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Mad Ax

6x6 Grand Hauler Tipper Truck

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Sunday dawned dry and bright and I was up in the studio nice and early to...  ...work on my new album.  Once I'd got a couple of hours in I inevitably got bored and went out in to the workshop to do more stuff on my tipper truck.

With the axle hangers installed, I could get back to my transmission relocation.  I found the position I wanted and screwed the transmission into two existing holes.

PB220043.jpg

And then (stream of consciousness warning) remembered I hadn't fitted the shocks yet.  In fact the shocks wouldn't even fit, thanks to the taller ride height on the rear.

So, out came the shock parts along with some longer shock eyes.

PB220045.jpg

One shock made and fitted to prove the concept

PB220046.jpg

shocking

PB220047.jpg

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I then turned my attention to the front end.  The problem here is the TLT axle - it has no standard location for shocks and is mounted all wrong for the standard brackets.  I considered making a new shock hanger before I realised I could just relocate the standard ones.

So I marked up the position I wanted on one frame rail, then fifteen minutes later had both rails stripped out of the chassis.  That's a lot of work.

PB220048.jpg

Stream-of-consciousness alert (this is what it is actually like being me) - here I realised the standard TLT axles have next to no steering angle.  And as this is a very long truck and has putty in the diffs and our club layouts are very tight (or at least they were, back in the Before Times when we actually had layouts, or even clubs), I figured I just had to do something about this.

First I filed away the edge of the steering arm

PB220049.jpg

and bonussed myself a bit of extra angle

PB220050.jpg

however the biggest angle-thief in the whole installation is the drive cup, which seems to be overly too big for this kind of thing

PB220052.jpg

PB220053.jpg

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Fortunately among the many bits of kit that I have acquired over the years, is the Spinny Device For Making Too Big Things Into Too Shall Things.  With care, it can also double up as a Making Too Big Things Into Just Right Things.

Here is my stub axle, a little bit less too big than it was before.

PB220054.jpg

As can be seen, there is still enough skirt to hide the drive pin on full lock, but I can now get way more steering angle.

PB220055.jpg

The second photo of this pair is conspicuous by its absence

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I floated a little further down my own stream of consciousness and decided to tidy up all the ugly mouldings on the bottom of my TLT axle.  This axle had previously been modified to fit a 4-link top bracket, so it's already been Touched by the Wheel of Dremel, however in this truck is it mounted upside down so as to give the correct direction of driveage when connected to the front of the big rig transmission.  Ergo all this ugly stuff was on the bottom and interfering with my 3D printed truck axle stands.

PB220057.jpg

A little bit more Dremel action and it was looking much more axle-ey.

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While I had the frame rails off I decided to fix another annoying little problem.  Because I made lift blocks for the rear axle, the axle now has about 10mm more travel before it hits the bump stops.  This pushes the axle mounts up past the frame rails, but the standard nylock nuts are too big and catch the frame.

PB220059.jpg

A standard nut and a Dremel fixed that.

PB220060.jpg

With my Dremel in my hand I began to randomly stalk around the workshop looking for other things that needed cutting, grinding, or making smaller, but I couldn't find anything, so I put it safely away and started putting the truck back together again.

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Here you can see my new front axle suspension assembly.  Shock tower moved up and back, and standard lower shock eye bolted on where the spring screw goes.

PB220061.jpg

PB220062.jpg

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At this point, the leaf of thought in  my stream of consciousness was caught by a fresh current and pulled out of the eddy in which it had become stuck, and I was back to fitting my transmission again.  I drilled and tapped two new holes for the rear transmission, then cut the body mount plate in half to clear it.

PB220063.jpg

Et voila.  It is not officially a 6x6 rig.

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And with the tipper fitted it is....  Oh :(

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Now, at this point, Ax v2019 would have thrown the teddies out of the pram and gone off to sulk for an hour, but if 2020 has taught me anything, it's to be patient with myself and not to break things I can't afford to replace

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I remembered that I have some Lesu mounting rails that came with the tipper bed, so I ran off to find them.  Then I found a piece of wood approximately the right thickness to get a feel for how rubbish the truck would look with the bed mounted higher.

