Tommy R's TTC Build - "Big Oly"

[Tommy R]

LOL. I had the same question and was about to go search out the answer this morning. "thumbsup"

Tommy, where are you making contact under compression? EDIT: never mind, I found it here. You and I look to be in the same boat; we need to fit too much burly in too little space. Hey, that's not necessarily a bad thing. Better than under-building. ;-) The rig(s) looks great, including your other project. Keep up the good work, dude.

I should get some updated pic of the front linkages. I think right now under straight bump the track bar contacts the axle housing and chassis simultaneously. And at the same time I think the drag link and tie rod are just touching. Under max articulation, I believe all clearances are good and it's the shocks are the limiting factor....which is the way I want it. I'm also toying with adding some more upper shock mounts to allow more droop travel and less bump.

Thanks for the kind words, too.

 

[Tommy R]

Got some lockers in from RPP today. Talk about fast shipping! I don't think these will be a weak link. EDIT: These are from RCP, not RPP.

Got my new mini driveshaft. Thanks, Tim, for the idea!

And I made a new, slightly better "tool box" for my battery today. I just need to source a small brass hinge.

 

[2JSC]

Got some lockers in from RPP today. Talk about fast shipping! I don't think these will be a weak link.

Aren't those the SS ones from RCP?

 

[Tommy R]

Aren't those the SS ones from RCP?

D'oh!! Yeah, I meant RCP. I'll update my post. I've got RPP on the brain 'cause I keep checking my order on their site to see if my 2.2 Swampers have shipped yet. They haven't.

 

[team3six]

I had no idea those were still made. I will have to hit up RCP then, thanks and glad to see your still at it. cant let Oly down.

 

[Nickle]

I don't think these will be a weak link.

Holy beefy, Batman. You won't have to worry about adding weight to your wheels. :ror:

The battery box looks good. Kinda looks like a miniature ice chest that the mob uses to hide bodies in. Not sure if that's the association that you wanted to make, but it's the first that came to mind. :mrgreen:

 

[2JSC]

D'oh!! Yeah, I meant RCP. I'll update my post. I've got RPP on the brain 'cause I keep checking my order on their site to see if my 2.2 Swampers have shipped yet. They haven't.

No prob - I know I've got RPP on my brain too, keep addin chit to my wish list. :ror:

I had no idea those were still made. I will have to hit up RCP then, thanks and glad to see your still at it. cant let Oly down.

I know, I bought mine like a year ago, should order another pair here soon.

 

[eric113]

Got some lockers in from RPP today. Talk about fast shipping! I don't think these will be a weak link. EDIT: These are from RCP, not RPP.

Got my new mini driveshaft. Thanks, Tim, for the idea!

And I made a new, slightly better "tool box" for my battery today. I just need to source a small brass hinge.

Tommy, here the website I was talking about

http://www.micromark.com/Hinges.html

 

[Tommy R]

Tommy, here the website I was talking about

http://www.micromark.com/Hinges.html

Thanks, Eric! That'll come in handy.

Last night I was reassembling the rear axle and ran into a clearance issue between the axle housing and the ring gear bolts.

I guess the RCP lockers are designed to not re-use the ring gear gasket that Axial provides because without it, the bolts barely....and I mean just barely....clear the housing. Barely. ;-)

 

[ecoli]

Ah, it's just a plastic housing. That screw head will wear a nice groove in it in no time, then no rubbing at all ! Seriously though, would a button head screw give you more clearance?

As for the hinges, pm me with what you're looking for. I've got a bunch sitting here that I've never gotten around to using. Be happy to throw a couple in the mail if they fit the bill.

 

[Tommy R]

Ah, it's just a plastic housing. That screw head will wear a nice groove in it in no time, then no rubbing at all ! Seriously though, would a button head screw give you more clearance?

As for the hinges, pm me with what you're looking for. I've got a bunch sitting here that I've never gotten around to using. Be happy to throw a couple in the mail if they fit the bill.

