SH Z-Car ZMXB-8 1/8 Buggy - Perfect for conversion! (56k take a break)
 

How many of you have seen this buggy?
http://www.shengines.com/Z-CAR/ABOUTUS_zcar.htm
Hobby People, type "z-car" into search, it's the first item

It looks pretty good! There's one in stock at the LHS in which I work, and I very much want to buy it. There are a number of features that set it apart from the average 1/8 buggy, I'll try to list as many as possible, that I can see from the pics:

-REAR DIFF-MOUNTED DISCK BRAKE
-cool non-hex wheel hubs should grab wheels much better and prevent wheel stripping with their wheels (I've stripped 17mm wheels when the wheel nut loosens)
-lower pillow-ball on the front, with upper ball joint should allow for some awesome and easy adjustability
-nice looking shocks (big bore) and milled out shock towers
-chassis has A LOT of material removed, hopefully that makes it nice and light
-interesting way of capturing hinge pins (no e-clips!)
-rear caster is adjusted by a single plate, looks easier than using little inserts in hinge pin plates

The most intriguing thing to me is the first item on the list. RC-Monster Mike and I discussed this feature on buggies. Basically, having the brake there keeps it away from the center diff, so you have more room for a brake servo, and you can also get away with a mini servo. Then, you use the rear brake with a combination of motor brake, so that you still have strong braking, but also have an adjustable rear bias to pitch the rear end into turns.

i sow this a few days ago. i did not konw you guys had one.

i think its kinda stupid for only one store to it lol.

It's cuz we're next to the warehouse :angel:

The Hobby People link doesn't work btw, but it definitely sounds like a pretty sweet buggy. I'll be in Huntington Beach on Saturday, so I'll try to stop by and check it out. :yes: Is it on display so it can actually be looked at or just a kit in pieces?

I am very curious how the brake is attached to the rear diff though. I can't imagine what it even looks like...

It's a bunch of parts in a box. Unfortunately I still need to put some funds together before I can make the purchase, but it will be soon :yes:.

Link fixed.

Yes its sweet buggy, I tried this on track it handles very good, suspension worked realy good btw shock pistons have special valves on some holes to to turn your shock progressive or regressive. brake solution is interesting and also rear A-arms are interesting too. It sold as KIT
In europe it sold as LRP buggy

So who came out with the rear brake idea first, Ofna or SH?

Good question. Ofna released their pics of the Hyper 9 a couple months ago. The SH buggy is sold under LRP in Europe as tom255 noted, and it's probably been out longer than the Hyper 9 pics have.

So Friday night, not too long after I posted this thread, I realized my NEED to get this buggy (and be the first person to convert one!). So yesterday when working at the LHS I purchased the only one there, and I had to wait until 6:45pm to start building it :surprised:.

Initial impression as soon as the box was opened: "This box smells weird." Then I got around to ripping the parts bags out, trying to see as much as possible as quickly as possible. This was my first 1/8 buggy kit, so as you can imagine I was quite excited! Unfortunately then I looked at the wording on the box and in the instruction manual, and there was much left to be desired: proper translations. But considering that I've had a good deal of experience with RC cars and generally have good intuition the build was not so difficult.

First up was building the diffs. This kit includes 500wt. (actually 50wt. shock oil), 1000wt, 3000wt, and 5000wt oils. The instructions specify 3000/3000/1000 F/C/R, but I went with 5000/5000/3000 because I know the diffs will be more likely to unload under brushless power than what "nitro" can dish out. Building the diffs was nothing special, I've built many a 1/8 diff before.

Next was the front end. This was where things got interesting. You might have seen 1/8 buggies like the Mugens with pillow ball suspension, and others with vertical ball stud-suspension (I think it might be called pivot ball?). The SH car utilizes both, with a lower pillow ball and a vertical ball stud on top. The pillow balls alone were surprising because they have a hard-anodized aluminum outer sphere and an inner steel core. This design makes them light, yet strong (amazing!). Having the upper vertical ball stud allows for typical camber adjustments with a tie rod, but also allows for the manipulation of the ball stud's height which I am guessing could alter roll center characteristics. Another thing I noticed when building the front end is the plastic of the suspension arms: it feels very sturdy, yet flexible. It just felt reassuring.

The rear end build was much unlike anything I've ever built before. For starters, there's a disk brake mounted to the diff case! The design of it is quite simple, and consists of two cylindrical pieces that squeeze the brake disc between them when pressure is applied. Then came attaching the VERY strange suspension arms. The arms have little rubber bushings inserted into them where the hinge pins go through to act as impact absorbers and they should hopefully decrease wear on suspension parts.

Finally came attaching everything to the chassis. The front and rear fit onto the chassis perfectly, and without a hitch. The steering servo mount is pretty cool because it is totally separate from the radio tray! There was absolutely no cutting involved to get the steering servo mount in its current condition.

