We’d use the original lower arm and the upper arm would be?

Sorry if that’s really obvious. 😳  Possibly making myself sound stupid now!

Upper arm would have to be the hop up turnbuckle with ball ends. It made my brain hurt trying to make the top mount angled as well which would be the only way the stock top arms would work. Google TRF201 and look at the rear suspension and you will see what I am aiming at here.

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43 minutes ago, ThunderDragonCy said:

Upper arm would have to be the hop up turnbuckle with ball ends. It made my brain hurt trying to make the top mount angled as well which would be the only way the stock top arms would work. Google TRF201 and look at the rear suspension and you will see what I am aiming at here.

With you now. 

So I’m assuming a ball connector on the axle cup and another on the top mounting point where the screw pin currently goes? 

Would that create excessive angle of the tie rod? Could the ball connector be mounted inside of the ‘bracket’ that the screw pin goes through to reduce said angle? 

Or maybe I’m not with you at all and you have a completely different idea in mind!

Interesting this. 

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Right then. I'm pretty happy with the design so I'm going to get some 3 deg toe in versions to really see what the difference it. I have 1 and 2 deg versions modeled up. If anyone else wants to take a punt and give them a go too, let me know on here or PM me and I'll add you to my order. Going to put the order in tomorrow night (Thursday). They will be £10 a pair plus shipping to wherever you are. 

Any takers?

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Completely missed this update. Was going to ask if you made any progress. Serves me right for having notifications set to weekly. 

Look forward to hearing how you get on. 

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3 degree toe in is optimal, - the more toe in the more stable the car is when the power is applied. - camber can be adjust via a turn buckle

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Nice design! Options from 0 to 3 degrees toe-in is perfect. Any more would be too much in most cases. The adjustment of roll-center with the 3 top holes is also great. This is how most serious racing chassis have it.

You could go as far as creating inserts for both rollcenter and toe-in adjustment like these from MST have:
mst-ht-aluminium-rear-upright-2pcs-color

Or a seperate piece on the top to adjust camber/rollcenter like the Yokomo YZ4 uprights:
YokomoOffsetHubs-2.jpg

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44 minutes ago, super gripper said:

3 degree toe in is optimal, - the more toe in the more stable the car is when the power is applied. - camber can be adjust via a turn buckle

Nice. Thanks. Got 3 deg on order to test against stock. Should be good!

18 minutes ago, Tizer said:

Nice design! Options from 0 to 3 degrees toe-in is perfect. Any more would be too much in most cases. The adjustment of roll-center with the 3 top holes is also great. This is how most serious racing chassis have it.

You could go as far as creating inserts for both rollcenter and toe-in adjustment like these from MST have:
mst-ht-aluminium-rear-upright-2pcs-color

Or a seperate piece on the top to adjust camber/rollcenter like the Yokomo YZ4 uprights:
YokomoOffsetHubs-2.jpg

I did see some parts similar to those top ones but I thought that was going a bit far! Yokomo flip chips are interesting though. Will report back once I have the new parts. Should be another couple of weeks.

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both of those are over engineered and the top one, well all not good. Certainly wouldn't want anything like that is it is all wrong. The top part should be all flat, have a look at the trf parts.

I have the alloy trf parts for my trf502

the top part needs to be flat not stepped like mst part !

You adjust the roll centre with different length turn buckles and the grip level with spacers under the balls studs

 

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Well it is a beautiful day here so i popped in on my favourite running location on the way to work. All was going well until i hit the transition from gravel to grass a little hard. Bottomed out to cartwheel to.....ooops!

2018-02-20_11-54-42

Looks like 3d sls nylon needs a lot more beef than abs plastic as these pivot bosses are same size as the kit items. Back to the CAD screen! They worked a treat up until this happened though. Rear suspension seemed better and put the power down pretty cleanly. Luckily i had a full pack in my Thunder Dragon too so that got a good run. Nice to actually run my cars again!

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44 minutes ago, Man1c M0nk3y said:

Argh no way. What a shame 😕

Yeah, but wasn't a dead loss as I had my Thunder Dragon with me too. Part of the process. Design, test, improve, repeat. It'll be reet.

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On 9.1.2018 at 10:20 PM, Juggular said:

Oh, I envy people with 3D skills...!  

Have a go at Fusion 360, its free and there are loads of training videos

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15 hours ago, ThunderDragonCy said:

Got the 3 deg uprights today and got them installed.

Did you had them made by shapeways?

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