Electric window tension screw replacement

[yellowelan]

Wanting to get the car back on the road and waiting for parts to arrive from overseas. I decided to fabricate my own screws with what I could find at the local hardware store. Having unsuccessfully drilled through dead center of 10 screws breaking a few drill bits I came up with this idea.

I found these 1/2 thickness hex nuts at the hardware store (unfortunately they only came zinc plated not brass or stainless)and some 1/4 brass thread rod.

[yellowelan]

As you can see the nuts are a lot thinner than the standard nuts.

[yellowelan]

I drilled a 2mm hole at the end of some of the threaded rod. The stainless wire sits snuggly through the hole. By winding the nut it will lock and tension the wire. I use the rubber washers from some roofing screws I had left over rather than fibre washers. I will use some Loctite to hold it in place. Doesn't have the craftsmanship of Alex Blacks screws but seem to work ok.

[billwill]

It seems you do not know of Alex Black's version of the same thing?

<later> ah I see you do know about Alec's version.

Can't quite work out if your version protects against the standard Lotus version needing to tighten to the stage where it might shatter the glass

[yellowelan]

The hex nut locks the wire instead of Alex's grub screw. In theory if you overtighten yes but as the hole the wire stops you from tightening hex nut any futher. As long as you tighten the hex nut on the other side at the very end once you are happy with the tension of the wire no not an issue.

Unfortunately I don't have a lathe to accurately drill though the centers of screws for grub screws.

I'm thinking in the long term of getting rid of the system and installing another cars electric window mechanism into the frame. Has anyone tried this successfully?

[UAB807F]

I don't know the answer to this one but if there's enough space at the top of the window travel, then you could use three nuts with two on the wire side and one to hold the assembly in the glass window. If you used loctite on the middle nut which would be on the "glass" side of the cable hole, then you could clamp the wire in place with very little chance of breaking the glass.

(of course, if you insist on breaking the glass, you still can with the other nut )

I like the idea though, and it's simple enough to do for those of us with only basic tools.

Brian

Edit to add; I don't know of anyone replacing the wire contraption with another system but can't see why it's not possible. There are cheap electric window conversion kits sold for kit cars that are quite small and no doubt could be adapted. The thing is though that as long as all the components are in decent nick you can get the OEM Heath Robinson version to work quite well, which is why I've never bothered about changing it.

[yellowelan]

I did trial using 3 nuts and their is sufficient clearance. I think a single stainless nyloc nut would also work as well. I've also now dremelling a slot on one end so you can stop the nut spinning with a flat head screw driver.

I did order some Alex Blacks screws and they arrived yesterday. IMHO they are a good bit of kit. I found my DIY nuts tension just as well. And no glass breakage!! I have taken a picture of my nuts compared with Alex's and the OEM ones.

I have mounted one of Alex nuts and my nuts on my windscreen. I will do a head to head long term comparison.

[yellowelan]

Front view

[yellowelan]

bottom view

[yellowelan]

Yellowelan DIY screw on windowframe. Blue stuff is loctite

[yellowelan]

Alex screw on one side and mine on the right. Notice I have extra tension roller and guide roller down the bottom of frame. I did not come up with this idea. The last owner of the car modified it this way and it works quite well to pickup any slack from the wire and stop any wire from slipping of the large pulley.

[69S4]

I did the extra roller mod on my windows as well some years ago - before I was the recipient of Alex's largesse - as a means of separating the tensioning and tightening simultaneously requirements of the original screws. You would just pull the cable through the bolt fairly loosely , tighten it up and then pull the cable over the extra roller to tension it all up.

It worked well enough but the issue of how far to risk tightening the nut clamping the cable was still there. In the end I developed a kind of half way house mod where I made a thin collar that sat in the hole in the glass and was (about) 20 thou wider than the glass. The bolt went through this so you were tensioning the bolt against the collar rather than the glass. That plus the extra roller was a reasonable fix but Alex's bolts were a much better option and that's what I use now.

[gherlt]

Hello,
bringing up an old thread with my current problem.
I bought and used Alex Black's screws, with great result. Love them.
But I only bought two ! Now I need two more.
Since Alex has not posted since September 2019 and did not respond to PM,
I do not have tools (nor abilities) to copy them, may I ask if somebody knows a source for similar solution ?
Thanks a lot

Guillermo

[gjz30075]

I, too, need two more. I'm sure we're on our own here and will start searching for machine
shops who are willing to take this on.

[gherlt]

really ?