Up next is making a motor mount and new plate above the center diff to mount the mini servo (Hitec 5245MG) for the rear brake. And then a battery tray will be made, probably using a spacer to raise it above the level of the dirt guard.

Overall, this kit was VERY fun to build because of all the minor things that stood out when I built it. Here are just a few that have not yet been mentioned:
-almost all screws are HEX head, and most are self-tapping which means less time to get those screws in or out
-only 6 screws were phillips head, including the four 45mm long screws that hold the front and rear gearboxes together, and two more on the front gearbox
-little covers for the front upper arms (they hide the turnbuckles) keep the front upper arms straight
-front and rear upper mounting points for the aluminum chassis braces have the little rubber bushings in them (impact absorbers), and the upper part of the front chassis brace is secured with a pin and body clip
-the hexes are 17mm, but are a star pattern which make them key into the wheels MUCH better than standard 17mm hexes (and these hexes should be compatible with standard 17mm wheels), and this star pattern makes the hexes weigh less
-shocks use rubber bushings instead of o-rings, which should provide a better and longer-lasting seal than o-rings
-CVDs throughout

Total build time was about 7.5hrs for the kit.

As you can tell, I am quite impressed with this buggy so far! Now, here are the pics you have been waiting for:
http://img.photobucket.com/albums/v1...r/IMG_7334.jpg
http://img.photobucket.com/albums/v1...r/IMG_7346.jpg
http://img.photobucket.com/albums/v1...r/IMG_7342.jpg
http://img.photobucket.com/albums/v1...r/IMG_7344.jpg
http://img.photobucket.com/albums/v1...r/IMG_7358.jpg
http://img.photobucket.com/albums/v1...r/IMG_7339.jpg
http://img.photobucket.com/albums/v1...r/IMG_7351.jpg
http://img.photobucket.com/albums/v1...r/IMG_7353.jpg

Now that looks awesome. I'm loving the Hybrid rear suspension arm. A mixture of trailing arm and normal arm. Does your LHS have spare parts for it?

Sweet looking kit!!! Hard to believe the build only took 7.5 hrs....wow!! When I built my mbx-5 it took me 15hrs+ (It was my 1st. 1/8 kit) The front suspension is v/interesting and I am curious as to it's durability and performance. All in all a nice looking buggy.

Very nice looking buggy. The blue and yellow look great together. :yes: Many features I have never seen before on any other buggy. I am looking forward to seeing it in person at the bash... Hopefully you'll bring it. :mdr:

Supposedly parts support will be very good as soon as the parts come in stock. Already I have special ordered ~$90 worth of parts for this buggy, but of course am hoping that they won't be needed.

Judging by feel, these parts should hold up very well. But I too am curious about the durability of the front suspension!

I like innovation, and that is something this buggy is definitely not lacking. This buggy will become a track-only vehicle, as bashing will obviously wear out parts. Maintenance is not something I'm fond of :whistle:. But this way my Hyper 8 can be moved over to bashing duties!

wow i think i might be getting one very soon lol.

hey i have a question. do you know of any motor mount that rcmonster makes that would work for this?

I would guess that none fit, although I have no idea. As is per my usual routine I will be making my own mount. If it would help I could post up a drawing with dimensions for the mount I will make.

Wow.. That’s a mighty cool build you have going on there Travis.., you are going to make you own motor mount??. Cool please post progress pics of that one…. How and the hell did you make the progress that you did in 7.5 hrs??. I'm loads behind you and with today’s / tonight’s progress I’ll have over double hrs in mine than you have in yours.. I'm totally jealous.. But I'm stoked for you at the same time and I'm looking forward to seeing you run that bad boy next week…

Quick question for you!!?? :oops: How are you going to utilize the rear breaking system?? Sorry for the newbie question I just can’t figure it out. The ESC does it so how are you going to do it?? and I didn’t install mine in my 808 for just that reason, should I have installed it?? (help)… :neutral:

Thanks for the cool thread and please keep the updates coming.. :yes:

Have a great night..

Shaun.

P.S.
I know how you did it!! (Youth and experience!!).. Outstanding job Sir…


P.S.S
What Droop setting are you using on the front and rear?? (thanks again)..

Thanks! I most certainly will be making my own motor mount, using 2" wide 1/4" thick 6061-T6 aluminum. It won't be the prettiest, but I value function over form anyways (not that it will be ugly, though).
If I had to set this thing up for nitro, I'd still be working on it. Just the brake and throttle linkages would take me two hours! My guess is I just knew more or less what I was doing, and didn't waste much time going over the instructions (which are pretty much just pictures). If you have any questions on your build, don't hesitate to ask! I'm working tomorrow at Hobby People 8am-3pm, so bring in your buggy if you like.

