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Elanmac's CV Conversion

PostPosted: Tue Apr 03, 2012 2:24 pm
by elj221c
With appologies to Gary for hijacking his thread. elan-f14/what-does-your-elan-plus2-look-like-today-t23626.html

elanmac wrote:
and a pair of homemade driveshafts which I will be fitting when my doughnuts give up the ghost.


Do you have any details of your drive shafts that you would share? Did you 'copy' commercially available ones or have you make your own design?


c42 wrote:

Did you cut and shut 2 driveshafts to get the new shorter shaft with the correct splines?

Regards
John


I am really quite interested in this as apparently Sue Miller is not doing CVs for our car anymore.

Any more detail would be very helpful.

Thanks,

Re: Elanmac's CV Conversion

PostPosted: Tue Apr 03, 2012 3:24 pm
by Spyder fan
I am really quite interested in this as apparently Sue Miller is not doing CVs for our car anymore.


I'm quite close to happenings at Sue Miller's through Don Hand's who assists her on a weekly basis, apparently the CV joints that she uses for her conversion are no longer being made to the previous very high standard which is resulting in failures, the manufacturer / factor states that they are within design tolerance and won't reimburse for the failures, hence Sue has decided to stop making them.

Spyder still do their conversion, which is a hybrid mix of CV and original rotoflex technology.
spyder driveshafts.jpg and


The Elan and Elan Plus Two Driveshaft Conversion Kits,
reference numbers AOCX010 and BOCX011 respectively comprise:
1. 2 no. fail safe/anti-surge cups.
2. 6 no. shear bolts, plated 7/16" UNF x 3.2" long x 2.5" shank c/w washers, table 3 heavy
pattern and Nyloc nuts, T-type.
3. 2 no. rubber drive couplings.
4. 6 no. shear bolts, plated 7/16" UNF x 3" long x 2.2" shank c/w washers, table 3 heavy patter
and Nyloc nuts, T-type.
5. 2 no. intermediate shafts.
6. 2 no. boot kits
7. 2 no. gaiter ties.
8. 2 no. constant velocity joints.
9. 2 no. c.v.j adapters.
10. 2 no. tubes of graphite grease.
11. 2 no. circlips, 23mm
12. 6 no. shear bolts, plated 7/16" UNF x 1.8" long x 1.0" shank c/w washers, table 3 heavy


Regards


Alan

Re: Elanmac's CV Conversion

PostPosted: Tue Apr 03, 2012 6:52 pm
by elanmac
I didn't actually need new driveshafts as the doughnuts fitted in 1996 are still good, but when I saw the price and write ups on the new ones I decided to go down the solid route.
I read up on previous posts and decided to use 16mm aluminium plate for the adapters and VW Polo cv's and shafts. I have attached photo's of the making stages. Although I used a small cnc milling machine to make the plates, if I did any more I would use a lathe as the miller I used was just too small.
Mac

Re: Elanmac's CV Conversion

PostPosted: Tue Apr 03, 2012 8:24 pm
by c42
Hi Mac

Thank you for the information, very informative and also very tempting.

Regards
John

Re: Elanmac's CV Conversion

PostPosted: Tue Apr 03, 2012 11:28 pm
by robertverhey
Hello Mac

Great post and a very tidy job. I'm making up some similar shafts using VW beetle driveshafts and some adaptor plates made up by a Forum member. Just wondering, what length did your shortened shafts end up at, and how did you calculate what would be the right length?

Robert

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 9:40 am
by elj221c
Hi, Mac,

Thanks very much for your information. A nice neat job on the shafts.

I too would like to know the shortened length.

Also looking forward to your road test report..........

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 9:58 am
by elj221c
Spyder fan wrote:
Sue has decided to stop making them.

Spyder still do their conversion, which is a hybrid mix of CV and original rotoflex technology.

Alan


Alan,

It would be interesing to know if they are likely to be manufactured gain if a quality product could be found.

I was never totally convinced by the Spyder approach. Neither one thing or the other and one is still tied to replacing couplings. Also I note that the price is ?475 + vat but excludes the couplings at ?70 each + vat!

I am very tempted to go Mac's way. The only other is to go the TTR route, it would seem.

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 10:06 am
by rgh0
Hi Robert

I made conversions for my Elan and Plus 2 many many years ago before there were any commercial kits being made.

