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PostPosted: December 12, 2019, 3:00 am 
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Not sure if anyone is reading this, but I'll continue posting!

I've managed to source a 1946 Ford chassis (possibly a 3/4 tonne truck chassis) to move forward with the project. I'm hoping it will arrive by the end of next week.

The chassis is WAY longer than I would like, I think it's about a 112" wheelbase originally, but I should be able to mount the subframes a bit more inboard than the original axles giving closer to a 100" wheelbase. The Jeep body design will be a little stretched to make the proportions look vaguely right, but T-buckets also seem to work with the body being miniature on a long-ish chassis so... I'm going with it!

I started to lathe the subframe locating pins yesterday and should be able to complete all the subframe mounting brackets before the chassis arrives. Then it's just a matter of boxing the chassis, welding the brackets on and I'll be rolling in no-time! :P Using a single donor with IRS subframes certainly makes getting to that point easier.


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PostPosted: December 12, 2019, 7:33 am 
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This is a builders forum. There will be more interest when you start building. :cheers:

It is unfortunate the loops you have to jump through to do anything down-under but at least the loops exist.

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PostPosted: December 19, 2019, 4:11 am 
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Miatav8,MstrASE,A&P,F wrote:
This is a builders forum. There will be more interest when you start building. :cheers:

It is unfortunate the loops you have to jump through to do anything down-under but at least the loops exist.

That... is a very fair point :lol:

I downloaded a picture of the chassis I've bought:

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And also started building...

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... alright so it's not the most amazing part, just a locating stub for the rear subframe, but it's a big mental step. I'm now officially building a car! :lol: I think I'll be able to pick up the chassis on Monday and I'm planning on spending this Sunday cutting out a few aluminium panels.


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PostPosted: December 19, 2019, 6:06 pm 
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Wow, minimal rust for the age. Probably take some tweaking to perfectly square it up before hanging the new bits.

Did the oem use a large cupped washer to limit subframe travel on the rubber mounts?
Will you square up the subframe based on the hubs or the mounts?

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PostPosted: December 28, 2019, 6:40 am 
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Miatav8,MstrASE,A&P,F wrote:
Wow, minimal rust for the age. Probably take some tweaking to perfectly square it up before hanging the new bits.

Did the oem use a large cupped washer to limit subframe travel on the rubber mounts?
Will you square up the subframe based on the hubs or the mounts?

Yeah I was very surprised! There's a couple of places where someone has cut and welded the chassis but they're all pretty minor. Easily fixed :)
The OEM setup - I believe - is to restrain the subframe in the event of the rubber mounts failing.
I was planning on using the subframe mounts to square it up, just because that removes any camber/castor adjustment from messing with the setup.

I started work on the chassis today. Here it is at the start:

Image

Then I unbolted all the brackets I could

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Someone has welded a few brackets and plates onto the chassis so these had to go

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I was worried that ^ was a rust repair patch but underneath the chassis looks perfect so... no idea.

Ground off a bunch of rivets

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Added to the pile of unnecessary parts

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Starting to look a bit cleaner

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Then I cut out the centre crossmember for boxing the chassis rails

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And finally set it down on the front subframe to get an idea of the attachment brackets

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Tomorrow I'll be plug welding up all the holes and boxing the chassis with 4mm steel plate (per the engineers recommendation). If there's time I'll also start on the subframe mounting. I'm hoping to have a rolling chassis by the 6th when I go back to work.


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PostPosted: January 1, 2020, 4:13 am 
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Little bit more progress to report: I've made the boxing plates for the chassis.

Image

Image

Image

I used a plasma cutter to cut out the rough shape

Image

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Then clamped it in place and ground it flush with the rails

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In hindsight I would have removed all of the original boxing at each end of the chassis, rather than filling it all the holes and welding it together. There would definitely be less work in making a single plate than the multiple circular ones. Ah well, live and learn.

Image

I've done both sides and all the circular pieces, they just need a weld prep ground into them and to debur the edges.

Tomorrow I'm hoping to have the chassis fully boxed and ready to attach subframes, then I have 2 days in which to attach the subframes to get it rolling by my self-imposed deadline. Wish me luck!


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PostPosted: January 1, 2020, 7:31 am 
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Looks good. When cutting out patches, I line up the pattern edge with the edge of the material (I know, curved, but as best you can), so there will be a larger scrap left over to use for the next patch without going to a new sheet or using multiple scraps to fill. I cut slightly undersize so the patch is two sheet thicknesses smaller than the outside dims of where it is going. This leaves you with a nice inside corner to fill with weld and less smoothing required with more welded area. Ultimately it is less cutting, less welding, less waste. Drain holes are a good idea if the ends are left open. I’d drill 3/8” holes every couple feet along the center of the bottom face. This also provides good access to rustproof the inside when it is done.