I don't know if a panhead would really do much better, but I may give it a try if I can find some that are small enough. At least without the gasket it does fit now.

Thanks for the offer on the hinges! Basically, I'm looking to hinge a steel box that's about 5" long. I initially wanted a piano hinge, but not sure if I could locate it. Now I think a single hinge about an inch long would suffice.

That being said, I may be changing my mind. I'd been contemplating the idea of using two batteries mounted "side saddle" in which case I may not even use this box at all. I appreciate the offer, but let me figure out what I want to do first.

 

[STANG KILLA SS]

tommy for the brass hinges go to hobby lobby in the doll house section. they have several sizes.
i have some ill try to remember to bring them to Rock the Lake

 

[ecoli]

I don't know if a panhead would really do much better, but I may give it a try if I can find some that are small enough. At least without the gasket it does fit now.

IIRC those are M2 screws. McMaster Carr does carry them in a button head, but they may not be the right length. It's definitely tough when you're looking for hardware that small!

 

[2JSC]

At least without the gasket it does fit now.

I was going to say, you were using the gasket weren't you. :ror:

 

[Tommy R]

tommy for the brass hinges go to hobby lobby in the doll house section. they have several sizes.
i have some ill try to remember to bring them to Rock the Lake

Great, now I've got to go to doll section. Thanks! :lmao:

IIRC those are M2 screws. McMaster Carr does carry them in a button head, but they may not be the right length. It's definitely tough when you're looking for hardware that small!

I may actually have some, but at this point I'm sure they're needed. At lunch I had to run home and while there I put together the rear axle and it seems okay. But if I have some other screws around I may give it a try. If nothing else, it'll be nice to have a rounded head just in case it does contact the housing.

I was going to say, you were using the gasket weren't you. :ror:

What can I say? At first I didn't even see it in there! It's only .5 mm thick, but that was enough. ;-)

 

[Tommy R]

Tommy, where are you making contact under compression? EDIT: never mind, I found it here. You and I look to be in the same boat; we need to fit too much burly in too little space. Hey, that's not necessarily a bad thing. Better than under-building. ;-) The rig(s) looks great, including your other project. Keep up the good work, dude.

Nickle, here's a few pics of the front end as it sits now. This is at approx. ride height since I added some slightly stiffer front springs. Note the odd assortment of endlinks I used to gain the clearances. I also have the tie rod UNDER the high steer knuckles and moved forward a bit to clear the axle housing. I wish I could have it higher, but not sure I can.

At full bump the drag link screw head contacts the tie rod. In addition, the track bar just contacts the top of the axle housing.

And another angle at full bump. You can see that the chassis is clearanced just above the drag link. They would make contact in roll before I did this. Likewise for the track bar.

In other news, I got the RCP lockers installed last night along with the Gunnar axle toobs. I also decided that I'm not going to use the metal tool box for the battery. Instead I'm going to run two batteries in a "side saddle" configuration. This should keep the weight more forward and a lot lower. Not to mention I won't need that giant box taking up half the bed.

What I'm trying to decide now is if I want to run two small 3s batteries in parallel or two 2s batteries in series. Right now I'm leaning heavily to running the 2s batteries in series. I've found some that are the right size and are 1750 mAH, which is comparable to what I'm running now. More capacity would be great, but I want a really slim battery and that limits my choices somewhat.

I know my Holmes TorqueMaster ESC will handle 4s without a problem. From what I've read in John's posts, the 10t puller will be okay on 4s, but I'll need to keep an eye on the heat. I'm not sure what will generate all the heat, but I suppose it would be primarily high current draw like when bound up or under a really heavy load. If that's the case, I think I would be okay.

If any of you have run a puller on 4s I'd love to hear your thoughts before I order the batteries.

