Author Topic: Able Dog Belly Tank  (Read 35724 times)

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Offline awelker

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Re: Able Dog Belly Tank
« Reply #15 on: February 18, 2015, 07:48:01 AM »
Take Nathan's advice and get to a meet to look at some cars, and study the rule book thoroughly before you do anything.  Also remember the rule book is the minimum requirement, when my own safety is concerned I prefer to overbuild.

Building a tank to meet the rules is a lesson in packaging, especially if you plan not to stretch the tank. 

On the budget side, I had a number in my mind when I started that I thought was reasonable, probably spent at least 3 times that initially and am currently in process on more upgrades.

Best of luck and don't be afraid to ask questions.

Andy

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #16 on: February 18, 2015, 05:06:06 PM »
I have been to EM a few times in the past and I plan on it this year too. In the past its just been to spectate but this year I'm taking notes. Hopefully I will get the chance to meet a few of you there.

DW... I do have a rule book but somehow I missed that, thanks for pointing it out. Its been a while since I carefully read through it and apparently I need to do it again.

As an engineer I am well aware of the importance of planning. I don't intend to cut or weld anything until I have finished my cad work and an initial mock up. I have been spending hours out there looking, measuring, and trying different ideas. At first the tank looked huge, almost hard to fill. Now its starting to seem like everything will barely fit. Im sure by the end Ill be lucky to squeeze it all in, something like 10 gallons of "stuff" in a 5 gallon bucket. I built a temporary mock up table and I'm currently playing with layout. Im leaning toward a space frame with four main longitudinal members supported by transverse hoops to maximize the interior space, but its still unclear how it will work. I have no plans to stretch the tank but I did have a notion to make it sectional, as Dr Goggles suggested, if I can pull it off. BTW I, like Dr Goggles, subscribe to the keep it low philosophy. I want to keep the Cg low so I intend to keep the axles on the body center line and cut the bottom. I have access to CFD programs at USC so once I get a wire frame worked up Ill have some grad students run it through the program.

I know it may seem strange to want to build something like this at my age Nathan, but I think I may be a bit unusual. My newest car is a 1965 dodge and I always appreciated the simplicity in the design and engineering of classics. I would rather dump 50 grand into a classic than go out and buy a new car for the same amount. Besides there is a certain pride in knowing every nut, bolt, clip, and span of metal in the car you drive. Also... chicks dig fast old cars.  :wink:

James

Offline tauruck

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Re: Able Dog Belly Tank
« Reply #17 on: February 18, 2015, 10:31:02 PM »
James, we're all strange so you're in good company. :-D

Nothing wrong with old cars either.

You'll have the time of your life on this project and as Andy said, ask questions.

The best move you've made so far was joining the forum.

The members here are special. :cheers:

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #18 on: December 17, 2015, 10:49:42 PM »
I realize its been a while but I'm still at it. After February the tax man came and the budget has been tight but I have been busy. I live in a small 1950s style house in LA and I am limited as far as enclosed or covered car space. I was originally going to build this in a car port on the side of my house but with the salt air around here I decided against the bare metal outside. I moved my dodge outside and the tank took the one car garage.

The garage floor is horrible. Im sure it was tailgated in the 50s and finished with a 2x4. I built a table to work on out of TJI joists spaced 10 inches on center with 1 1/8 ply on the top. Those TJIs can take a few thousand pounds each and are very straight. I put a sheet of 1/2 steel on the top 4 foot wide by 14 foot long, one piece. I screwed it down to take out the wiggle and leveled the table to within a 1/16 corner to corner. I scribed a deep line down the center for reference and a square line at one end to pull numbers off of.

With a good surface to work off of I started by scribing the outline of the tank. I cut the tank in half and found the cleanest edge to scribe. I went down to HF and got one of their tubing rollers. That thing is the biggest POS I have ever used. Im sure it works fine for EMT or small thin stuff but I'm using 1 3/4 .188 wall mild steel and boy let me tell you. It took almost a day a bar to curve them to fit the inside of the tank. I ultimately had to redesign the HF roller to work but thats another story. Eventually I had four bars curved to match the outside of the tank they all turned out to be within a 16th of each other. I also cut the bottom of the tank and scribed a line for the bottom tubes and rolled them as well.

Now I said before this will be rigid front and back. For the front I cut out a circle out of 1/2 steel that fit the tank where I wanted the front tube axle to sit. I tacked it up in place after drilling some holes for the axle mounts. Im not sold on these mounts. I had them laying around and at the time seemed ok. They are leaf spring brackets out of 1/4 inch and have 4 9/16 bolts each. I was going to bridge between them with 1/4 plate to tie them together to keep them from bending during side load. Has anyone used a set up like this? I wanted to have vertical adjustability but with this setup I won't. Not sure what I will do here yet. I am open to suggestions.

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #19 on: December 17, 2015, 10:54:34 PM »
On to the rear. I used another 1/2 plate for the back and made some brackets to solid mount the QC to the plate. The brackets themselves are made from 1/2 plate and bolt to the 1/2 plate on the frame with 6 9/16 bolts each. These are solid as i can make them i don't think the will fail. I am however still considering running some doth of diagonal brace to limit movement from side loading. Simple is better.

