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NEED ACTUATOR SUGGESTIONS???

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b3rb3ts

New member
Hi, i just want to ask for some help for some members who has linear actuator on their sterling. i have this linear actuator on mine but it only has a 112 lbs dynamic load rating

http://www.ebay.com/itm/10-Linear-A...H_DefaultDomain_0&vxp=mtr&hash=item1e5c83e426

but im planning to change it to something much better, something heavy duty and will last longer. ive called the linak company but im having a hard time getting in touch with them and even with the warner company. so maybe someone could give me any suggestions where to get a good actuator... thanks

vince
 
Y

ydeardorff

New member
I have talked to Dave about the weight of the top and he told me he thinks its about 250 lbs.

So a single actuator at the weight you described wouldn't do it without a mechanical advantage.

Mechanical advantage means loss of speed. The real trick is to have a high power, short stroke actuator, through mechanical reduction, you can increase speed and stroke, and still have plenty of power for lifting the top.

Many linear actuators have a built in limit switches which also reduces the amount of gizmo's needed to keep the top working properly in its stroke cycle.

I prefer linear actuators to hydraulics. No mess if they fail. No lines to route to the pump.
And built in limit switches.

Many linear actuators can be had in up 400lb strokes at 1 inch per second for just over 100 bucks.

Later Sterling GT's used power boat plane control linear actuators, and a booster spring. Heres a couple of pictures of Greg's (Unofun) Sterling GT hinge system I took earlier this year. Some unpleasant yellow and black occupants prevented me from actuating the top to see it in the opn and closed position.
DSCI0333.JPGDSCI0334.jpg

I looked into these boat actuators, and they are very expensive. I found them around 500 dollars.

Some people prefer the Hyd system, other the linear actuators. Either way, when you decide on what your going to do, make sure you install a panic, or emergency release system in it. So if for some reason, the canopy wont open. You can still get out.

Ive had the canopy close on me without any mechanicals connected, and by your self, this top is almost impossible to open.
 
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B

b3rb3ts

New member
so you think one actuator (112 lbs dynamic load) on both sides wouldn't work? acutally, im most concern more of the durability of the actuator rather than the speed. i pretty much satisfied with it's speed. the linak salesrep atlast sent me an email and here is what he recommends.

http://www.linak.com/corporate/pdf/ENGLISH/DATA SHEET/Linear Actuator_LA31T_Data Sheet_Eng.pdf


With a stroke of 10” (9.84” or 250mm) the installation dimension (fully retracted) will be 16.65” (423mm). It will then extend to 26.49” (673mm). The minimum dynamic load is 225 lbs. (1,000N) with the static load (or self locking) of 225 lbs


by the way, what kind of actuator are you using?

thanks
 
Y

ydeardorff

New member
With Daves estimate of 250 lbs with the windshield installed, I think the 112 lbs load rating would be a bit shy. When actuator strain they slow down, in this case they will get hot. Resulting in a possible fuse blowing, or worse.
Just for murphies sake, Id shoot higher. Its about the mechanical load at the connecting points, not so much as the overall lifting weight. Remember the hinges are attached below the tip of the hinge connection at the ends. Hence they are mechanically lifting more than the overall weight due to mechanical disadvantage. It may be minor, but the difference could be enough to make a dramatic difference in the actuators ability, and speed. Not to mention longevity.

Even in the hyd system which I have had both installed on my car. The first 6 inches of travel are very difficult for the system to operate. Perhaps if you rigged up some sort of helper gas spring into the system the lesser actuators would be sufficient.

Ive been talking with this company for about a year. http://progressiveautomations.com/

I haven't bought any yet, but getting there.
 
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letterman7

letterman7

Honorary Admin
Er... I've never seen an electric trim tab system set like that... ever. That must be a really old system :D. But yes, Yaughn's right, rate your actuators for at least the weight of the canopy at one unit - the Linak dealer has the correct specs as you posted. I think Dave's weight is his shipping weight with the crate - as mentioned in a PM, the overall weight with all the glass is probably a hair less than 200 pounds. Trying to push the canopy open when you're inside is all about mechanical advantage - from a sitting position it's almost impossible... you'll have to crawl out from under the steering wheel and brace your legs on the seat.

