cbaker65

Thats some awsome detail!...

Frederik_b

Thanks!!


I just received the Traxxas E-revo 1/16 diff (part number 7078). I will eventually try to fit it in the SDI axle, not right now though but I thought I would show you a preview.


Thanks to Williezcr8's help (member at scale4x4rc forums) and idea who did the same to convert his T-Rex 44 axle to open diff, and also to Prestonlal (Trini2DBone) for bringing back the idea and pointing me! You can find the T-Rex axle thread here:


http://www.scale4x4rc.org/forums/showthread.php?t=67962









It is just a tad too large on the gear towards the housing, but it looks like I could just grind the outer side of the gear (the side not in contact with the pinion) so it is at a slight angle and not contact the housing:









See how it does not sit fully in because of the crown gear:







Also another problem to solve will be how the shafts attach to the diff inside gears. I will have to drill a hole in my current axle shafts and replicate the attachment method, and remove the small shafts:









I will also have to find a pinion that will fit, best solution might be to buy E-Revo pinion and mod it to lengthen it (because it is not long enough out of the housing to mate to a driveshaft).


But that will be a project for later now that I have the axle assembled, mounted and working, I will move on to other areas. Can't wait for tomorrow and work on the front!

Frederik_b

Tonight I made some progress on the front of the chassis. I bent some sheetmetal to form a beam the same inner size as the frame flatbar, and plugged the end with a small piece of the same flatbar so I can eventually bolt a transverse reinforcement in the front.


Made two of these to lenghten the chassis:












Then I drilled and bolted everything up:


















I then started to figure out what control arm lenght I need up front, no pics of that though. To have a feel for the width and space occupied by the strut I had to assemble the first version of strut I made, but with the disc brake.


The disc brake hex is like only 4mm thick, and maybe 2 mm of disc. The hex holes in the mini wheels are much deeper than 4mm so it makes the wheel pop out more than it should because the wheel actually sits on the disc not at the bottom of the hex.


So I machined one wheel, and removed a bit more so I can hopefully clear the venom rc bike brake calipers:







Next up will be actual struts and control arms!


Fred

Frederik_b

And another "pretend that there is more done than there actually is" mock up pic the strut assembly mocked up under the fender:

Frederik_b

Tonight I made some progress on the front struts (well only one side!) I made the upper mount, and also redid the strut itself better, with an extra untrimmed piece where I will attatch the steering arm. I need to go to sleep now so I will let the pics do the talking




Here are the F104 parts used to do the upper mount:
























That's it for tonigh, baby steps I guess! Lol I did not even start doing the lower crossmember, I wanted to have the upper end of the strut located first.


Fred

Frederik_b

Just weighed it with on board all parts I could think of that will be used, it currently weigh at 4 lbs which is not all that bad I think I left the masking tape body shim in there just to account for some of the added crap I will add lol


How much weight is a regular 1/10 car with battery and everything loaded? I'll have to weigh my 1/10 Tamiya TB-01 Rally Subaru to compare I guess.






Quick view with body on and the high offset wheels in the back (and less offset in the front). Also I loaded the car with some parts to compress the suspension a bit though the front is still high for now.

Frederik_b

I found out the weight of a tamiya tb-01 rally, from rcuniverse tb-01 resource thread:


Weight Fully Equipped: 1775g (including TP-S3003 servo, CPR Unit, motor, RC2400SP battery)
Mine: 4lbs = approx 1810g

I like the comparison to the tb-01 rally because 1) I have one! 2) it is a car known to be fairly heavy (pig? lol) so i have some comparison basis! And I was surprised the weight is not all that much more than a TB-01!! Of course I am not done but at least I know it won't be 2x heavier than ALL other cars hahaha

Fred

cbaker65

That is the most realistic rc model that Ive ever seen...

That sub frame & suspension came out awsome!

Frederik_b

Thanks a lot buddy! I appreciate the comments, I might not be able to work on it this week but I am refining the plan in my head while stuck in traffic and other low CPU activity I am currently thinking of ways to hold the front lower link.

Lars from Norway

LOL! That's when the cpu is on red level here, deadtime is thinking time! I love the look of it now, so close to the real thing.

Frederik_b

Update! I thought I would have to use the tamiya avante ball links instead of the RW4WD ones, but they ended up giving just the right amount of movement, provided the arms are short enough to give some negative camber when compressing, and positive camber when in droop (which is what the real escorts do anyway with their short arms).


I made the lower cross member as well as another cross member up front where I will attach the sway bar (which will at the same time triangulate the control arm).


I think I got the geometry pretty right! The wheel tucks in the fender nicely when compressed.




Here is the first cross member, kind of dummy for now but it helped put the main cross member and keep the right width between frame pieces:







The main cross member partially made:







And the pretty much finished piece:




















And here is a short vid of the strut movement, of course I will need a link to prevent the link from moving fore-aft:


http://youtu.be/5nfOoTxr2tw
That's it for now! The cross member was pretty long to do, I did not want to mess up the dimensions and geometry, I am very happy with the result!


Fred

Frederik_b

Tonight I tried to think of a way to do the sway bar/triangulating arm combo like stock escorts but I was unable to find a way to attatch my big piano wire to the middle of the control arm. The Escorts have a hole in the center of the control arm, and there is simply a threaded rod going in with bushings. Here it is too smal to do that...


So I went with the second idea, like they modify the escorts for rally they tend to lose the double purpose sway bar, by adding a separate link to triangulate, and the sway bar is just like any other car, and does not do the triangulation.


