wider wheelbase stearing axels 1/14 rig

[Stefan(2)]

A good day,

Came to this bit of the forum as the most mod's are done here i guess

With my project rig, i overdone it a bit with extra bits mounted on the chassis, so at this point a servo is a bit in the way of the wheel at almost max right-turn.

-oeps-  but there is just no other way to mount the servo, no more room!

As you might know, the stearing axels of the 1/14 rigs are like buggy's  , just with bearings, no hex.

In a perfect world i would like to increase wheelbase with 5mm "a wheel" (but more like 10mm is accepteble)

Should be just enough to clear the servo.

Are there any bits i could use , or tricks to use?  When using shims or a spacer, the bearing hitting the nut-thread so that does not work (going to be a runner).

Thanks, Stefan

 

 

[Backlash]

OK, Im just trying to get a clearer picture of what your trying to acheive.

Do you mean increase the wheel base (length of the truck) or wheel track, (width of the truck)?

To Increase the track, just make longer axles. Cut down some old Frog or hornet rear axles, drill a hole through for the hinge pin, and space the wheel out with old 5x8 bushings. You could also try using the complete unit from the front of some buggies like the Mad Bull or Monster Beetle etc, as these had longer axles because of the truck rims..

Will the servo fit between the chassis rails, behind the gearbox??

I will be watching the ideas you get, as I plan to build myself a twin steer truck, and im sure I will have the same problem.

Cheers

[Stefan(2)]

Hey,

I should be more clear, i intend to increase the wheel track.

I shall check out the frog bits, got little stash of parts hidden away for those oldy's so that could be a trick

I wish the servo would fit after the gearbox, but the reduction unit is placed there already.

If i move the servo more to the back, the stearing system would jam (i tried), hard to explain but you need to stear the wheel hub withing a certain agle, or you hit with the rod the tire, or the thing jams up.

I also thougt about making a "reversel leaver" , so i could place the servo further away (bought a airplane thingy for that), but that is all to big

Arrggghhh, hard to translate!! :) :)

But i will have a go on the axels, see if i can slay a car or find something that fits.

One positive point, with the placed extra servo i did got the wanted extra -oempf- for stearing. as it is going to be a bit of a heavy dog when finished.

EDIT:

Problem might solve itself, figured that if i want a clean turn with the rig, i need to have less stearing on the 2e axel as the 1e axel on the front needs to "stear" more to turn around the center of the turn.

<does this make sense? , translation problem!>

Anyway.. i figured.. if the front axel servo needs to turn 100% to make the turn, the 2e only needs to do 70% to avoid scraping the tires over the floor.  This diffrence might be just enough to keep it with shimming the trouble axel a bit.

When i figured out how to program the tx set, i can make some stearing links to do a little test.

Hopefully this will work. ( maybe... someday... i wish.. lol )

 

Stefan

[Backlash]

 

Problem might solve itself, figured that if i want a clean turn with the rig, i need to have less stearing on the 2e axel as the 1e axel on the front needs to "stear" more to turn around the center of the turn.

<does this make sense? , translation problem!>

Anyway.. i figured.. if the front axel servo needs to turn 100% to make the turn, the 2e only needs to do 70% to avoid scraping the tires over the floor.  This diffrence might be just enough to keep it with shimming the trouble axel a bit.

When i figured out how to program the tx set, i can make some stearing links to do a little test.

Hopefully this will work. ( maybe... someday... i wish.. lol )

 

Stefan

Stefan, dont worry, the translation is fine.

I think what you've written in your EDIT is going to work the other way around, ie. the front set of wheels will turn 70% and the 2nd steer will have to turn 100%, because the 2nd steer is closer to the pivot point (the rear wheels) and therefore they will have to turn a tighter (smaller) circle.

OK another idea. The Mercedes 1838 (and others Volvo?) uses a "relay box" to steer the front wheels. By placing one of these where your steering servo is now, and then moving your servo further toward the rear of the truck (still on the outside of the chassis)  to where it wont rub on the wheels when you turn. This should solve your problem.

If you are concerned with the scale appearance when you've finished this, simply hide the servo in a cutout in one of the fuel tanks, or custom make cover to look like a tool or battery box from aluminium.

Also, You could overcome the 70% / 100% steering problem mechanically by simply placing the steering rod (link) in the inner hole on the front steering servo, and placing the rod in the outer hole on the 2nd steer servo. Use a Y harness and run both servos from 1 channel on your radio.

Cheers

[Old Busted Hotness]

Have you thought about mounting the servo up front, as in the Knight Hauler?

When you increase the width of the axle, moving the tire's contact patch away from its pivot point, you will make your problem worse. The tire will swing in a larger arc and interfere with more parts than it is now [] This will illustrate the problem:

Another problem, is that increasing track width increases the load on your servo.

Moving the servo is your best choice. There has to be some place it will fit.

