gyrate

The turret can be fixed by reducing epa to 80. Then it responds when you go all the way on the stick just fine. EPA 80> confuses it. speaking of turret, my turret has a deadzone of about 50%... so you might as well just smash it either direction since feathering it does nothing until you are near the end anyway. cool!

Did you even watch the entire video? Mashing the sticks?! really? Do you really think that it starting from 25% power and missing everything between 50 and then 100 is PROPORTIONAL control?

I know people hump tamiya but for all that you believe in sakes, stop making excuses and show me another esc that acts that way. Not even 5$ chinese ones do. I can get a 5 year old traxxas intellisport to go in increments of 1% and it is smooth from 1 to 100 using the same equipment that cannot make this thing well.. do any better than the video shows.

RE: gear reduction. Again excuses. All it does is it slows the motor spool up. Torque is not applicable since there is no actual resistance to speak of in the test video i've posted. Without it, the jerks are even faster since the GB spools up faster while it winds up the slack and then smashes the sprockets into drive/reverse.

Re: " just deadzone". 25% deadzone is normal? since when.

Anyhow, you can now see how a 400$ esc acts and apparently that's normal according to the tamiya fanclub (which is why tamiya never fixes their crap, people make excuses for them their entire lives). This is all getting torn out and i am going with proper electronics.

PS. I have the odd feeling this is built in to simulate engine spool up with the speaker (i forgot to connect it, it's in the basement, i am not going down there to get it). Aka you hit the throttle and the dmd just sits there and sends sounds to the speaker to spool up the throttle. then it "goes" after 1-2 seconds. It would almost make sense if it at least was proportional.

tomhugill

Did you even bother to watch the video of my entierly stock leo? Im not mashing the sticks and its rather smooth. Maybe you have a faulty dmd? Mine and the others Ive used at our club are also fine. I run my leo through some pretty tough terrain, as did the previous owner. No issues.

RE geardown, how is this an excuse, if your running your tank off road and encounter extra resistence from the crap which gets caught in the idlers you will rip up your TUs. Not an excuse just engineering fact....

gyrate

what obstacle is there on my smooth level floor mate?

new escs are on order as of 10 minutes ago, should be here before week's end. then i'll make another video as comparison.

the thing is that you say it might be faulty but then make up excuses as to why what im showing you should be considered normal. you can't have it both ways! my brand new turret servo (high torque ANALOG futaba) glitches when given inputs. the whole circuit feels like there is intereference (aka bad servo) hooked to it somewhere. i tried to remove the j-4 one by one and see if it's a particular channel that is causing it. no change.

then i hooked said brand new servo to the receiver and used a bec to power it all up and it was fine (sans the little analog delay). connect it to the dmd.. eh not smooth.

then i connected the tsu01 back and that servo looked smooth (no horn but just looking at the sprocket). granted the tsu is so weak and slow you wouldnt be able to see if it was skipping anyway.

i've had that happen before and a bad servo will cause glitches and disproportional response across the entire system. but is not quite the same. once you throttle it up it holds said power without glitching. so who knows. let me get the new ESCs in there and see what happens.

tomhugill

You said you had ripped up TUs and Ive seen in your past posts complaining about them being worn out. You have also showed pictures of the tank being run off road.....its not an unreasonable assumption about it being run off road. Anyway that has nothing to do the jerk you seem to be having, was just meant to be an observation.

Right all im saying is im showing a video of a stock leo with nice smooth imputs running nice and smoothly. You show a video of you mashing your sticks and having your tank run jerkily. Again I dont think my assumptions are unreasonable. But ok despite me having seen 4 different leos running just fine, which leads me to belive you may have a faulty dmd (which tamiya will repair for free as long as you havnt tampered with it) you seem to dismiss this and anything else I post. Im not making excuses or am some kind of blind tamiya fanatic, im just trying to point out if your issues are not cause by you stabbing at your sticks then its probably a faulty DMD.

Its not skin off my nose if you chose to waste more money on this with new esc's etc when you could send back your current dmd. I am just trying to help a fellow forum member.....

gyrate

Correct. first one was because the sprockets broke (they are epoxied together... you would have read that part too) and the set screws that hold them on the hubs were rusted due to mud and water hiding behind the sprocket guides (W parts). so i had to drill those out destroying the shafts.

i rebuilt the box.

then again down the road because i was not happy with the quality of grease i used first time (low duty lithium).

for the record to prevent seizing set screws, grease them up and put some good tape over them then either put the sprocket guides or leave them out (leaving them out will result in the track jumping off very easy with any real traction at turns).

just another mindless little quirk i guess

Lincs Winks Wayne

Hi:
I have been building my Leo over the past year, my 2 other tanks are not tamiya but I believe run grate and look great and they run on SLU.
I have to say That after assembling all the many parts to my Tamiya Leo I was suprised and so happy that all the major parts work great, smooth and powerfull.
My Pershing with 400's 3:1 gears with bearings is a great runner and climber but the Leo is better and I am no expert.
I must say I halve to learn to be a gentler driver with the Leo but I am getting there and I am not a gentle person.
I have been a model builder for 45 years but a n RC tank builder for 3 to 4 years and tanks have become very enjoyable experience.
Some times using the suppliers equipment as designed provides a better experience then jumping in and trying to upgrade various parts that no longer work well together.
I hope you can help with the problems of the Leo but it sounds like a slippery slope.