On my first attempt I put the link in the front:











Quick video with the link in the front:




http://youtu.be/9Ep1GdI7oss




But then I thought that would cause issues when I would do the steering (steering is in the front of the wheel on escorts). So I unscrewed the link and brought it to the back on the chassis, tada! just like the real ones I saw on google lol














http://youtu.be/anRR8Z7mCZM


I think it will have good steering angle











I had to make a hole for the wheel to turn, will need to glue some rounded shape inside:








And a view of the quick steering attachment I made to be able to test. It is pretty flimsy but I need something to test the geometry so that will do. The real one will likely have more meat to it and two screws attaching to the strut assembly, not one like in this pic.









Sorry if I take too many pics for not all that much change Also in these pics I attached the strut at a higher position, kind of like raising the suspension on coilovers, that's why it is a bit higher than previous pictures. Adjustable suspension FTW!

Lars from Norway

I love this project more and more! I was hoping to see a compression or tension strut-setup here. The steering angle is almost like on a fork truck, hehe!

Frederik_b

Thanks Lars!! What do you mean by compression or tension by the way? I hope what you saw is what you were hoping to see hahahah

I eyeballed the steering geometry and I think I'll be able to make the steering linkage so it makes use of all the available angle, which is cool because I plan to have this thing sideways a lot!!

Lars from Norway

I saw, and it was good. Or as in "Bruce Almighty" ; 't's gooooooooooooooooooooood, hehe! Crap aside, i saw what i wanted to see! I never remember the difference between compression and tension struts (which of what is in front or behind the TCA), but google it and you will see!

Frederik_b

lol!! cool buddy! glad you like it! I see what you mean, and I guess mine is a compression strut, and the initial idea of installing the arm at the front would have been a tension strut (I guess!)


For a steering rack, I thought I would be using seals similar to shocks, at either end of a rack, so it would slide nicely, and possibly using bearings, but I found in my parts some shiny shaft probably used in some touring car's drive train. It just happens to fit exactly inside of the larger size of brake line I have! And it slides effortlessly!


Just need to make a slot in the brake line, put a screw in the center of the pin, and this screw will be what the servo will attach to. Then the servo would be where the radiator would be, servo horn facing down. I imagine a steering system similar to kid's pedal car, if that makes sense to you.


On to the pics, and the now usual video I guess videos are useful now that things get moving (literally) !















http://youtu.be/O5vyLE-7-XY


Thanks for looking!!

Frederik_b

Update!! Well past due update hahaha It sits on its four wheels for the first time!


I was able to complete the second side of the front suspension, minus the steering knuckle which is not done on that second side, the final steering knuckle is not designed yet anyway. The suspension is completely compressed on the front in the first pic as there are no springs on the struts. The rear is sprung though.













Here you can kind of see how I plan to do the steering, I will have two pull cables attached to the M3 screw in the center, one cable to the left and one to the right.









It looks as if the brakes cables I got from Preston (thanks bud!) might just work, I thought it was smaller but had a look and it is bigger than I recalled (the yellow one).






And now that it sits on four wheels, the mandatory flex shots! lol believe it or not all four wheels are on the ground in the pics. Well there are no springs on the front so that's kind of cheating, it obviously help get to max droop on the lifted wheels:









Regarding the cable steering, I will use guitar strings as to not scrap the piece of brake cable I got. It fits in the plastic sheat, it is pretty much the same size as the cable and already comes with loops at the end to attach to my M3 bolt lol Once I sort out the lengths and details, if it looks like it will work I will cut the actual brake cable.





Thanks for looking!

Lars from Norway

I am exited to see more pics from the project! And looking forward to see the push-pull-steering setup.

Frederik_b

Thanks Lars! Yes steering needs to be done and after that I move on to the trans and driveshaft tunnel.

And for you guys who like these little Escorts, I put the MK1 shell on to see how it looks standing on its wheels:









And also the Mk1 shell halves are not bolted together, so it makes for a nice scale work in progress

spool1387

This build is absolutly amazing great work!!!

Frederik_b

Thanks a lot for the nice words! I had to skip this week and could not work on it but hope to do some Tuesday night. I would like to sort out the steering system with the dual pull cables.


Meanwhile here is a picture of the suspension at full droop, I would like to have a bit more travel in the rear but that would be only if I do a different shock setup (which might happen in phase 2! ). Keep in mind the body is not trimmed completely in the arches, so it actually has like 0.25" more fender gap than in the pic (you can see a reflection of the actual fender line):

Frederik_b

Update!


I did a little bit of work tonight, but first some teasing Anyone guesses what this is? Obviously it is not finished in that pic, but you won't wait long to know, just the time to write the post and link the pics

Frederik_b

Brand sparkling new transmission tunnel! lol









Just like Preston did on his Escort build, I trimmed the tranny so it fits nicely in the transmission tunnel:









This is how I drawn the tunnel in 2D first, this is the height I am aiming at for the motor and tranny, I want the bottom of the tranny to be about floor height. And I want the motor to sits on the wheels:








I will have to lengthen the driveshaft by approximately 1 inch, I will do that with a solid extension on tranny output shaft. Some pics on the car:









And some comparison to a reference pic:








The driveshaft tunnel should be same size as the small end of the tunnel,and I might be able to get away not doing a diff tunnel in the rear, because the height of the small end (and eventual driveshaft tunnel) should be just enough to clear the diff at current full compression.

prestonlal

Wow....! Man that came out great! Awesome job!

Lars from Norway

I saw what it was straigt away without any doubt