So, What Have You Done Today?

[Tamiyastef]

1 hour ago, BuggyDad said:

I don't think I've ever had a servo where the saver/horn goes on at exactly 90°. Is there a trick I'm missing? 

I was thinking exactly that while reading you can have a servo horn at 90° without trim 

[BuggyDad]

5 minutes ago, Tamiyastef said:

I was thinking exactly that while reading you can have a servo horn at 90° without trim 

Do those servo tester things give you the ability to recalibrate a servo's centre point? 

[skom25]

1 hour ago, BuggyDad said:

I don't think I've ever had a servo where the saver/horn goes on at exactly 90°. Is there a trick I'm missing? 

 

53 minutes ago, Tamiyastef said:

I was thinking exactly that while reading you can have a servo horn at 90° without trim 

It does not matter, if there is adjustable link between servo and steering parts.

It is super annoying on cars which do not have this part and steering rods are attached directly to servo saver/horn. In my DT-02 I had to set Trim to around 20 points to run car in straight line!

[BuggyDad]

1 hour ago, skom25 said:

It does not matter, if there is adjustable link between servo and steering parts.

I haven't done the maths but you're going to get an asymmetry in the steering rate left to right if you don't start with the horn centred 90° to the link (in fact I think you often will even if it is, depending on geometry). A little off centre won't matter but I don't know how far off centre it needs to be to create a noticeable issue.

For me, I use sub trim to centre it as best I can before I adjust the links to a visual centre, then I know the mechanical start point is as good as reasonably possible. After that, end points. Then trim is only a driving refinement. Trouble is, transmitter settings can get changed by accident or a change in equipment, so in a perfect world wouldn't it be nice if a servo could be reset centred, then all you're relying on the transmitter for is end points. And, I'm not sure my older models were set up quite like this, so ideally they'd get a recalibration from scratch. 

[skom25]

1 hour ago, BuggyDad said:

I haven't done the maths but you're going to get an asymmetry in the steering rate left to right if you don't start with the horn centred 90° to the link (in fact I think you often will even if it is, depending on geometry). A little off centre won't matter but I don't know how far off centre it needs to be to create a noticeable issue.

I can be wrong, but it will happen only if you try to reach maximum rotation points in servo. In four cars I had, I was never even close to this.

If Servo can rotate to 90 degrees on both directions ( 180 degrees in total) and you are using e.g. 60% of range because of chassis limitations, it does not matter if center point is on 0 degrees or 15 degrees, because you still have a lot of movement available.

Steering also can be adjusted by horn length. Longer horn = less servo movement to reach the same steering angle.

My procedure is simple. I start with link length as in manual. Then I set Radio EPA for low value left/ right and increase it, till one hub hits limiter on upright or just hits upright. At this point I adjust position of steering parts using turnbuckle. To check this, I move wheels left/ right to see if distance between hub/ upright is the same on both sides. If it is the same, I increase EPA on Radio to be around mechanical limit of chassis. If you do this right, car will run perfectly straight without any trimming needed.

My XV-01:

Summarizing: as long as servo is not blocked by internal limiters, it does not matter how horn is installed.

 

[Grumpy pants]

5 hours ago, JimBear said:

It's just me who doesn't get a handle on door handles ...

I only know as I checked mine as well 😂

[Busdriver]

The RC version of cleaning out your sock drawer      I have no idea what I’m going to do with them all. I have some odd numbers as well!!! 5 I get, 4 wheels and a spare but 3??? What’s that about. Maybe there’s one in another box somewhere. May put some up for sale. If there’s anything anyone wants let me know and ll move them to the sales section. Next up is the other two brown boxes with “spares” in

[Rinskie]

12 hours ago, BuggyDad said:

I don't think I've ever had a servo where the saver/horn goes on at exactly 90°. Is there a trick I'm missing? 

