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-   -   4wd Corr/Pro-4 Truck REDESIGN POSTED 12/23/09 (https://www.rc-monster.com/forum/showthread.php?t=14174)

TruckBasher 12.02.2008 08:41 PM

I do agree with Travis, my E-Slayer is considered a conversion since I used an existing platform of E-Revo to convert it to a CORR type truck. This one is totally new and I just wish Travis will consider mass production :whistle: so a new standard will be set for CORR truck (RC) or maybe some manufacturer buys this design and give it a go on the market...just my 2 cents....BTW, I like Shawn's truck too :yes:

Travis, wheres the video?? :yipi: just kidding I know school and work is keeping you busy...hope to see vids soon :party:

MetalMan 12.02.2008 10:32 PM

It's gonna be over a week before this truck can do anything major on film... The rest of this week is pretty busy for me, then next week is finals. At least I'm done by 10am on Thursday (11th)! Then I can head over to the track at about 3pm when it opens.

Quick update: Got the body painted up, and have found some weak-er things with the lower links causing screws to bend (albeit not high strength steel). So I will have to ditch the nice-looking aluminum rod ends on the lower links and go to plastic to allow the links to flex more, and will have to work on the spacing between the links where they are triangulated.

Thinner weight oil (35) in the rear shocks definitely helps, but GS shocks SUCK. No wonder they were Red Tag... So that means this truck is getting some Ofna Super shocks up front that WON'T leak. That will make the handling a lot more predictable.

A rear sway bar is in the very near future as well. On-power steering will benefit greatly from it.

TDC57 12.02.2008 10:36 PM

Just and outstanding JOB Sir all the way around.. :yes:

Now where is the Video?? :whistle: or better yet when are you going to the track next :neutral: I'll bring my slash :wink:

MetalMan 12.02.2008 10:50 PM

Quote:

Originally Posted by TDC57 (Post 238374)
Just and outstanding JOB Sir all the way around.. :yes:

Now where is the Video?? :whistle: or better yet when are you going to the track next :neutral: I'll bring my slash :wink:

I guess I posted right before you did, as the answers are above your post :angel:.

TDC57 12.02.2008 10:53 PM

Sorry I missed that!..

rschoi_75 12.03.2008 01:52 PM

Wow... :surprised: :yipi:

DickyT 12.03.2008 02:13 PM

Quote:

Originally Posted by MetalMan (Post 238212)
TBH I don't think the word conversion is very fitting. Conversion is the word we use for turning nitro into electric, turning a buggy into a truggy, etc. This truck was not anything to begin with (albeit the front end was from a MT2 and the rear axle was from a Wheely King). Besides, if it were just another Corr truck conversion, then why is it that that there are 10+ Corr truck conversions (buggies) on RC-M, but only two totally custom trucks with this IFS/4-link-solid rear axle setup? I wish building this truck were as simple and non-time consuming as a conversion, I could have gotten a lot more sleep :lol: But thanks for the comments.

ok you win, poor choice of words on my part that detract from the amazing work you have done. this is a very close #2 for me for best build of the year.

MetalMan 12.08.2008 10:46 PM

After some parking lot/street testing I have found the KMS 2826-06 to be quite inadequate, even with an Axi fan mounted to the back. Under normal usage the motor would run about 170 deg. F and cog quite a lot. In the last (and final, for this motor) outing I noticed the truck seemed to be slowing down, and I knew the batteries were far from cutting off. It was almost like the motor was going "soft".

Maybe 15sec. later the motor decided enough was enough and put out quite a nice puff of white smoke. I continued to provoke it, and it rewarded me with some more smoke and even a light show from inside the motor! This was quite a sight and I felt compelled to continue feeding it so my co-workers would get a chance to witness this spectacular sight.

As you can imagine, that motor is done for. That is the last time I will purchase a KMS motor for an application where some performance is desired (this same size/wind of motor works terrifically in my crawler). This has led me down an somewhat interesting path - the path of motor choices.

I was contemplating a typical inrunner (Medusa 36-50-xxxx) and a spur/pinion gear reduction with slipper clutch, and making the mounts to go with that, but was unable to come up with an adequate design which would allow minimum driveshaft angles (vertically and horizontally) as well as a more centered motor position.

