Rotoflex question?

PostPost by: 512BB » Fri Mar 13, 2015 1:45 pm

And here's the rub. Bolt hole size of the topper 13mm. Bolt hole size of an original donut 11.22mm., I have just measured one. No doubt the other mearurements are out as well.

Oh well, back to the drawing board.

Oh and, you've left your hazzards on Alan :lol:

Leslie
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PostPost by: Chancer » Fri Mar 13, 2015 1:55 pm

512BB, there was no need for the rolly eyes but no offence taken, when I asked if they were thinner it was because of the photos of the Imp installation showing spacers and if the driveshaft length had not been changed it would imply that they were thinner than the ones that they replaced I wasnt trying to say that Imp and Elan ones were different thicknesses, I have always known them to be interchangeable.

I completely understand that a pair of thicker couplings would not fit on an Elan without reducing the length of the shaft.

Perhaps there are several BMW guido couplings?
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PostPost by: 512BB » Fri Mar 13, 2015 2:32 pm

Chancer wrote: 512BB, there was no need for the rolly eyes but no offence taken,...............And non meant, I just roll my eyes a lot :lol: :lol: :lol: Just like I did not take offence when you stuffed my chances of selling my engine stand, when you stated that it was only ?2 cheaper than buying a new one. I had no idea they were that cheap, I thought I was doing someone a favour. I was not selling it because I needed the money, I just wanted it out the way. Anyway, I have given it to the local charity shop now :lol: :lol:

And just for the record, if you read the board rules, it clearly states no comments to be left on somebodys advert, and all negotiations to be carried out privately.

Chancer also wrote: I have always known them to be interchangeable..........what since birth.

Good afternoon, I am off to practice for tonights show at the Paladium.

Leslie
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PostPost by: Spyder fan » Fri Mar 13, 2015 3:02 pm

512BB wrote:And here's the rub. Bolt hole size of the topper 13mm. Bolt hole size of an original donut 11.22mm., I have just measured one. No doubt the other mearurements are out as well.

Oh well, back to the drawing board.

Oh and, you've left your hazzards on Alan :lol:

Leslie

That was quick work on the measurements? Do you have a grass topper in your collection. ......

And first to notice the change of picture

regarding your reply to Chancer, have you been taking your righteous pills today?
Kindest regards

Alan Thomas
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PostPost by: 512BB » Fri Mar 13, 2015 3:58 pm

Spyder wrote: That was quick work on the measurements? Do you have a grass topper in your collection.

No, but having just been out to survey my land, I think a ride on is fast approaching. That is the ONE thing I hate about this time of year, cutting the f...in grass. Everything else is just dandy.

regarding your reply to Chancer, have you been taking your righteous pills today?

Again no, but since turning 50, I like to be politically correct. Dont ask about my pre 50 days.

Leslie
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PostPost by: StressCraxx » Sat Mar 14, 2015 4:29 am

512BB wrote:And here's the rub. Bolt hole size of the topper 13mm. Bolt hole size of an original donut 11.22mm., I have just measured one. No doubt the other mearurements are out as well.

Oh well, back to the drawing board.

Oh and, you've left your hazzards on Alan :lol:

Leslie


Leslie,

Consider making press fit steel sleeves down to 11.22mm for the bolt holes? As an alternative 7/16" AN bolts have a larger diameter grip than regular UNF bolts. They come in 1/8" increments of length so you get a grip that is long enough for the coupling and ears do not act against the threads. You can also obtain AN 6 point or 12 point locking nuts that are shorter than nylock nuts.

The coupling shown at least has molded in, solid inserts, not the folded sheet metal inserts in the current offerings from the usual suppliers. The folded inserts often collapse when the bolts are tightened to the half shafts and stub axles.

Perhaps find the supplier/manufacturer and obtain the data sheet of available sizes, torque ratings and allowable angular misalignment. These couplings are commonly used on cardan shafts in industrial applications. http://www.missionsupplyonline.com/pdf/rotoflex.pdf Metalastik is the brand, now owned by Trelleborg.

As far as the guibos are concerned, perhaps someone could do the same and obtain the engineering data to see if they are suitable. Otherwise, its all speculation and assumption.

Regards,
Dan
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PostPost by: 512BB » Sat Mar 14, 2015 8:01 am

Stresscraxx wrote:

Consider making press fit steel sleeves down to 11.22mm for the bolt holes?

I thought of that Dan, but to much agro, and thats if all the other measurements tie up, which I doubt.

The coupling shown at least has molded in, solid inserts, not the folded sheet metal inserts in the current offerings from the usual suppliers. The folded inserts often collapse when the bolts are tightened to the half shafts and stub axles.

Correct, this feature is a big plus point for these couplings.

Perhaps find the supplier/manufacturer

I thought of that too, but maybe ask them to make to exactly the spec that WE require. But I am also sure that they would want an order of say 100,000 units, and who is going to pay for that. NOT ME !

Just my thoughts, I suspect that we shall have to dream on, and hope that our friend on here, who is making them up, is progressing well.

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PostPost by: Chancer » Sat Mar 14, 2015 9:25 am

If the PCD is correct and the thickness allows fitting I would not faff around speculating, I would not hesitate to fit a couple and see if they will function whilst turning the transmission by hand, then a parking speed test followed by quicker and quicker road tests.

However easy that is to say from the comfort of my keyboard I cannot put my money where my mouth is because my Elan has been off the road for the 2 d?cades since I bought it and is currently in storage.

I found some Turkish couplings very cheap on EBay, or at least a Turkish seller, cheap enough to buy a couple to try.
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