 

[ecoli]

Does the drag link servo screw bind with the steering link at full compression, full left steer? Looks like it might. If so, might want to make some bump stops or suspension limiters. Also, I would look at raising the track bar axle mount just a tiny bit. Should give you more clearance over the axle and a more parallel line with the drag link (the two look just a little off from each other). I say that not having a trackbar on my most recent rig which will probably result in all sorts of bump steer ! I will say setting up front end steering the biggest pain on a scaler. If you get that figured out, you're golden!

As far as the puller motor. I've regularly run 7t pullers on 3s. Even without any binding, the motor gets warm, but not to the point that it's melting anything or unmanageable. A 10t on a 3s runs much cooler. I have a feeling on 4s it'll run warm, but you should be fine.

 

[Tommy R]

Does the drag link servo screw bind with the steering link at full compression, full left steer? Looks like it might. If so, might want to make some bump stops or suspension limiters. Also, I would look at raising the track bar axle mount just a tiny bit. Should give you more clearance over the axle and a more parallel line with the drag link (the two look just a little off from each other). I say that not having a trackbar on my most recent rig which will probably result in all sorts of bump steer ! I will say setting up front end steering the biggest pain on a scaler. If you get that figured out, you're golden!

As far as the puller motor. I've regularly run 7t pullers on 3s. Even without any binding, the motor gets warm, but not to the point that it's melting anything or unmanageable. A 10t on a 3s runs much cooler. I have a feeling on 4s it'll run warm, but you should be fine.

No, the servo arm/link has ample room turning in both directions. The closest "issue" is the chassis and the exposed screw threads when turning driver side. But it does clear.....barely. ;-) I installed some Axial CVDs again last night....this time with Gunnar music wire pins so hopefully they'll last longer. But the point is I now have more available steering so I may need a longer "pitman arm" on the servo. So I may need to do more chassis clearancing. Should know more later tonight.

The only problem with raising the axle end of the track bar is that it would then hit the chassis sooner in roll. Well, that and I'm using a Hand Bros. mount and it only has one link mount location on it. It does have a bit of bump steer, but for crawling it's negligible. For higher speed stuff it *might* be an issue, but overall the drag link and track bar points are aligned fairly well.

That's good feedback on the motor stuff. Thanks! I'm feeling more and more confident that going 4s will be okay as long as I don't get stupid with the power and romp on it for too long at a time. The 4s batteries have rather low C ratings (lower current output) so maybe that'll help keep the temps down? Or might it have the opposite effect?

Thanks for the feedback, ecoli. Much appreciated! "thumbsup"

 

[ecoli]

Ah yes, I missed that on the track bar. Looks like you already notched the chassis to clear it? If it's working well, then leave it I say!

The puller motors are pretty power hungry. The low discharge rating means you'll be placing higher stress on the batteries themselves. If you take it easy, should be ok. It's when you hit the throttle or bind it up that it really stresses the battery, that's why a high burst rating is important. For the 10t puller HH recommends 40A continuous on 11.1V, so a 25C battery (about 55A) should be fine for 4s. Go for one with the highest discharge ratings for the size you need for the longest life.

 

[Tommy R]

Ah yes, I missed that on the track bar. Looks like you already notched the chassis to clear it? If it's working well, then leave it I say!

The puller motors are pretty power hungry. The low discharge rating means you'll be placing higher stress on the batteries themselves. If you take it easy, should be ok. It's when you hit the throttle or bind it up that it really stresses the battery, that's why a high burst rating is important. For the 10t puller HH recommends 40A continuous on 11.1V, so a 25C battery (about 55A) should be fine for 4s. Go for one with the highest discharge ratings for the size you need for the longest life.

Well, I wouldn't go so far yet to say that it's "working". :ror: But it didn't do too poorly at Sunday's comp in the limited time it was not snapping driveshafts. So it's encouraging at least. ;-)

That's the kind of input I'm looking for with regard to the battery/motor situation. So you think if I go with two 2s batteries, that they should have at least 25c ratings?