M548 tracked vehicle - Cooper

cooper

Active member
Nice touch on the window rubber... Sometimes just making a little progress keeps you from loosing steam.

Yes,totally right. I like to work with no deadline. Allows to think twice on every solution

You almost have it! Great details.

I' m sure this will be an awesome project. ::2thumbs

Thanks, there's a couple important things to do. My priority it's seeing it running and I'm closer to that. Figured how to do the suspension for the first pair of wheels.


But for now, not a great update but well...Did a quick mockup with it sitting at the correct height and the tracks:

t6bhxv.jpg


30938mw.jpg



And this 2 videos of the suspension working on the new springs. Think that's the ones!!








Bonus pic,next to a 2dr JK:
2py6ka0.jpg
 

iceman88

New member
Yeaah!! It looks awesome ::2thumbs I think you finally got the right springs. I' m not sure if I found them. We will see :hmmm:

Post some images when you have set up the electronics. I'm not sure If I have it clear ::pray

Keep on keep on!! I want to see it running!! :luv:::bigdrool
 

cooper

Active member
Hi!

Things moving slowly but steady. I'm working on the last road wheels. These ones have a different suspension setup than the other ones. Settled on a simple design. A pivot bolted to the chassis where the arm rotates(ball bearings) and a shock. The 1:1 also has a shock on the first arm, assisting the torsion bar, so this it's not unrealistic

Mock-up:
o7lzxi.jpg



Not happy with this shock so I've made my one:

2vu11eu.jpg


It's an axial one, gone from 93mm to 62mm,53mm compressed and 71mm extended. Shorter shaft and a "cap" hidding it to look more scale. On the next post, I'll show them mounted and a video of it working
 

cooper

Active member
The shock mounted on the first photo, it's not the same of the 2nd.

The definitive shock, working. Not much travel but fully functional with 2 springs and oil
 

cooper

Active member
Long story short: Needed some shop time to do the parts for the tension wheels, only had time to do one for this weekend. Atleast, my objective of try the tension wheel system was acomplished. First, some pics:

121gawj.jpg



25u2sy1.jpg



Now, the truck dealing with an obstacle:



I think i shouldn't do this with 1 track only but the anxiety was huge! The reason I went reverse only was that the track slips when going forward. Think i need the shorten the track and put more tension on the tension wheel system. All easy things to do so I'm very very happy with this outcome!!!

 

iceman88

New member
Love it!! :luv::luv:

I have questions. Which batteries are you going to use? (how many mAh) I'm affraid this vehicles need much more energy than an rc car of the same scale. The other question is how do you adjust the track tension? I have an spring at the last wheel which can be modified but I still have some problems when the M548 goes backwards.

Great work! It looks awesome even with just one track! :laugh:::2thumbs
 

cooper

Active member
Thank you!

My first idea was using 1 battery for each esc but because i don't have 2 matching batteries, I went for a Y harness that allows 1 battery to 2 ESC. I'll use a 6000mah 2s bat 100c.that should be enough. The 55t don't draw much. I don't plan to do long trail runs. Something will break first :)

About the tension system, mine it's fairly simple and was the only thing i did not resembling the 1:1,because it was hard to replicate.

It consists on a "lever", similar to the suspension arms, rotating on a pivot and with a shock pushing outward.

33ys0uv.jpg


Putting different springs inside of the shock, adjusts the tension

Here's a video :
 

iceman88

New member
Perfect. It is clear. I'm using the same system and I'm now trying different spring lengths. I asked you about the batteries because I did some test with 2200 mAh 2S 40C (conected to both esc using a Y harness) and the voltage drop from 8,2V to 7,8V in... 10 minutes? We have made such real M548s that they even have the same fuel consumption as the 1/1 scale :laughing:

I'm thinking about buying something like this:

https://hobbyking.com/en_us/zippy-5700mah-2s3p-25c-saddle-pack.html

That should be enough :laughing:
 

cooper

Active member
Ahaha... Limited range


Those batteries have a low C rating. I think you should go for a higher C because you're running twin motor/esc and that strains the battery.
 

cooper

Active member
Well guys, don't know about you but I'm super excited about pulling this off. A year of work but paid off. The drivetrain works and the truck moves. It's close to been finished. Only cosmetic details and mechanical adjustments


First, the usual flex shot:
29uo9dh.jpg


And now, the video proof:

Again, have to adjust the teeth on the traction and keep adding tension on the tension wheels. It moves well back and forth but turning it's still a problem. Tracks keep going off the guides.
 

iceman88

New member
I love the Flex shot!!!:laughing::laughing:

It looks awesome. It is true that the track tension is a problem. I have my chassis running and I have problems when I go backwards. However I hope everything depends on the tension. What about the speed? It is too fast or too slow?

Awesome work Cooper! Congratulations :beerchug:
 

cooper

Active member
I love the Flex shot!!!:laughing::laughing:

It looks awesome. It is true that the track tension is a problem. I have my chassis running and I have problems when I go backwards. However I hope everything depends on the tension. What about the speed? It is too fast or too slow?

Awesome work Cooper! Congratulations :beerchug:



Yes, the tension will need more fiddling. Still not found the perfect spring. It can't be too firm because it could stress the tracks. Mine don't have problems going backwards, it works better,actually .The problems start when turning.But well, at this point,I'm not turning back and quit.

About the speed, is slow but seems perfect. I tried on a patch of sand and there's little chance of getting stuck in the future...


I accept your thanks but... When do you make a thread of your build? all the pretty pics included....:)
 

iceman88

New member
I accept your thanks but... When do you make a thread of your build? all the pretty pics included....:)

You are right. I should start a thread with the printed M548. I promise I'll do it soon. This month I hardly find time to finish the design (I'm now with the cabin) :mecry:
 

cooper

Active member
So...couldn't wait to test it. Here's a quick and crude edit from that day. We're still learning how to drive it and see it's limits. Tried some soft climbs, it reaches the top, eventually. Have to stiffen the last 2 springs and adjust again the tension. Tracks slipped out twice but doesn't stuck like the first attempts.

Hope you like it!


By the way, it was my first time with this particular video editor,Lightworks
 

imthatguy

Putting it in "H"
Very impressive! Love this thing. I wonder if your tension issues are from having the front cogs doing the driving... I don't have these issues on the half track, as the drive cog is in the rear.
 

snapon12

V.I.P. Member
I agree with Matthew I think if possible the rear drive would help. Very awesome work still amazing

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
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