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Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 1:52 am
by askbob
Did you get a chance to browse your notes for the exact pieces that worked with the Dynotech arms?

Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 1:57 am
by carloco8
Looks awesome Sean! Have you tried using velcro to hold down the body?
Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 11:04 am
by Orange
askbob wrote:Did you get a chance to browse your notes for the exact pieces that worked with the Dynotech arms?

Oh man, sorry I forgot about you Bob...
You have to use SC10 front hex mounting hardware with SC10 rear hexes and a few extra shims to get the width out all the way. You have to shim them differently than normal with that setup, but it will get you close to the same width. Use the AE hardware though, not the JConcepts adapters.... You can't shim the JC axles the right way. You don't have much room to shim them perfectly because you run out of room with the axle pin... But it can be achieved. This part of the build had me a little stumped because originally I was going to use the Klein/B4 Hub/Sc10 Hex front setup. But the shimming was not as neat as I had liked.
Also, using reversed hub carriers helps heal some of the ackerman issues you get with using the trailing axle setup on the swept arms. The problem this creates is that the arm hits on the back side of the carrier. I just took a dremel to mine and have not had any issues with them.. You still get some negative Ackerman though. I'm working on something to help adjust that better, will see how it turns out soon.

.
Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 11:42 am
by kaiser
this thing is too cool. makes me want to get back to my OIN project. (too many damn projects! lol)
Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 1:07 pm
by Orange
I don't know if I ever showed these pictures comparing it to a b4.2...
Hard to tell, but the tires on the RC10 are a little bit wider and taller than what's on the 4.2. Ill take some pics with just wheels on them. They line up perfect.
Re: My RC10.2 build. (OIN)
Posted: Fri May 31, 2013 1:41 pm
by Y'ernat Al
[quote="OrangeAlso, using reversed hub carriers helps heal some of the ackerman issues you get with using the trailing axle setup on the swept arms. The problem this creates is that the arm hits on the back side of the carrier. I just took a dremel to mine and have not had any issues with them.. You still get some negative Ackerman though. I'm working on something to help adjust that better, will see how it turns out soon.

.[/quote]
Negative Ackerman? That's more toe-in as the wheels are turned if I'm not a$$ backwards

. I wonder if using the 10T bellcranks is the dominant, or at least a significant player here Sean. The longer radius on those bellcranks has got to be playing into it. On my oin, I put short 8-32's in on the rear nose plate holes and ran regular length bellcranks from the front holes, becasue I was thinking it may matter. I've never compared it apples to apple with the 10T crank ackerman though.
Re: My RC10.2 build. (OIN)
Posted: Sat Jun 01, 2013 12:39 am
by askbob
Orange wrote:askbob wrote:Did you get a chance to browse your notes for the exact pieces that worked with the Dynotech arms?

Oh man, sorry I forgot about you Bob...
You have to use SC10 front hex mounting hardware with SC10 rear hexes and a few extra shims to get the width out all the way. You have to shim them differently than normal with that setup, but it will get you close to the same width. Use the AE hardware though, not the JConcepts adapters.... You can't shim the JC axles the right way. You don't have much room to shim them perfectly because you run out of room with the axle pin... But it can be achieved. This part of the build had me a little stumped because originally I was going to use the Klein/B4 Hub/Sc10 Hex front setup. But the shimming was not as neat as I had liked.
Also, using reversed hub carriers helps heal some of the ackerman issues you get with using the trailing axle setup on the swept arms. The problem this creates is that the arm hits on the back side of the carrier. I just took a dremel to mine and have not had any issues with them.. You still get some negative Ackerman though. I'm working on something to help adjust that better, will see how it turns out soon.

.
Thank you sir!

On my way, swiftly collecting parts to build my 'Seanster'!
Use the ASC9892 front and rear and SC10 front axles and steering arms? I suppose a guy could use the FT blue aluminum rear hubs too.
Re: My RC10.2 build. (OIN)
Posted: Sat Jun 01, 2013 4:43 pm
by Headling
Haven't been on rc10talk for a while, just read this whole thread, amazing build, well done

Re: My RC10.2 build. (OIN)
Posted: Sun Jun 02, 2013 1:24 am
by Orange
Y'ernat Al wrote:Orange wrote:Also, using reversed hub carriers helps heal some of the ackerman issues you get with using the trailing axle setup on the swept arms. The problem this creates is that the arm hits on the back side of the carrier. I just took a dremel to mine and have not had any issues with them.. You still get some negative Ackerman though. I'm working on something to help adjust that better, will see how it turns out soon.

