Racing brushless 1/8 scale

[glassdoctor]

Looks good... a solid conversion.

Did you say it was nosing on the jumps? It looks like the cg should be back farther than a nitro to me. That layout is similar to my 8ight but I have the battery forward more and it flies pretty level, seems balanced. I wonder if the rear was slapping the jumps?

Only thing I would change is just based on personal preference... where to stick the esc and rx. I like to put the rx over next to the servo and esc either right in front or right behind the battery, down on the chassis. Putting in the front is the best spot but does require a little more wire to reach the motor plugs. With it up front theres' plenty of room for a ubec and a big fan. The battery would have to slide forward to fit it behind. Not a big deal...

One last detail I try to do is get the rear of the motor secured. It's not always easy but it makes the motor really solid. If you are using the motor heatsink that bolts on, you could use the rear bracket to tie onto.. with a simple piece of L angle, bolted to the chassis. Something like this only bolted to the heatsink:

Notice in this pic I have the esc in the same place you do :)

I still haven't settled on the wire routing yet. I had them zip tied to the center diff top plate. I want to get them out of the way, but keep everything accessible, just in case I have to do repairs between races. The same reason that I don't have my steering servo laid down. Four fewer screws to deal with.

I'll try to shoot some video the next time I'm out clowning around at the track. Things are too hectic on race days to worry about it. I have a video camera that shoots straight to compactflash in mpeg format, so it'll be pretty easy to post something. You guys are going to have to go easy on my driving though.

I'm using 7075 for the new motor mount I'm making. I've found that it's a lot stronger than 6061 and isn't that much harder to work. I don't want the mount flexing at all, especially when my buggy is doing cartwheels down the track.

I like the delrin, and it isn't that expensive. Although I may be mistaken, my personal experience is that delrin taps well and really holds the threads.

ohhh ok

and lol i dont think i could do much better on the track lol

glassdoctor,

I put the esc where I did because, as luck would have it, there are no aftermarket manufacturers of bodies for my buggy. All of the Sportwerks bodies have the holes pre-cut for the engine and fuel tank. I figured that I'd take advantage of that and put the esc where it could get a good source of cool air. As for the Rx, I put it there for accessibility. Although I usually run a Spektrum, you never know what's going to happen on race day. I actually had one occassion where I had to run a borrowed am radio system. With the Rx there, I could do a quick switch with any system and be assured that interference from all of the current flying around would be at a minimum. I really put a lot of thought into the accessibility issue on this buggy. You can get to just about everything without having to mess with something unrelated. I also didn't have to drill any non stock holes, so all I have to do is keep a spare chassis in my box and I can do a swap in about 30 minutes, if need be. I just can't emphasize how bad a driver I am. I do like racing, but do it for the thrill rather than to win. I like hitting the jumps hard, just to see my buggy fly, when everyone else is taking it easy to hit that turn at just the right angle. What can I say, I'm careless.

As for the nose diving, I don't think that the weight is too far forward. When I went to light springs in back, the buggy's behavior improved. I was thinking that the back was way over sprung and it was pushing the nose down when I left the jump. I don't think it's slapping, although I'll have to check for that.

Is the rear support for the motor really necessary? On that note, does anyone know exactly how deep the threads are in the mounting holes? I want to get screws that will utilize as much of the threading as possible without danger of screwing anything up.

I'm still patiently awaiting my orders from RC Monster, Maxamps, and a few other places. At least Mike emailed me to tell me that my order shipped yesterday. Of all the people that I ordered from, Mike seems to be the only one on the stick. Maxamps says that my batteries are shipping today or tomorrow. That means that I won't get it until Monday. No racing this weekend.

Thanks for all of the input.

[TruckBasher]

Nice conversion, One of this days i will convert a buggy to brushless also....

Anyway, I think the idea of the rear motor mount is to lessen the motor movement, lessen the flex on the motor mount. This way you'll have a solid setup that doesnt move, good for you pinion i bet :)..

Mike will always be mike he so fast....look af the testimonial page...though he might have some issue (we dont usually know) he will find a way to make it work best for his customers

[glassdoctor]

I haven't seen many others doing a rear brace... but I really like to have it, if I can find a way to get it done. I have run without it also without anything bad happening except maybe the motor sliipping a bit, but no doubt a brace at the rear makes it stronger.

