Sab-a-dab-a-doo! The back-country LJ build has officially started
- Thread starter sab
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This is exactly why I purchased a Switchpros instead of a new Spod this weekend at the Offroad Expo to replace my failing one. It would have been much easier to just purchase a new Spod and swap the accessory wires one for one and be done in minutes. However after having switch position #1 fail a while back and now intermittent failure of switches 5&6 which operate my lockers, I decided to go a different direction this time.
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We got back from our trip back home this past Monday, and I had a few commitments during the week that kept me out of the shop. Also, I started mounting the Warn 9.5XP that I bought during their 40% off deal to replace the Smittybilt winch on my Expedition. Thanks again, @mrblaine, for disrupting your busy schedule to get me the dimensions on the mount opening required for your fairlead! Despite all that other activity, I did manage to do a little work on the LJ build. Not wanting to deal with the massive kink in the floor that resulted from my tunnel hack job just yet (a plan to address this is just beginning to form in my noggin), I puttered around on other things.
I really like my Hutchinson Rock Monster beadlock wheels, but as I mentioned in the post when I mounted tires on them, I realized that the one fault I could find was that the plastic caps for the massive studs that hold the two halves together don't fit very well. Being worried that they'd eventually just fall off, I left them off until I had the time (patience, really) to deal with it using my disc sander. The problem is caused by the slight radial offset caused by tolerance stack-up. The result is a varying gap between the nut's flange and the spotfacing on the wheel. The cap's O.D. doesn't account for the tightest gap possible:
As I posted in my earlier post (see link in the paragraph above), the caps don't sit flush with the spotface surface with offsets like shown above, and that small amount of seating depth is critical to thread engagement between the studs and the plastic caps. I had to reduce the O.D. of 75 caps to get them to fit properly. With so many caps, I had plenty of tries to find the easy way to do it without it looking horrible (machining plastic can result in ugly surface finish.) Eventually, I found the easy way - tapering them by rotating them in my hand opposite the sanding disc direction, similar to climb milling. Here's an unmodified cap on the left, with one that I tapered on the right:
It's sad that I even had to do this, since the engineer that drew up the caps should have accounted for tolerance stack-up! However, it was worth the time, as long as these caps stay on (I do have my doubts, though). Here's a finished wheel:
Next up: a report on another tub clearance issue discovered with the Atlas 4 Spd installation...
I really like my Hutchinson Rock Monster beadlock wheels, but as I mentioned in the post when I mounted tires on them, I realized that the one fault I could find was that the plastic caps for the massive studs that hold the two halves together don't fit very well. Being worried that they'd eventually just fall off, I left them off until I had the time (patience, really) to deal with it using my disc sander. The problem is caused by the slight radial offset caused by tolerance stack-up. The result is a varying gap between the nut's flange and the spotfacing on the wheel. The cap's O.D. doesn't account for the tightest gap possible:
As I posted in my earlier post (see link in the paragraph above), the caps don't sit flush with the spotface surface with offsets like shown above, and that small amount of seating depth is critical to thread engagement between the studs and the plastic caps. I had to reduce the O.D. of 75 caps to get them to fit properly. With so many caps, I had plenty of tries to find the easy way to do it without it looking horrible (machining plastic can result in ugly surface finish.) Eventually, I found the easy way - tapering them by rotating them in my hand opposite the sanding disc direction, similar to climb milling. Here's an unmodified cap on the left, with one that I tapered on the right:
It's sad that I even had to do this, since the engineer that drew up the caps should have accounted for tolerance stack-up! However, it was worth the time, as long as these caps stay on (I do have my doubts, though). Here's a finished wheel:
Next up: a report on another tub clearance issue discovered with the Atlas 4 Spd installation...
Back to the Atlas installation. I decided to fit up the shifter linkage assembly for the main case. First, I noticed that just from sitting in the box in my shop for about six months waiting to be installed, the threaded rods for the shift linkage were rusting pretty badly. They appear to be uncoated, in-the-white, steel, so I ordered up some 316 stainless threaded rods. Here's a picture of a rusted carbon steel rod and a 316 rod to replace it:
Next, I followed AA's instructions for assembling and fitting the shifters. To get it right was a very tedious process that took several hours. After getting them set up, I discovered more tub interference. The top of the tower that holds the levers hits the tub, and the front lever itself hits the tub:
I gained about an eighth-of-an-inch by sanding the top of the tower and putting a radius on the shoulder screw's head:
However, it wasn't enough. I could hear the tower hitting the tub while shifting, and upon removal, I found this witness mark on the freshly-painted screw head:
I'll have to bump out the tub in the areas marked up in the third photo up, but I'll do that when I have a plan to fix the kink in the floor. Stay tuned for that.