Anwer: this rubbish:

PB220067.jpg

However, there was a better solution, which resulted in a truck that didn't look rubbish after all and only required the drilling of two more holes and a second helping of the trusty hit and kill set.

Basically I moved the transmission forward one more set of spare holes.

PB220068.jpg

PB220069.jpg

I had to shorten the front propshaft even more, but even on this angle it still runs smoothly enough.

PB220070.jpg

And there we have it - one 6x6 truck with a tipper bed.

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2 minutes ago, Randylandy666 said:

Tipper is looking good!
Do you know which model the body came off?

P.S. if you need a finishing panel for the back for the day cab I make them: https://stegs4x4.co.uk/product/kh-day-cab/ hope this helps!

Thanks for the link - I've seen similar on Shapeways but I think yours are better priced - I wasn't sure if I would try to fab my own from styrene or order something ready-made.

Body is a Grand Hauler (the whole cabundle is based on an NIB Grand Hauler with as new new parts as possible).

If you're asking what the tipper bed is from - it's a modified Lesu but that's all I know, I got it from a friend who had a fair bit of work done to it.  The standard one has ribbed sides but this one has had another panel welded over it for a smooth look.

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Anyhoo - after doing all this, I then spent a couple of hours playing around with the tipper mechanism.  I've got to be honest, given how heavy this thing is, I can't see how I'm ever going to get a motor to lift it - to get any kind of lift the scissor needs to be installed quite far rearward, and as far as I can tell the mechanism is transposing a small input to a large output, which means it's going to need heaps of torque.  I have a 540 motor with a planetary box but I don't know if 2S will be enough.  Ideally I'd install hydraulics, but we've had a financial setback in the House of Ax so there's not the spare cash there once was for stuff like this.

More to follow next Sunday (unless we have another day-long internet outage here - I spent most of this afternoon decalling my CFX-W when I couldn't get access to the work servers.  WFH does have its upsides.  I might have to pay one of the local kids to chop my broadband cable next week).

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5 minutes ago, Mad Ax said:

Thanks for the link - I've seen similar on Shapeways but I think yours are better priced - I wasn't sure if I would try to fab my own from styrene or order something ready-made.

Body is a Grand Hauler (the whole cabundle is based on an NIB Grand Hauler with as new new parts as possible).

If you're asking what the tipper bed is from - it's a modified Lesu but that's all I know, I got it from a friend who had a fair bit of work done to it.  The standard one has ribbed sides but this one has had another panel welded over it for a smooth look.

Cheers!
and sorry yea I meant the complete tipper body, I will have a look at the Lesu bodies! Thanks

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@Randylandy666 I have just spotted the single speed conversion kit - I already have a planetary like that but I don't have that bracket, do you supply those individually?  TBH having seen it in the photo I could hack something together like that myself but seems rude to blatantly steal your design :)

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4 minutes ago, Mad Ax said:

Anyhoo - after doing all this, I then spent a couple of hours playing around with the tipper mechanism.  I've got to be honest, given how heavy this thing is, I can't see how I'm ever going to get a motor to lift it - to get any kind of lift the scissor needs to be installed quite far rearward, and as far as I can tell the mechanism is transposing a small input to a large output, which means it's going to need heaps of torque.  I have a 540 motor with a planetary box but I don't know if 2S will be enough.  Ideally I'd install hydraulics, but we've had a financial setback in the House of Ax so there's not the spare cash there once was for stuff like this.

More to follow next Sunday (unless we have another day-long internet outage here - I spent most of this afternoon decalling my CFX-W when I couldn't get access to the work servers.  WFH does have its upsides.  I might have to pay one of the local kids to chop my broadband cable next week).

Have a look at RCP57's tipper bodies, he mounts a lead screw and motor under the body which makes reasonable pace and heavy lifting system.
Lead screw can move big loads but it slow so his mechanism fixes this.

2 minutes ago, Mad Ax said:

@Randylandy666 I have just spotted the single speed conversion kit - I already have a planetary like that but I don't have that bracket, do you supply those individually?  TBH having seen it in the photo I could hack something together like that myself but seems rude to blatantly steal your design :)

I will have a look tomorrow if I have any spare brackets, I typically only sell them as a complete ready to install unit to ensure the pinion mesh is correct and gearbox is well greased so tend to buy in bulk and matching quantities.

