Rebuilding this Armortek Gamo Halftrack
#1
Thread Starter
Rebuilding this Armortek Gamo Halftrack
I'm almost done building the Panzer IV and I've been driving it around a LOT, just need a few more detail parts then I'll finish painting it.
So til then, with lag time while sitt'in in the garage drank'in BEE... refreshments, I figured I should start tearing this German Sd.Kfz. 7 halftrack apart so I can see what I need to order to fix it.
Yesterday I took off the upper bodywork, finished getting the motors out, took the winch drum off, steering servo, and removed all the electrics (which I'll have to figure out HOW to connect'em back in but I do have the manuals...)
This morning I 'jacked up' the front and took out the leaf springs, beadblasted'em, and repainted them Tamiya TS-3 (cause they were painted gloss gray.) The camo is flat enamel over Tamiya yellow base. I'm probably going to repaint it while I have it apart cause I don't care for this camo.
I short tracked the chassis so I could roll it out, put the Simple Green to it, and wash the old grease/dust off.
I DO know one of the nylon gears (off the motor worm shaft) is bad and it needs two new drive sprockets. I'm going to check the roadwheel bushings too cause a couple wheels wobble pretty good.
Just wanted to give ya an update without having to bring the old, original post all the way forward. More later.
Mike
Last edited by Old MSgt; 09-25-2016 at 01:31 PM.
#3
Thread Starter
Yeah, I had to use those Vice Grips to get ahold of the main pin at the top of the springs. After I got the back nut off the pin sure didn't want to come out easy. No oil or grease was on it...
I went to adjust the rear idler swingarms and they were TIGHT! Finally got'em apart and there was NO grease in anything. Cleaned'em, greased the posts, and now they move free.
Gonna check every other pivot point and make sure THEY have grease.
Hope you get the Panther soon! I LOVE to watch builds progress!
Mike
I went to adjust the rear idler swingarms and they were TIGHT! Finally got'em apart and there was NO grease in anything. Cleaned'em, greased the posts, and now they move free.
Gonna check every other pivot point and make sure THEY have grease.
Hope you get the Panther soon! I LOVE to watch builds progress!
Mike
#4
Thread Starter
I've been sitting in here THINK'IN and reading thru the Armortek Option 1 'rc' manual of this model. From what I can gather, one receiver channel does the forward/reverse and another channel does the main motors steering (like all our tanks do.)
BUT, the manual sez you also use a THIRD radio channel to STEER the front wheels! Meaning, they're SEPARATE from the main drive motors steering... (from what I can deduce from the manual)
I'm thinking about using a Sabertooth ESC instead of those big Armortek ESCs cause they're hard to figure out.
SO, I'm trying to 'wrap my little brane around this', when DRIVING this halftrack I'd need to not only steer the tracks BUT also the front wheels. That's doing THREE radio levers together at the same time!
I was wondering: WHAT IF the steering channel wire that's coming from the receiver to the ESC was spliced together with the front steering servo... would THAT make both the ESC and steering servo make the same turn? Both small and little turns?
It's a 24v system. The steering servo is big. The ESC probably don't care because it's just reading the impulses to do something (how much and how little) from the receiver then IT directs the main voltage from the battery to the drive motors. So would it be possible to have the steering from the receiver to control BOTH the steering AND drive motors together off the same wire?
I'm asking this because EVERYBODY on here is BRAINS on electronics! I'm an IDIOT when it comes to electrics. What do you think? ANY help would be really appreciated!!!!!
Mike
BUT, the manual sez you also use a THIRD radio channel to STEER the front wheels! Meaning, they're SEPARATE from the main drive motors steering... (from what I can deduce from the manual)
I'm thinking about using a Sabertooth ESC instead of those big Armortek ESCs cause they're hard to figure out.
SO, I'm trying to 'wrap my little brane around this', when DRIVING this halftrack I'd need to not only steer the tracks BUT also the front wheels. That's doing THREE radio levers together at the same time!
I was wondering: WHAT IF the steering channel wire that's coming from the receiver to the ESC was spliced together with the front steering servo... would THAT make both the ESC and steering servo make the same turn? Both small and little turns?
It's a 24v system. The steering servo is big. The ESC probably don't care because it's just reading the impulses to do something (how much and how little) from the receiver then IT directs the main voltage from the battery to the drive motors. So would it be possible to have the steering from the receiver to control BOTH the steering AND drive motors together off the same wire?
