Go Back  R/C Tech Forums > General Forums > Electric Off-Road
MRC / Academy SB Sport 4wd Buggy >

MRC / Academy SB Sport 4wd Buggy

MRC / Academy SB Sport 4wd Buggy

Old 08-06-2004, 11:23 PM
  #691  
Tech Regular
 
threeEwes's Avatar
 
Join Date: Mar 2003
Posts: 493
Default

Yes we have one here. Today became lazy friday so we'll be working on it tommorrow. Let me know and I'll send /exchange my file with yours.
threeEwes is offline  
Old 08-09-2004, 05:38 AM
  #692  
Tech Apprentice
 
Join Date: Jan 2004
Posts: 51
Default

hey guys, I can machine most anything you need made, just email me or get me a sample of what you want machined. as soon as I can get ahold of an SB I am going to start machining graphite parts for them.
I called ultimate saturday to order one and they were out. hoping they will have one in by the end of the week so I can get started.
I'm working on aluminum bulkheads for b4's right now
fatboy383 is offline  
Old 08-09-2004, 05:40 AM
  #693  
Tech Legend
Thread Starter
iTrader: (294)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 34,378
Trader Rating: 294 (100%+)
Default

For me right now, the thing that I would want the most is going to be the steering arms.

if you do some colored chassis parts in graphite I would love to see some of them.

Got a quick race report from this past sunday:

Buggy turnout was very light and didn't run as not enough was ready to go as a class. I was put to run with the stadium trucks. The track layout was completely changed, more technical but the straight was now not quite as bumpy.

1st heat: I ran my vehicle and was in the lead on the first lap or two, felt to second but was consistently battling for first. the vehicle felt pretty good but didn't have the rear plant that I was looking for. After hitting a few monster jumps I started to hear a weird noise coming out of the rear of the vehicle. was very strange and as I pulled it off it felt some binding at one of the rear wheels after the race was over, I managed second.

during the down period I rebuilt the diff and did pretty much everything I could think of to find out what the binding was coming from. I didn't get a chance to identify the problem so i skipped the second heat. Turns out that a bearing had gone bad that the diff rides on . replaced this bearing and it felt better but I was still getting some crunching sound from the tranny. So i took apart the rear again and found that I stripped the rear gear that goes on the slipper. I bought a set of new gears ( love that hobby shop support ! ) and installed the new gear to replace the one that stripped. the diff gear looked to be still in good shape ( big mistake ) so I ran it .

Third heat: The rear of the car just wandered too much and I decided that I would change the tires ( i tested a lighter oil, it helped but was still wandery in the rear at times ) from the ifmar studs to proline step pins. I figured that the design should give me good bite on the straight wear it wasn't so loamy and give me good rough track handling on the bad parts. I ran it and it tested great, much better than the previous tire selection. I kept the studs up front.

On the track the setup felt dialed. It jumped true and handled the rough sections of the track quite well. The turning ability was also much better, just let off the throttle and turn and it would come around but was controlable and wouldn't spin out. I ran this was during the heat and was doing well but connector popped out twice costing me a good finish. I also noticed that crunching again very lightly and pulled it off. I decided to switch the diff gear and that did the trick.

I moved the shock lower position on the front to the middle hole with gave me a bit more stability.

Main: I managed to qualify second and started off with a great shot off the line. This vehicle is just a beast when it comes to that. I managed to battle for first but on about the third or 4th lap I took a turn tight at speed and clipped a barrier pretty hard which spun me around about 4 times and I heard a snap.

Figured I broke an arm but looking I managed to break the front mount an dits ball hole, the arm and pin looked fine.

All in a bad day but my setup for next week should be spot on. I am planning to do a complete teardown this week and rebuild the vehicle and examine the gears to make sure they are in good shape. I am pretty happy however with my current setup and I plan to record it. If anyone is interested I will post.
Cain is offline  
Old 08-10-2004, 04:32 PM
  #694  
Tech Regular
 
threeEwes's Avatar
 
Join Date: Mar 2003
Posts: 493
Default

Cain:
The motor mount will be made out of 6061 aluminum-camless -will be different from the kose.
threeEwes is offline  
Old 08-10-2004, 07:53 PM
  #695  
Tech Initiate
 
Join Date: Jul 2004
Location: Texas
Posts: 29
Default

You may want to use something harder than 6061. I used 6061. When I mount the motor it start leaving grooves on the aluminum. I was thinking 2024 or 5052, i think that is the correct number. Mount did well, but the gear I made did not work out so well. I went to the 67 gear and could not get a low enough gearing, so I just about thermalled my speed control. So I just gave up. I have already order the parts from tim. How much would you charge to machine parts for me if I sent the files and material?
C:\DUH! is offline  
Old 08-11-2004, 05:12 AM
  #696  
Tech Legend
Thread Starter
iTrader: (294)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 34,378
Trader Rating: 294 (100%+)
Default

threeEwes: the spurs you have made, will they work with the slipper?

