# Modifying car steel rims on a lathe



## GoceKU (Apr 19, 2018)

I've been asked to modify an space saver spare tire to fit vertically in the trunk of a sedan, there was couple of difficulties, first of which the car has big brakes so i have to use 15" rim. And there aren't any rims in the correct bolt pattern. so i did some research and come up many failed re drilled rims, after considering this is a spare tire for very limited use the strongest solution was to cut the middle of it and one from a rim with the right bolt pattern and join them, so you can see the flanges i made earlier and my setup using hand ground HSS parting tool, the charter was incredibly loud so i slow down my lathe to 16 RPM and that did the trick for the second rim i angle grind the centre in between the vent holes. Then i had to finish the second flange to accept this centre and from there i did almost the same machining except i left about 1mm edge so they can locate one in other, i'll tack weld it then check it if all alright then fully weld it both sides.


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## Ray C (Apr 19, 2018)

You must have a pretty big lathe!


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## brino (Apr 19, 2018)

Nice job. "watching"
-brino


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## GoceKU (Apr 19, 2018)

Ray C said:


> You must have a pretty big lathe!



Not too big, but proper industrial machine.


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## tjb (Apr 19, 2018)

Interesting.  Keep us posted.  Can you share what this is going in?

Regards,
Terry


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## GoceKU (Apr 19, 2018)

tjb said:


> Can you share what this is going in?



It's going vertically to the side of the trunk, on a Ford Mondeo MK3, the space for the spare tire is already taken by a LPG fuel tank.


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## tjb (Apr 19, 2018)

GoceKU said:


> It's going vertically to the side of the trunk, on a Ford Mondeo MK3, the space for the spare tire is already taken by a LPG fuel tank.


Thanks.  Would love to see some follow-up photos as you proceed.

Regards,
Terry


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## GoceKU (Apr 21, 2018)

This project is close to the timeline i've set for myself so is getting all my free time, that said i tack weld the rim on couple of spots then mounted it on the lathe check it it has little runout less than 1mm, then i testfit it on the car, sorry no pictures of those steps but the offset is good and is clearing the brakes with millimeters to spare, for full welding i took it to a friend's shop he recently bought an industrial pulse mig welder, so this was a good candidate to test it. He welded both sides in less than 5 minutes, he did some side to side welding to avoid distortion but i will mount it again on my lathe and check it, the weld shrunk down in the channel i cut for full penetration nicely i'll probably just hit the highest spots with a flapper disc, the good thing of welding with pulse mig is full penetration without putting extra heat so no peeling paint.


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## brino (Apr 21, 2018)

Nice Results!
It looks like your friend has already had some practice with pulse MIG.
-brino


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## GoceKU (Apr 22, 2018)

brino said:


> It looks like your friend has already had some practice with pulse MIG.



Yea he is a pro at welding, i just finished painting the rim with black primer, should have the tire mounted tomorrow or next day if the tire store is opened when i finish from work.


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## GoceKU (Apr 23, 2018)

Here is the rim in black, i'll take it to the tire shop to have the tire mounted and balanced to see how good i did.


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## GoceKU (Apr 24, 2018)

I got the tire mounted and surprising showed 0-0 on the balancer, perfectly balanced i asked the guy how is this possible, he thinks is so small and narrow is acting like a flywheel by looking it when is turning looks straight. When it come time to mount it in the trunk of the mondeo, surprise surprise won't fit i had to let some air from the tire to put it in the opening to the side. This means the tire will be flat, so i'll have to put an small 12v air compressor, Otherwise looks and fits nicely.


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## tjb (Apr 24, 2018)

Nice work.  Is there any way to open up and re-fabricate the wheel well from underneath to allow more room?

Regards,
Terry


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## GoceKU (Apr 25, 2018)

I was thinking just to grab a rubber hammer and hammer out the trunk floor but this being a Ford, spot weld will fail first or all the paint will peel not something i want to deal with, if this was a french car i will have used a hammer without any fear.


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