I'm asking this because EVERYBODY on here is BRAINS on electronics! I'm an IDIOT when it comes to electrics. What do you think? ANY help would be really appreciated!!!!!
Mike
Last edited by Old MSgt; 09-25-2016 at 02:12 PM.
#5
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Sounds to me like you need to put in a TX mix for the steering of the front wheels and the track speed. Never done this on a tank but in aircraft it's quite common to mix channels together to give you the correct flight characteristics like mixing together elevator and aileron on a delta wing airplane. or mixing in rudder with ailerons on a biplane to give the thing a correct and active turn.
Hope this is useful advice.
Cheers
CaptB
Hope this is useful advice.
Cheers
CaptB
#6
Thread Starter
Thanks CaptB! I'll search and try to find out how to do that. Thanks Again for the help!
This morning I pulled the top off the winch to see if it had grease AND to see the insides.
Mike
Last edited by Old MSgt; 09-26-2016 at 05:53 AM.
#7
From what I understand you have one motor to drive the tracks through a diff is this not the case? Steering the front wheels should be on 1 channel all alone and the tracks another; the way the Sdkfz 7 was described to me was it needed x2 channel x1 for drive and x1 for steering.
#8
Thread Starter
Hi Rivetcounter! No, this halftrack uses two drive motors, one for each side just like the tanks so. Then there's a BIG steering servo up front for the wheels that uses a third channel to steer them.
I'll try to find something on the merging'em together like CaptB sez, or I'll just have to use three channels like I think the manual sez.
Mike
I'll try to find something on the merging'em together like CaptB sez, or I'll just have to use three channels like I think the manual sez.
Mike
#9
Morning Mike, I see then you need x3 channels x1 for main steering on the front wheels the other x2 channels need to be on a mixer this is where the secondary steering comes in, in certain conditions you may need a little extra steering this can be done with the tracks mostly you won’t need this, for instance left stick forward/reverse drive and left/right steering through front wheels right stick left/right steering through the tracks.
All German halftracks steered through the front wheels and partial track breaking for sharper turns this was done through the steering wheel.
All German halftracks steered through the front wheels and partial track breaking for sharper turns this was done through the steering wheel.
#10
Couldn't a "Y" cable running to both the steering servo and motor control between receiver and control board serve? Unless your radio
has the option to mix(couple) channels?
Jerry
has the option to mix(couple) channels?
Jerry
#11
Maybe a turngy v-mix?
#12
Thread Starter
Thanks Rivetcounter, Tanque, & Maus45, I REALLY appreciate (and NEED) the advice. When I get the motors in and start the rough wiring I'll try both ways. But remember, I hardly know anything about electronics. Just how to plug things in.
I'll have get a couple of Sabertooths for it like in my tanks... on the Sabertooths there's tiny levers to initially set'em up and I'm pretty sure there's one (or two) for 'mixing'. I'll find the instructions and check on that.
AND one of these extra radios I have (the 7 ch. that came with the Panther and I never figured out) does have 'mixing' on one of the display screens. But I don't know how to program it...
And Tanque, I'll look for a Y receiver cable on Hobby King and see what they got. And a turngy v-mix? What is that Maus?
Thanks again for the help!!!!! Mike
I'll have get a couple of Sabertooths for it like in my tanks... on the Sabertooths there's tiny levers to initially set'em up and I'm pretty sure there's one (or two) for 'mixing'. I'll find the instructions and check on that.
AND one of these extra radios I have (the 7 ch. that came with the Panther and I never figured out) does have 'mixing' on one of the display screens. But I don't know how to program it...
And Tanque, I'll look for a Y receiver cable on Hobby King and see what they got. And a turngy v-mix? What is that Maus?
Thanks again for the help!!!!! Mike
#13
Mike, here is a link to a Turnigy V-Mixer. it allows mixing of two channels. Most used by r/c airplane guys to get the flaperons or elverons on delta wing aircraft. I attached the user manual as well for you to down load and look at.
http://www.hobbyking.com/hobbyking/s...FdgagQodMRULWg
http://www.hobbyking.com/hobbyking/s...FdgagQodMRULWg
#14
Would Armortek have done steering the same as the real Halftracks?
When the steering wheels were turned greater than 15 degrees in a direction the inside track would degrade in power (clutch mechanism) while the outer track got full power... (three channels with a mixer curve of left or right track effort connected inversely to steering? Is that even possible?)
