.png.94a0d1c33952e15a35e0b13d13e1c498.png)
Didumos69
-
Posts
3,045 -
Joined
-
Last visited
Content Type
Profiles
Forums
Gallery
Everything posted by Didumos69
-
.thumb.png.116032e930e483fb4ebbfdc62183bd34.png)
The only real test for my stronger front suspension with 4 shocks and Ackermann geometry was to finish Box 3 and 4. So I did and the ground clearance turns out very satisfying. So far I used 361 extra parts and my current list of improvements now reads as (apart from the implemented fixes to reduce friction and getting the shifting mechanism to work): - 4th to 1st gear block - Hand of God steering - Hand of God shifting - Sturdy without body - Geared up engine - Dash gear indicator - Ackermann steering - Gear rack slider - Secured wishbones - Improved clearance -
Perhaps it's time to build box 3 and 4 Are you sure you have the same geometry? You need 4 of the hardest shocks. I'm quite certain the resistance is stronger than the original geometry. I tested with a prototype before actually building this. The weight of Box 3 and 4 together is approximately 1kg, so I tried with 1050gr soya milk leaning on the dashboard and the roll bar behind the seats. The center of gravity in the middle of the car and this is the result:
-
I just did this mod to the front axles to: - Eliminate bump steer - Improve ground clearance (also with body) - Eliminate wobbly suspension arms And I'm really happy with the result: http://youtu.be/hzBsmUNvg-c Using the full length of the suspension arms means they effectively have the same length as the steering rods, hence no bump steer. By using two shockabsorbers on each side the overall suspension resistance has increased, which gives a better ground clearance, also with body. And widening the suspencion arms to 3L and mounting them between 2 liftarms instead of to only one, completely removes the slack in the suspesnion arms. These changes also made space to gear up the rear HoG steering a bit by replacing the 20T/12T combination with a 24T/8T combination. That is convenient, because steering needs quite some force due to the weight of the whole model. This setup still has Ackermann geometry and fits within the space given by the stock body. The only thing I had to drop were my gear rack stoppers, so I will have to find another way to limit the steering angle. LXF-file can be found here. I will write a more detailed build report on the ultimately playable thread later. EDIT: I might as well replace the outer shocks with the original red ones. I actually like the looks of these shocks sticking out of the upper suspension arm:
-
Thanks!
-
I still have to build it, the images are renders. To be honest, I still have to finish Box 3 and 4
-
I like the simplicity! But what I'm a bit affraid of is that the second shock will slightly dealign the suspension arms, because it only puts force on one side of the suspension arms. This doesn't need to be a problem if the suspension arms were mounted such that they were less sensitve for assymetric forces. Actually, I don't like the way the suspension arms are mounted in the stock model at all. The setup is really wobbly. It would be much better to have liftarms on each side of the suspension arm instead of only one in the middle. Or widen the suspension arms upto 3L with levers along the sides and then mount them between two liftarms. There is a reason behind the terms wishbone and A-arm . I think it should fit. Where the shock is mounted there was a 3L axle with end-stop sticking out taking more or less the same space. The hub needs the space above the lower mount of grey shock.
-
I think it looks more complex than it actually is... I hope . Maybe I can simplify some things while building. In this setup the additional yellow shock is also slightly compressed when the red one is completely expanded. I don't think it's that bad, because the weight of the body will stress the shocks even more. I'm curious what your version of Ackermann geometry will look like. And rear wheel steering sounds indeed ambitious!
-
Unfortunately the 3x3 levers collide with the steering rods in my build. Because of the Ackermann steering the steering rods move more towards the 3x3 levers than in the stock model. I think it's still a good concept for the stock model though. So I've been playing around with LDD and came up with something that I plan to implement in my playable build soon. By making use of the full length of the suspension arms I could increase the ground clearance by half a stud without introducing more angle in the suspension arms, Too much angle will cause the upper suspension arm to hit the inside of the rim in turns. Another advantage of using the full length of the suspension arms is that bump steer is eliminated, because the steering rods and suspension arms now have the same length. This setup also improves the way the suspension arms are secured; they are far less wobbly than in the stock model (I did some prototyping). And finally, I could add two extra shocks to make the suspension more resistant. The setup still includes Ackermann steering and a gear rack slider. The suspension travel is one stud.
