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Shorty Project In The Works....

Greatscott

Greatscott

Too much build, not enough drive
Subscribed Member
Joined
Jul 11, 2005
Messages
3,737
Location
North Idaho
Tonka TRX4 Tow Truck

I have a project I am working on where the chassis and WB have to match the body, and I am using the TRX4. Once I get it done I will post up a proper build thread, but given all of the work still to be done, it will be a while.

For this project I needed the WB to be just 9 1/8", that made me get creative. the back end wasn't that big of a challenge, it is just a shortened 4-link, but the front end with the pan-hard bar challenged me a bit.

Also, the suspension is really short. I am running droop in the front with a compressed eye-to-eye length of 80mm. The back is even shorter and I am still looking for shocks, I am thinking of maybe 4-Tec. For now I just put solid links where the shocks would go, but I am amazed how much articulation I am getting.

Untitled byUntitled by
Untitled byUntitled by
 
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That is short lol. Caught my intrest, subbed my friend

Sent from my SM-J327VPP using Tapatalk
 
Looking at running droop in the back, anyone know of a shock that is 40mm (ish) eye-to-eye when fully compressed?
 
Subscribed! I'm curious to see where you are taking this. Looks good so far.
 
Progress continues on this project. I am starting to get the parts and pieces put together, but it is a little disheartening to know that it all has to come apart before it can all go back together again.

But, I do have one major shareable milestone in the bag...

Untitled
 
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When I saw these rear portal mounts with shock mounting provisions, I thought they could help on builds like this.

$_10.JPG


I believe they could be installed in the opposite direction so the shocks mount on the back of the axle which would move the upper mount higher on the chassis like this:

DNrt4p0l.jpg


With raising the upper mount and lowering the bottom mount, you would be looking for a shock closer to 60 mm compressed (about a 80 mm uncompressed) which would be much easier to find.
 
More work on McShorty... Other than a few odds and ends, the chassis is almost ready. The body is almost ready as well, almost time to strip and repaint. One thing really left to do, and it is really giving me fits to get it right, but that is half the fun of this project.

Here are a couple of pics...

This one shows the difference in WB from my 12.3" TRX4 and McShorty.

https://flic.kr/p/QFbmtp by https://www.flickr.com/photos/152929997@N08/

The drive shafts took a little bit to get right as well...
https://flic.kr/p/2erv9ac by https://www.flickr.com/photos/152929997@N08/
 
Now it gets serious... 12 channels!!!

Untitled by https://www.flickr.com/photos/152929997@N08/, on Flickr

Just need to install the kit to get it out of mode 2 and we'll be in business.

As far as the truck itself goes, just waiting for Spring, literally... It is too cold in my garage for stripping and painting right now. Can't wait until it warms up, 10*/f almost feels like shorts and tanktop weather...
 
Re: Tonka TRX4 Tow Truck

Brake Weight said:
That’s cool as fvck.
Click to expand...

Many thanks!

Here is some running video of this guy. Like I said in the previous video, the booms still need some tweaking. I am thinking about getting rid of them altogether and just going with a big winch in the back.

https://www.youtube.com/watch?v=O-k6ET8WW4o

And, some pictures with it lit up...

Untitled by Scott O, on Flickr

Untitled by Scott O, on Flickr

Untitled by Scott O, on Flickr

Untitled by Scott O, on Flickr

A pic of its belly...

Untitled by Scott O, on Flickr
 
such a cool build, I've got a full windshield tonka tow truck waiting for a build - even have a few spare TRX chassis..... you've got me thinking on a build now!
 
It is time to dust this rig off and get it working properly...

When I left off the drive train worked fine, but the winches didn't work right and the tow masts looked like a retarded chicken when I tried operating them. This time around I am going to use servo winches for the winches, and linear actuators for the arms. I am also going to use a different radio, most likely the RadioMaster MT12.

My goal isn't to revamp the whole mess, there is a lot about this rig that works, but there is a BIG difference between when I built this rig and now. Everything fabricated for this rig was hand-built using aluminum and/or various bits and pieces out of my spare parts bin. Now I have the ability to design and print my own parts, there there will likely be some low-hanging fruit items I go after to improve.

One BIG thing I would have done if I were building this rig from scratch now is to put in a spacer plate between the cab and bed sections, stretching the whole mess so that I did not have to chop the WB down so much. As it sits, the chassis and body work well together, so I will likely leave that alone. But, this is my winter project, and who knows how the winter winds will blow...

It seems that I always need a project, and after finishing the last two, my Bruder semi and trailer conversions, I either what to start on a new semi, which will be a base Tamiya Globetrotter, or go back and correct some of my past RC sins. Not needing another RC, I am going to correct myself on a couple of projects.

The last two projects... They started off as this Bruder push toy, which is advertised as 1/16 scale (the earth movers is an RC)...

323287457_495578819377454_3923301728709539497_n by Scott O, on Flickr

I started with the trailer first, here it is behind my King Hauler...

Untitled by Scott O, on Flickr

After that, I converted the Bruder body using a Knight Hauler chassis, which was a terrible choice, because its the longest chassis there is and had to be cut down by 128mm.

Untitled by Scott O, on Flickr

I got creative with the batter placement, designing and printing a box for the back with a magnetic lid.

Untitled by Scott O, on Flickr

These two took me the better part of nine months to get done. That is, over course, with breaks necessitated by a healthy (or unhealthy) amount of OT at work, along with just having to take a week or two off from the build to work out how I wanted something designed, or to think about problems.

And... just for kicks I threw some love at my King Hauler with a new set of RC4WD wheels. Them buggers are as sharp as they look.

Untitled by Scott O, on Flickr
 
Well... Third time is the charm...

For the third time I have gutted this truck and rebuilt it, this time, I am liking what I have.
One of the key issues were the servos I had moving the booms, between the cheap servos and sloppy linkage, the booms made the truck look like a blue retarded chicken when moving. I have replaced all of that with linear actuators ran off RC4WD winch controllers. While they are not quite perfect, it is good enough... for now.

Right now, the only thing that isn't working is the cheapy Amazon flasher, I need to replace that with something better, but I am ok with it for now.

I also changed radio, now using a Radiomaster MT12.

Untitled by Scott O, on Flickr

by Scott O, on Flickr

by Scott O, on Flickr

by Scott O, on Flickr

One of the big changes are the winches. The gear and motor system I had going just didn't work right, so I replaced the whole mess with servo winches.

Due to space limitations, I had to mount the servos vertically, winch causes issues with wreathing the line onto the spool. With no load on the hook, the line wants to fall off the bottom, with a load, and due to the pulling on the end of the boom, the line wants to go to the top of the spool. I printed a guild that keeps the line in the middle when it is under load, it seems to work fairly well.
by Scott O, on Flickr

The drive train is excessively noisy, I think I need to rip the transmission apart and replace off of the bearings.
Here is a video of it running...

 
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