I used 295 mm shafts for the Elan and 360mm for the Plus 2.
(I have seen a reference from another Sydney based Plus 2 user of 367mm but i dont know the other detils of the assembly). The standard beetle shaft was approx 405mm long I believe between the grooves

This was with 12mm thick adapter plate assemblies between the Lotus 3 arm flange and the cv joint mounting face and is the shaft dimension is from the inside of the circlip groove at the end of the shortened VW beetle shafts I used.

The plates were 12.5 mm thick (1/2 inch) with a 1mm countersink for centrering the cv's and a 0.5mm sealing plate between the adapter and the Lotus 3 arm mount making the 12mm adapter dimension. The adapter seal plate has a dome formed in it so the end of the shaft which protrubes through the adapter at minimum length does not hit it.

I determined these by measurement by determining shaft length variation over full range of movement at full droop and rebound on my cars and then setting up the cvs to accomodate this range of movement. I also used cables to limit droop on both cars to the same angle as provided by the rotoflexs but this is dependent on the shocks you use and is normally only really necessary on the Elan due to cv angle limits not the Plus 2 with its longer drive shafts.

Check the dimensions suit your car before cutting and welding steel.

cheers

Rohan

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 10:23 am
by elancoupe
elj221c wrote:


The only other is to go the TTR route, it would seem.


Elantrikbits, Rd Enterprises, JAE, Dave Bean, and probably others, have quality CV kits available.

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 10:34 am
by elanmac
Hi Robert,
I used 292mm length but my plates are slightly thicker than Rohans. I used the dimensions which i found by googling for information. I will not be fitting them until I need to, as I am happy with the doughnuts.
Mac

Re: Elanmac's CV Conversion

PostPosted: Wed Apr 04, 2012 6:39 pm
by elanmac
This is one of the useful articles that I used for the dimensions etc when making my driveshafts.
Mac
elan-archive-f16/solid-driveshafts-t8557.html

Re: Elanmac's CV Conversion

PostPosted: Thu Apr 05, 2012 3:00 am
by Andy8421
Spyderfan wrote:
I'm quite close to happenings at Sue Miller's through Don Hand's who assists her on a weekly basis, apparently the CV joints that she uses for her conversion are no longer being made to the previous very high standard which is resulting in failures, the manufacturer / factor states that they are within design tolerance and won't reimburse for the failures, hence Sue has decided to stop making them.


Damn. I had planned to buy a pair from her.

I had thought Sue used standard GKN Lobro CVs. Is the problem with the GKN part, or did Sue source CVs elsewhere? I don't want to find I have similar problems if I go down the home build route and use GKN parts.

Thanks.

Re: Elanmac's CV Conversion

PostPosted: Thu Apr 05, 2012 3:59 am
by robertverhey
Okay, just measured my adaptor plates and they're each 14mm thick....so based on Rohan's calculation (shaft shortened to 295mm with 12mm plates), I should subtract 4mm to give a shaft length of 291mm between the circlip grooves. Is this correct?

Robert

Re: Elanmac's CV Conversion

PostPosted: Thu Apr 05, 2012 7:30 am
by rgh0
Hi Robert sounds right to me- Length between the inside of the circlip grooves on the shortened shaft should be 291mm with a 14 thick adapter plate assembly based on the measurements i did on my Elan.

The post referenced from 2003 had an overall shaft length of 11 and 3/4 inches
which is 298.5mm and there is about 5 mm of overhang from the inside of the groove to then end of the shaft so not far out at 288.5mm between the grooves on that basis. This is a little short by my measurements for the 12.5mm adapter plates also referenced. But I would expect a few mm tolerances in the overall assembly length from the diff on the car centreline to the outboard hub assembly given all the components in the diff, chassis and suspension that set the actual shaft length required.

cheers
Rohan.

Re: Elanmac's CV Conversion

PostPosted: Thu Apr 05, 2012 12:05 pm
by 512BB
Spyder fan wrote;

I'm quite close to happenings at Sue Miller's through Don Hand's who assists her on a weekly basis, apparently the CV joints that she uses for her conversion are no longer being made to the previous very high standard which is resulting in failures, the manufacturer / factor states that they are within design tolerance and won't reimburse for the failures, hence Sue has decided to stop making them.

PLEASE EVERYONE NOTE, THIS IS NOT CORRECT, and will short change Susan out of business.

FACT. Susan still sells her CV drive shafts for +2's. It is ONLY the Elan that she does not make them for, due to the increased angle's that they have to work to. Her +2 drive shafts work fine because they are longer than the Elan's, and therefore the angle on droop is less, and does not mash up the cage and balls.

So Andy, if you want a set of her CV's for a +2, you can still get them from her. I bought a pair 2 weeks ago.

Leslie