Australian RC Forums banner

Another Associated MGT 8.0 brushless conversion

68K views 94 replies 20 participants last post by  GTMonster 
#1 · (Edited)
Greetings to all.
First and introduction.
My name is Damian and I have been playing with RC for the last ........well lets just call it 20 years. Most of the time was spent with gliders and control lines (remember those???)
I got into nitro buggies about 15 years ago last racing a Mugen MBX5 about 5 years ago.
About a year ago I decided to get back into cars. I had a look around for a while, then I went down to OZ-RC and they showed me a brushless setup.......holy cr@p.
Since then I haven't looked at another nitro.
Currently I have a RC8be, RC18t, RC18b........I think you can see a pattern forming here.
Which leads on to this project.
I had a couple of CC 1717 motors laying around so I had a bit of think of what to do with them........
Too big for the RC8 (just)
Waaayy too big for the RC18's.
Kept a look out on fleabay and pick up a brand new MGT 8.0 for small money...perfect.

Fresh out of the box.


Clothes off.


Non essentials gone


I looked around for some conversion ideas but alot of people seem to be using the original gearbox. I didn't like the idea of that as it looked like it would end up with too much weight at the back. I like the solid feel to the MGT chassis so I grabbed a spare RC8 center diff ( most likely go to a solid slipper later) and started taking measurements.
In theory the way I am setting the motor/batteries I should have a fairly even balance....but will see as this progresses.

I have done a sketch up of a possible mount as I want to keep the modifications to the chassis to a minimum.




The way it stands I will still need to drill and countersink 4 holes underneath to fix the bottom of the diff carriers.

Due to the size of the motor I will also be making a support for the end of the motor to minimise the amount of flex in the mount caused by rough landings.

I also still have to wait for at least one of my MMM's to come back from the states before I can really finish. But I thought some people may like to see the progress as I go.

If anyone has any ideas I am more than keen to hear them.

Damian
 
See less See more
5
#2 ·
Nice work mate, I see u love your associated cars to. Have a look in the mt nitro section, I'm sure someone else did a conversion to, I want to try a thunder tiger eb4 g3 out. Can the 1717 take 8cell lipos?

Keen on getting a rc8.2e ?
 
#3 · (Edited)
I usually am pretty brand loyal. Before the MBX5 it was mainly Associated stuff, but when you are given a buggy to race what are you suposed to do?
The 1717 is rated at 6S but alot of people use 8S.The set up I am looking at using is 4s 2p. I may have to use a crappy Trackstar ESC to start with.
Flibbs did a conversion as well but for some reason only a couple of his pics show up.
I am not sold on the eb4 G3. I looked at it and it is just a buggy with big wheels on it. where the MGT /Sledgehammer have the extruded chassis rail.
Since I started this project I managed to buy another MGT.....mainly for the hop up parts that were on it.
Damian
 
#4 ·
my bad, i meant the mt4 g3, i think the trackstar is only rated for 5s to

nice truck, if u dont mind answering, how much did u buy it for? and the 2nd truck
 
#5 ·
Sorry...I meant MT4 as well. It is an EB4 chassis.
I got the one in the photo for about 400 never started and still strapped in the box and the other one 150 as a roller.
Anyone need a gearbox??
I think 4S should be enough to start with on this build...after that we will see.

I forgot to mention, I designed this mount so it can be machined in one set up except for the drilling/tapping. And if someone wants the solid model or converted to 2D give me a yell.
 
#6 · (Edited)
Quick update....
I have been looking for a set of dog bones to suit as I want to keep spares as simple as possible.
A few measurements and a quick trip to OZ-RC and I have a set from a savage XL that should do the job nicely.
First problem....
The position of the center diff is a little bit further to one end than I had originally planned but I still have plenty of room to move battery boxes around to get the balance I am after.
As you can see in this render of the mount I have had to modify the carrier a little bit as it now sits in a narrower section of the chassis. I have had to cut down the bottom section to fit the extruded dimension instead of the machined section. Also the top chassis plate tapers in at this point and I have to undercut the carrier there as well.


Hope to start machining these parts this week.

Not sure on the battery boxes yet. I may machine them from delrin/acetal or pop down to the LHS to see what they have. I need 2 that will fit 4S hardcase bricks.

Damian
 
#9 ·
Did you use a program called Inventor to design all this? Because it looks great! Can't wait to see this finished. Flibble's was a beast of a car, took out all of the cars in MT class at phdr at least once :D
 
#7 · (Edited)
Just had a thought......hurt a little bit.
To the mods, there seem to be more and more 1/8 electric MT lately. Is it time for it's own section.
I didn't know which section to put this in so I just put it in the same as Flibbs conversion thread.