Next, I followed AA's instructions for assembling and fitting the shifters. To get it right was a very tedious process that took several hours. After getting them set up, I discovered more tub interference. The top of the tower that holds the levers hits the tub, and the front lever itself hits the tub:
I gained about an eighth-of-an-inch by sanding the top of the tower and putting a radius on the shoulder screw's head:
However, it wasn't enough. I could hear the tower hitting the tub while shifting, and upon removal, I found this witness mark on the freshly-painted screw head:
I'll have to bump out the tub in the areas marked up in the third photo up, but I'll do that when I have a plan to fix the kink in the floor. Stay tuned for that.
Today's project is to remove the old, rotten corrugated plastic loom from the rear of the wiring harness (from the crank position sensor back) and replace it with more modern loom. In my years in racing, I was always the electronics engineer for every team I was lucky to be on (even though I'm a mechanical, by degree). I've designed and built dozens of custom harnesses, but I can't afford the Raychem DR-25 heat shrink tubing and associated pre-formed boots I used for those, so I had to find a more cost-effective alternative for the looming. After a bit of "research" on the Interwebs, I chose Techflex's F6 Woven Wrap Braided Sleeving. I purchased it from WireCare.com.
First, I documented the harness in case I couldn't remember which connectors were where during re-assembly:
Then, I removed the old loom from the main run:
Next up is the tedious process of cleaning and inspecting all the wires, re-taping the junctions, and finally, wrapping it. But, first - it's lunch time!
First, I documented the harness in case I couldn't remember which connectors were where during re-assembly:
Then, I removed the old loom from the main run:
Next up is the tedious process of cleaning and inspecting all the wires, re-taping the junctions, and finally, wrapping it. But, first - it's lunch time!
Being acutely aware of the need to access the shift tower shift handle shoulder bolts from both sides, we do a removeable close out panel. Also, the shift boot is an odd duck in that it needs to have the long axis about 45 degrees to the shifter path. If you put it longways like logic dictates, the accordions bind up since the shifters are one behind the other. The metal ring is also the wrong size to work well. We made a new one and then a copy of it so it is easy to bolt it down without the screws wadding up the rubber.
I just finished up the re-looming. I didn't tape the joints, yet, because I may be adding other wires (Speedohealer, locker solenoids, etc.) as the build progresses. Here's the harness laid roughly in place near the Atlas switches and speed sensor at the back of the case:
And here's the loom as it runs over the transmission:
It's still hotter than Hades down here (>100°F!), so the rest of the afternoon will be spent in the air conditioning. I have to patch the cover for the LJ. For some reason, it does not make a good grinding backstop - it melts! Don't ask me how I found that out...
And here's the loom as it runs over the transmission:
It's still hotter than Hades down here (>100°F!), so the rest of the afternoon will be spent in the air conditioning. I have to patch the cover for the LJ. For some reason, it does not make a good grinding backstop - it melts! Don't ask me how I found that out...
I spent today figuring out how to fit the skids. In conversations with Mr. Blaine, he warned that the length of the NSG370 could pose problems with the transfer case skid location, so I started the day by mounting the blank I got from him. Knowing that it would need to be moved back as far as possible, I started by placing it so that the front-most skid nutserts were right at the front of the skid:
This position allows just enough room to put an L-shaped stiffener at the rear of the skid:
This also gives enough room for the rear of the engine/transmission skid to bolt up to the front of the transfer case skid:
For the front mounting of the engine/transmission skid, I ended up using equal-length mounting legs with the longer driver-side mount that gives more clearance for the mid-arm control arm:
This nearly centered the skid on the engine oil pan and put the drain diamond in an acceptable location:
Tomorrow I'll paint the steel mounts and start designing the transmission mounting bracket and then, if I have time, the cross-member.
This position allows just enough room to put an L-shaped stiffener at the rear of the skid:
This also gives enough room for the rear of the engine/transmission skid to bolt up to the front of the transfer case skid:
For the front mounting of the engine/transmission skid, I ended up using equal-length mounting legs with the longer driver-side mount that gives more clearance for the mid-arm control arm:
This nearly centered the skid on the engine oil pan and put the drain diamond in an acceptable location:
Tomorrow I'll paint the steel mounts and start designing the transmission mounting bracket and then, if I have time, the cross-member.
Oh, yeah - I forgot to add this comment to the post above. Another reason to dislike the Rubicon Express Long-arm Kit that was on this LJ when I bought it is that there are some large-diameter holes drilled into the frame right where I wanted to add more nutserts for the skid. I guess I'll have to weld in some circular patches before installing the nutserts:
I've spent an inordinate amount of time trying to work out a great way to use vertical tubes that are threaded for the skid bolts. All it takes is one loose bolt and a drop onto a rock to make that a miserable idea. And, it is only slightly less miserable that how offended I'd be using 5" long flat head through bolts. That said, I'm not convinced nutserts are that great other than we are very familiar with them.
I've spent the last three days working on a single part - the transmission mounting bracket. 
I have the transmission held up by a screw jack at the correct height, and I have a piece of the 1"x3" rectangular tubing that will be used for the cross member clamped to the bottom of the frame. Since the blank from @mrblaine has a 1" drop, the top of the 1"x3" tubing is exactly where it should be once installed, and the bottom of it represents the top of the skid, which is convenient for mocking up.