This is one of the things that makes this particularl buggy so special. Many of us 1/8 electric buggy/truggy veterans know that motor brake can never be as good as mechanical brakes in terms of control and tunability. Often we opt for motor brake because it is MUCH simpler to use and is the most weight effective solution.

At one time Mike and I held a conversation about the ultimate compromise: a combination of motor and mechanical brakes. Basically, you retain the brake on the rear wheels for the ability to "swing around" the rear end of the vehicle in turns, but then you use the motor brake to eliminate the mechanical brake for the front wheels. Also, having a mechanical brake over only the rear wheels means you can use a smaller and lighter servo for the brake (as opposed to a larger heavier servo for front and rear mechanical brakes).

If your radio is good enough and your skills with it are sufficient you can actually use your radio to control the front/rear brake bias between the front and rear ends on the fly! This is the ultimate in brake tunability if you ask me (or Mike).

Those two do help :party:.
As for droop, I have yet to actually set it. Right now the bottoms of the droop set screws are flush with the bottom of the suspension arms. I will wait until I get to the track to set droop, so that the track will help me determine the best setting.

I'm sorry to ask a Newbie question here, but what is the recommended shock rebound setting for buggys?? The instructions give me three options (low, 50% and 100%) what are your thoughts / suggestions.. what are you running your at Travis??.

Thanks again..

shaun.

WWWOOooooowww you know so much more than i do.. (that’s SSOOOO COOOL) I just love reading your information.. Thanks for the schooling and your time.. I will bring my buggy to your office tomorrow with several questions (sorry!)..

Thanks again for your time and have a great one..

LOL, I just put up some answers to your questions over in your thread. It's neat that we are doing parallel builds :yes:.

Thanks SIR...

Isn't this the car Greg Degani has been pushing? I know he's experienced a couple durability issues. Hopefully it was in the name of testing and they've fixed the bugs.

It is a cool design. I'm looking forward to seeing the conversion.

BTW, did anybody else notice the copyright belonging to the Lego Group on the bottom of that Z-Car page? I always loved Legos growing up, I guess now is no different!

This is the buggy that Greg Degani had a part in. I am interested in hearing about the durability issues, if you could find out what they are.

I don't know too much. In talking to him at RCX he said it was real durable except when he nailed the boards at near full throttle and it broke an arm (to be expected). Ironically, in that afternoon's supercross he broke also. I guess that doesn't mean the car has durability issues, the comedy of it just stuck with me I guess.

Hey guys I stopped by LHS this afternoon and had the opportunity to see MetalMan’s buggy up close (NICE…) :yes::yes: that thing is really nice.. luckily I’ve have the opportunity to see at run next weekend at the track.. I can’t wait to run mine with his, :whistle: of course he’ll smoke me on the track dam (youth and experience) :diablo: but it should be blast none the less.

Great job on your build MetalMan..

Wow... it looks great. Can't wait to hear how it drives.

I finished painting the body today, although it's not nearly the best paint job out there. Usually I only do the fade (metallic blue to metallic black), but I had to throw in some flourescent yellow :yes:. This was pretty much my first time masking, which is odd considering I've been painting bodies (albeit without skill) for at least 4 years now.

http://img.photobucket.com/albums/v1...r/IMG_7359.jpg
http://img.photobucket.com/albums/v1...r/IMG_7364.jpg

Current weight with a Hitec 5955TG and the kit minus the nitro crap is 5lbs. 5.9oz.
http://img.photobucket.com/albums/v1...r/IMG_7374.jpg

And I just finished designing the motor plate:
http://img.photobucket.com/albums/v1...otor_plate.jpg
(yes, I did use Mike's mounts for inspiration, because they are so nice!)

it looks good man. cant wait to see it running.

BIG Update
 

This buggy was finished a week ago, but I didn't have time to upload pics then since I was busy preparing for the 1/8 electric race in the JBRL electric series. But here it goes:

Here's an overall view without the battery/battery tray:
http://img.photobucket.com/albums/v1...r/IMG_7384.jpg

I took inspiration for the motor mount from Mike's line of motor mounts, but obviously my design isn't as good. It's completely functional, though!
http://img.photobucket.com/albums/v1...r/IMG_7393.jpg

And now, the revolutionary part of this kit in action:
http://img.photobucket.com/albums/v1...r/IMG_7387.jpg
http://img.photobucket.com/albums/v1...r/IMG_7389.jpg
That's the best place I could find to mount the brake servo. All it is is an upper deck mounted above the center diff/motor mount, that extends toward the rear, and is bent down after the motor mount to keep the CG of the added servo as low as possible.
Then you can see the MMM mounted. There's industrial strength Velcro under it, and a zip tie holds it down securely (although the Velcro alone would allow the MMM to hold the entire weight of the buggy).