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11 hours ago, Mad Ax said:

Anyhoo - after doing all this, I then spent a couple of hours playing around with the tipper mechanism.  I've got to be honest, given how heavy this thing is, I can't see how I'm ever going to get a motor to lift it - to get any kind of lift the scissor needs to be installed quite far rearward, and as far as I can tell the mechanism is transposing a small input to a large output, which means it's going to need heaps of torque.  I have a 540 motor with a planetary box but I don't know if 2S will be enough.  Ideally I'd install hydraulics, but we've had a financial setback in the House of Ax so there's not the spare cash there once was for stuff like this.

More to follow next Sunday (unless we have another day-long internet outage here - I spent most of this afternoon decalling my CFX-W when I couldn't get access to the work servers.  WFH does have its upsides.  I might have to pay one of the local kids to chop my broadband cable next week).

Do not underestimate the power of the 540 to lift stuff. The blade on my skidder can lift the front end off the ground and the model weighs nearly 10Kg. That's fitted with a MFA unit with a reduction box, can't remember the ratio now, I've got a felling it's about 50:1. OK, it's running on 3S, but from memory it still does the job with 2S. 

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Sunday 29th November dawned dry and bright and crisp.  Possibly not as cold as Saturday, but cold nonetheless.  My main workbench is at the back of the workshop, on the opposite side to the log burner, so a week ago we installed a new shared workbench near the fire, so we can stay a bit warmer in what looks to be a long winter of social isolation.  I was awake early but got caught up in reading forum posts, downloading software updates for my studio and jamming on some music.  It was gone 10am before I got the fire lit.

PB290001.jpg

With my Grand Hauler Tipper still on the old bench from last weekend, I figured it would be good to try to get the tipper mechanism installed before I went on to anything else.

My first plan was to take out the bottom of the tipper bed.  I figured this would give me better access to the mechanism while I got it all installed.  The entire thing had been assembled by someone else, modified, and professionally painted - so it was a bit of a wrench to have to start working on a nice paint job, but this is going to be a runner and will have rocks, gravel, sand and other stuff inside it at some point, so I guess I shouldn't worry too much.

Unfortunately the paint had filled three of the tiny countersunk hex screws that hold the bed in place, so I had to drill them out.  A lot of people say they hate JIS "because it rounds off too easily compared to hex" but in my experience the opposite is true - since buying my Tamiya screwdriver set several years ago I can't recall a single rounded off JIS screw, and the drivers are both still in tip-top condition.  However recently the smallest hex driver is now completely rounded and almost useless and the middle one is heading the same way, so I'll have to replace the set soon and consign the "still OK" drivers to the spares bin (or maybe to a small toolbox for racing).  I have some other metric and imperial hex drivers but none of them could get these screws out either.

Here's the results of drilling out one screw:

PB290002.jpg

PB290003.jpg

Unfortunately one of the screws was next to the side structure, so I couldn't get a drill bit square onto it.  I had to use some bigger drills and drill on an angle, which made quite a mess of the bed.  This probably won't show that much once fitted and painted but it's still a shame to have to make a mark on such a tidy (and expensive) piece of kit before I've even used it.

PB290004.jpg

But at least I got the bed removed

PB290005.jpg

Once the tension was removed, these studs screwed out no trouble with a set of pliers

PB290006.jpg

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With the wheels off the rig, I installed the lifting mechanism on existing holes in the chassis rails and bed.  This is only a prototype - the final version will have a single threaded rod and some nicer spacers, assuming I stay with this design.

PB290008.jpg

Note: I have no instructions for this lift mechanism and can't find any pics of it installed online.  If anyone sees a problem with how I have installed this mechanism, please let me know

Another benefit of this position is the lifter can be locked out by inverting it and resting it on a crossmember.  This is nice for servicing, otherwise I have to wedge a stand in place.  A Clod tyre works well but makes it impossible to get to anything, and anything smaller is liable to slip, slam closed and trap my fingers.  This isn't a lightweight truck :o

PB290009.jpg

Next plan was to install the lifting screw.  The screw and the UJ came in a separate kit.  The screw was 100% threaded end-to-end but that made it too big to fit in the UJ; I don't have a lathe, so I used a bench grinder to take off a section of thread - I did a pretty rough job and it looks terrible but at least is hidden behind the UJ.  I junked the two short grub screws in the UJ and instead drilled a 2.5mm hole right through the rod, and used a longer grub from an Axial UJ to properly lock the rod into the UJ.