I guess I got lucky for once in my life 

[Mouc-RC]

On 11/26/2024 at 3:06 PM, Busdriver said:

The RC version of cleaning out your sock drawer     I have no idea what I’m going to do with them all. I have some odd numbers as well!!! 5 I get, 4 wheels and a spare but 3??? What’s that about. Maybe there’s one in another box somewhere. May put some up for sale. If there’s anything anyone wants let me know and ll move them to the sales section. Next up is the other two brown boxes with “spares” in

Not sure you'll bother with shipping to France, and if those Falken Wildpeak are 1.9 (looks like and I love the rims), but sure there are some nice lots in your "socks" drawer

[Busdriver]

3 hours ago, Mouc-RC said:

Not sure you'll bother with shipping to France, and if those Falken Wildpeak are 1.9 (looks like and I love the rims), but sure there are some nice lots in your "socks" drawer

May be a bit pricey and I believe they may have a second life, maybe on the Bronco they came off!!

[Nikko85]

Little bit of 3D printing and design to create this

It's a LB on QD chassis. Going to paint up in satin black and see how that looks.

Need to add mounts but overall it is working nicely on this chassis.

Apologies for poor photo, camera phone plus evening plus black subject matter!

[Pylon80]

On 11/26/2024 at 5:37 AM, skom25 said:

I can be wrong, but it will happen only if you try to reach maximum rotation points in servo. In four cars I had, I was never even close to this.

If Servo can rotate to 90 degrees on both directions ( 180 degrees in total) and you are using e.g. 60% of range because of chassis limitations, it does not matter if center point is on 0 degrees or 15 degrees, because you still have a lot of movement available.

Steering also can be adjusted by horn length. Longer horn = less servo movement to reach the same steering angle.

My procedure is simple. I start with link length as in manual. Then I set Radio EPA for low value left/ right and increase it, till one hub hits limiter on upright or just hits upright. At this point I adjust position of steering parts using turnbuckle. To check this, I move wheels left/ right to see if distance between hub/ upright is the same on both sides. If it is the same, I increase EPA on Radio to be around mechanical limit of chassis. If you do this right, car will run perfectly straight without any trimming needed.

My XV-01:

Summarizing: as long as servo is not blocked by internal limiters, it does not matter how horn is installed.

 

I don't think that is correct @skom25 That link and horn should be made to be at 90deg when neutral as much as possible. Else you will get asymmetrical steering response even if the end points are the same. But your hand is not functioning in a symmetrical way on the transmitter either, so in practice it's probably fine. Might just as well do things straight when you can. To illustrate how the angle matters, look at the steering tierods. Their angle is actually used to tune Ackerman, by purposely not being at 90deg to the knuckles. The effect is very large even for small angles. For instance with just a few degrees at neutral you will obtain 25deg on the inside wheel and say 17deg on the outside one, so that is a rather large effect. Of course the geometry of the knuckles also plays a large role as well, but that angle is still how you tune it.

Not that I expect anyone to understand what I tried to write above without bothering to include a picture 😵‍💫 sorry.

[Verskis]

For the first time I had some real fun driving the rear wheel driven Embieracing XV-01.

I made some setup changes and had a less powerful motor in it, I think those made the difference that now I could actually control the car pretty well. The basic silver can seems to be plenty of motor for RWD on gravel.

Please forgive me for the inappropriate bodyshell for the RWD car! 

[Pylon80]

5 minutes ago, Verskis said:

For the first time I had some real fun driving the rear wheel driven Embieracing XV-01.

I made some setup changes and had a less powerful motor in it, I think those made the difference that now I could actually control the car pretty well. The basic silver can seems to be plenty of motor for RWD on gravel.

Please forgive me for the inappropriate bodyshell for the RWD car! 

Oh very interesting! Do they have a website of sort so we could see what the conversion consists of?

[Verskis]

Just now, Pylon80 said:

Oh very interesting! Do they have a website of sort so we could see what the conversion consists of?

Yeah, they do:

https://embieracing.com/

 

I have the XV-01 all-in-one kit.

[Wystan Withers]

Cleaned the garage... superficially anyway. Finally finished upgrading my baby CNC into an adolescent CNC (two month project) and tramming the table left little snowflakes of whatever weird polycarbonate sheet I found at the surplus store all over everywhere. A veritable blizzard of flaky (likely cacogenic) snow clinging to everything. So 3/4 of a Hefty bag later of plastic shavings, metal shavings from the band saw and aluminum chips from the lathe I'm almost not ashamed to post pictures again.

Almost.