When the steering wheels were turned greater than 15 degrees in a direction the inside track would degrade in power (clutch mechanism) while the outer track got full power... (three channels with a mixer curve of left or right track effort connected inversely to steering? Is that even possible?)
#15
Thread Starter
The Armortek Option 1 manual recommends the radio channels be setup like this:
"Channel 1 track steering
Channel 2 both track forward/reverse
Channel 3 winch
Channel 4 (front) wheel steering"
Then how to check if everything is hooked up right:
"Move the left hand stick forward and both main motors run in reverse.
Move the left hand stick back and both motors run forward.
Move the left hand stick from side to side and one main motor runs in the opposite direction to the other..
(then it tells how to check the winch... then)
Move the right hand stick from side to side and high torque servo operates."
And Maus45, I ordered that turngy v-mix thingy and'll try to figure it out when it (and the motors) get here. Thanks!
And here's a pic I just took of the original Armortek wiring harness. The two BIG boxes on the left is the two ESCs, one for each track.
This all came out of the rear of the halftrack (the two batteries were in the front under the hood). I'm going to do just like I have been and replace all this with Sabertooth ESCs cause they take up a LOT less room and are, in my opinion, easier to wire (especially for ME!)
Mike
Last edited by Old MSgt; 09-27-2016 at 09:01 AM.
#16
Those are some really big modules. How much do they weigh? If you went with LiFe batteies you would reduce the weight even more.
#17
Thread Starter
Oh, the ESCs and those other boxes hardly weigh anything, they're pretty light. But it's the size of the boxes (and the original Option 1 is still in the Panther) that makes placing and locating them (cause some have switches on'em) a pain.
I went with Sabertooths in the Tiger (cause it's original ESCs wouldn't work) and in the Panzer IV. And with Sabertooths it's like an 'empty basement' in there.
I'm going to use a couple of 12v lead batteries wired for 24v. I'm scared of Lipos. I'm planning on putting the Sabertooths under the front hood and the batteries in the rear.
Thanks for the help! Mike
I went with Sabertooths in the Tiger (cause it's original ESCs wouldn't work) and in the Panzer IV. And with Sabertooths it's like an 'empty basement' in there.
I'm going to use a couple of 12v lead batteries wired for 24v. I'm scared of Lipos. I'm planning on putting the Sabertooths under the front hood and the batteries in the rear.
Thanks for the help! Mike
#18
Thread Starter
FYI: I've been wondering about the rear idler system and wanted you to see it and maybe help me figure out the reason for how it's designed. I'm just curious and somebody may know.
The two rear idler wheels each have pretty beefy idler arms independent of each other. There's a slide adjuster on each one that can be set where ya want it, up to down. THEN the idler itself has it's own brass idler angle adjuster.
One pic shows the frame swingarm down and the other side shows it up. Down is almost level with the roadwheels on the ground and the other is up high like an idler. And you can see the heavy swingarms and the slide adjusters on each side.
When I took this apart the swingarms, adjusters, nuts, shafts, were 'frozen' in place cause they didn't have any grease on'em. I took'em apart, cleaned, and greased'em and now they all move free.
It's just a wonderment to me WHY it has swingarms to adjust up/down AND idlers for back and forth track adjustment. Was it for extra ground pressure over soft ground? Do anybody know? Just curious.
Mike
Last edited by Old MSgt; 09-27-2016 at 01:33 PM.
#19
Thread Starter
OH-BA-KAY-BEE!!! I got this half track going so figured it was time for an update. I installed the new drive motors, drive sprockets (with new rollers and tires), front steering servo, linkages, and repainted the body. Installed a cooling fan up front in the radiator grill to blow on the Sabertooths under the front hood. Put grease everywhere it'd never been and needed. Tightened up the roadwheel bushing, stuff like that.
I ordered some Y receiver cables and the V-Tail Mixer. I first installed the VTM but that didn't work cause everything was jerky. Then I tried the Y cables... about the same thing.
SO I emailed the Sabertooth Help Line, explained what I had, wanted to do, what I'd done, and nothing worked. They came back and said OOHH NOOO! the Y and VTM cables shouldn't be used with the Sabertooth! (..oops...) They helped a LOT on how to set the ESC switches (once I explained how this half track operated.)
