Westfalia T3 with Chevy Bolt drivetrain

72256 Views 174 Replies 26 Participants Last post by remy_martian, Jan 7, 2022

Yabert

Discussion Starter · Oct 12, 2018 (Edited)

2

VW Vanagon T3 with Chevy Bolt drivetrain

Hi

I'm asking myself if DiyEcar is still the best place to put a build thread and to obtain help.
It was the case many years ago when the overvolted forklift motor was the rule, but now?

Well, my plan is to put a 200 hp 60 kWh Bolt drivetrain in a Westfalia... Exciting right?
Yes, but all the electronic and control in the Bolt fear me a bit.
Anyway, I will have the crached Bolt in few days and the West in few weeks.

Let me know if you have advice or help.
Thanks

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101 - 120 of 175 Posts

Yabert

Discussion Starter · #101 · Apr 14, 2019

3

Reid_in_QC said:
if there's anything I can do I'm ready to do favours for the born and unborn EV enthusiasts in your family

For sure, thanks.
Here is the last version of the 3D model for the electric Vanagon.

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Yabert

Discussion Starter · #102 · Apr 14, 2019 (Edited)

3

And now the real stuff.
The battery supports fit well on the battery and under the van.
Also those are the front motor supports. The TIG welder is working very well.

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Yabert

Discussion Starter · #103 · Apr 17, 2019 (Edited)

This post at the page 4 about the shrink fit cv join shaft was wrong: https://www.diyelectriccar.com/forums/showpost.php?p=1027191&postcount=32
The press fit dimensions wasn't good, the stress on the sleeve was to high and the friction coefficient was not fully understand.
Anyway, I redid the calculs and with a friction coefficient between 0.10 and 0.20 a shrink fit assembly would give me a torque transmission capability of around 500-1000 Nm.
As the Bolt max torque per cv shaft is around 1250 Nm I had to search another solution.
http://www.roymech.co.uk/Useful_Tables/Tribology/co_of_frict.htm
http://www.tribology-abc.com/calculators/e3_8.htm

Weld was out of question because for such a low diameter shaft any weld will affect the steel and cause the shaft to be weak.

Conclusion, I ordered two custom shaft EMPI 15 5/8" AXLES 33 SPLINE. 15.625'' is too long as I need 14.375'' long shafts, but I will cut it and rebuild the c-clip groove as the spline are long enought.
After all, I need to cut 5/8'' each side of the shaft. It's not much.

Of course a 14.375'' Vanagon cv joint shaft is not ready to fit to the Bolt transmission, so I have to rework the Bolt output shaft to fit the Vanagon cv joint.

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brian_

· #104 · Apr 17, 2019

Yabert said:
Of course a 14.375'' Vanagon cv joint shaft is not ready to fit to the Bolt transmission, so I have to rework the Bolt output shaft to fit the Vanagon cv joint.

... or buy shafts (presumably custom-made) which are splined for the Vanagon outer CVs on one end and the Bolt inner tripod joints on the other end. Is that a possibility?

Yabert

Discussion Starter · #105 · Apr 20, 2019

brian_ said:
... or buy shafts (presumably custom-made) which are splined for the Vanagon outer CVs on one end and the Bolt inner tripod joints on the other end.

This is of course the ideal solution.
But I don't know were to ask a quote and I bet the price will be massive.

At the moment, I pay 220$ for two shafts and 10$ for two adapters.
Yes, I have some rework and weld to do, but this seem a cheap alternative to have the perfect cv shafts.

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brian_

· #106 · Apr 20, 2019

Yabert said:
This is of course the ideal solution.
But I don't know were to ask a quote and I bet the price will be massive.

Likely. A lot of people get a lot of shafts made with splined ends, so someone might do them at a tolerable cost. But there's no way to know without asking.

Yabert said:
At the moment, I pay 220$ for two shafts and 10$ for two adapters.
Yes, I have some rework and weld to do, but this seem a cheap alternative to have the perfect cv shafts.

So what's the plan? Cut off the cups of the Bolt's inner stub shafts, turn them flat and true (if they were not cut off on a lathe), machine flanges with holes to match the VW CV joints, and weld the flanges to the stub shafts? I assume that the Bolt stub shaft cup bases are not large enough in diameter to match the VW flanges, leading to the need for an added flange; something needs to precisely centre those flanges (perhaps a dowel on the centreline?). If paying someone else for machining and welding, this isn't going to be cheap, either.

Yabert

Discussion Starter · #107 · Apr 21, 2019

brian_ said:
So what's the plan?

You fully understand the plan.
By chance I have access to a lathe and a TIG, so the extra cost is my time.

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brian_

· #108 · Apr 21, 2019 (Edited)

Yabert said:
You fully understand the plan.
By chance I have access to a lathe and a TIG, so the extra cost is my time.

Thanks

The machined locating step looks good.

Once you have worked this out and proven a set, you could have a side business in providing these to other builders. Anyone using a production EV drive unit and adapting to a suspension/axle that uses joints with flanged inner joints could use the same solution.

Reid_in_QC

· #109 · Apr 22, 2019

Yabert said:
You fully understand the plan.
By chance I have access to a lathe and a TIG, so the extra cost is my time.

That looks like a solid good plan to me.

If you need to machine relief for bolt heads into the Bolt stub axle portion (I think I see one in the CAD model), you'll need a dividing head or rotary table on a mill. I just spotted both at a friend's recently. His mill isn't set up yet but I'm sure he'd lend us the accessories if you don't find a better solution elsewhere.

