Underground Crawlers FF-4 "Frame Forward" Chassis

[C*H*U*D]

FF-4 "Frame Forward" Chassis

We have been working on this for a few weeks, and thought it was a good time to start building. I like being as transparent as possible in what I do, so I invite you along as this chassis unfolds. After all, you should know what your paying for!!

I have been reading quite a bit about 60/40 chassis setups, and I really like this idea, but there is a problem when using a symmetrical chassis such as the original F-4. Once you start moving a chassis like that too far forward, the shock mounts move too far out of proper position. I wanted to try a 60/40 setup, so a new Chassis was needed.

I really like the low, narrow profile of the F-4, so this new one follows it's design closely. It's designed to use the same full width skidplate as the F-4 to help keep costs down. I like a full width skid since in helps protect the side plates, and slides better than aluminum.

Pictures can probably speak better than I can so here they are:







Here is a shot with the Original F-4. The skid, transmission and motor will be moved roughly .6" forward......much more than I could have done previously.

I'll be putting together links this week, and moving my Original F-4 Chassis parts over. I'd really like to do a completely new build so that I could compare them side by side, but right now my R&D budget doesn't allow that.


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[Mad4Rnr]

I like the "forward" thinking

[TOMCAT18T]

Damn thats looks sweet! and a Killer idea, too.
I was debating between an F-4 and "another chassis" but looks like I might be changing my mind now.
Very cool.

[Sharkey]

i do like the 60/40 chassis idea. i myself would almost like to take it further to a 70/30, but im guessing i wouldnt get enough front suspension travel.

[chris w]

I think you guys need to incorporate more shock and link holes. And the upper link mounts could use some room to move back to allow equle lenght upper/lower links. I like the chassis but this is why I yet to consider buying one.

[C*H*U*D]

Originally Posted by chris w

I think you guys need to incorporate more shock and link holes. And the upper link mounts could use some room to move back to allow equle lenght upper/lower links. I like the chassis but this is why I yet to consider buying one.

This is exactly the type of comment I'm looking for and a very good point.

The original F-4 prototype was the typical "Swiss Cheese" chassis, and that was required to determine link mount locations. After a lot of testing, tweaking, redesigning and machining, I found there were only a few locations that could actually be used. For aesthetic as well as weight/strength reasons, I chose the locations that worked best, and added holes on either side of it.

I have received many comments that either praise the clean design, or feel that there are not enough options for mounting location. One thing I want to do with this chassis is make sure that both camps are pleased. After machining out these plates, I also felt the front upper mounts could be moved back to allow for more equal length front links. I've read Reflection's views on equal length links and agree with him.

This is not a final version by any means, and all suggestions are appreciated and will be considered.

Thanks for the comments



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[Semi Pro]

it looks great, i like the clean and simple look combined with the 60/40

how much do you think the production version will cost?

[Duuuuuuuude]

x2 on a bit more adjustability. Another row of holes would be pretty easy to do all the way around.

Looks nice though, I'd run it if I was in the market.

Are new links included in the package?

[TOMCAT18T]

What if you tried putting the front upper link mounting holes on the other side?
You could also extend the rear so that you could run the same length upper in the rear as well. That way the only thing that would be effected are the lower link lengths and the foward weight distribution. Although I dont know how that would effect the overall articulation...or weght.

I hope you dont mind my little "mock-up". You can see the F/R upper links and the shock mounting locations would remain virtually the same to the F4.

[axeten]

I like it
how long you think till you have these available?

Alex

[chris w]

Originally Posted by TOMCAT18T

What if you tried putting the front upper link mounting holes on the other side?
You could also extend the rear so that you could run the same length upper in the rear as well. That way the only thing that would be effected are the lower link lengths and the foward weight distribution. Although I dont know how that would effect the overall articulation...or weght.

I hope you dont mind my little "mock-up". You can see the F/R upper links and the shock mounting locations would remain virtually the same to the F4.

that looks more like something I would run....

