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Lifting force of canopy struts

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Brett Proctor

Well-known member
I know this topic has been brought up but I'm not sure if it was answered so here is the answer.

I was going through my surplus of stuff and I came across an old strut. On it the force is marked as being 1200N or 270lb of force.
When I installed the new struts I did have to release some pressure. How much was removed I couldn't say

This should at least give you an idea of the force required when looking for options
 
Y

ydeardorff

New member
Wow 540lbs of lift, According to Dave the entire canopy with the glass installed is 250lbs. But when you factor in the mechanical advantage/disadvantage of the paralell bar system, then 270lbs per side may very well be needed.

Ive been trying to find the kinematic formula to be able to equate this linkage travel in lbs per degree of movement, but thus far no luck.

If I can find the formula, and know the variables of the formula I can equate exactly what force is needed for our canopies through the entire movement.

I may need to ask my faculty to see if I can get some help.

I did use a salt water fish scale to record to force needed to cause movement at the closed position on the canopy (at the hinge point) and I got it to start to lift at around 68lbs. But that is different from where the rams connect. There the force would be much more.
 
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Peter

Peter

Active member
I used a luggage scale to lift the doors at the mounting point and bought the actuators to suit, only 50Lbs needed so I could go for a bit more speed as actuators will always be a trade off between speed and force.

I seem to remember one of the Nova guys some years back worked it out by putting timber across the canopy between the arms of the hinge and then a bar down from that to a bathroom scale to get the weight at various heights. with hydraulics of course there is power to spare so it doesn't really come into it I guess.
 
Y

ydeardorff

New member
Brett Proctor said:
I'm going to get some Linear Actuators from this place

Linear Actuators from Progressive Automations

I'll post what I get and let you know how they work out
Click to expand...

That's where I got mine...well built!
Mine are Linear Actuator IP66 | Progressive Automations
But they are short stroke high power models since Im using a 2:1 bellcrank system.
I get 200lbs per side out of each 400lb actuator, but get double the speed on the throw 1.96" per sec instead of .98" per second.

Are you looking for perhaps the MODEL: PA-03-12-200 12" stroke and 200lbs of force @ 1.6" per sec?
Or the MODEL: PA-03-10-200 10" stroke and 200lbs force @ 1.6" per sec?
 
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B

Brett Proctor

Well-known member
ydeardorff said:
That's where I got mine...well built!
Mine are Linear Actuator IP66 | Progressive Automations
But they are short stroke high power models since Im using a 2:1 bellcrank system.
I get 200lbs per side out of each 400lb actuator, but get double the speed on the throw 1.96" per sec instead of .98" per second.

Are you looking for perhaps the MODEL: PA-03-12-200 12" stroke and 200lbs of force @ 1.6" per sec?
Or the MODEL: PA-03-10-200 10" stroke and 200lbs force @ 1.6" per sec?
Click to expand...


I'm going to first pull one of my struts and see how much force it has. That will tell me how much force it takes to balance the canopy in a neutral position, then I'll have to figure how much more force is required to lift the canopy.

Once I know how much force is needed to lift the canopy then I'll see whats out there

The stock strut has 8" of travel
 
B

Brett Proctor

Well-known member
Are you looking for perhaps the MODEL: PA-03-12-200 12" stroke and 200lbs of force @ 1.6" per sec?
Or the MODEL: PA-03-10-200 10" stroke and 200lbs force @ 1.6" per sec?
Click to expand...

Both of those models wont work.

They are to wide to fit in the strut opening. Both are around 6" wide, I need something around 3" wide to fit in the opening
 
Y

ydeardorff

New member
Ok,
But I would just modify the pocket, and turn them. Motor facing aft, or outward should keep them out of your way. It just depends on if they will be in the way of the wheel well.
I am mounting mine inside the side pod and using a push rod through the back of the actuator pocket.
 
B

Brett Proctor

Well-known member
OK lets get this post back on topic.

Went out and bought a bathroom scale and found out how much force is required to lift the canopy.

150lb of force or 667.2N (each strut)

Thats for a manual lift top.
I would say thats minimum force to use because I had a little more pressure in one strut than the other(165lb) and I could lift the canopy with one finger but after I balanced the struts out its not a one finger job any more but the canopy does go up and stays up.

So I'm guessing a pair of 200lb(890N) linear struts(min) would be required to lift the canopy all by its self

Now you know the answer. No more guessing. It only took 40 years to find out*laugh*

If Rick was still around I'd ask him to make this a sticky.
 
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