I can't wait to see what you guys have for designs for the mount.
Cain is offline  
Old 08-11-2004, 05:47 AM
  #697  
Tech Master
iTrader: (1)
 
Join Date: Jun 2004
Location: United Kingdom
Posts: 1,870
Trader Rating: 1 (100%+)
Default

Cain, no they wont as the Academy spurs have little drive lugs to locate the slipper pad onto the spur, otherwise the spur gear will turn into another slipping part of the slipper.
DA_cookie_monst is offline  
Old 08-11-2004, 08:32 AM
  #698  
Tech Adept
 
YoKoMo-MX4's Avatar
 
Join Date: Oct 2003
Location: ND, USA
Posts: 204
Default

Originally posted by C:\DUH!
You may want to use something harder than 6061.
Actually, you'd probably want to go with 7075-T6. I think that is about as hard/durable as common aircraft aluminum gets.

'nuff said,
MX4
YoKoMo-MX4 is offline  
Old 08-11-2004, 06:01 PM
  #699  
Tech Regular
 
threeEwes's Avatar
 
Join Date: Mar 2003
Posts: 493
Default

You all have good suggestions. For now we are still testing.

Duh you said your motor left grooves on the aluminum? Are you saying the end can left grooves or indentations on one side of the mount?
We haven't run into that yet but I'll be looking for that...

I dont have gear issues anymore since I now can gear 78 spur/ whatever pinion.

As for that slipper I havent seen one yet but I should go ahead and order one and see what can be done with it.

my quote of the month:

"Nothing is impossible when you combine some imagination, laptop and a machine shop together."
threeEwes is offline  
Old 08-11-2004, 06:21 PM
  #700  
Tech Regular
 
threeEwes's Avatar
 
Join Date: Mar 2003
Posts: 493
Default

I forgot to add that 7075-T6 would raise costs significantly. My projected prices will have to ge lower also.
If the parts are too expensive people will just run out and get the losi or the tamiya!
threeEwes is offline  
Old 08-11-2004, 09:55 PM
  #701  
Tech Initiate
 
Join Date: Jul 2004
Location: Texas
Posts: 29
Default

No the screws holding the motor left a lot of indents. Which is ok I guess.
C:\DUH! is offline  
Old 08-11-2004, 10:05 PM
  #702  
Tech Elite
iTrader: (20)
 
jk racing's Avatar
 
Join Date: Aug 2004
Location: Placentia, CA
Posts: 2,730
Trader Rating: 20 (100%+)
Default

threeEwes, the SB019 slipper kit uses the stock spur gears with a notched slipper pad. the spur gear rides on a 10 X 15 bushing/bearing. I am assuming your 78 tooth gear is designed for the direct drive application and not the slipper from your post. do you have a picture of your gear off the car? wondering if it can be modified to accept the slipper pads.
jk racing is offline  
Old 08-11-2004, 11:10 PM
  #703  
Tech Regular
 
threeEwes's Avatar
 
Join Date: Mar 2003
Posts: 493
Default

You are correct about the slipper. We worked on that before the slipper was made available to US buyers. I'm interested in the slipper because of the different possiblities that could be done with it.
The spur (already manufactured) is quite simple actually, but time it takes to set it up and run each one is the headache
Today the camless mount had to be redesigned partially in mastercam due to a miscalculation.
Our camless mount is the exact height of the stock diecast mount. Because of this there isn't a lot of room to play with in regards to the placement of the electric motor mounting screws. The counterflush look really looks trick but it adds another run of cuts. Its an amazing tight fit.
Also I located a local anodizer who would get that part done for me at a reasonable price too.
Better to sort out the headaches on the laptop than in production. Have a good one everyone.


P.S. Duh- did you use small washers with motor mount screws?
threeEwes is offline  
Old 08-12-2004, 09:18 AM
  #704  
Tech Initiate
 
Join Date: Jul 2004
Location: Texas
Posts: 29
Default

I had no room for washers. I have opened up the counter sink and this should give me the extra room I need. I should also be able to fit in Lunsford Titanium screws now.
C:\DUH! is offline  
Old 08-13-2004, 06:28 PM
  #705  
Tech Legend
Thread Starter
iTrader: (294)
 
Cain's Avatar
 
Join Date: May 2002
Location: West Fargo, North Dakota
Posts: 34,378
Trader Rating: 294 (100%+)
Default

Hey guys,

here is the RC Car Action article:

http://www.rccaraction.com/articles/mrc_academysb.asp
Cain is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.