Then I came back to the original plan of direct-drive-to-diff with an outrunner and set out to find a similar sized motor to the KMS 2826 but with more power and a reasonable price tag. The Scorpion motors seem like an excellent option:
http://www.innov8tivedesigns.com/pro...products_id=83
http://www.innov8tivedesigns.com/pro...roducts_id=391
If only their HK3026 came in a kv in the low 700s, then it would be perfect.
That 3032 is not only longer than the 2826 I was using, but also larger in diameter. I think it should run much cooler due to the size and better quality. If you guys think this is a good option, or can point out something else, I would like to hear about it.

Whew, long post! Anybody who has read this far deserves a cookie!

Andrew32 12.10.2008 12:55 AM

holy dirt! there has been alot of development on this little baby! IM LOVING IT!

TDC57 12.10.2008 05:16 AM

Quote:

Originally Posted by MetalMan (Post 240154)

Whew, long post! Anybody who has read this far deserves a cookie!

I like oatmeal please.. :wink: again Travis just a outstanding build, :yes: you raise the bar for all every time you post!... :diablo:

MetalMan 12.10.2008 03:20 PM

Glad you guys like it!

I did order the Scorpion 3032-12 yesterday, should be here soon.

Lately I've been reading up on building/winding motors (what sikeston ended up doing for his direct-drive-to-diff Revo conversion). I will probably end up either rewinding the motor that is on its way, or get a kit version of the same motor and wind that. By having my own winds I can pack more copper onto the stator than the factory does, which in most cases means a better/cooler performing motor.

For now I have 2 Hobby City HXT DIY outrunner kits (12pole stators just like the Scorpion 30 series) and I will wind them DLRK (14 magnetic poles), but not sure if wye or delta will be chosen (I can choose after each slot has been wound).

Andrew32 12.11.2008 02:06 PM

hmm looking at the pictures i have ONE recommendation... if im allowed:lol:

The lower links at the chassis looks like its gonna take BUNCHS of force. I think the lateral stresses on that will transfer to the Chassis plates and ultimately fatigue the plates. I think even a ziptie to hold it straight would help!

just a thought

MetalMan 12.11.2008 10:00 PM

You're right, the forces at the chassis from the lower link are huge. The lower links do carry the majority of the load from the rear axle.
I will be honest and admit that this design I came up with for mount the lower links is far from the best option. Basically the ends of the two lower links have a long set screw running through them and the two threaded posts on the sides of the links are tightened against each other to put tension in the screw. The screw in the pictures actually bent, and since then I have removed most of the spacing between the link ends so that there is more support. Also, the aluminum link ends shown in the pics were replaced with some Jato rod ends. This will provide more flex in the lower links, which is good (especially since the links are steel and won't flex much at all).

As for fatigue on the chassis plates, TBH I think this is a non-issue. One of my concerns from the get-go was the potential for poor integration between chassis components - this sort of project has not been attempted by many, and thus there isn't much information on what works and what doesn't. So for this reason (among many) I chose polycarbonate to be the chassis material. As I'm sure you are aware it is highly flexible depending on the thickness, and in this case the vertical chassis plates provide adequate flex to nearly eliminate fatigue.

But I do need to work on better lower link mounting... ideas are much appreciated :yes:.

MetalMan 12.12.2008 04:32 PM

Something nice came in the mail yesterday!
http://img.photobucket.com/albums/v1...k/IMG_7979.jpg
http://img.photobucket.com/albums/v1...k/IMG_7983.jpg
http://img.photobucket.com/albums/v1...k/IMG_7988.jpg
http://img.photobucket.com/albums/v1...k/IMG_7990.jpg
http://img.photobucket.com/albums/v1...k/IMG_7993.jpg

And here is the carnage from the KMS:
http://img.photobucket.com/albums/v1...k/IMG_7995.jpg
http://img.photobucket.com/albums/v1...k/IMG_8000.jpg
http://img.photobucket.com/albums/v1...k/IMG_8001.jpg

And some comparisons:
http://img.photobucket.com/albums/v1...k/IMG_8006.jpg
http://img.photobucket.com/albums/v1...k/IMG_8014.jpg

On that last picture, note the large silver ring at the "business" end of the Scorpion motor. That's a ball bearing! It sits inside the spinning part of the motor and provides extra support.

suicideneil 12.13.2008 06:47 PM

Fubar...

New motor looks very beasty, should give that truck plenty of grunt.


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