Go Back   RCCrawler Forums > RCCrawler General Tech > General Crawlers
Loading

Notices

Thread: PTI Project Crawler

Reply
 
LinkBack Thread Tools Display Modes
Old 02-18-2010, 10:22 PM   #41
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default Video!

Quick video of some "office crawling". I stacked up a few items from around the office and made up a hill. Still feeling out the strengths and limitations of this rig for sure but overall, not bad but I'm still going to make improvements.

http://www.youtube.com/watch?v=zriMDiMj-08

Speaking of which here's what I invested in:

2 Sets of Proline 2.2 Eight Shooter Wheels $37.80
2 Sets of Proline 2.2 Chisel G8s with foams $40.10
Integy 85 Turn V11 Pro motor $34.99
Proline Progress Clear Lexan Body $24.39
HPI GRU for WK $19.99
Novak Rooster Crawler/55t Combo $109.99
Two Tower Coupons (-$25 and -$10)
Two Hitec 5625s ~$85 (don't ask)
No estimate on materials since I've had them all (scrap or large quantity purchases)

Total chassis investment for this rig (ie what would have put towards a kit to build): $122.28
Total Electronics investment for this rig (stuff I would have bought if I had invested in a brand new Axial or Losi kit) $229.98
Knock the $35 bucks in coupons off and I've invested: $317.26



Was it worth it? Dunno yet but here's an apples to oranges comparison I was considering:

1) Losi 1/10 Comp Crawler Roller: $284.99
2) Single Hitec 5625 ~$43
3) (I have extra micro servos for the DIG shifter) $0.00
4) Xcelorin Brushless motor $79.99
5) Xcelorin Brushless ESC $129.99

Total for a brand new Losi comp crawler rig that is pretty well outfitted (for comparison to my investment): $537.97

So given the >$220 difference, I'm not sure I've made the best investment for performance but this was a fun learning experience and definitly has been interesting as a machining project. No real regrets.... Yet.

Last edited by pbarsamian; 02-19-2010 at 01:29 PM.
pbarsamian is offline   Reply With Quote
Sponsored Links
Old 02-19-2010, 01:37 PM   #42
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Pulled the Axles last night:

1) Used Red loctite to lock the bearings to the shafts on the pinion shafts going into the axles
2) Used 5 min epoxy on all bearing seat surfaces to get the bearings seated and "locked" into the axle housings
3) Shimmed each gear/spool
4) Drilled through the rear axles case screw holes and used 3mm through bolts with steel standoffs to go through the case and ball links, with a 3mm Locknut on the end. Tightened down significantly.


Result: A LOT better. No gear mesh probs now even on hard torque climbs, the axles seem much more locked in.


Now I just need to play with suspension tuning. I'm not quite happy with it yet.

Also considering doing some flat stock CNC cut lower link arms with a bend in them to allow better link clearance underneath.


So question now is: "What is left of the original PTI kit?"

1) Axles Cases
2) Bearings
3) Axles Gears
4) Center Spool
5) Ball link ends
6) Steering Knuckles
7) Drive shafts, bones and out drives for wheels
CVDs cut in half (but still from original kit)
pbarsamian is offline   Reply With Quote
Old 02-19-2010, 04:23 PM   #43
Rock Stacker
 
Join Date: Oct 2009
Location: Huntsville
Posts: 77
Default

Nice Work!!!! I may have missed it, but how did you do the axle shafts?
76 warlock is offline   Reply With Quote
Old 02-19-2010, 05:09 PM   #44
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Thanks Warlock!

For the shafts, I cut the old CVDs in half at the middle. I then lathed two 3.5" long 3/8" diameter steel rods bored out (using drills not actual boring bars) to within 2 thousandths of the CVD shaft diameter. I milled a flat on one side of the steel shaft, drilled double set screw holes on each end, and put a 10 degree taper on each end as well. Essentially this made it an adjustable length shaft extender. Since these are not high speed shafts, I didn't need to do the 120 degree set screw and balance routine but even then they spin pretty true. In one of the very early pics I posted there should be an under belly shot where you can see one of them completed...
pbarsamian is offline   Reply With Quote
Old 02-19-2010, 05:11 PM   #45
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

You can see one of the shafts in this picture on the left side of the pic on the bottom of the rig...

http://www.photoshop.com/accounts/5e...37ded284dbc5d9
pbarsamian is offline   Reply With Quote
Old 02-19-2010, 06:58 PM   #46
jwo
Rock Crawler
 