[skom25]

9 hours ago, Pylon80 said:

I don't think that is correct @skom25 That link and horn should be made to be at 90deg when neutral as much as possible. Else you will get asymmetrical steering response even if the end points are the same. But your hand is not functioning in a symmetrical way on the transmitter either, so in practice it's probably fine. Might just as well do things straight when you can. To illustrate how the angle matters, look at the steering tierods. Their angle is actually used to tune Ackerman, by purposely not being at 90deg to the knuckles. The effect is very large even for small angles. For instance with just a few degrees at neutral you will obtain 25deg on the inside wheel and say 17deg on the outside one, so that is a rather large effect. Of course the geometry of the knuckles also plays a large role as well, but that angle is still how you tune it.

Not that I expect anyone to understand what I tried to write above without bothering to include a picture 😵‍💫 sorry.

I think we need to talk about this more in new Topic 🤔

[CRC505]

Took my TT02B to the woods to kick up some dust

 

[Kpowell911]

Re Arranged the Tamiya’s. Got a few Brand new in box ones now…. Need to make some changes, maybe sell a few, build a few and buy some new ones….

[Hypoxic]

Spent my Thanksgiving alone building up the pillars of my « Stable Queen » Lunch Box..

[chris.alex]

1 hour ago, CRC505 said:

Took my TT02B to the woods to kick up some dust

 

Wow, this is one of the most beautiful Dual Ridge variants I have ever seen. 👌

[BuggyDad]

11 hours ago, skom25 said:

I think we need to talk about this more in new Topic 🤔

What I was getting at is that if your horn is off centre and you make that up with link length to a crank that's at 90°, you'll get something like this:

If my servo on the left is centred at 7° off the vertical, and that is linked to a crank arm that's on the vertical, then if the servo horn rotates right 45° the crank only rotates 41.5°. Servo horn 45° left rotates the crank 47.8° left. Quite a big difference. 

You can deal with that by reducing the left end point by a bigger amount than the right, but the turn rate isn't linear so it's not going to be as good as if you'd centred the servo horn to 90° before setting the length of the link. The right turn will be initially insensitive and later in the throw it'll get over sensitive. 

Sorry for both the crap drawing and the heavy geekery! 

[skom25]

51 minutes ago, BuggyDad said:

What I was getting at is that if your horn is off centre and you make that up with link length to a crank that's at 90°, you'll get something like this:

If my servo on the left is centred at 7° off the vertical, and that is linked to a crank arm that's on the vertical, then if the servo horn rotates right 45° the crank only rotates 41.5°. Servo horn 45° left rotates the crank 47.8° left. Quite a big difference. 

You can deal with that by reducing the left end point by a bigger amount than the right, but the turn rate isn't linear so it's not going to be as good as if you'd centred the servo horn to 90° before setting the length of the link. The right turn will be initially insensitive and later in the throw it'll get over sensitive. 

Sorry for both the crap drawing and the heavy geekery! 

That is great!

After @Pylon80 I started to think about this and you both are totally right!

[TurnipJF]

Today I put the finishing touches to this:

I decided at the outset that I'd be running white wheels with narrower tyres at the front and wider ones at the back as per the Mini 4WD version as I think they look nicer than the stock black same-width-all-round ones.

I didn't do a build thread as I did one for my Thunder Shot, so doing another for this would be mostly repetition as they use the same chassis. However I included a couple of little refinements during the build which I will cover in the "Tips and Tricks" section at some point.

[BuggyDad]

I got back into the CAD modelling for stock Astute parts. I've now got as close as I think I can without running off test prints or cuts. I'm not with either machine though so I can't do that yet. 

(two pics - not to same scale)

Once these are refined, I intend to model a LWB version, which is very little extra work. Then also a version to take the BBX gearbox, but bracing the top attachment point of that gearbox forward will require some more thinking and a look at the real life parts. 

Slightly frustratingly, printing drawings to paper is inaccurate - over 0.5% out, which is a lot over the length of a chassis. And even the graph paper I bought to help plot out hole positions is about 0.5mm out over 300mm. Doesn't sound like much but I reckon I should be able to get everything well within 0.5mm and Mr T generally goes for relative hole positions in whole mm, only occasionally down to 0.5mm. A hole position 0.5mm out is way out.