And a view showing the not-so-low CG:
http://img.photobucket.com/albums/v1...r/IMG_7394.jpg
With refining it would definitely be possible to get the brake servo and ESC mounted directly on the chassis plate, but I didn't have the time or determination to do so.

Then came the two-piece battery tray, including the spacer to offset it from the chassis (to clear the dirt guard) and the actual tray:
Open, demonstrating the ability to adjust for different battery lengths:
http://img.photobucket.com/albums/v1...r/IMG_7399.jpg
Showing the height adjustment capability:
http://img.photobucket.com/albums/v1...r/IMG_7403.jpg
With the top strap in place (notice the outer velcro on the height adjustment strap, more on that soon):
http://img.photobucket.com/albums/v1...r/IMG_7401.jpg
My favorite part, showing how the length adjustment strap actually helps secure the top strap!
http://img.photobucket.com/albums/v1...r/IMG_7407.jpg
Another complete view:
http://img.photobucket.com/albums/v1...r/IMG_7404.jpg

Complete "nude" view:
http://img.photobucket.com/albums/v1...r/IMG_7411.jpg

Overall CG view:
http://img.photobucket.com/albums/v1...r/IMG_7417.jpg

Cool:
http://img.photobucket.com/albums/v1...r/IMG_7421.jpg

Just over 8lbs fully RTR!
http://img.photobucket.com/albums/v1...r/IMG_7425.jpg

Since racing this buggy, I gotta say that so far it's working very well. I didn't have time to set up the mechanical and motor brakes properly, but they still worked flawlessly. Nothing on the buggy broke which was nice because I had no spares...

Only problems I had were when the switch turned off (my fault, and immediately after the race I cut the switch off), and two wing mount screws came out all the way (again, my fault since I didn't thread-lock them).
Although, I did have to run a lot of preload on the springs to keep the arms level, which is an indication that the springs were too soft. Indeed, I would have been much happier with stiffer springs, but they aren't yet available.

The rear end was very loose in corners, but the track also had a loose top surface since all the water had evaporated from the dirt. Also, better tire choice could have fixed this.

Steering is great on this buggy. On a certain u-turn on the track I was accidentally cutting other buggies off because it was taking the turn so sharply.

I definitely look forward to fine-tuning the handling, braking, and acceleration of this new buggy!

It looks awesome.

Edit: Try the following springs: http://www.amainhobbies.com/product_...ducts_id/12695. I have the one for the Hot Bodies LSP and they are awesome.

hi there, nice job! could you please show me how you mounted your reciever/antenna mount thingy... this is something i need to work out! thanks,
ryan :)

Any chance you can get the inner diameter at the top of the spring and at the bottom of the spring? The shocks on the SH buggy use springs with a larger innder diameter at top, and they taper to a smaller ID at bottom.

It is just a simple receiver mount:
http://www3.towerhobbies.com/cgi-bin...?&I=LX3355&P=7
This is my only Nomadio receiver, so there's velcro on the bottom of it, enabling me to quickly swap it between cars :whistle:.

Thanks for the comments!

WWooowww :party:that looks great Metalman.. I see the mount worked out quite nice and it looks like you CG or good?. Great to hear nothing broke!.. And I do like the micro servo for the rear brake..:yes: Did you end up hooking to your 3 channel??. What is your gearing? And do you know what that bad boy weights?? I thinking what 7.5lbs??

Looks great!..:yipi:

Wow nice conversion but I dont like battery box, becouse material is too weak, if it not polycarbonade otherwice it too fragile. I dont trust velcro tape too on front of battery box. Maybe when it fresh it will hold battery but in dirt and after copuple battery replacements it goes weaker

The CG is decent, but because I wasn't able to fit the components on the floor of the chassis the CG could be better.
I did use the 3rd channel mixed in with the throttle to control the rear brake.
Check out the last picture :tongue:. Just over 8lbs :party:. Not bad for the first electric conversion to the SH buggy in the US :gasp:.

The material is 1/8" thick polycarbonate - it's very strong. This is my third time making a battery tray using similar methods of velcro mounting (and it's worked for the last YEAR), and it's gotten better each time I have made a battery tray. In racing last Sunday there were no problems with the battery even close to falling out.

Besides, dirt doesn't get in the velcro fibers. I don't get the buggy dirty without the battery in there, and when the battery is in there, the velcro straps are on, closing off the inner fibers from whatever might get on them.

You got me there :lol:. Give Amain a call or send them an e-mail with the diameters you have.

I just bought one of these buggies from the LHS :yipi:. Mine is an LRP S8-BX RTR but I am going to pull the radio gear and motor and sell them. It came with a LRP Z.21R which is a nice motor and I had better sell it quickly or i'll be tempted to run it. I'll run it as nitro for a while with a different motor until I can fund the conversion to brushless. Expect some questions from me MetalMan. :party: