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  1. #1
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    [Project] Custom Reverse Chassis Mid-motor ruslter

    Hello,
    First a little backstory... Ever since I have gotten my bandit, that I had converted to a wide-bandit with slash arms (rusty I guess?), I had wanted to do the midmotor mod. I researched tons of threads and almost all of them were either kits that were expensive (I'm on a budget here) and had to run a shorty battery. Since I already have non-shorty batteries that I am happy with and don't have anything else to use them it, I decided to try to make mine the first I have seen to keep the original wheelbase, have mid-motor, and run full sized packs.
    I started by taking my Bandit apart to get to the chassis, once I got there I studied it and realized that it would be impossible to keep the original geometry keeping the original chassis, so I thought. I put the chassis down and took a break, later I went back into the shop, the way I had put the chassis down was backwards, then I realized that the chassis almost looked exactly the same as high-end buggies and truggies. I started doing some math then drilling holes for the rear gearbox, I found that with light filing and some small hand saw cuts, it fit perfectly with even the right anti-squat (No RPM gearbox needed!).
    I moved on to the front, found out the ESC plate pattern is the same as a servos, than began prototyping a steering linkage, I found out that with the original steering linkage there was no possible way to make it work without the servo sticking out hugely. I hit a wall and worked on it for a solid 3 days, I tried over 10 different methods and none of them worked, I originally wanted reverse-bellcrank but there is no way to do that with the original bulkhead so that was a bust from the start. I started to dig around my parts and found my 2.5 T-Maxx steering linkage, I started to work with that and discovered that if I cut them down and made a vertical bellcrank system, similar to reverse, it worked perfectly, with a few mm to spare. Granted it has a little less steering lock, but for using cobbled up aluminum angle of unknown grade, I think I did OK.

    Enough talking-writing, here are the pictures
    IMG_1995 by JJ2Sam, on Flickr
    IMG_1994 by JJ2Sam, on Flickr
    IMG_1997 by JJ2Sam, on Flickr
    IMG_1996 by JJ2Sam, on Flickr
    IMG_1999 by JJ2Sam, on Flickr
    IMG_1998 by JJ2Sam, on Flickr
    I will make a follow up post of the build pictures, and diagrams of how to make it.
    I also plan on making a custom body for it, any suggestions on body styles?

  2. #2
    RC Qualifier Synnergy's Avatar
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    What?! No you didn't!! Wow! That's some serious customization.

    You could add a brace or body mount to the front shock tower, it would stiffen the front end a bit.

    You could go a bunch of different directions with the body...what about a porsche or some mid motor model?

    That's really cool, how do you like how it handles? I hope you took a bunch of pics along the way to show how.
    MTFBWY

  3. #3
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    Quote Originally Posted by Synnergy View Post
    What?! No you didn't!! Wow! That's some serious customization.

    You could add a brace or body mount to the front shock tower, it would stiffen the front end a bit.

    You could go a bunch of different directions with the body...what about a porsche or some mid motor model?

    That's really cool, how do you like how it handles? I hope you took a bunch of pics along the way to show how.
    I was thinking of a brace, the front is basically held together the same as the original, but there is still lots of room for improvement. I mainly just want to get better shock towers, I don't like the front RPM one and the rear one is worse because of flex, I could buy a carbon front tower. For the rear I want to make a low profile tower, because this one sticks out like a soar thumb.
    I'm thinking a buggy body, but I could check out other ones, this is more for off road, but I guess having a good on-road full coverage body would be nice also.
    I havn't driven it much, I just drove it for about 3 mins on a half charged battery, just from that I love it, I flies strait, and turns much better. Also it seems to take grass a little better, but I might be imagining that.
    There should be enough pictures, I kind of skipped on the steering, but its pretty self explanatory, and I am using angle stock that varies in thickness .3mm so the diagram won't work well for anyone else (+ I totally didn't mess up the math when drawing it so it is not right at all...)

  4. #4
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    I did a double take, then a triple take, then a quadruple take...

    That is some seriously good thinking. I didnt even realize the chassis flip until the third or fourth time looking at it.

    For the body, do a cab forward like all the race buggies. They look amazing. Oh and have to add the wing!
    6 Traxxas vehicles and counting...

  5. #5
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    Quote Originally Posted by kevinatfms View Post
    I did a double take, then a triple take, then a quadruple take...

    That is some seriously good thinking. I didnt even realize the chassis flip until the third or fourth time looking at it.

    For the body, do a cab forward like all the race buggies. They look amazing. Oh and have to add the wing!
    Thank you
    Definitely there will be forward style body, maybe a Tekno one, they look like they might fit, for the wing, I just have to select which one, because my stock one is cracked and I hate the way it looks floating so high above the chassis.