A hand held bandsaw with a 14tpi blade is a great backup for a plasma torch and also good fine trimming without using an angle grinder to make noise, sparks, and dust.

If you are not going to build a jig, consider stitch/tack the boxing and everything else going into it before fully welding so it won’t warp as bad. Just final weld now the areas where you won’t have access when the crossmembers are in place.

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PostPosted: January 5, 2020, 5:47 am 
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Miatav8,MstrASE,A&P,F wrote:
Looks good. When cutting out patches, I line up the pattern edge with the edge of the material (I know, curved, but as best you can), so there will be a larger scrap left over to use for the next patch without going to a new sheet or using multiple scraps to fill. I cut slightly undersize so the patch is two sheet thicknesses smaller than the outside dims of where it is going. This leaves you with a nice inside corner to fill with weld and less smoothing required with more welded area. Ultimately it is less cutting, less welding, less waste. Drain holes are a good idea if the ends are left open. I’d drill 3/8” holes every couple feet along the center of the bottom face. This also provides good access to rustproof the inside when it is done.

A hand held bandsaw with a 14tpi blade is a great backup for a plasma torch and also good fine trimming without using an angle grinder to make noise, sparks, and dust.

If you are not going to build a jig, consider stitch/tack the boxing and everything else going into it before fully welding so it won’t warp as bad. Just final weld now the areas where you won’t have access when the crossmembers are in place.

Thanks mate, some good info there. I've wanted to get one of those portable bandsaws for a while but I'm stuck with noisy, sparking angle grinders for the moment.

As far as boxing the chassis I agree an outside corner weld is the best way to do it, but the guidelines I need to follow specify either internal or external boxing as in this screen cap
Image

So I've ground a bevel into the edge of the plate and gone external

I also made some plates to fill in the existing holes in the reinforcement

Image

I'll be seam welding the existing panel as well as the new boxing plates to seal up the side rails and prevent rust.

Roughly sat it on the subframes to get an idea of how it will fit

Image

Image

The rear is higher than it will be in the final setup.

To line up the subframes I ran a stringline between the crossmembers, making sure it was mid-way between the rails at each end. I also clamped an piece of SHS perpendicular to the stringline so I can make sure the subframes are parallel.

Image

Finally I made a couple of plates to attach the rear bolts of the front subframe; the smaller plates are just spacers.

Image

I didn't manage to get it rolling by the 6th, but I've got the front subframe located perfectly and all the mounting brackets (for front AND rear subframes) cut to size. All I need to do now is to drill them, weld them to the chassis and it's rolling! I've got a couple of evenings this week and a day next weekend to work on it, and providing I can source some thicker 50x50 SHS I think I'll have it on wheels by then.


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PostPosted: January 5, 2020, 9:43 am 
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Nice shop. Some water will get in no matter what so you may want a few drains so it can get out. Don't know that this will ever get wet except for washing though and occasional puddle.

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PostPosted: January 11, 2020, 9:17 pm 
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Miatav8,MstrASE,A&P,F wrote:
Nice shop. Some water will get in no matter what so you may want a few drains so it can get out. Don't know that this will ever get wet except for washing though and occasional puddle.

Thanks mate, and I'm thinking you may be right about the water. I'll try not to drive it the rain (no roof, windscreen, etc.) but other than that it's going to be my daily drive. Do most people just spray heaps of fish oil in the chassis every 6 months or so? I *REALLY* want this to last a long time so I'll be having the chassis thermal arc-sprayed on the outside, which is sort of like galvanizing but won't warp the chassis.

I suppose worst case if parts of the frame rust out in 15 years I can always replace it with standard rectangular tubing.

I've tacked in 6 out of 10 subframe mounts, and the rest of them won't take long to finish this week after work. Once that's done I'll set the engine where I want it, put the center crossmember back in and I'll be ready to fully weld up the frame. That is a major milestone that I'm really looking forward to finishing, so I can make a start on the bodywork and get it actually looking like a car.


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PostPosted: January 12, 2020, 11:43 am 
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Linseed oil straight (traditional light aircraft frame internal coating) or mix "waxoil' or "waxoyl" after it is done and painted. Tape holes, then pour an excessive amount into the open end then rotate, tilt, flip, etc to get it coating every corner inside. You find areas you though were totally sealed but no big deal. Makes quite a mess but it is cheap. Another alternative is to use commercial products with a long hose and garden pump sprayer, fitted with a special tip that sprays radially. Run it all the way into the rails then pull it out as it sprays to coat everything.

