'28 A Modified/Trayless RPU - first build

Just catching up with where you're at, Owen. Got some wierd deja vu feelings going on.

Just wondering with your ladder bars, they look like they will run right through your lower back. i.e. where you want to be sitting. What's the go there?

Pete

 

I use my Mini to haul a lot of stuff too. I got a roof rack, You should see the people look at me like I'm crazy for hauling things on the roof. That's fine with me I don't really care what they think............

Nice looking project...

 

Hey Pete, the lower bar sits level with the bottom of the chassis at ride height with the cross member fitted up. If I have my seats about the same height as yours there will be plenty of room for travel.

I should probably get a roof rack for my mini.

 

Bit of progress, got my cross member in and got a few more final welds done on the frame. Laser cut parts aren't in til monday but trying to score a day off next week to get some things done.

 

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any more progress?

 

Hey Zombie, little bit of progress - have been busy with other stuff but back on it again now.

Got my laser cut kick up parts so started on the rear rails last night.
also got my boxing plates so things should start motoring along.

 

Ohhh how I dont miss welding up my rear clip and cleaning up all my welds. Looks good

 

Got the kick up and rear x member setup and mostly welded in.
Boxing it up tonight (once again overestimated how much I'd get done in a session)

 

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As a suggestion... When building a boxed section, such as boxing stock c- channel style frames, or fabricated frame rails from scratch, a stronger end result can be obtained by setting the inner frame member inside the rail and using fillet welds, such as shown below.

 

hey lakesroadster, I wanted the end result to be able to be ground smooth.
the outer C I built by a full length fillet on the inside, then both web panels are welded by doing a v prep on the edges so the weld penetrates the full thickness of the joint (if that makes any sense)

I do agree that the method you've illustrated is a very strong way to to it.

 

Lamb,

And that will likely work just fine. Most folks lack the skill to weld an open root and get a smooth full penetration weld. They either blow through and get dingleberries, or get incomplete penetration, both of which are problematic on a cyclically stressed structural member. At the fab. shop I work at, guys weld open root all day long. On bigger vessels where you can actually see inside of them you'de swear the inside surface was welded, but it was all done from the outside. Impressive stuff.

Also worth noting is that a properly made weld is stronger if it isn't ground smooth. The grinding process adds residual stresses.

My problem is at my day job my role is to review and inspect this kind of stuff. Is it absolutely needed on a Hot Rod, nope. Does it produce better results.. yep, at least from from a strength perspective.

Thanks for taking my comment as a helpful hint and not as criticism.

Awesome build you have going there. Looking forward to updates.

John

 

Hey John,

I am not the best as far as weld presentation goes. The plan is to over-engineer the chassis for what it's required to do because of 2 factors - 1) It's the first one I've ever built, 2) I'm not a professional welder.

I work at material handling equipment design and manufacturing company (engineering desk job rather than on the tools though - bridge/gantry/davit cranes, hoists, take-up winches, lifting beams etc) so get to see some pretty impressive welding taking place and appreciate the skill that it takes. Due to my job I guess I know a fair bit about the paperwork side of welded joints (design/procedure/selection).

The plan is for minimal grinding, I will give the outer weld a smooth finish (to match the existing rail) - as there is a fillet on the inside of the box and the fill weld on the outside it should be pretty well strong enough, however the inner boxing plates will just get tidied up so they look decent, not necessarily ground smooth.

Thanks for taking the time to check out my build.

-Owen-

 

got the boxing plates for the rear half of the chassis in last night finally and drilled the new ladder bar brackets I got laser cut (they have a flat section to the back which the shock mount will be welded to). Going to box the front and make the x bars tomorrow (fingers crossed)

 

looks pretty good so far

 

I like this when you posted up on our local forum. I wondered what happened with the project. Glad its moving forward. Nice job and looking cool.

Mark Shearer

 

While we are on the welding subject. It's a bit late for you, Owen, but I positioned my frame sections inner corner to inner corner. Then welded a fillet weld into the resulting 90 deg channel. It made it very easy to get good penetration and required very little grinding to end up with a nice radius to match the original rail sections.