  6. #6
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    Here's the tutorial on how to make it.
    I started with JB welding some of the old bolt holes
    IMG_20180727_133417 by JJ2Sam, on Flickr
    IMG_20180727_133420 by JJ2Sam, on Flickr
    I then drilled holes for the transmission
    IMG_20180727_134924 by JJ2Sam, on Flickr
    Countersinking the holes
    IMG_20180727_141133 by JJ2Sam, on Flickr
    You can add and subtract washers to adjust the anti-squad (caster angle)
    IMG_20180727_141200 by JJ2Sam, on Flickr
    File down the taps in the rear of the chassis and cut off some material.
    IMG_20180727_143802 by JJ2Sam, on Flickr
    Sand down servo holes, don't do as much as I did, I would just shave off enough to fit the servo horn.
    IMG_20180728_102744 by JJ2Sam, on Flickr

  7. #7
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    skipped ahead a bit here, just mounted the rear trans, and made the front steering brackets, I made a diagram, but it's completely wrong, I need to make a new one. Also made a top plate, it's the original top plate but I filed the lines off it and cut it down.
    IMG_20180802_121402 by JJ2Sam, on Flickr
    IMG_20180802_121409 by JJ2Sam, on Flickr
    IMG_20180802_121620 by JJ2Sam, on Flickr
    IMG_20180802_121638 by JJ2Sam, on Flickr
    Here are the diagrams of the rear, front, and steering. You can use the physical pictures and these as references
    IMG_20180728_102831 by JJ2Sam, on Flickr
    IMG_20180728_102826 by JJ2Sam, on Flickr
    The steering rack is right, just the angles measurements are wrong.
    IMG_20180728_102839 by JJ2Sam, on Flickr
    Hopefully this is enough, if you need any more pictures just ask and I will take some more

  8. #8
    RC Champion RazorRC22's Avatar
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    That’s awesome!
    youtube.com/c/RazorRCvideos

  9. #9
    RC Champion lektro's Avatar
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    Dag gone sure is awesome Sam..... That is sweet. everthing looks like it's supposed to be there. A thing a buddy and i use to always say. At least in the first three pics....
    Last edited by lektro; 08-02-2018 at 05:48 PM.
    Choose Life !!!

  10. #10
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    Thank you, I'm working on the body right now, and starting to work on a running video

  11. #11
    RC Qualifier PJbottoms's Avatar
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    Cant wait to see the vid!

  12. #12
    RC Turnbuckle Jr. Greatscott's Avatar
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    Very nice fabrication!!! With the weight transferred forward like that it should sail off jumps like a pancake.
    Submarine Qualified, Chief Inducted, Navy Retired

  13. #13
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    Quote Originally Posted by PJbottoms View Post
    Cant wait to see the vid!
    It's uploading right now, youtube I guess is being slow because it is taking forever
    Quote Originally Posted by Greatscott View Post
    Very nice fabrication!!! With the weight transferred forward like that it should sail off jumps like a pancake.
    I does, I did put the stock wing on though, it would nose dive after it launched, but when I put the wing on it stays nice and level now.

  14. #14
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    Here's the running video, I'm sorry for the potato camera, I just got a cheap action camera and wanted to test it out. Also, forgive my hamfisted driving
    https://www.youtube.com/watch?v=GWNQ...ature=youtu.be

  15. #15
    RC Qualifier Synnergy's Avatar
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    That's cool BrickitSam! It's amazing that the small wing would make that much difference!
    MTFBWY

  16. #16
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    Quote Originally Posted by Synnergy View Post
    That's cool BrickitSam! It's amazing that the small wing would make that much difference!
    Yeah I was doubtful the wing would do much, I'm looking into a wing now, maybe the 8ight one or a AE wing.

  17. #17
    RC Qualifier Trentbaby65's Avatar
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    Brilliant! Top job.

  18. #18
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    Long overdue update time. Last week I went over to my "Local" rc track to test out this rigs performance and durability. I'm sure with appropriate tires for the track, hard packed clay, I might have been able to almost keep up with the 1/8 Losi's and Tekno's that were also running the track but since my tires have no grip I had to take corners way slower than them and skid out way too often even with me trying my best to control my trigger finger. I was able to make the 10-15ft jump in the middle with ease with a battery even after 15-20mins of driving and it flew super strait in the air, almost no need for inputs while jumping. After the abuse of over 4 hours and my horrible crashes, I only broke one thing I skid out right in front of a ET48.3 and got T-boned hard on the rear wheel breaking my rear camber link, but the link was from a ruster steering assembly so it was not nearly strong enough for the task, so I am very happy with durability.

    I also picked up a body and the old traxxas fiberglass front shock tower, I was debating getting a TLR 22 body, but went with a ET410 body, the tapir is slightly too small, but it is an easy fix and I will make some velcro tabs to keep the body on better. For the shock tower I instantly noticed that it was more responsive to steering inputs without the RPM tower bending all over the place.

    Last update, before I cut out the body, I made a plaster casting so I can make a vacuum form to make the body again with mods that I will do to it by moving the shock tower clearance bulges, changing the chassis tapir, and removing the small velcro tab spots for the ET-EB410 because I will use a different placement.
    Here's a link to all the updated pictures of the body, casting, and new shock tower.
    https://www.flickr.com/photos/136426...57697399996222

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