Join Date: Jul 2009
Location: waterville
Posts: 525
Default

looking good, some bent lower links would def. help. that way you tires have a better chance of grabbing before it cases out on the links. as far as eliminating the tt. check out the axial ax10 forum. search for torque twist stuff in there.ill look around as well, if i find some good info for ya ill post it. if you could make a link mount for the axle and offset the links on it . like one link on bottom of plate and one on top that should eliminate it. you just got to tune your link geometry, it will take some time. but you will get it. axle link mounts w/ adjustments would be a nice mod. i never cared for those little extenders for them.
jwo is offline   Reply With Quote
Old 02-20-2010, 04:33 AM   #47
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Thanks Josh, I think I saw some suggestions similar to what you described and have a few ideas. frankly I think just having different sized stand offs would accomplish the same thing on the rear but that's never good enough for me, I might actually CNC an aluminum link mount with a few adjustment holes and see if that works any better, more to come...
pbarsamian is offline   Reply With Quote
Old 02-20-2010, 04:52 PM   #48
jwo
Rock Crawler
 
Join Date: Jul 2009
Location: waterville
Posts: 525
Default

yeah that would work too. im sure you will come up with something good.
jwo is offline   Reply With Quote
Old 02-21-2010, 01:12 PM   #49
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Well I didn't get rid of it of it completely but between triangulating the rear lowers, offsetting the rear uppers (left lower, right higher) at the axle, and adding some of the spring ride height shimms to the left rear shock, it's a bit better.

I have the harder Integy springs on order from the LHS and hope that will help as well.

The biggest improvement I've seen was in adding 6oz of stick lead around each of the front wheels in addition to the 3 that were in each previously. It's a LOT easier to crawl really steep objects now. Getting better with each tuning....
pbarsamian is offline   Reply With Quote
Old 02-21-2010, 03:45 PM   #50
Newbie
 
Join Date: Feb 2010
Location: Phoenix
Posts: 3
Default

65Catalina is offline   Reply With Quote
Old 02-21-2010, 03:47 PM   #51
Newbie
 
Join Date: Feb 2010
Location: Phoenix
Posts: 3
Default

i dont know how much articulation you are looking for but i went to a 8 shock setup with a pivot in between them, and either axle can go totally vertical. pretty simple mod to.
65Catalina is offline   Reply With Quote
Old 02-21-2010, 08:12 PM   #52
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Quote:
Originally Posted by 65Catalina View Post
Would love to see it but can't view this pic?

Sounds like a neat idea...
pbarsamian is offline   Reply With Quote
Old 02-25-2010, 09:37 PM   #53
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

Nearing completion (though true projects are never really done)

Body pretty much complete I'm still considering doing lights on it but not sure. I might just do them on the Jeep Rubicon and switch between scale and comp as my mood hits.

Had to trim away a good portion of the front grill and rear tail light area to make it work but still seems to fit and look ok.

Pics of the comp body on the machine:
http://www.photoshop.com/accounts/5e...25b9b6fac7e8cc

I'll use a better camera to snap a glamour shot when I get a chance, phone pics are not always best at show true color.


Next two upgrades on the list:

1) Finish alu bent links and fit them up (question is if they'll still fit with the rears being triangulated may try undoing triangulation to put them on)
2) I found a large sheet of 1/4" black delrin in the stock pile, going to work on a slippery skid plate for the bottom that includes rounded/angled edges to help avoid hangups
3) Waiting on stiffer shock springs from the LHS.
pbarsamian is offline   Reply With Quote
Old 02-25-2010, 09:42 PM   #54
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default

I'm officially crawler crazy. I'm now looking at my second project, a full on super class MOA based on clod axles. I'm thinking no body, just a CNC alu and carbon tuber/alien style machine with custom micro controller based DIG system that will allow 4ws and 3 mode DIG operation on a 3 ch controller. I have some ideas I'm kicking around.


Now I need convince the wife to allow me to use that pallete of stone in the back yard to build a crawler course instead of another garden!
pbarsamian is offline   Reply With Quote
Old 03-01-2010, 02:00 PM   #56
Pebble Pounder
 
Join Date: Jan 2010
Location: Glenview
Posts: 129
Default Bent Lower links

here's a first attempt at some bent lower links, I'm still looking at where adjustments may be needed, I think the angle is pretty close but I may have overshot it a bit. Also working on an upper link mount bracket to allow some adjustment up there and reduce flex in the mount point...

http://www.photoshop.com/accounts/5e...83325e62ce9989
pbarsamian is offline   Reply With Quote
Reply



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 05:59 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO ©2011, Crawlability, Inc.
Copyright 2004-2014 RCCrawler.com