Lotus Elan and Lotus Elan Plus 2 Forums

I recently acquired a 1967 SE FHC project car with a number of missing items which included both window motors long gone. Contacted the previous owners and found out they had broken gearboxes & dead motors and got lost somewhere along the way. Being a mechanical engineer who designs mechanisms for a living, I thought there must be a better solution than the old wiper motor which seem to be close to impossible to find and when I could find them, they were expensive & all needed rebuilds. Since things were already taken apart on my car and I measured up all the mechanism components. I found a window motor from a modern US GM car which has a very similar window mechanism drive ratio and window size. The combination is also smaller in size than the original. I have designed a drive adapter that just slides onto the motor & into the original cable drive and a motor bracket that bolts to the 3 original 1/4-28 mounting points. So no modifications to the window mechanism or window frame or door opening are needed. I've driven 1 of my windows up/down successfully a number of times, it stops nicely at the top and bottom even when holding down on the switch (got to love modern current limiting motors). So I'm wondering if there are others out there that might benefit from my work. I'm considering making up kits (brackets, drive adapters, window motors, connector for the motor and new hardware) for sale. So any interest?

As I'm new to the Elan world, I know this fits my 67 S3, I'm assuming it would fit a S4 since I'm told the original window motors are the same part as are the cable drum.

Got any pics? What kind of price do you have in mind. I'm also an ME and years ago I thought about adapting so industrial motors, even perhaps stepper motors, but I'm retired now and lost most of my contacts who could have helped electrically.

Roger

hey Roger,

attached is a picture of the assembly inside the passenger door. I don't have any separate pictures at the moment. the beauty of this design is that it would work with the existing wiring in the car, just 2 wires, positive and negative that are flipped polarity to run in the opposite direction, so no electrical changes.

Pricing is a bit of a challenge, as you know, building 1 is expensive, building 10-20 much cheaper. the sheet metal I cut out on my cnc plasma table but doing more of these I would contract someone to laser/waterjet them & insert the standoffs. the drive adapter I printed out of sintered nylon at work, doing more of these again I would contract with a 3d printing house for the parts again in sintered nylon. I haven't tried to get any quotes as yet, looking to see how much interest there might be to see what volume discounts would be available. guessing at this point, the kit would be around $300 per door.

Hello,
While i welcome the idea and offer, I would say that 300usd is a lot of money, especially when the cardone 40-265 is a 90usd solution for a tired motor. Shipping over the pond and sales tax/VAT makes it even more expensive for the UK/EU residents. Not sure you will sell many of them.
I would suggest you sell the plate, the nylon bit and the small parts as a package, and the buyer sources the GM part in his country, even could be second hand or from a breaker...

how much lighter is it than the original setup ?

as mentioned above, you should post photos of the parts of the kit, also detailing how it is attached to the orignal frame (is it only the 2 screws one see on the plastic shell?), than people would visualize more easily what they would get for their money...

lighter, I'm sure it is but I have no idea how much since if you read the original post, I don't have any of the original parts. the motor, adapter and bracket weight 1lb 8oz according to my wife's cooking scale. though I'm sure this was meant as a joke but here is the data for those who want it. So yes, I'm adding lightness and making Colin happier

again if you read the original post, there are a number of components, 1) the actual brand new (not a remanufactured) window motor 2) the drive adapter, 3) the new motor bracket, 4) the misc mounting hardware (bolts & washer) and 5) a connector with bare terminals to splice onto your original wires in the car to plug into the modern window motor. Everything could be included so you don't need to find anything to bolt this new drive into place. The custom parts are really the drive adapter & bracket.

the added pictures show the bracket bolted with all 3 of the 1/4" screws to the unmodified window frame. I'm using allen head bolts since that is what I have on hand, normal hex bolts fit just fine. it also shows the 3 mounting locations for the window motor. my earlier picture only had 2 of the screws in place on the motor since I only had 2 #10 screws on hand when I put the prototype together and tested it (it worked just fine with just 2).

the other picture shows the drive adapter in place on the window motor. the 2 pins thru the plastic are just for some reinforcing. Probably not necessary but made me happier to have them in place.

Pricing really depends upon the interest, the drive adapter prices drop some after about 4-5 pieces and the sheet metal parts drop after about 6-10 pieces typically. no price drop on the motors or hardware unless I'm ordering more than a 100 pairs. As I haven't gotten any quotes, I'm just using my personal knowledge is gestimating a price for the parts and adding a little for my time & effort. Actual cost with enough interest could be quite a bit less. I hadn't considered VAT for those of you in the UK/EU, the motor should be available in Europe but all the custom bits would still be coming from the USA.

to me this has 2 benefits, replaces old tired motors and gearboxes and adds the safety of current limited modern window motors. those make breaking any of the stock Lotus window pieces very difficult.

As I said before this is not what I do for a living, I'm a design engineer, I just thought there might be others out there in a similar dilemma with either missing parts or dead gearboxes

Michael, this is a good step forward. However, I'd like to see a design that would drive the window without the
cable. There are many hot rod kits out there that simply clamp to the bottom of the glass and use
pivoting levers but I don't think we have room in our doors for that. Good work, thank you.

Very nice! Bound to be some folks who need those. Thank you for your efforts, hope you sell a few!

Definitely would be interested in a pair for my S3. I've investigated motor alternatives, and picked up a couple of motors, but haven't worked out the adaptors for mounting and drive, so if you have a solution, I'm in.

As for price point, I think if you can get down around $150, you'd be able to see some volume. The motors I found, from a science project website of all places were about $20 each, clones of a GM design, but no doubt cheap knockoffs.

You could perhaps have a word with Sue Miller, she might be interested in retailing such kits.

Very interesting. Let me know when you get to the decision point. If they are a direct swap and will use S4 rocker switches I might put the origionals on a shelf.

webbslinger wrote:Very interesting. Let me know when you get to the decision point. If they are a direct swap and will use S4 rocker switches I might put the origionals on a shelf.

+1

I'd talk to Ken at Dave Bean, and Ray at RD Enterprises, to get an idea of the market. Tough sell, imo, at $300 each, but I have 2 working motors. If I didn't, yes, I'd be happy to pay $300.

ae_mike wrote:no price drop on the motors or hardware unless I'm ordering more than a 100 pairs.

the motor being about 50 I suppose the bulk of the cost lies in the Lotus drive adapter (the plate appears rather simple and not costly in material)

e.g. from a quick random search on an auction site

https://www.ebay.com/itm/Power-Window-Motor-Base-AWD-GM-GENUINE-PARTS-CANADA-fits-13-14-Buick-Encore/313485652846


https://www.ebay.com/itm/Power-Window-Motor-Front-Right-ACDelco-GM-Original-Equipment-22836737/313487164674


with a plate that may be recut
https://www.ebay.com/itm/Power-Window-Motor-and-Regulator-Assembly-Rear-Right-TYC-660511/313486141665


then the question might be narrowed to how to manufacture the adpater...

I would recommend just selling the kit with a list of approved window motors to use. The kit would be primarily an adaptor kit for mounting to the frame and mounting the winding mechanism.

This would lower the product cost and shipping. Most of the window motors can be bought cheaply from Ebay.

This would remove you from dealing with returns for any electrical issues.

What would that do to the overall price?