[Stefan(2)]

Heyaa<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

I'll do my best (the translating thing)

Regarding the Front 100/ 2e 70%  "rule",  ODD !

I drive a 2x8 on almost a day to day basis, hence the 2 wheel front steering, and just back from work. Always nice to have a 1:1 example

And, without joking, the front steering axel does a "100% and the 2e one more like 80%"  Now, this is a old basher-rig so it could mail function.  When doing about 40km/u  (don't try this at home), and you look, the 2e axel actually almost stops to do his steering-thing.

(but i bet that is almost impossible to re-create), so i skip that part.

But, i must say, this is a rig with a quite short wheelbase, the chassis i am using is from a king hauler so there is a decent space between the 2 front and 2 rear's.

 

Anyway.. do think you guys are right, i should move the servo, i'll have a look trough the parts stock if i still have the "FH12" thingy. (i must have... somewhere...) I must move the servo anyway, as i did a test-fit for the modified body this morning, and to clear the servo i need a 25mm lift. (as the gearbox is mounted higher also due the extra axel)  Now, that is a bit overdone, in fact.. it looks like junk!  It’s not going to be a crawler, going for the scale look.

To bad, just made all the new steering rods!

The 100/70 problem is also solved for the con<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />trolling bit (for a part), i still own a Graupner MC16/20 and a guy told me it has extensive mixing options to do exactly what i need.

 

If i can't make that work (am no MC tx set guru), i go for the 2e hole option.. more easy anyway :) Using the mixer option would allow max fine tuning, so hoping for the best

(and the help of a Dutch forum to help me program the thing ) , the chopper guys are the guys to speak to regarding the setup of a computer tx set.

Thanks for the thinking guys, this rig is a harder nut to crack as expected! 

Stefan

 

 

[Stefan(2)]

I must be going insane (regarding the 1:1) , or the rig is.. anyway, logical wise , backlash is fully right.

Anyway, just swapped the 2e axel around, so it makes a natural tighter turn at max push or pull,

did not find the eurotruck bit, going to figur out something else.

The solution must be so ovios, but just don't see it yet

"yes, this might work.. - no gearbox in the way"

"yes, this might work.. -no not enough room"

"yes, this might work.. - no.... "

EDIT:

Ok, i had it ... the mercedes going to give donor parts

will repair/replace that later on - i really, really hate to rip parts from other cars -

But.. close to having full steering

...

Stefan

[Backlash]

Please post some photos when you are finished so we can all see what you have done.

As they say, a picture tells a thousand words.

I hope it all works out....

[Stefan(2)]

Will do that, give me a couple of days and i have something to show.

it's all fitted now, but working on the control-part now, giving the new battery's for the tx a "forming" now so in a day or 2 it should work   The chassis is starting to look like a swiss cheese by all the extra hole's and tapping i had to do on it!

Tonight i go make a posting in a Dutch forum for a "programming a MC tx for dummies lesson"  , as the quistions i have to ask are just to complicated to do here (ehm, language wise).

I found the manual for the tx set, but figuring out how to use the mixer option and servo travel limiter is a other story. 

The next biggest mission is getting my lath & milling machine working, as i need that one for some parts i like to have on the rig.

- i'll be back! -

Stefan

[Stefan(2)]

Well, having holiday right now, so it became 02:00 last night

But, have something to show for now.

Movie (to get the idea), not fully happy with the TX programming right now, as the left stick does the stearing left/right ,  but due the mixing i have to use, the left up/down stick (a chopper/plane non spring loaded one), is doing the contra stearing now.

Nice effect but useless when driving i guess, have to figur out something for that.

Anyway, the show part ->

http://www.tamiyaclubdata.com/movies/1546/m8T2MOPM0U8.avi

If that link does not work, first video in my showroom-video part, 1,5mb download.

And, the pic's =>

http://www.tamiyaclub.com/showroom_model.a...56&sid=1546

Coffee time!

Stefan

 

 

[Backlash]

I had a look at the pics and that looks great. I'm really keen to start my 8 wheel truck project now.

I have been doing a lot of drawing, measuring and planning, and what I was considering doing was mounting the servo as you have done, and then using 2 relay boxes, and running both axles off one heavy duty 10Kg servo. Again using the linkages to arrange things so the front wheels turn 70% and the 2nd steer 100% or vice versa, or simply have both turn the same.

I'm just sorry, I couldnt get the video to work.

[Stefan(2)]

Do it,

nice to have more then one thinking about a problem, why

invent the wheel multiple times. I always prefer a good copy over a bad original.

Actually, already started on the body now The drivetrain is tested & ready, but i do have a bit of doubt about the short axel between the reduction unit and the gearbox, time will only tell if it is good enough for the job.

But, will be a long time before it is ready, still have a shedload of work to do regarding body, and then the rest...

a well, keeps me busy!

Stefan