21 replies to this topic

[mick_in_oz]

Just finished another project on the Hatch.

 

Had been thinking about power steer for a long time, but as everyone knows there are very few suitable donors available, plus I didn't want to clutter up the engine bay any more, EFI, Air Con and an electric vac pump for the brakes have done a good job of keeping me from adding anything more under the bonnet.

 

So, enter the thought of an EPAS conversion. After some reading it looked as though a Vauxhall Corsa C (XC Barina) column would be cheap, available, and a good candidate with all of the info available in the web.

 

The conversion entailed moving the motor from left to right to be able to get it under the dash, grafting the lower outer tube, and upper sections onto the new column. I have made a point of maintaining all or a bit more of the amount of collapsibility that was built into the Vauxhall column, there are separate sliding sections upper and lower as the central drive unit has to be securely mounted to the dash frame as it has to contend with torque from the power assist motor.

 

Also needed was a road speed input signal as the Vauxhall column changes the amount of assist in relation to road speed when given the correct speed input signal.

 

I might just throw up a handful of pictures and add a a few notes here and there as needed.

 

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[mick_in_oz]

Some more pics.

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[mick_in_oz]

And some more...

Last few.

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[mick_in_oz]

The road speed trigger wheel has been made with 32 teeth, the Vauxhall originally is 29 teeth, the difference is due to the larger dia tyres I'm using, this keeps the column's original assist in relation to road speed characteristics about the same.

 

The coupling between the column output shaft and the Torana output shaft I chose to make a simple keyed coupler as I couldn't find a suitable one off the shelf, and cutting the fine spline originally on the Vauxhall column wasn't a challenge I was keen on at the time.

 

The upper shaft sections are simply pressed together and held with roll pins.

 

The last few pics are of how obtrusive or unobtrusive it appears in the car, its easy enough to see if you go looking for it, but being painted black wrinkle it does tend to disappear if you are not looking for it.

 

End result, it almost feels wrong in the driveway being able to so easily do a three point turn to get it out ready for a drive, the steering feels as good as it used to, direct etc, but without the extra input needed at a round about or parking, the assist level change is seamless and you don't know its happened. I've not had it at speed yet but I really like the idea of it having less assist as things get quicker.

[Lc69]

Very impressive work

[UC308Hatch]

Awesome job well done


Sent from my iPhone using Tapatalk

[mick_in_oz]

I have something to resolve with the EPS, I think the issue lies with the torque/torsion coupler, its a kind of spring loaded wedge, and as you apply load it moves a grooved collar that provides a variable resistance to the control unit to adjust the amount of assist needed.

 

I find that sometimes the steering won't self centre as good as it should, but I have seen reports of the torque coupler getting stiff and doing the same as I have.

 

Another thought was the lubrication I used on the drive gear and worm assy, as I cleaned it all off to relube before assembly but then found no lubricant manufacturer could provide me with a specification for this area. I've gotten some 99% pure Teflon grease to put on the assembly and will try the same in the torque coupler.

 

All of that said, I really like how it drives, its great in the shed and driveway, and around town and through round-a-bouts, and at speed it feels nice as far as the level of assist goes, pretty much like a modern car, and there is no hint of it changing the amount of assist offered while driving.

 

I'll get the lube job done on it and report back, but not gonna be for a bit, always a million jobs on around here.

 

Any questions please ask!

 

Cheers, Mick.

Edited by mick_in_oz, 16 July 2018 - 07:35 PM.

[myss427]

So when are you offering them as kits and how much?

[ozyozyozy]

Nice work mate.
Caster angle also affects self centering, if you dont have any they dont self centre.

[mick_in_oz]

Caster, its got a fair bit, has a heap out of the A pillar where they always touch, about 2" from memory, and UC upper arms. From memory its 3.5Deg or more. I actually want to do some modified lower bushes with an eccentric to gain a little more.

 

As for kits, it was a passing thought, and I'm probably not against such an idea, its more a case of time. I might ponder that one for a bit and let you all know at a later date.

