540i Swapped Rat rod Build thread

[ThatRatRodProject]

Quick update. with some actual fab work being done.

The past couple weeks I have been putting in some hours gettin some of the front frame done. I’m gonna attach some photos if you have any questions let me know. I’ll try to explain. 

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[ThatRatRodProject]

87C94C13-2CBA-459A-B93C-C9D60E18578E.MOV

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• 87C94C13-2CBA-459A-B93C-C9D60E18578E.MOV

[RobZR]

ThatRatRodProject said:

I would not recommend using a stripper bolt in this manner. They are not intended to handle lateral forces and have a inherent stress riser at the base of the thread that is prone to failure.

Ideally you would support both sides of the pivot point from the subframe.  if you must support it from one side a spool and bolt design will bend before failure, since it keeps the bolt in tension.

[ThatRatRodProject]

RobZR said:

I would not recommend using a stripper bolt in this manner. They are not intended to handle lateral forces and have a inherent stress riser at the base of the thread that is prone to failure.

Ideally you would support both sides of the pivot point from the subframe.  if you must support it from one side a spool and bolt design will bend before failure, since it keeps the bolt in tension.

I 100% agree with you. If you are using a Harden alloy shoulder bolt. But with that being said I will be mostly turning up a custom shoulder bolt . But any side load should be transferred to linear load with the thrust bearings. Not 100% transferred but lessened a great deal. I’m not saying you wrong in anyway and I will take any input I can.

[Jdesign]

CAD to Metal overnight. I like your fast pace.

What did you use to cut the parts? Waterjet?

[ThatRatRodProject]

Jdesign said:

CAD to Metal overnight. I like your fast pace.

What did you use to cut the parts? Waterjet?

I work In a Tool Shop so i May have utilized Our CNC Laser.

I did have some of this work done Prior to posting the cad up date. 

Its been after hours progress the past 2 weeks . I have 3 of the 4 Control Arms done. So you should see up-dates later this week.

Attachments:

• 982107D5-5A86-4410-A3D0-1E57EAA905F1.jpeg

[ThatRatRodProject]

Update. 

I gotta finish welding up the last control arm but here’s 3 of them. 

I used 3d printed jigs to replicate the tube lengths and made up a quick fixture. 

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• AD34B246-ADD6-4A4C-8B34-FB7E0FD25502.MP4

[Jdesign]

Chugga chugga. I cant wait to see the whole assembly!

[ThatRatRodProject]

Jdesign said:

Chugga chugga. I cant wait to see the whole assembly!

I got a lot of welding to do on the subframes but hopefully soon. My ball joints are on back order sadly.

[ThatRatRodProject]

All 4 done and ready to go. They will be powder coated in the future but first I gotta get some mock-up done. 

[ThatRatRodProject]

RobZR said:

With some help from RobZR. I believe we have reached a much safer option from using a shoulder bolt. I made up this spindle design last night. This will have a castle nut and cotter pin in its end form. I did tighten it all down and I’m very pleased with how it turned out. zero play. 

[B C]

Great work man! You may also consider using oil impregnated solid thrust washers instead of roller bearing thrust washers if the loads are low enough and you want to improve environmental protection.

The castle nut is a great idea

[ThatRatRodProject]

B C said:

Great work man! You may also consider using oil impregnated solid thrust washers instead of roller bearing thrust washers if the loads are low enough and you want to improve environmental protection.

The castle nut is a great idea

I would like to possible try 3d Printing some bushings for weather protection. Out of some soft filament. Or Nylon

[ThatRatRodProject]

Quick up date. 

Got some of my hardware to assemble my front end just waiting on ball joints and got a finish up some welding

[ThatRatRodProject]

Happy thanksgiving update. This is gonna be a Picture update. Photos might not all be in order. 

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• IMG_1238.MOV
• IMG_1253.MP4
• IMG_1259.MOV

[ThatRatRodProject]

Pulled the frame out from underneath the car and worked on getting the front end mounted to the frame. Holiday week is letting me get some shop time in. I’m just waiting on the rear wheels  From basset racing. and then I will have everything to make it a roller. Glad to see all me card board templates and napkin drawings are working out. 

[ThatRatRodProject]

Today’s progress flipped the frame back over and set the body back on. Dropped the motor in and line up the drive line components. 

Up next motor mounts and rear sub frame modification. I have to finish weld the the front subframe. And waiting on rear wheel from bassets racing.  So I can start string lining gauging for. Rear sub Frame mounts.

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Attachments:

• IMG_1269.MP4

[ThatRatRodProject]

Sunday progress motor mounts done (wil have small pad between mounts. Next up is transmission mounts should be easy lots of room. Then to the rear subframe where heavy modifying will need to happen.

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• IMG_1275.MP4
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