Re: 777 HAUL TRUCK (1/12 size)
 

DADSGARAGE-you are doing some great work on this build. I have enjoyed watching your progress. A bit more on the akerman steering (if you care):confused: I think for proper akerman geometry with both front wheels pointed straight forward, the steering arms should be aligned with the center of the rear axle. Here is a neat diagram that shows how it works.
http://quaxio.com/steering/. Keep up the good work!!!

Re: 777 HAUL TRUCK (1/12 size)
 

Thanks for the info, getting the steering geomerty right is a tricky thing and challenging...mine will not be exactly right but it will be close"ish".. I found this picture of a truck standing on it's tail...interesting veiw of the steering


[IMG]http://i1291.photobucket.com/albums/...ps5bd58807.jpg[/IMG]

Re: 777 HAUL TRUCK (1/12 size)
 

That CAD drawing of the truck turning is exactly what you want. Perfect, in fact! I think the problem is your steering drag links do not travel equally, nor in a parallel / linear fashion, if that makes sense. Take a look at this picture.

http://i4.photobucket.com/albums/y12...ps892dbab3.jpg

Because your center steering arm swings in a substantial arc, the drag links do not maintain much parallelism with each other. With the wheels turned to the left, the more steering throw you add, the more out of parallel the right side link becomes. The result is the right link pushes the right knuckle more than the left link pulls the left knuckle. The knuckle on the right is at a greater angle, which is exactly the opposite effect you are after. Does that make sense, or am I barking up the wrong tree? :D

Re: 777 HAUL TRUCK (1/12 size)
 

That is a very interesting photo! In all honesty, your steering set-up looks like a very good facsimile of the 1:1 trucks! Makes me wonder if they have the proper ackerman effect or not? It could be that the 1:1 truck's links to the knuckles are longer, reducing the parallelism problems encountered in small scale, and the travel arc of the center arm may be less, if it's pivot point is further back from the bolts that secure the steering links?

Re: 777 HAUL TRUCK (1/12 size)
 

I was wondering if you took the two tie rods at the center pivot point and swapped them so that they would be close to the center pivot point if that would work better. Ed

Re: 777 HAUL TRUCK (1/12 size)
 

That's what Cat called "sprunion" steering on there forklifts,
If I remember correctly?
Cheers, Neil.

Re: 777 HAUL TRUCK (1/12 size)
 

I say call it good enough on the steering, finish the truck, and get on with the shovel already...:p

Re: 777 HAUL TRUCK (1/12 size)
 

Love the work you've done on the truck and the dozer, very impressive. I with Reg, good enough on the steering, lets see it haul a load.

Re: 777 HAUL TRUCK (1/12 size)
 

I have to agree with you both (RCP57,dirtpusher9)....enough on the steering already....this is a topic that could go on and on...I don't want to get into a debate on something that is right or wrong, debates only end up with someone getting offended at one point.....so at this point we will say my steering geometry isn't the best ( and no I'm not offended by any comments or suggestions...takes more than that to hurt my "feeling"...LOL) my only concern with the steering idea was if it would be strong enough to turn with/without a load on the truck...the other concern is the fact it has no diff. which could be the biggest problem when steering the truck no matter how good the steering geometry is or isn't. I do appreciate all the suggestions and ideas!!! Thanks guys for all the input!!! Building stuff from scratch is a challenge and any help from others is great and always welcome!!!

Re: 777 HAUL TRUCK (1/12 size)
 

Well said...now did you weld it together and paint it this afternoon or what?

Re: 777 HAUL TRUCK (1/12 size)
 

Ummm...no.....:p......but I will add some pics....

[IMG]http://i1291.photobucket.com/albums/...ps762534d1.jpg[/IMG]


[IMG]http://i1291.photobucket.com/albums/...psf32c159f.jpg[/IMG]

[IMG]http://i1291.photobucket.com/albums/...ps51b8e8b7.jpg[/IMG]

[IMG]http://i1291.photobucket.com/albums/...ps027c8d0c.jpg[/IMG]

Re: 777 HAUL TRUCK (1/12 size)
 

awesome job on the ladders :cool:and the whole truck , I've been watchin it on the tube before you posted here .:cool::cool: H2O jet ? if so it's giving me some new ideas in the future .

Re: 777 HAUL TRUCK (1/12 size)
 

Quite a bit of dirt on those tires now hey...


The ladders look great!...The whole truck looks great actually. With some paint it's going to look awesome! Do you find that with each model, you want to create more detail?

Re: 777 HAUL TRUCK (1/12 size)
 

Ya...look at all the dirt hey...tells you how clean my floor is...I would like to get them really dirty but this time of year dirt is hard to find,or should I say just hard and under snow....

I'm happy with the ladders even though it would be better if they were round and not square...but if I can cut the parts out all the better...good thing I'm not a true scale builder !!
Yes...having a bit more detail does seem to be getting more important for me even on my "Plain Jane" builds!! There are some details that just have to be on the model...just not the same without them. The hardest part is making it all work right...then it seems once you get it working properly you just want to paint it and go use it... adding the details seems to get forgotten...or put off for along time,so the trick is never paint your model that way it is always a work in progress!! LOL :D

Re: 777 HAUL TRUCK (1/12 size)
 

Hi Ed...Thanks....and yes having access to a waterjet is a big plus!! Good thing....because it supplies the "talent" !!;) Hope my build can help you with yours...if I can be of help in anyway let me know. Thanks again glad you like it....

Re: 777 HAUL TRUCK (1/12 size)
 

Thanks IH......being able to cut parts on a waterjet has been very helpful...hopefully more builders will consider getting parts cut on a waterjet or lazer....it is a big time saver!!! The challenge might be in finding a shop to do small jobs....so this link might be of interest to some builders...small plazma cutting tables at "Torchmate"

http://torchmate.com/products/torchmate_2x2/ http://www.youtube.com/watch?v=ozZ52TatcIA

Re: 777 HAUL TRUCK (1/12 size)
 

A few more pics......

[IMG]http://i1291.photobucket.com/albums/...ps2f0998f2.jpg[/IMG]


[IMG]http://i1291.photobucket.com/albums/...ps8fd90df4.jpg[/IMG]

[IMG]http://i1291.photobucket.com/albums/...ps5363871e.jpg[/IMG]

Thanks again for looking....

Re: 777 HAUL TRUCK (1/12 size)
 

Very nice!

Re: 777 HAUL TRUCK (1/12 size)
 

Thanks...slowly getting this built....

Re: 777 HAUL TRUCK (1/12 size)
 

The Tipple 7 is coming along nicely. When I do one it will be made out of aluminum easier to machine and lot lighter. I got the wheels for it and that is as far as I got. I could have it water jetted I have a place that does it for me at a very reasonable price. Right now though I have 3 other projects that are taking up my time. Keep up the great work it. Ed