PB290010.jpg

At this point I figured I would test the whole thing using a cheap 3.6V Li-ion powered screwdriver.  I screwed a 3mm hex bit into the UJ, connected it into the screwdriver, and wedged it up against the transmission housing.  When I pressed the button, the bed went up.  However it didn't work that well: the supplied UJ is a double UJ (I think it is what they call a double cardan joint) and under compression it wants to fold over and lock out.  I'm not really sure it's intended to be used for this solution.  A conventional single UJ would be much more practical (I have a bag of cheap ones so all is not lost).

The next plan was to dig out my 540+planetary assembly that I bought ages ago for something completely different, and see if I could mock up a bracket to get it into the chassis.  Unfortunately, I couldn't find it.  I know for sure I haven't thrown it away (after I didn't use it on the other project I know I kept it specifically for this one) but it isn't in any place I'd expect it to be.

So - after a lot of screwing, drilling, grinding and generally destroying things, I ended up with a pile of bits that I couldn't finish.  I wasn't really enjoying myself as much as I wanted to anyway, so I relocated everything to my other workspace to do something else.

More to follow on this once I've found my motor :) 

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15 minutes ago, Mad Ax said:

With the wheels off the rig, I installed the lifting mechanism on existing holes in the chassis rails and bed.  This is only a prototype - the final version will have a single threaded rod and some nicer spacers, assuming I stay with this design.

PB290008.jpg

Note: I have no instructions for this lift mechanism and can't find any pics of it installed online.  If anyone sees a problem with how I have installed this mechanism, please let me know

Another benefit of this position is the lifter can be locked out by inverting it and resting it on a crossmember.  This is nice for servicing, otherwise I have to wedge a stand in place.  A Clod tyre works well but makes it impossible to get to anything, and anything smaller is liable to slip, slam closed and trap my fingers.  This isn't a lightweight truck :o

 

Next plan was to install the lifting screw.  The screw and the UJ came in a separate kit.  The screw was 100% threaded end-to-end but that made it too big to fit in the UJ; I don't have a lathe, so I used a bench grinder to take off a section of thread - I did a pretty rough job and it looks terrible but at least is hidden behind the UJ.  I junked the two short grub screws in the UJ and instead drilled a 2.5mm hole right through the rod, and used a longer grub from an Axial UJ to properly lock the rod into the UJ.

PB290010.jpg

At this point I figured I would test the whole thing using a cheap 3.6V Li-ion powered screwdriver.  I screwed a 3mm hex bit into the UJ, connected it into the screwdriver, and wedged it up against the transmission housing.  When I pressed the button, the bed went up.  However it didn't work that well: the supplied UJ is a double UJ (I think it is what they call a double cardan joint) and under compression it wants to fold over and lock out.  I'm not really sure it's intended to be used for this solution.  A conventional single UJ would be much more practical (I have a bag of cheap ones so all is not lost).

The next plan was to dig out my 540+planetary assembly that I bought ages ago for something completely different, and see if I could mock up a bracket to get it into the chassis.  Unfortunately, I couldn't find it.  I know for sure I haven't thrown it away (after I didn't use it on the other project I know I kept it specifically for this one) but it isn't in any place I'd expect it to be.

So - after a lot of screwing, drilling, grinding and generally destroying things, I ended up with a pile of bits that I couldn't finish.  I wasn't really enjoying myself as much as I wanted to anyway, so I relocated everything to my other workspace to do something else.

More to follow on this once I've found my motor :) 

A bit late now@Mad Ax but if you need things like the threaded rod turned down, I will do it free if you send it to me with a self addressed envelope.  I can also machine flats on shafts and drill holes through them fairly precisely. You're doing such a good job on this, I would be happy to help out if I can. :)

 

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Thanks @MadInventor, actually I did think of you as I was grinding the thread off the rod, but when I'm on a roll I like to keep going, had I stopped and posted the rod off the project would have halted an hour earlier, only to resume and halt again within an hour whenever the part came back because I wouldn't have discovered that I'd lost my motor.