.
Negative Ackerman? That's more toe-in as the wheels are turned if I'm not a$$ backwards

. I wonder if using the 10T bellcranks is the dominant, or at least a significant player here Sean. The longer radius on those bellcranks has got to be playing into it. On my oin, I put short 8-32's in on the rear nose plate holes and ran regular length bellcranks from the front holes, becasue I was thinking it may matter. I've never compared it apples to apple with the 10T crank ackerman though.
I'm not even sure it's positive or negative on the terminology. I think Ackerman its actually the name of someone and the theory is geometrical. But anyway, with the hub carriers mounted normal, the steering lever was moved towards the rear of the car further creating a bigger angle of the steering link. When I turned the wheels to full lock, the inner wheel was at like 45 degrees and the outer was at like 10 degrees. If that is positive, okay? Sounds like simply toe-out to me and in Seanster terminology, "toe out" has a negative reaction to "steering", where as "toe in" has a positive effect to steering. All I know was when I compared my B4 or any other car, it wasn't like that. When I reversed them, they were more natural Ackerman. I'm sure the 10t steering bellcranks might have some effect because of the bigger radius, but It was plain obvious that the steering link angle was a bigger problem and reversing the hubs fixed it by moving the knuckle forward and increasing that lever action to the outside wheel.
For sure yes, the radius plays a factor, but that's not the only thing that plays into it. Link angles and lever action all play a part. The whole Ackerman theory came about for horse drawn carriages. Simply turning the wheels caused the outer wheel to skid. Ackerman is the outer radius being less than the inner and they figured out a way to mathematically calculate what is needed for proper steering. Ackerman was the guy that patented it.
Re: My RC10.2 build. (OIN)
Posted: Sun Jun 02, 2013 1:28 am
by Orange
Bob: I forgot ... Klein arms... Yes in the rear, b4 hubs.
The rear SC10 hex on front, the front SC10 hex on the rear.
Re: My RC10.2 build. (OIN)
Posted: Sun Jun 02, 2013 1:01 pm
by Scott S.
Diggin the new car Sean....Looks bad ass. Looks like our vintage class may take off, we are running a demo class next weekend at the ROAR Regionals here in Albuquerque we are limiting the cars to 17.5 brushless motors....hope we can get some era correct brushed motors for the class too at some point. I still have my Reedy comm lathe and lots of brushes.

Re: My RC10.2 build. (OIN)
Posted: Sun Jun 02, 2013 1:57 pm
by Y'ernat Al
Orange wrote:...When I turned the wheels to full lock, the inner wheel was at like 45 degrees and the outer was at like 10 degrees. If that is positive, okay? Sounds like simply toe-out to me and in Seanster terminology, "toe out" has a negative reaction to "steering", where as "toe in" has a positive effect to steering. ....
Yep. Got it. Ackerman looks like toe out, but the effect is something all together difeerent as you point out.. Negative is generally lack of or opposite of Ackerman.
Re: My RC10.2 build. (OIN)
Posted: Mon Jun 03, 2013 8:35 pm
by Orange
It depends on who's theory you look at. F1 calls the toe in version "Positive" Or "Accentuated" because most F1 cars now use it. So does Drifting.
However you want to call it... It doesn't matter. I fixed it with the reversed hub carriers. RC10 steering rack was never going to be an option with this build and I doubt it would have helped much if any.

Re: My RC10.2 build. (OIN)
Posted: Tue Jun 11, 2013 8:32 pm
by Norman
did you use the short shock tower in the rear to use the b4 shocks?
Re: My RC10.2 build. (OIN)
Posted: Tue Jun 18, 2013 8:56 am
by jaro
Sean, how did you find the longer wheelbase front end. I'm looking at starting my own OIN and I'm undecided weather to go with the longer front end as per yours or shorter. I would be racing in UK on high grip astroturf tracks.
Thanks.