Custom 4 Link Trophy Truck Based on HPI Mini Trophy

[Jackington]

I found a HPI Mini Trophy on ebay a few months ago because I was getting the trophy truck itch and I had seen a few guys had done a fairly simple looking conversion on the Mini Trophy from the IRS to Solid Rear axle using an Axial SCX10 axle. I had an SCX10 so I thought, why not try it? 'How hard can it be?'

So I tore apart my beloved SCX10 and after an encounter with a dremel and a hacksaw, the mini trophy chassis was rendered in twain and I bodged the axle onto the back of the truck.

As time went on, I was a little disappointed with the performance of the mini trophy, mostly due to its super low chassis and the terrible job I did of cramming in the 4 link onto the chassis, so I decided to have another bash at it. This time taking inspiration from trucks like idealrc have built.

First job was to chop out all that I wouldn't need, which turned out to be everything apart from the from suspension assembly, which would leave me to build a whole chassis.

Cardboard test.



After I made the cardboard template I used some old Alu plate I had to make a metal mockup of the chassis to see how it would fit. Then I made a pair of upright panels to mount the rear suspension on.



The next task was to make the actual chassis, I called round to a friend of mine who supplied me with a sheet of stainless steel, about 1mm thick. Turns out cutting and shaping 1mm thick stainless with only hand tools is a tough job, but 3 jigsaw blades and some shrapnel injuries later I managed to make something worthwhile.







I am currently in the process of mounting up an SCX10 transmission between the two upright panels, its a tight squeeze! After that its just a case of finding somewhere to put the servo, and the finding some way of making that servo steer the wheels! Joy!

Thanks for looking! :D

[MojaveMonster]

Just a question but what is wrong with using the stock tranny? I kept it in my conversion in progress, only re-arranged it's placement. Personally I think its a rather cool Tranny. If you don't want it any more please PM me a price.
Thank you and good luck on your build.

[Jackington]

Originally Posted by MojaveMonster

Just a question but what is wrong with using the stock tranny? I kept it in my conversion in progress, only re-arranged it's placement. Personally I think its a rather cool Tranny. If you don't want it any more please PM me a price.
Thank you and good luck on your build.

I probably would have gone for using the stock tranny had it fitted into the truck itself, but the gap between the two upright panels was just too close for the tranny to fit in, plus with the high up outputs there would have been a problem with the driveshaft angle in the rear.

Sorry, but I plan to keep hold of the tranny, just in case I come up with another build, thanks for asking though, to be honest I think the postage from UK to Cali would be more than the tranny is worth :P

I think maybe your Mini Trophy custom build was what inspired me to buy a Mini Trophy and build this beast in the first place, so how about that?

[BLKXJ 96]

The past few trucks I have seen are all sheet metal, seems like tube would work better.

[Gdog427]

what are those lower trailing arms off of? SCX10?

[Drew]

Originally Posted by BLKXJ 96

The past few trucks I have seen are all sheet metal, seems like tube would work better.

A proper truck will have both. When I built real race cars I was often asked square tube or round tube for a chassis and people were dumbfounded when I said both. Each build method has its pro and cons. Sheet is easy to work with and much more forgiving than tube for something like a chassis.

[Jackington]

UPDATE:

I have finished off the truck now, got the SCX10 tranny mounted up, 4WD is fully operational, turns out there is about 1mm of leeway in every direction for all the parts to fit in, but its in so I'm happy.

Managed to get the servo bolted up onto one of the upright plates and the linkage is pretty good, I would even go so far as to say I have improved slightly on the frankly shoddy original HPI steering setup.

I am running the brushless setup out of my SCX10, which is here; http://www.rccrawler.com/forum/axial...-cherokee.html and its a pretty damn fun truck, going to take it out to my local BMX track tomorrow to see how it compares to my Slash.

I also managed to get a body sorted out and mounted, at the moment I am using the Cherokee body from my SCX10 again, but I have ordered another Cherokee body, this one with the longer wheelbase for E-Maxx trucks, its only 3mm out so thats good!

Hopefully I will get some pictures and maybe even some video uploaded in the next couple of days or so.

Thanks again!

Originally Posted by Gdog427

what are those lower trailing arms off of? SCX10?

Lower arms are straight off the HPI Mini Trophy.

Originally Posted by BLKXJ 96

The past few trucks I have seen are all sheet metal, seems like tube would work better.

I would like to have done some tube work on this truck too, nice rear cage for a bumper and spare wheel mounts etc, but this way I don't have to invest in any brazing gear and learn how to do that, plus it keeps the weight down, with loads of tube it would be super top heavy, and this thing loves to flip over enough as it is!

[Jackington]

Took the truck down to the BMX track today, heaps of fun to drive, I have to say I think it was moving faster than my Slash, although that may have been down to a dodgy battery. Ended up knackering up the brushless motor in it, the motor spins up but theres no drive when theres load, so it spins fine out of the tranny but just makes lots of noise when its mounted up. I guess thats probably something to do with the rotor in the motor, but I can't get it apart to have a gander, maybe I'll try harder tomorrow.

[Jackington]

Time for a Christmas update!

I am finally back from uni for Christmas and can get back to playing with my toys, and boy do I have some toys to play with, the trophy has been waiting patiently for this week because of one special thing! NEW MEATS!

I decided there was only one thing that could make this truck beautiful, Vanquish wheels and RC4WD tyres. So I bit the bullet and shed the 150 or so quid from my wallet and splashed out.

But first, I finally got to painting and mounting the body. I decided to go with a blue on white scheme, and I am so happy with it.



Not a great photo, its shinier in real life, and I have a few more stickers to plaster on it.

Now for the tasty part, the first time I saw these Vanquish OMF wheels I was blown away by two things, how epic they look and how friggin expensive they are, but in the end, its only money. Plus there's so Many pieces! And everybody loves doing up 200 odd screws so what the hell!









Problem is now I don't wanna take it out and get those things dirty!

[YFZBOB]

Holy Crap! I think you need more screws and a few more wheel parts. I do admit, that is one good looking rim setup! I like it.