Good Luck

Wayne

tomhugill

I did read the bit about the sprockets being in two pieces. Now mine came in two halves and I had to glue them, once or twice the outer half has come off whilst turning on grass. The two part sprocket is a strange (poor design idea), if one had knackered my tus I wouldn't be happy. To be fair though you can completely rebuild the Leo tu for £20 (gear bag and three differentials) which is 1/5 the price of the other tus so it's not too bad!

Ive run my Leo on pretty log grass and never had an issue with tracks skipping once I got the track tension sorted (I bought the metal idler arm upgrade for finer adjustment) . Prior to that it was aweful. Getting debris caught in the rear idlers central guides is a pain but I'll take that over tracks skipping off any day!

Ps Wayne I can't help but agree about the upgrades, I can't help thinking the engineers that designed the Leo have made things that way for a reason in a lot of cases. Thinking of a lot of battlers now is light is better, soIf plastic tracks will do then metals pointless. Quite often you just end up chasing your tail with these things.

gyrate

I will get it working right. So far i've put in

idler adjuster (had to sue backyard armor to actually ship that, then they went out of business a few years after.. people told me i was full of it about them too back then... lol?)
idler wheels
torsion bar retainers
tracks
sealed bearings
metal arms
metal torstion bar shafts
hull reinforcement kit
detailed barrel option
battle system
some souped up nothing fancy higher torque than stock 540 motors (will go to 55t with the new controllers)
2x gear reducers
about 4 sets of batteries
custom welded sprockets (no more splitting!).

not counting all the stock parts

2 sets of transmission internals
torsion bar sets
countless sets of sprockets.

on order:

swedish style headlights to replace the plastic stock buckets
turret gyro


what i want to do in the future:

full cnc roadwheel set (ugh)
those metal storage baskets. but can't really justify them yet.


what's another 300$ in ESCs on a 10 year old model...................

i should get a chunwai but you see i have never seen one in person and am wary if i put myself through something similar.

tomhugill

Well if you replace the Dmd im sure there are a fair few people who would take your arm off to get one! That's a lot of upgrades for something your not happy with. I hope your quest is sucessful.

no12skyline

I put a digital volt meter to the motor output leads and found that the voltage output jumps from 0 volts to 7-plus volts at the first increment for both motors. For the turning motor its about 25% of travel, for the forward motor it appeared to be 20% or less. The T-07 put out a maximum of 8-plus volts at full throttle but there didn't seem to be many "steps" in modulation. My stick is notched which probably played a part too.

rcleo

2 cent tip:

Why not do a simple test using the KISS concept, swap out your Leo radio system.

Suggested is a simple Futaba 4YF 4-Channel 2.4GHz FHSS Radio System for easy setup and smooth tank operation.

Buy the Futaba here for fair a price: http://www3.omnimodels.com/cgi-bin/w...I=FUTK4200&P=7

Make sure you do your test with a new tank battery at full charge and new fresh transmitter batteries, but you know that.

If that solves all your Leo 2 "operation & run issues", then order a right stick spring loaded self centering kit from the Futaba Service Center, usually sent to you free (and simple to install).

If the radio swap out is a fail, your DMD Unit is a probably a rare fail; call Tamiya USA for a service replacement, usually free to USA customers.

Customer Service Address:
Tamiya America, Inc.
Attn: Customer Service
36 Discovery #200
Irvine, CA 92618 Phone: (800) TAMIYA-A
Fax: (949) 362-2250
Customer Service Hours
Monday through Friday, 8:00 a.m. to 5:00 p.m. PST

Good luck.

heavyaslead

gyrate, the stick to DMD response does not look right. Also the accel from forward and reverse seem non-uniform.

This is not the normal operation of the DMD/radio IMO. The Leo states PCM radios may have issues with the DMD.

I get imediate response to stick on my radios. The forward and reverse does have a slight delay in transition between, (acts as a stop on hard reverse before reversing) but the DMD response should be even throughout the range.

tomhugill

The ESC dont work by varying voltage afaik

gyrate

thats exactly how it works... it regulates the voltage it sends to the motor.

its not a servo to use a signal pulse....



indeed. keep in mind my camera (70$ bargain special since im old school and my dslr doesnt do video) skips enough frames to smooth it out more than it is in actuality.


if it is a radio issue my findings remain. AM is useless to me due to interference. so is 5.8ghz actually. 2.4 SS/FAST works fine where i am. i havent had the desire to test the dmd output with the old 4wd futaba. i've moved past this.

my next step is to fix the track jumping due to overfriction. im thinking impact full metal grousers, with the grousers being filed down so they glide and not bite. anyway...

tomhugill

Actually I thought they sent out pulses of the same voltage.

THE_BREED

You are both right. Its not a servo pulse but does pulse at the same voltage with varying pulse widths from 0% to fully on. On an O-scope the pulses and widths can be read but not with a simple DMM. On a DMM, reading across the motor, which acts as an inductor, you should read a fairly smooth DC voltage ranging from 0V up to close to battery voltage.