-
Did you apply all of these MODs? Getting rid of the friction-generating gear and replacing it with a simple 90 degree limiter helps smoothening the shifting mechanism. Part of these MODs is dropping the upper two silicon bands which makes the operation of the paddles more user friendly.
-
I didn't see you posted this here too. I'm going to try to integrate it in my ultimately playable build. Thanks for posting!
-
There are some known issues with the shifting mechanism causing the orange paddies to be off there supposed 90 degree positions, which in turn causes gears to be double engaged. It will be hard to fix this without moving many parts. I summarized most issues and solutions here: http://www.eurobricks.com/forum/index.php?showtopic=136251&view=&hl=&fromsearch=1
-
The first thing that comes to mind when I look at your video: you should test by rotating both wheels in the same direction, or at least block one wheel while rotating the other.
-
The difference is obvious! I forgot there was a liftarm inside the suspension arm, but apparently the half pins are not more limiting than the stock limiters. I'm going to try to combine this with Ackermann steering in my ultimately playable build. That won't be straight forward, because my gear rack sliders also use the space where you mounted the shocks to the chassis.
-
Nice idea! I wouldn't use a towball though. I'd say you need a pin or pin hole (facing downwards) at the bottom to be able to make the spring and wheel hub a solid unit. The wheel hub should then be able to rotate around the bottom of the spring. That"s also how real MacPherson setups work. The top of the spring doesn't need to change IMO.
-
I was already expecting you to come up with something. I like the concept. Did you test it with body? There is more travel, but the resistance is less. I'm a bit affraid the weight of the body will completely compress the shocks. But like DayWalker already suggested, it could be extended with a second shock. Can you make the half pins point inwards. Requires maybe a bit of stress on the suspension arm while putting them into place, but I even managed to put a 3L pin inside this type of suspension arm for the same purpose without damaging it. They are quite flexible.
-
Thanks for this clear and exhaustive report. What exactly breaks? Does the gearbox split? Would it help to have lengthwise liftarms along the midsection of the gearbox? EDIT: Like in my sturdy without body MOD:
-
Exceptionally clean build! Great job!
-
Cool concept! I like the use of sliders combined with the 6.5L shocks. I've seen attempts where the 6.5L shock had been wrapped with all kinds of parts to keep it in position. This is much better.
-
For what I know Efferman had the best shot at it sofar. I had some problems with LDD crashing after moving the outer body, box 3 and 4, but box 1 and 2 are surely okay. Box 3 and 4 can be selected from the group's tab to move or remove them. Btw, great thanks to efferman!
-
About the bushes in the D+N+R-gearbox. They can actually be left out completely, so no bushes or half bushes at all. The 12T gear is locked up by other gears and the axle - with end-stop - is locked up by an adjacent 13L liftarm. I think it was DayWalker's model where I saw this first. But of course, the half bush in your image won't harm either. I have no opinion on the calipers. Btw, thanks for taking your hat off
-
I would love to see a more sophisticated solution.
-
Did you see my quick fix somewhere at the end of the previous page?
-
Good to know!
-
I didn't think it was relying on friction in pins, my concern was that it relied on slack to compensate for the tilting of the liftarms. But it's probably only a very small amount as the angle between the liftarms and the shocks is not far from 90 degrees. And it doesn't affect steering. So alltogehter this makes a very nice McPherson setup!
-
You're right, 7:1 is big enough, so forget what I said about bigger. Somehow it doesn't look very big but that's probably because of the wheels. I immediately believe this is rigid enough for several kilo's. I didn't mean that the thin liftarms would bend, what I meant was that they should be able to swing along with the pin that connects them to the shocks. This pin will swing slightly forwards and backwards in turns. Part of the rotation of the shocks in turns will be passed on to the thin liftarms, just like how a U-joint passes rotation. However these liftarms can't rotate/twist/swing. If there would be a 90 degree angle between shocks and liftarms, then the liftarms would not twist. Hope this helps making clear what I mean.