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[ozyozyozy]

3.5 caster is good on a standard setup, well good but not not good, hard to get much more without modifying.

[mick_in_oz]

Hi John,

 

1 and 2- I used a 2002 Barina column. I referenced the Vauxhall column as that is what most of the info on the internet refers to. I cut up the main housing as the motor was in an unsuitable position. Ideally you'd find a left hand drive column or motor housing, these are available but like hens teeth and need to be imported. I actually found someone with them available new but it was too much money for me.

 

If you put the column in as it comes out of the Barina the motor sits too far to the left and fouls on the park brake and I think maybe also the console (or maybe it meant I couldn't easily operate the park brake), if you rotate it and put the motor to the right it ends up high on the drivers side and fouls on lots of stuff, so I decided it needed to be a mirror image so that I had a low mounted motor but on the right side of the column. So I cut the motor mounting flange off and put it on the other side, I made sure I maintained the correct relationship between the pinion/worm and motor mounting face. The layout of the area lets you simply turn the pinion/worm end for end and rearrange the bearings and it all fits back together easily. I added a spacer in between the housing and the motor mount when I welded it back together to allow for the changes and to be able to remachine the motor mounting face back to true. From memory I only used 6mm material, but also machined a couple of spigots to have the parts self align.

 

3- Nope, the motor shaft is standard, as is the Pinion/worm. Where these two meet is via a fine spline, male on the pinion, female on the motor, maybe only 10mm-12mm dia and the pinion has rubber shock absorters each end and this lets the Pinion move in and out of the motor coupling without anything bottoming out or binding.

 

4- The road speed trigger wheel sits inside the disc, I have HQ Drum Spindles with R32 4-spot calipers on custom brackets with UPC hubs and VT Commo discs. I don't have a pic with the wheel on, but can grab one if you like. There is about 10mm of the nose of the sensor sticking out past the caliper bracket. The UPC hubs already had the parallel dia and shoulder on them so I made sure my trigger wheel fitted without modification. All of this is done at home by myself.

 

5- The DC Input and the additional signal input connectors and wiring came from a wrecker, I called them up and they said yup no worries we'll just cut em out. The wiring for the trigger wheel sensor I made up myself (electronics tech by trade and jack of all trades).

 

If you want a bit more info, extra pics, I can add them to drop box or a google drive or some such thing and you or anyone else can see all the pics, good and bad, let me know if you want the extra info.

 

If I missed anything say the word and I'll try to clear it up a bit more for you.

 

Cheers, M

 

I just noticed the pic I grabbed from the internet of a complete column is actually a LHD column!!! I already had the Barina column apart before I remembered to start taking pics.

Edited by mick_in_oz, 05 November 2018 - 08:02 PM.

[mick_in_oz]

Just to clarify, the Vauxhall Corsa is available in both RHD and LHD, it seems that most of the available columns are RHD, making the LHD column not an easy find.

 

Good info here,

 

http://www.super7thh...-steering-epas/

[Dr Terry]

Just to clarify, the Vauxhall Corsa is available in both RHD and LHD, it seems that most of the available columns are RHD, making the LHD column not an easy find.

I know it's only a badge, but to my knowledge the RHD Corsas are badged as Vauxhalls, because they are unique to the UK, while the LHD version is badged Opel for the rest of Europe.

 

The XC Barina in Australia is virtually identical to the Vauxhall Corsa-C.

 

Dr Terry

[mick_in_oz]

I can't really comment, I had seen the Corsa D column, but not found enough info for me to be confident it was going to be easily gotten working, I simply didn't want to reinvent the wheel, and I wanted it to have the variable road speed assist rather than  the simple quick pot and PCB to set the assist and leave it like that, the ones available on ebay etc.

 

The is a website, Rallywiz? that was selling kits and reco columns etc but they seem to have closed the shop.

 

If you could find enough info on the Corsa D column it might be a simpler conversion, I was tempted, but my Barina column turned up for the right money.

 

A consideration is that the column you choose is a self contained unit, as in it doesn't need to talk to another engine ecu or body control module etc.

 

https://drive.google...zRo?usp=sharing