I like the look of your rear frame step. Nice and smooth.

Pete

 

Cheers Guys,

Hey Pete, I think I'll be doing the front of the frame that way, I did the boxing of the original section of the rear end that way and it worked really well.

Did you take any pics of your clutch linkage?

 

I made a custom fork that comes out on the RHS of the bellhousing. The push rod from the pedal works directly on that. Doesn't get much simpler. I just went the long way to get to that point.

 

once again didn't get as much done as I thought I would.
chassis is mostly boxed now, just need to flip it over and weld up the bits I couldn't get to from the top, pretty pleased with how it's going so far.
I started making the sections up for the rear K, hole saw is a slow thing (should have probably bought a bigger drill press)

 

bit of progress, few quotes at work so long days but snuck in a few hours after work
changed my plan with the x member (I wanted to be able to run a 12" glass pack - wouldn't have fitted with the RHS idea), I'll add some more tubes once I have the suspension and pedals fitted up. Chassis is out of the jig finally, I welded in some cross braces prior to taking it out so hopefully it doesn't shift too much while I'm finishing attaching the boxing plates. I have a fair bit of cleaning up to do with the welds etc.. Planning on getting the rear end fitted up by the end of the weekend and maybe starting on the front and dummying up the engine.

 

got some more done saturday.
dismantled the jig and cleaned up shop (there goes half a day)
Finished welding up a few corners on the chassis and boxed the part underneath the front x-member, I bent the back edge of the chassis down in between the sides of the x member to lock it all in and create a tiny bit more clearance.
got my ladder bar brackets onto the diff and adjusted my spring brackets a little (had them at 0 degrees pinion angle before , now it's +3 to match the engine.
dropped the engine and box in to see what needs doing, she's definately not a compact lump of iron.
also shortened my ladder bars a touch and re-tapped them (5/8" threading gives my little arms a work out), drilled my bones out to fit the machined bosses.
sat in the drivers spot and made car noises and drank scotch.
should be able to make the clutch pedal go straight into the bell housing (striper did his this way apparently)

 

made up the trans mount last night from some scrap angle iron... then got side tracked before I finished the engine mounts....
talked to Chris Casny (fellow hamb'er) who has 322'd an A to get my engine placement right (leaving enough space for a fan and radiator) - added about 3/4" to his spacing as I'm a bit of a hack so wanted to be doubley sure about fitting everything in.

I'm considering attaching my split bones to the top of the rails to get my 7 degrees in the front.
mocked up the front end and started making a new headlight bar using the original (had a big bend in the middle) , it's about 2" wider than stock width between mounts.
Measuring the body up it looks like I'm going to have to de-crown? the grill shell at the top to get everything sitting right and still being able to fit a radiator in (ie not chopping the overall height of the shell any more).

 

Ah! Found you..

Now that I have a better idea of what you're shooting for, I like it even more. Consider me subscribed.

 

I gotta say, I really like what you're doing here!
You have a great eye and imagination.
The frame flows just beautiful and all parts seem to just meld together as intended.
BEST part for me is that it still has that "home fabbed" vibe to it...that human element that gets lost when stuff is over precise and anal.

This is just one of those damn good builds that I love the HAMB for!!!

 

Thanks for the kind words gents.
Hackerbilt: cheers, I'm trying to keep it smooth and well executed visually but still retain the rawness. Very much home built - I definately lack the skills of some of hambs well known favourites, their work is amazing.

not much weekend progress, just a start to the floor subframe.
ladder bars are a bit of a pain to work around, I'll have to do something fancy for the seat base for clearance while keeping it low.
will hopefully start on the body frame during the week. ordering some more bits and pieces so I can make progress with most things.

 

Hey good work man, love the rails.

 

Hi Owen, looking good so far mate.

Cheers
Steve

 

got a tank, promise I'm trying not to copy striper pete too much...

 

You're zipping right along, Owen. Love the tank.

Don