On driving it, the radio right lever is forward/reverse (with Turnigy speed regulator) with lever side to side front wheel steering. The left lever side to side is TRACK steering like a tank but ya got to GENTLY move the lever or a neutral turn could happen. The left lever up down is the winch.
It runs fine AND (surprising me!) the steering on pavement can be done with just the front wheels. Turns pretty good! BUT in sand or gravel (as you can imagine), or if the front wheels are off the ground (when driving up on the bench or like in the last sand picture) and ya need a little assistance, then lightly do the left side to side lever and it's like the actual vehicle.
ALSO, the winch is EXTREMELY SLOOOW. I mean, when I went to play it out some, for the longest time pulling the cable, I didn't think it was working! That was a waste of time putting a 2X12 ESC on just for THAT. I could've (still might!) just put a manual switch in IF I'd ever even USE the winch.
And see how much the two Sabertooth ESCs take up compared to the original system in the post above? And do the same thing. I use Sabertooths in two of my tanks and they're GREAT.
I wasn't impressed with the speed or handling (in sand) when I first took it out but it's kinda grown on me. Not as fast as I thought it'd be and the steering takes getting used to, but it's 'interesting'... we'll see if anything breaks... Still have to paint camo, put the windshield and stuff on, but give me something to do this winter.
Mike
Last edited by Old MSgt; 11-15-2016 at 03:27 PM.
#21
Mike, you may be pleased to hear that I've taken my first steps into the world of 1/6 scale. My 1/6 scale Schwimmwagen will be here today, and I'm gonna do my best to RC this bad boy. It's the 21st Century model, not the Dragon, so it may lack the detail of the Dragon kit but they say the 21st Century can be easier to RC because it's made to be waterproof so it floats well.
One day I'll do a 1/6 scale Tiger One, but I think that won't be until after the car is paid off, in just 23 more payments!
One day I'll do a 1/6 scale Tiger One, but I think that won't be until after the car is paid off, in just 23 more payments!
Last edited by Crius; 11-16-2016 at 03:03 AM.
#22
Sorry the VTM didn't work with the Sabertooth? I wonder if they have changed the programming? I got the idea from a guy who used it in his 1/8th scale RC Armory Jagdtiger kit to patch the Tamiya control/sound MDF's into his gun elevation and depression. Glad the help line was abole to sort it out for you. Nice restoration on this beast!!!
#23
Whoa, what a beast.
I can't image how this must look lumbering around on the ground! Nice work.
Jeff
I can't image how this must look lumbering around on the ground! Nice work.
Jeff
#24
Loving the build so far! Oh and for control a Sabertooth is great for mixing, but as far as I know the 2x5 and 2x12 only support two channel mixing. Since adding a mix in the TX will be tricky, I would suggest putting the two channels on a mix to control with one stick and the other stick for front steering. I think this would give the most control but of course you would have to sacrifice something else. What are you using to drive this? There might be an easy way to trick the motherboard actually. If you are running without a control board you might have a bit of difficulty mixing channels.
#25
Thread Starter
Thanks everybody, I'm trying to make it decent.
The two OLD 12v 7amp batteries I installed in it wouldn't hold charge worth a poot. SO today I took'em in to town to the battery store. Right beside the new same size batteries were 12v 12amp ones! About half again as wide but same length/height! And the price difference was about $4 each more! And since there's LOTS of room in the rear (without those original bulky ESCs) I got the larger batteries and they fit perfect! Strained my shoulder patting myself on the back!
Hey Crius! Looking forward to your posts r/c'ing the Schwimmwagen! That'd be PERFECT if it could drive AND float! Hope you get it soon and show it!
And Dimension Engineering kind of said the Sabertooth SHOULD NOT be used with any splitting Y cables or some things might be 'voided'. Luckily I didn't damage the ESCs but the way they were jerking, starting, and stopping, it kinda 'concerned' me. I have one channel fwd/rev, one channel front wheel steering, and the third channel track steering. I've already gotten pretty used to it. The only time to gently use the track steering is for sand or really sharp turns.
I had to pull the T1 off the bench so I could get the half track off. So while driving the half track out in the sand, figured: Heck, I already have a tank out and parked, might as well drive it over too and take some pics. Here's a couple just to compare the sizes.
Now I'm dreading having to paint the camo on this half track and P4. Might just think about it and wait til next summer...
Mike
Last edited by Old MSgt; 11-16-2016 at 12:41 PM.