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #20 on: December 17, 2015, 11:04:09 PM »
With the front and rear somewhat sorted and the 1/2 "bulkhead" plates takes in place on the table I started positioning the tubes between them. Starting with the mid tube then the bottom. The mid tube is simple it sits right at the seam on the tank. The bottom tube was a bit more difficult. First it is on a slight incline and at the front needed to come up to follow the curve of the tank. I rolled the tubes long and after measuring and messing with it for hours they were cut where a bend up needed to be made. Once I had the correct angle figured out I had two tubes bent to suit. I sleeved the tube joint and made holes for rosette welds. Those two bars took the better part of a day to get just right.

Oh it might be good to mention that at this point the only things tacked in place are the tubes to the "bulkheads" the front and rear axles are just in place. After all the cage and frame welding is done then I will attach the axles once the twisting from welding is done.

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #21 on: December 17, 2015, 11:12:04 PM »
Next I installed the last two long top tubes and the main hoop. It took some time to make sure I had the required clearances. My friend and I took turns getting in and out with various driving positions to make sure we had it right. Once we were satisfied we had enough room behind the hoop for the mechanical bits and in front for the fleshy bits we made a pattern for the main and front hoops to suit the required clearances. This also set the location for the top tube as the width of the hoop where it meets the tube was unknown until then. When I envisioned doing this I rolled the top tube to match the body and simply rotated it about the center of the body to find the best position. I wanted to keep the main hoop as low as possible and I think we did well.

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #22 on: December 17, 2015, 11:19:49 PM »
After the main hoop was positioned we sorted out the front hoop and started the notching game to fill in the other bits. Apparently I don't always learn from my mistakes and purchased a HF notcher. Total waste. I had to completely rework that thing too and now it works ok. Its good for a first rough cut but I still get better results with a chop saw and a grinder. I am a bit of a perfectionist with these joints. I posted a picture above and I have maintained that quality on them all. It takes a little more time but its with it to save my a** later. Here are some other pictures. Currently I have about 20 more bars to fit and the number drops every weekend.

Offline kiwi belly tank

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Re: Able Dog Belly Tank
« Reply #23 on: December 18, 2015, 01:17:00 AM »
Remember you need to get in & then out of there in a hurry with all your $hit on, that tube right in front of the driver might make that tough. A leg net & swing out steering can make a big difference there.
You probably should feed the driver more, he's as thin as a board! :-D
  Sid.

Offline Rex Schimmer

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Re: Able Dog Belly Tank
« Reply #24 on: December 18, 2015, 05:12:53 PM »
Pickle,
Great start! Love your work table too. Not many tools, especially metal working tools, from HF work with out lots of rework, as you are finding out. Some times it just makes more sense to go to the better tools and save a lot more time for working on the car. Look at this web site for some things that make HF tools work better. http://www.swagoffroad.com/

With both ends being solid mount you do need at least one end that can be adjusted vertically just to be able to get the corner weights close. If you make things pretty square, which it looks like you are doing, the making the required adjustments, which should be small, on one end should work. On the front axle if you are going to weld the axle to the mounts you have shown make sure that you use at least .188 wall or even better .250 wall tubing, min 2 inch OD. Tubing with high cyclic loads, like a solid mount front axle, like to break at the welds.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline Glen

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Re: Able Dog Belly Tank
« Reply #25 on: December 18, 2015, 06:53:47 PM »
Pickle,before you weld in the roll bar and all controls etc. Try everything for your fit complete with fire suit and helmet. That includes arm restraints. This critical and you have to do a bailout for the inspectors. There are several people in your area to help you with any questions.You are going the right directions with your build. :cheers:
Glen
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South West, Utah

Offline Stainless1

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Re: Able Dog Belly Tank
« Reply #26 on: December 19, 2015, 12:54:05 AM »
Sound advice from Glen... the first cross top bar forward of the cage looks really close, maybe pic angle but hang all your parts and dress up before your finish weld.
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline Pickle

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Re: Able Dog Belly Tank
« Reply #27 on: December 19, 2015, 11:40:39 AM »
Yeah we have the same idea. My buddy who is bigger than me can get in and out ok all dressed up. You have to slide your a** forward then sit up and slide back ect. He thinks its fine but I told him try that when your a** is on fire. I was thinking to put two double sheer pins on either side of that tube and hinge the whole assembly up toward the front. I don't want to cut it until I have the steering started so nothing binds. I would just feel better with something solid between the side tubes there, I don't want any weak spots.

Rex, the front tube is indeed 2 inch 1/4 inch wall. I was thinking about a set of brackets to rotate the mounts horizontal and attach to the bottom of the bracket so the axle can be shimmed on both sides for corner weighting. Not sure just how to do that yet, it will come to me.

James

Offline bearingburner

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Re: Able Dog Belly Tank
« Reply #28 on: December 19, 2015, 08:31:04 PM »
I feel you should carefully review your decision to run solid axles. If you run El Mariage I am told that the surface can deteriorate quickly and from what I read Bonneville salt has not been good  for several years. Here in the East those running solid axles complain about the smoothness of the asphalt and concrete runways. If you run some suspension
you can tighten down to solid and then free it up if you need to.

Offline wobblywalrus

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Re: Able Dog Belly Tank
« Reply #29 on: December 20, 2015, 01:54:52 AM »
This is based on experience with designing stuff the highway department maintenance crews welds together.  I have not built a car frame so it is not gospel.  Circumferential welds or gross cross-sectional changes are avoided on critical cantilever members under cyclic loading.  This is engineering talk for axle tubes.  A saddle is welded to the frame and the tube is welded to the saddle.  This reinforces the tube, spreads the loads out, and avoids circumferential welds.