What did you do to your GMT today?

[Shdwdrgn]

I can see a table saw helpful for splitting pvc.

That's what I used, but the center piece was over 24" long and apparently I couldn't hold the piece perfectly square while simultaneously trying to protect my fingers. One side is pretty close, but the other side needs about 1/4" knocked off to square it up.

I was planning on getting back to this tomorrow, but it looks like now my day off will be spent trying to figure out why the wife's blazer won't start. Best guess is battery, even though it wouldn't turn even when someone tried to jump-start her. Then again, they have a Ford, so I thought I'd take a shot at jump-starting with a *real* truck

[v7guy]

James, have you considered some locking header bolts?

[Trail X]

No, but please enlighten me.

[v7guy]

There's a few versions, one with a wing, one with "cammed" (for lack of a better term) washers and one with a set screw in the bolt head

http://www.jegs.com/p/Stage-8/Stage-8-L ... 5/10002/-1

http://www.proformparts.com/product-exe ... ory_id/320

http://www.jegs.com/p/Percys/Percys-Vib ... 9/10002/-1

[Opeth]

Somebody is running around naked....



....and it's not meeeeeee!!

[TBYODA]

Looking good buddy! I wounder who tippied off.

[Opeth]

Some good guy in Rochester

[Shdwdrgn]

I actually got a small functionality test of my bumper on Thursday. Had to tow the wife's Blazer back to the house so I could work on it, but first we had to get her out of the parking lot. I got a HF snatch-strap awhile back, so I looped it around her rear hitch and pulled her out of the parking spot. Yeah it wasn't a big deal, but it was sure nice having an option other than trying to push her uphill by hand. Then I towed her home and got her parked in front of the house. In other news, I think I got too heavy a snatch-strap. While towing, it didn't seem to have any snap at all, which would have been nice since she's never helped tow a vehicle before. I think this strap was rated at 15,000. Oh well, still a really nice strap to have for moving vehicles.

Oh, and it turned out to be both the battery and starter failing. I managed to get a couple more hesitant turns out of the starter before the battery went dead. By the time I took the starter out of her truck yesterday, it was completely gone (parts store tried testing it, couldn't get it to do anything). So I'm out $200 for repairs, but she shouldn't have any more problems for awhile.

[ErikSS]

Not all nylon straps are intended to stretch. There is a good amount of information on that topic.

[Shdwdrgn]

It was sold as a stretchable recovery strap. Just looked it up, it appears to be an 18,000 pound strap, plus I was using it doubled-over between vehicles. I got it because it was on sale cheap (actually on sale again for $16), and it's easy to carry in the storage area along with jumper cables, hitch, and tow loop. I seem to remember that a recovery strap rating was supposed to be about 2x the vehicle weight? I dunno, if I used it as a single line, it would probably have some snap to it, but doubled-over it was just the right length for towing through my neighborhood.

[Chango]

Went to Bundy Hill and gave her a workout. Surprised me and everyone I was with what it could do in 2wd!

And saw a north face tb too.

[Shdwdrgn]

I don't know why I didn't think of this before, but I found the perfect place to mount my inverter today... Under the rear passenger seat where the OnStar unit used to be. I made up a plexiglass plate to fit in the slots, then siliconed the inverter down (there are no mounting slots on the case). There's actually quite a bit of space under the seat, leaving it open for airflow around the fans, and it sits perfectly where you can plug something in by opening the door.





Yes, it's only a tiny 750W (1500 peak) unit. Its more of a just-in-case thing, although it appears I have plenty of room to upgrade to a larger model later if needed. I'm just going to tie the ground to one of the seat bolts, and then run a wire over to the 125A line in the fuse block. It appears the unit has an internal 35A fuse, but I might add another external fuse. Any suggestions on what gauge wire to hook this up with? It came with 00 wires (9mm) which are too short to reach, but that seems a bit overkill if it draws less than 35A?

[Edit] Hmm a quick calculation shows that 1500W at 12V is 125A... So how are they using a 35A fuse in this thing? Yeah I definitely need to do some more reading before choosing my wire size.