Low cost Waxoyl recipes:
1) two toilet to floor sealing rings dissolved in one gallon of mineral spirits. Add one quart of non-detergent engine oil. Adjust amount of spirits for desired consistency.
2) Some use turpentine instead of mineral spirits.
3) 12 oz bees wax dissolved in 2.5 quarts of turpentine. Add 1 quart light machine oil.


viewtopic.php?f=39&t=14537&p=154672&hilit=waxoyl#p154672

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PostPosted: January 15, 2020, 4:46 am 
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Miatav8,MstrASE,A&P,F wrote:
Linseed oil straight (traditional light aircraft frame internal coating) or mix "waxoil' or "waxoyl" after it is done and painted. Tape holes, then pour an excessive amount into the open end then rotate, tilt, flip, etc to get it coating every corner inside. You find areas you though were totally sealed but no big deal. Makes quite a mess but it is cheap. Another alternative is to use commercial products with a long hose and garden pump sprayer, fitted with a special tip that sprays radially. Run it all the way into the rails then pull it out as it sprays to coat everything.

Low cost Waxoyl recipes:
1) two toilet to floor sealing rings dissolved in one gallon of mineral spirits. Add one quart of non-detergent engine oil. Adjust amount of spirits for desired consistency.
2) Some use turpentine instead of mineral spirits.
3) 12 oz bees wax dissolved in 2.5 quarts of turpentine. Add 1 quart light machine oil.


https://www.locostusa.com/forums/viewto ... yl#p154672

Cheers mate, I like the sound of that! I'd be pretty confident it wouldn't rust out of I did that every 5 years or so, as well as have the outside of the chassis galvanized (well, thermal arc sprayed which is essentially the same thing)

Over the past week I made the front most mounts for the front subframe (no pics) and attached the rear mounts for the front subframe with some 50x50x5 tubing I picked up (super overkill, but it was that or 50x50x1.6 which I wasn't confident in)

Image

I finished off the front mounts for the rear subframe

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Image

The rear subframe rear mounts are also done but I didn't get a picture. They use the 50x50x5 SHS down from the original rear crossmember to a 6mm plate which the original mounts bolt onto.

Finally today I put the engine roughly in place so I can locate the center crossmember

Image

Image

It sits a little further forward than this photo suggests, but it's pretty close

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By placing the center crossmember in backwards, there is a lot more room available for the engine and gearbox

Image

Image

Image

I'll need to trim the forward pieces, and angle the rearward pieces more towards the outside of the chassis, but it looks like it will work perfectly!

A slight issue is I assumed the engine/gearbox would sit perfectly level, so I set the pinion angle to be perpendicular to the ground. Now I find out the engine and box actually tilt backwards slightly so I have to find a way of angling the diff up slightly. The easiest option, i believe, will be to take a small amount off the top of the front diff bushes, causing the diff to tilt upwards slightly. I only need a couple of degrees.

Anyway, let me know what you think!


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PostPosted: January 15, 2020, 8:35 am 
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I set the pinion angle to be perpendicular to the ground. Now I find out the engine and box actually tilt backwards slightly so I have to find a way of angling the diff up slightly.
Mornin' -- If I remember correctly, there is supposed to be a bit of an angle between output shaft, drive shaft (or "prop shaft" to you?) and the diff. A few degrees, either L-to-R or in the vertical plane. So, you may not need to alter that angle you mentioned. Check my info, by all means, but I'm pretty sure that I remember that bit correctly.

:cheers:
JDK

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PostPosted: January 15, 2020, 6:05 pm 
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Looking great! I love that crossmember. :cheers:

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PostPosted: January 15, 2020, 6:39 pm 
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Since the front subframe is aluminum, to ensure bolting down the sub doesn't stress and possibly crack it, you might try a different technique for this part. Instead of the 50x50, I'd use that sheet of what looks like 3-4mm plate used for boxing the frame and CAD (cardboard aided design).

I'd cut a strip of cardboard about 50 wide, long enough to cover the flats around the bolt holes in the front xmember plus 75mm, probably about 320mm in all, then thumb over the bolt holes to transfer the hole location to the paper, cut out the holes with a hole punch set and hammer, drop in the bolts to hold it in place, then bend the front edge (extra 75mm) to mark the pattern for the front bend. Transfer to metal, bolt it down tight to the aluminum, tack the nuts to the top of the plate, then tack the strip to the frame. It will take several pieces to fill each side since it doesn't line up with the rail but it will look very clean when done.

To make room for headers, use a similar technique at 2nd xmember.

I'll draw a pic of what I'm talking about.

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