TBH it's why I tend to buy a heap of parts before I start on a project - 2020 has been a learning experience but even now I have real trouble finding motivation to get started, once I've started anything that stops me can plunge me into a pit of indecision from which I find it very hard to drag myself :) 

Thanks for the offer though and I will definitely keep you in mind, I'm sure I'll need more parts sorted later on.  I might even want / need to shorten this particular rod once I know exactly how much length I need, you can probably do that on the lathe better than I can with a Dremel, then remove the thread and add the flats and pin hole for me ;) 

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13 minutes ago, Mad Ax said:

Thanks @MadInventor, actually I did think of you as I was grinding the thread off the rod, but when I'm on a roll I like to keep going, had I stopped and posted the rod off the project would have halted an hour earlier, only to resume and halt again within an hour whenever the part came back because I wouldn't have discovered that I'd lost my motor.

TBH it's why I tend to buy a heap of parts before I start on a project - 2020 has been a learning experience but even now I have real trouble finding motivation to get started, once I've started anything that stops me can plunge me into a pit of indecision from which I find it very hard to drag myself :) 

Thanks for the offer though and I will definitely keep you in mind, I'm sure I'll need more parts sorted later on.  I might even want / need to shorten this particular rod once I know exactly how much length I need, you can probably do that on the lathe better than I can with a Dremel, then remove the thread and add the flats and pin hole for me ;) 

No problem at all.  Just PM me when you're ready :)

 

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OK - had a much more successful day today :)  It started bright and early with blue skies and frost on the roof, so the first thing to do was light the fire.  Then I went rooting around in the storage area until I found my lift motor with its reduction gearbox.

So - after last week's problem operating the lift screw with the double joint, my first plan was to install a conventional UJ.  I have a plethora lying around from some order I did from a Chinese warehouse years ago, but they were too small to fit the outdrive.  I don't have a lathe to sort this out the proper way, so I used the drill press and some good eye protection.

PC060001.jpg

Jobbed

PC060002.jpg

Then I had to make a bracket to install it, using an idea I blatantly stole from @Randylandy666's shop.

I didn't have any 3mm alu sheet with a nice corner on it, or even a nice flat edge, so I had to chop off an edge, file it flat, then use it as the datum for all the other edges.  So that took a fair bit longer than normal.

PC060003.jpg

PC060003.jpg

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Having made an accurate-enough square (which isn't actually square), I had to chop some slots on it

PC060007.jpg

Then I got out the heavy equipment.  That torch will get hot enough to melt aluminium* so I had to heat up the bend carefully and bend it a little at a time

PC060008.jpg

PC060009.jpg

PC060010.jpg

PC060011.jpg

 

*so will the inside of my log burner.  This is a 1" square scrap of 3mm alu that I threw in to see what would happen.

PC060005.jpg

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I drilled the holes to mount the gearbox and rounded off the edges

PC060012.jpg

PC060013.jpg

I had to drill and tap four new holes on the bottom of the chassis

PC060014.jpg

PC060015.jpg

PC060016.jpg

 

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Soldered on some wires - I left them deliberately long as I have no idea where I'll mount the ESC for this

PC060017.jpg

Installation installificated

PC060018.jpg

PC060021.jpg

PC060022.jpg

as promised, I also re-made the mounting thing.  This was a bit of a pain as I had to bend the rod to get it in, then realised I'd made it about 2mm too short so the nuts don't want to tighten up properly.  And I've run out of 3mm threaded rod...

PC060025.jpg 

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So - does it work?

Well, yes.  Very well, actually.  I had worried that the mechanism would bind, or require too much torque, or that the bracket wouldn't support the load, but actually it all works pretty well.  The motor has plenty of torque to lift the trailer to full height, and it does it in just a few seconds.  It's easy to forget just how fast a 540 spins at 2S LiPo voltage (although this rig will run on NiMH as it will be running with an MFU-01).

So - job jobbed for today, I'm happy with progress, I need to sit back and think about where the project goes next as there's a lot of electrical stuff to get in, gear shift linkage to make and a host of things like fuel tanks and air tanks that will need to be fitted down the sides to hide all the functional non-scale stuff.

All in all, not a bad day in the workshop :)

 

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