[Trail X]

My guess is that the 35 amp fuse is an internal circuit protection, and does not fuse the A/C output supply.

[ErikSS]

I'm not an electrician, but I think your math is off. I'd bet its closer to 12.5 than 125. Do we have an electrical engineer that can confirm or deny his amp rating based on Watts and volts?
Edit: I believe its 1500 amps at 110 volt, that's the output not the power draw.

[Shdwdrgn]

Yeah you're right, I was figuring from the wrong side of the power rail. 1500W at 120V is 12.5A. And no real idea how that converts to the 12V side. I could guess at 90% efficiency, and calculate about 13.9A draw, but I could also guess that peanut butter makes it run cooler... its just meaningless. The stupid manual that comes with it has no useful information -- no recommendations for wire size or current draw. They just assume everyone is going to use the included clips and connect directly to the battery at all times, and there couldn't possibly be any other way this thing would be used. Ugh. Maybe some digging online will turn up some info that others have found.

[ErikSS]

Most manufacturers spend as little as possible. So the guage they used would probably be as thin as I would suggest.

[Trail X]

Power is what stays the same across the voltage conversion. You had it right to begin with.

[ErikSS]

James, have you tried to use a 30 amp appliance on a 1500 amp peak inverter? It doesn't come close. I can hardly use 5 amp appliances with my 750 constant/1500 peak inverter. Amps are a ratio of wattage at a certain volt. It is directly affected by both. It sounds like he has the right formula but had mixed up input and output for numbers to plug in.

[Shdwdrgn]

So it seems folks on other offroad forums are suggesting 6ga or 4ga wire to hook this thing up. What I don't understand is that this seems a lot larger than the wire used for the 125A feed to the rear fuse box. Did I mis-read the rating on that wire, or am I just totally off in left field here?

James, you would think I would know these things -- my dad was an electrician and I have an EE degree. You're right, power stays the same, so the 750W is the same on both sides of the rail, meaning that a lower voltage requires an increase in amperage. So 125A at peak usage is reasonable. Now the only question is if I actually HAVE that much power available under the seat, or if I need to run a dedicated line up to the battery.

[Trail X]

James, have you tried to use a 30 amp appliance on a 1500 amp peak inverter? It doesn't come close. I can hardly use 5 amp appliances with my 750 constant/1500 peak inverter. Amps are a ratio of wattage at a certain volt. It is directly affected by both. It sounds like he has the right formula but had mixed up input and output for numbers to plug in.

30 amp appliance on a 1500 watt (I assume you meant?) peak inverter will certainly not work. 30 amps x 120 volts = 3600 watts. Peak ratings are also not meant to be sustained current. They're really only talking about the instantaneous peak requirements of things like motors to get spinning. The amperage trace of an electric motor spikes at the beginning of use. 5 amp 120v appliance pulls 600 watts, so that sounds about right for a 750 watt inverter.

So it seems folks on other offroad forums are suggesting 6ga or 4ga wire to hook this thing up. What I don't understand is that this seems a lot larger than the wire used for the 125A feed to the rear fuse box. Did I mis-read the rating on that wire, or am I just totally off in left field here?

I think there's a difference between a wire sized for chassis aka non-constant pull wires, and power transmission wires. They sized it a bit liberally, not expecting to ever really reach a draw the size of the mega fuse. At least that's my take.

James, you would think I would know these things -- my dad was an electrician and I have an EE degree. You're right, power stays the same, so the 750W is the same on both sides of the rail, meaning that a lower voltage requires an increase in amperage. So 125A at peak usage is reasonable. Now the only question is if I actually HAVE that much power available under the seat, or if I need to run a dedicated line up to the battery.

Just remember that the peak rating of the inverter is an instantaneous rating, it won't pull that for longer than a fraction of a second. Probably not long enough to blow the megafuse, but I'd still keep a spare all the same. You can probably fuse the inverter at 80 amps and be safe.