[C*H*U*D]

Originally Posted by TOMCAT18T

What if you tried putting the front upper link mounting holes on the other side?
You could also extend the rear so that you could run the same length upper in the rear as well. That way the only thing that would be effected are the lower link lengths and the foward weight distribution. Although I dont know how that would effect the overall articulation...or weght.

I hope you dont mind my little "mock-up". You can see the F/R upper links and the shock mounting locations would remain virtually the same to the F4.

Don't mind it at all.....like I said, I like transparency in what I do, and appreciate comments.

One thing to consider about extending the upper rear mounts rearward.....this would make the rear upper links much shorter than the rear lower links....much like the issue with the front. Currently I run very similar lengths in the rear of my own F-4 Chassis. I really think Reflection is on to something with equal lengths.....I've seen much smoother rear articulation with my setup, and would rather not shorten the upper rear links.

I do plan to move the upper front link mounts towards the middle. With this chassis it will be with drilling holes......future revisions will be machined.

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[C*H*U*D]

Originally Posted by Semi Pro

it looks great, i like the clean and simple look combined with the 60/40

how much do you think the production version will cost?

This will cost a bit more to machine, since they are no longer identical plates. I'm still shooting to keep it no more than $50 shipped in the US, so about $5 more than the standard F-4.

Originally Posted by Duuuuuuuude

Are new links included in the package?

Links would be up to the builder. This chassis is a base to build your own truck around.

Originally Posted by axeten

I like it
how long you think till you have these available?

Alex

It will be a few weeks of testing and tweaking but I hope by the beginning of February.

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[axeten]

i'm in Australia, would you be able to send one to me? what sort of price for shipping?
thanks
Alex

[BEELZEBOB]

Its good to see so many top knotch products coming out of Longmont! LOL

keep it up chud! great idea from concept to fruition!

[theslowguy]

Where can I get it and when!

[C*H*U*D]

Originally Posted by axeten

i'm in Australia, would you be able to send one to me? what sort of price for shipping?
thanks
Alex

Hey Alex.......this chassis will follow the same shipping format as the original F-4......Only $8 more than shipping in the US. I really want to keep the price reasonable, and I'm shooting for no more than $50 shipped in the US, so it would be $58 shipped outside the US.

Originally Posted by BEELZEBOB

Its good to see so many top knotch products coming out of Longmont! LOL

keep it up chud! great idea from concept to fruition!

Thanks Bob! Just trying to keep up Longmont's rep

Originally Posted by theslowguy

Where can I get it and when!

It will be available here on RCC and on our website. I don't believe in selling anything I wouldn't use myself, so it will be a few weeks until I get a chance to run it through it's paces. I'm shooting for no later than the beginning of February.



I spent some time working on links today. I want to keep everything the same as my own perdonal F-4 truck, so that's the reason behind the RC4WD shocks, and 3-link front.......I want to test the chassis only.

Obviously I couldn't use the same links, so it was time to break out my "Chassis Holding Utility Device".



After that it was just the usual method of measure, cut, grind, tap and fit. I use Jato and Revo links with 8-32 allthread to make my lower links......very strong and easy to adjust. I wait until I have a chance to run the truck a bit before I cut the 1/4" stainless sleeve to cover everything up. You never know when that little adjustment will be needed.













I'll have everything moved over tomorrow and should have an update with it running. Everything went together pretty easy so far, so I don't think I'll run into any problems. The transmission and DIG fit pretty nice, so there shouldn't be any issues there.

Thanks for looking.


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[Duuuuuuuude]

I like that rear 4 link mount...I've been messing around with the same exact thing for a few days now. I think its gonna be good.

[C*H*U*D]

Originally Posted by Duuuuuuuude

I like that rear 4 link mount...I've been messing around with the same exact thing for a few days now. I think its gonna be good.

Thanks Duuuuuuuude......it's the same setup that was on my other F-4 crawler, and I really liked it there. It almost seems smoother now that the links are longer.

I wanted to post up some pictures with just the transmission and dig unit in, before I put any electronics in.







I'll have more up tonight with it fully finished.

[InFlames]

Interesting design, i like.