~ reid

Yabert

Discussion Starter · #110 · Apr 22, 2019

Reid_in_QC said:
If you need to machine relief for bolt heads into the Bolt stub axle portion (I think I see one in the CAD model), you'll need a dividing head or rotary table on a mill. I just spotted both at a friend's recently. His mill isn't set up yet but I'm sure he'd lend us the accessories if you don't find a better solution elsewhere.

~ reid

The solution is in fact simpler.
I order laser cut Weldox steel parts with VW bolt pattern (few $$) and I will weld it to the machined Chevy Bolt transmission output shaft.
It's the same solution I used for my Smart 10 years ago and everything is fine today despite the max torque at CV joint is higher on the Smart (1600 Nm in first gear compare to 1250 Nm with the fix ratio of the Bolt)

brian_

· #111 · Apr 22, 2019

Yabert said:
The solution is in fact simpler.
I order laser cut Weldox steel parts with VW bolt pattern (few $$) and I will weld it to the machined Chevy Bolt transmission output shaft.

I assume that Reid understands that, and is referring to the shallow notch on the far outside edge of the machined Bolt cup which is visible in the rendering.

I assumed that this feature is not intentional, but just the remainder of one of the axial grooves which are normally found in tripod joint cups (and are visible in the photo in posts #105 and #50), but it's a good point - the heads of the bolts (or the nuts on them) which hold the VW joint to the custom flange need to clear the material of the Bolt cup.

Yabert said:
It's the same solution I used for my Smart 10 years ago and everything is fine today despite the max torque at CV joint is higher on the Smart (1600 Nm in first gear compare to 1250 Nm with the fix ratio of the Bolt)

I have no doubt that the welded joint can handle the torque.

That welding, and especially with a joint which is not simply circular, does raise the issue of balance. Before welding all of the parts will be rotationally symmetric and balanced. If the weld filler material is not perfectly evenly distributed, the balance will be slightly off. I assume that the plan is to get the completed assemblies balanced... or is the imbalance expected to be too small for that to be an issue?

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Yabert

Discussion Starter · #112 · Apr 23, 2019

In fact, the adapter is tapped with M8 holes. So, no nuts or heads bolt on this side.
It's why I use weldox steel instead of 44W. The yield strength is 700 Mpa instead of 300 Mpa, so the tapped holes will be stronger.

About the welding, I hope the imbalance will be too small for that to be an issue.

brian_

· #113 · Apr 23, 2019

Yabert said:
In fact, the adapter is tapped with M8 holes. So, no nuts or heads bolt on this side.
It's why I use weldox steel instead of 44W. The yield strength is 700 Mpa instead of 300 Mpa, so the tapped holes will be stronger.

About the welding, I hope the imbalance will be too small for that to be an issue.

All worked out, which is what I expected.

The rendering didn't show the threads...

Yabert

Discussion Starter · #114 · Apr 26, 2019

3

Here is the cv shafts. The slide fit of the splines on the female splines of the 1980 cv joint is simply perfect.
Also, you can see the 4x2'' reinforcement beams I added to the Vanagon floor. Really there are too strong/thick for this frame. I used 1/8'' steel (11Ga), but 14 Ga shoulded be enought and reduce the weight as the original VW frame is build from 2mm steel (0.08'').
Next step is to weld in place the battery supports on the frame and the reinforcment tubes (lifted by a jack on the picture).

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CanadaLT28

· #115 · Apr 26, 2019

Yabert said:
Here is the cv shafts. The slide fit of the splines on the female splines of the 1980 cv joint is simply perfect.
Also, you can see the 4x2'' reinforcement beams I added to the Vanagon floor. Really there are too strong/thick for this frame. I used 1/8'' steel (11Ga), but 14 Ga shoulded be enought and reduce the weight as the original VW frame is build from 2mm steel (0.08'').
Next step is to weld in place the battery supports on the frame and the reinforcment tubes (lifted by a jack on the picture).

Looks like we are going through the same process. I am making new rails of 11g CRS (200mm web) C channels to make room for the 4 Volt packs side by side. It's interesting to see your work. What is the outer dimensions of the Bolt pack?

Yabert

Discussion Starter · #116 · Apr 29, 2019

CanadaLT28 said:
It's interesting to see your work. What is the outer dimensions of the Bolt pack?

Here are the rough dimensions of the Chevy Bolt 60 kWh battery.

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Yabert

Discussion Starter · #117 · May 1, 2019

Open question for all: What is the best OBD2 PIDs to have access to chevy Bolt details like min/max cell V, cells temps, charge power, electronic temps, and others?

Yabert

Discussion Starter · #118 · May 7, 2019

I've putted the motor of the Bolt in place in the Vanagon prior to finish the welding of the rubber mount motor supports.
There is two front supports and one in the back of the motor.

Things are going to be exciting now as I've welded most of the supports for the battery / powertrain.
The plan is to assemble everything and have the first wheels spin in fews weeks.

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bilbo

· #119 · May 8, 2019

Yabert said:
Open question for all: What is the best OBD2 PIDs to have access to chevy Bolt details like min/max cell V, cells temps, charge power, electronic temps, and others?

This thread contains contains a link to a google spreadsheet with all the PIDs you are probably interested in.

Yabert

Discussion Starter · #120 · May 8, 2019

2

Thanks bilbo!

Here is the link between the chevrolet Bolt spline of the gearbox and the 6 holes flange of the VW cv axles.
So the link between VW and Chevy!

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