Or you could make it 1/8 MT and 1/10 MT only
 
#8 ·
Slight delay to the plans........
Our second baby arrived a bit earlier than planned so I am away from work for a few weeks so have not been able to get the parts machined.
In the mean time I saw a different style of mount that was very interesting.
The elite RC system.



I was thinking of using somthing like this but re-designing it to be able to use all 4 threads on the motor face.
Has anyone used on of these before and if so how do you find them strength wise?
 
#10 ·
I use Solidworks for drafting. The best program I have used for designing. Way better than using 2D. I have used Inventor once but we use Solidworks for work so it's a bit of a no brainer for me.
For some reason I can only see a couple of the pics from Flibble's build thread and I think he used a CC1515 2200kv motor(not certain) So hopefully this motor doesn't rip it to pieces.
Damian
 
#11 ·
Oh yeah, I forgot to say I am tracking the weight of components removed and added but I forgot to check the weight balance before I stripped it down. I am aiming for a 50/50 balance.
Damian
 
#14 ·
Ok....where were we.
Back at work and while I was away I changed the mount slightly.


Not that you would notice....apart from the colour.
Sent the models around the corner to a little CNC shop as My current posistion doesn't give me access to CNC gear at the moment....Working on that one.
Just got them back.


And a quick assembly.

Now just need to find the time to trial fit the parts.
I have to pop into one of the LHS to look for some battery trays as well.
Then just sit and wait for my ESC's to come back from Castle.
Damian
 
#16 ·
Just a bit longer than a piece of string......
The problem is in the packaging. This mount has to get around a few fixed parts and that determines the shape, so I have had to model the chassis as well.
Realistically the design time was only about an hour including the measuring of the parts.
I forgot to ask my machinist how long his time on it was. Probably a couple of hours including programming time.
No economical if you don't have access to the right gear.
Damian
 
#18 ·
OK.....
trial fit up.

Had to drill out the 3.5mm holes to 4.5mm.

Motor in

Tight fit:cool:

Battery placement....very close to 50/50 weight distrubition.








After I get my ESC back and mounted and battery trays in hand I can posistion the trays for the balance that I want. I may make it adjustable.....probably not.
Damian
 
#19 ·
A picture of the arrival of my twins......




Finally made it back to OZ. The ones I sent were beyond repair.
Before


Need to pop over to the LHS and find a couple of battery trays and maybe something for the ESC to mount onto.
Oh and I had better get some more 6.5mm fittings for the ESC.
Damian
 
#20 ·
nice, that was 1 toasted mamba

back on track with the conversion then?
 
#21 · (Edited)
Toasted alright.
The shell didn't fair too well either. One of the harcase batteries deformed a bit. The 1515 lost some anodising and the center and left rear drive shafts lost their chemical black. Apart from that and the fire alarm going off all is good.
 
#22 ·
That looks awesome.....
 
#23 ·
Ok....
Trimmed the receiver/battery box. The RX will now be where the hump pack use to be.


I am tossing around the idea for inital trials of just using one 4S mounted like this.



Not sure though.
I picked up that battery tray today from OZ-RC but they only had one and after trying it in it is just a little too bulky to mount on the sides. It is a two piece one from a Vorza I think.
I was at Mild to Wild and they had a couple of generic light weight ones that may be more suited.
While I was at Oz I got myself a cool little clamp for the ESC and the 6.5mm Castle bullits I needed.
Next problem........finding the time to finish. Will try to mount the ESC and solder the wires but the battery trays may have to wait as I have to head out west for a few days for work....Damn this work thing getting in the way again.
 
#24 ·
Here is the little clamp thingy.




Just to check the drive train setup first I am going to use the single pack and mount the ESC temporarily beside the motor so the leads can reach but the final one will be lighter battery trays that fit either side of the motor as in before so I can change up to 6S 1P easily.
Damian
 
#25 ·
Well that was frightening....
Was impatient and rigged up a quick 4S setup. I think I need to rethink my gearing a bit. It wheelies as far as you want but the top speed is too much. I have a larger spur gear I can throw in and drop down to a 16t pinion and soften the punch a bit. After about 10 minutes of pi$$ing around the motor was at 34 C and the ESC was 45 C
Not too bad.
Won't get to work on it again until monday .
 
#26 ·
Well.....it got a bit dirty today.
Ran 2 packs through it with out any real issues. Apart from wearing out the wheelie bar...........
All I can say is this thing can take some punishment!!!
This was at the jumps at petrie and by no skill whatsoever I cleared one of the big doubles with a perferct back flip with a perfect landing. No way I could do that again. And just to prove it I tried and received the damage to the shell in the second pic.
Handling is "interesting" to say the least after the RC8. I have some bits and pieces to fit soon to help this.
I used an old shell just in case. I will up load some vid soon(nothing flash as I couldn't film and drive).
I need to sleep now, 4am start and a 7hr drive.



 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top