As you have said, 1/8 buggies can see some wild action on the track. It's just a little something extra to keep the motor locked down tight.

I have heard talk about bracing the rear of these big motors, but I don't know if anyone else actually does it but me.

I hear you on the layout... a million ways to do things. It's looking good. I like how it's a bolt-on conversion and that you didn't just stick the battery on the side guards, but made a really good strong mount for it. I don't think you will see your $$ lipos come flying out or get smashed during a wreck...

When you get the ubec it may be tempting to put it up by the rx.... but some say they can cause glitching so watch for that if it's near the rx.

Hey, good things come to those who wait right? :035:

[pinolelst]

I think a rear brace is a good idea.Particularly with the xl can motors.Think of how heavy they can me and all that mass supported sometimes solely by screws in a press fit endbell and how it's going to react when you cartwheel down the track or even just bottom out on landing after a jump...
just my $.000000000000000000000000000000000000000000002 worth

pinolelst

Would the use of one of RC Monster's heat sinks help? I'm just thinking that a rear brace could make quick pinion changes a PITA. I'll see what I can come up with.

I just finished version two of my motor mount. I used a piece of 3/16 aluminum. I was going to go 1/4", but felt that it would be overkill. I'm at the point that I'm watching the weight. It's plenty rigid. Attempts to "jiggle" the motor results in the whole center diff mount shimmying (is that a word?). It's what I want. I want the motor to move with the center diff. I got in some aluminum diff mounts too. With the aluminum diff mounts and the new mount I was able to attach the mount to the diff mount at five points. Two through the top and three from the side. It think I'm going to be sticking with this mount. Now I just have to figure out the suspension.

[glassdoctor]

Originally Posted by AAngel

Would the use of one of RC Monster's heat sinks help? I'm just thinking that a rear brace could make quick pinion changes a PITA.

Yeah, it can make it a pain to change gearing or swap motors. You can go without while still experimenting with gearing, etc... or when not doing any hardcore racing. Maybe just use it on race day to help bomb-proof (some bomb :) ) the car. Again... most guys don't use one anyway.

The brace on my CRT isn't bad at all to work with... I'll just get a pic rather than try to describe it.

As far as watching the weight, have you thought about doing carbon fiber type stuff for the battery tray, or thinner alum? Oh... and what is holding the pack in the tray?

I'm gonna give some thought to the motor support. My head is scrambled from work right now. Maybe I can come up with something out of the box that I could live with.

As for the CF, I'm surfing CF vendors right now. I figure I'll go CF for the battery tray, and anything else I can think of for that matter. I wonder if a CF motor mount would work.

I have some Gorilla straps ordered. I don't know. I have things up and running right now and am tired of working on the buggy. I'm going to play with it a while and see if anything pops into my head with regard to improvements.

I really hope that my RC Monster order gets here tomorrow.

What I really should do is put all of this spending on hold and get myself another mill. If I had that, I could make all sorts of things.

[sleebus.jones]

Originally Posted by AAngel

I wonder if a CF motor mount would work.

Well, I'd think it'd have too much flex. CF is strong, but it's not as rigid as Al. It's definitely got spring in it.

Sleebus

I have heard talk about bracing the rear of these big motors, but I don't know if anyone else actually does it but me.

I made one for my racetruck, dual motor brace. :027:

Well, I'd think it'd have too much flex. CF is strong, but it's not as rigid as Al. It's definitely got spring in it.

Sleebus

No way you could flex 5mm carbon that size, a 50mph headon into a wall wouldnt phase it. Get the good stuff, quasi layed, 100% carbon and its not going to flex.

[neweuser]

Originally Posted by Bomb-Proof

I made one for my racetruck, dual motor brace. :027:




No way you could flex 5mm carbon that size, a 50mph headon into a wall wouldnt phase it. Get the good stuff, quasi layed, 100% carbon and its not going to flex.

That's nice BP, how about a pic of the whole thing! :027:

[neweuser]

Looks good so far. I would definately get some CF for the batt trays. Go to graphiteelegance.com, best you can get for the price. Also, some velcro would work well, but as glass stated, do not put it on bare cells! lol