TR7 Pod Motor

PostPost by: 111Robin » Thu Sep 08, 2022 11:27 am

Is anyone using a TR7 headlamp pod motor ?. In operation my headlamps don't come up to the fully raised position however when switched off they continue to rise up fully open then return to fully closed. I've only just figured out why. When functioned to open the motor arm rotates approximately 150 degrees. When the lights are switched off the arm continues to rise from this position then returns to the fully closed position, 210 degrees of rotation. Is this "normal" for a TR7 motor or should it be 180/180 ?. I can see no reason for the reduced arc on the opening cycle. Before anyone mentions it, I know it's noisy, I have lubricated the bush but obviously haven't got to the correct location yet with the lubricant.
https://youtube.com/shorts/ksbBTngVO_g?feature=share
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

PostPost by: 111Robin » Thu Sep 08, 2022 1:57 pm

I'm guessing that the motor pinion with the on/off "ramp" must be out of synch with the arm position so I need to firstly position the arm with the pods down then install the pinion such that it is tripping out the motor. It should then hopefully rotate 180 degrees before cutting out again, pods up.
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

PostPost by: 111Robin » Thu Sep 08, 2022 3:30 pm

Still the same. Mechanically it is free to operate through the full open/close cycle. Electrically the two contacts on the motor are 180 degrees opposed to each other so there is no reason for each cycle to be anything other than 180 degrees rotation so I'm at a loss.

https://youtu.be/0XXOo1o-LOE
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

PostPost by: Spyder fan » Thu Sep 08, 2022 3:39 pm

The TR7 / 8 Headlamp lifters have an unequal up and down rotation cycle as you have observed. approximately 216 up and 144 down. They also have a reputation for unreliability. I think you will have difficulty getting them to work on Elan headlamps.

The Mazda MX5 (Miata) headlamp motors have equal 180 degree rotation periods and lots of people on here have done this conversion as well as it forming part of the kit from Spyder.

You should be able to pick one up for less than £40, they are tough and reliable.
Kindest regards

Alan Thomas
User avatar
Spyder fan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2843
Joined: 11 Jun 2009

PostPost by: 111Robin » Thu Sep 08, 2022 3:50 pm

Spyder fan wrote:The TR7 / 8 Headlamp lifters have an unequal up and down rotation cycle as you have observed. approximately 216 up and 144 down. They also have a reputation for unreliability. I think you will have difficulty getting them to work on Elan headlamps.

The Mazda MX5 (Miata) headlamp motors have equal 180 degree rotation periods and lots of people on here have done this conversion as well as it forming part of the kit from Spyder.

You should be able to pick one up for less than £40, they are tough and reliable.

Ok thanks for confirming that, I was going off my head trying to figure it out. I'm just trying to use what was already on the car before spending anything on alternative solutions. I'm wondering if I can convert this motor to 180/180, might be worth a try.
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

PostPost by: 111Robin » Thu Sep 08, 2022 8:00 pm

Solved.
Just required the connections to be reversed so that the long arc is opening the pods. Admittedly this must be how it was originally wired but I didn't take note when removing the motor.

https://youtu.be/HLb5NQmorb8
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

PostPost by: Spyder fan » Fri Sep 09, 2022 5:56 am

Sorry,
But I can’t get my head round that :lol:

I didn’t realise that the system had been working previously, I thought that you had cobbled together some parts that were lying around.
The TR7 motors are strange with their offset rotation, but it’s probably a geometry thing in that unless you use one of the original lotus headlamp springs with the mx5 motors, the downwards action of the pod is very jerky and in fact they seem to drop free fall for about 20 degrees unless the spring is smoothing the action.

Well done
Kindest regards

Alan Thomas
User avatar
Spyder fan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2843
Joined: 11 Jun 2009

PostPost by: 111Robin » Fri Sep 09, 2022 6:19 am

Sorry, I didn't mention this had been fitted previously. However before I removed the motor the lamps were slamming down so hard it shook the car. Now, although slightly jerky, the closing action is not too bad. There is no spring but I do intend to fit one to hopefully smooth the closing action.
111Robin
Third Gear
Third Gear
 
Posts: 270
Joined: 06 Feb 2021

Total Online:

Users browsing this forum: Elanman99 and 23 guests