One of the biggest issues is that there is very little extra vertical space above and below the Atlas case because I want to use the factory rubber mount for the transmission so that I don't have to worry about vibration as much. I have less than 1/4" of room to play with, so I did a lot of real-CAD and old-school-CAD work, and dozens of trips from the computer/printer in the house and the LJ in shop (it's a 400' round trip each time!) Basically, I'd draw up the cross-section of the main plate for the mount, print it out on cardstock, cut it out with a scissors, and then test fit it, like this:
I just looked at my Fusion model, and I saved it 26 times. However, I didn't save it every time I made changes, so I'd guess I could have made close to 50 changes to it to get the fit just right! Here's some of the cardstock spent on this task:
And this is what I ended up designing (note - only one side plate is shown, but it will have one on each side):
As long as I didn't screw something up (
), this should be a pretty simple weld-up and installation once SendCutSend gets it to me. Tomorrow, I'll either start on the cross-member or the skid mounting (probably the skid-mounting).
I have the transmission held up by a screw jack at the correct height, and I have a piece of the 1"x3" rectangular tubing that will be used for the cross member clamped to the bottom of the frame. Since the blank from @mrblaine has a 1" drop, the top of the 1"x3" tubing is exactly where it should be once installed, and the bottom of it represents the top of the skid, which is convenient for mocking up.One of the biggest issues is that there is very little extra vertical space above and below the Atlas case because I want to use the factory rubber mount for the transmission so that I don't have to worry about vibration as much. I have less than 1/4" of room to play with, so I did a lot of real-CAD and old-school-CAD work, and dozens of trips from the computer/printer in the house and the LJ in shop (it's a 400' round trip each time!) Basically, I'd draw up the cross-section of the main plate for the mount, print it out on cardstock, cut it out with a scissors, and then test fit it, like this:
I just looked at my Fusion model, and I saved it 26 times. However, I didn't save it every time I made changes, so I'd guess I could have made close to 50 changes to it to get the fit just right! Here's some of the cardstock spent on this task:
And this is what I ended up designing (note - only one side plate is shown, but it will have one on each side):
As long as I didn't screw something up (
), this should be a pretty simple weld-up and installation once SendCutSend gets it to me. Tomorrow, I'll either start on the cross-member or the skid mounting (probably the skid-mounting).
TheYonderGod
Member
That's really cool, I like your combination of new and old CAD. I'm trying to learn how to 3d model soon so I can 3d print some interior parts.
Well, I did it part time, for work, for about 15 years (using the original parametric modelling software - ProEngineer), and then I switched careers and became an engineering manager and didn't touch it for over 15 years before doing it again for this build, but this time using Fusion. Fusion is pretty easy to use, but having some design experience is very helpful. Learning it can be like a roller coaster - extremely satisfying one minute, extremely frustrating the next!
As the Nike pukes say, "Just do it."
Pro-E was my favorite it had such an efficient workflow.
Had a lot of seat time on NX which was extremely capable but more than most people would ever need.
Fusion is more like NX, functional but a little more cumbersome to work with. But Fusion is free and gets the job done, I needed to watch a few Youtube videos to figure some things out.
I've spent the last three days working on a single part - the transmission mounting bracket.
One of the biggest issues is that there is very little extra vertical space above and below the Atlas case because I want to use the factory rubber mount for the transmission so that I don't have to worry about vibration as much. I have less than 1/4" of room to play with, so I did a lot of real-CAD and old-school-CAD work, and dozens of trips from the computer/printer in the house and the LJ in shop (it's a 400' round trip each time!) Basically, I'd draw up the cross-section of the main plate for the mount, print it out on cardstock, cut it out with a scissors, and then test fit it, like this:
View attachment 566372
I just looked at my Fusion model, and I saved it 26 times. However, I didn't save it every time I made changes, so I'd guess I could have made close to 50 changes to it to get the fit just right! Here's some of the cardstock spent on this task:
View attachment 566373
And this is what I ended up designing (note - only one side plate is shown, but it will have one on each side):
View attachment 566375
As long as I didn't screw something up (
I am never posting any of my armatureish fab projects again…
That’s another nice piece of work, Scott.
Jeff, thank you for the kind words, but I've seen your build thread - you're no amateur.
We both know the investment in time (not to mention money) it takes to do good work, don't we?
One more thing - it's currently only nice on screen and on paper. Plenty of time to "louse it up," as my old man use to say.
I never had the chance to use ProE…my school used some wireframe 2d software (not autocad) and SDRC- Ideas. They switched to Pro-E when I was a Junior, I think, and I was already well down the path of Ideas. I graduated and didn’t to any 3d design work for 12 years…then picked up solidworks. Solidworks reminds me of ideas…and everything else, nowadays. I now use inventor which is similar to fusion 360.
At IMTS this year, they had a modeling competition using 360. I’ve never used that program, but completed the model about mid pack on my time. It’s amazing how similar they all operate.
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