One thing to consider, actuators are actually fairly difficult to time correctly so they open at the same rate. With a hydraulic system you can add a limiter on the line to slow one or the other... without some fancy electronics you can't do that with an actuator. It would be a bad thing for the canopy to skew on the way up...
 
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ydeardorff

New member
Yes, hearing that horrible crunch of fracturing fiberglass wouldn't make your day. And i think would qualify as a "Failed Rock Star Moment"

It is imperative that you ensure your hinges are free in motion and travel. And that they are in the best shape possible. more expensive actuator model offer an electronic scaling method that tracks each actuator so they can be made to operate perfectly together. But of course its more money.

My design has each actuator rated at 400 lbs, but through a bell crank system reduces the lifting weight to 200 per cylinder. This way the actuator wont be struggling at the peak of its abilities.

Another thing to consider too, is how are your going to mount them? There is only so much stress fiberglass can take. I'm working out a way to tie into the pan directly myself.
 
letterman7

letterman7

Honorary Admin
Few people know that the original design of the hinges included a mount point for cylinders. The triangular plate that is usually present on the bottom hinge and goes down into the cylinder cavity of the body was made not only to help anchor the hinge, but to provide a stable mounting point for a hydraulic cylinder. Welding on an extension and bringing it to the floor level and anchoring it there makes for a wonderfully strong mounting plate... *thumbs up*
 
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ydeardorff

New member
b3rb3ts said:
YAUGHN, what do you think about this one http://progressiveautomations.com/l...oke-size-force-400-lbs-speed-059sec-p-58.html

it has the same length as the linak LA31, less speed rating but much cheaper. the linak LA31 is $450 each. this one is just $130
Click to expand...

Yes, These would work well i think. The strength is more than is needed but thats fine. Make sure you get them properly mounted, and not mounted into fiberglass. 400 lb pushing strength will rip fiberglass apart like confetti.

I have been looking at the PA-02's myself but in a shorter stroke. Some of the actuator models also move at .96" per second so look into those.

Another note. Ensure the actuators pull/push from fully closed, to fully open is free, and not going to bend or twist in any way. I had a set from another manufacturer, that ripped the end out cause the canopy went too far over center, and bent the rod against the body. Ironically it still works, it just cant pull anymore. LOL
 
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b3rb3ts

New member
thanks yaughn, actually the actuator is mounted on the metal bracket and not on the fiberglass body. the reason why i need a longer stroke is for me not to redo the bracket that the previous owner did. my only problem is, this is my current actuator http://www.ebay.com/itm/10-Linear-A...H_DefaultDomain_0&vxp=mtr&hash=item1e5c83e426 and it has a swivel ball joint at the end/rod eye/mounting holes

all actuators that i could find does not have those unless i custom frabricate it. because the bracket that is on the sterling bends.

anyway thanks for the suggestions. it really helps. im just kinda new in this so i still have alot of learning to do.
 
S

Sheri

New member
ydeardorff said:
I have talked to Dave about the weight of the top and he told me he thinks its about 250 lbs.

So a single actuator at the weight you described wouldn't do it without a mechanical advantage.

Mechanical advantage means loss of speed. The real trick is to have a high power, short stroke actuator, through mechanical reduction, you can increase speed and stroke, and still have plenty of power for lifting the top.

Many linear actuators have a built in limit switches which also reduces the amount of gizmo's needed to keep the top working properly in its stroke cycle.

I prefer linear actuators to hydraulics. No mess if they fail. No lines to route to the pump.
And built in limit switches.

Many linear actuators can be had in up 400lb strokes at 1 inch per second for just over 100 bucks.

Later Sterling GT's used power boat plane control linear actuators, and a booster spring. Heres a couple of pictures of Greg's (Unofun) Sterling GT hinge system I took earlier this year. Some unpleasant yellow and black occupants prevented me from actuating the top to see it in the opn and closed position.
View attachment 2256View attachment 2257

I looked into these boat actuators, and they are very expensive. I found them around 500 dollars.

Some people prefer the Hyd system, other the linear actuators. Either way, when you decide on what your going to do, make sure you install a panic, or emergency release system in it. So if for some reason, the canopy wont open. You can still get out.

Ive had the canopy close on me without any mechanicals connected, and by your self, this top is almost impossible to open.
Click to expand...

This GT has the same set up and with that spring it snaps down for the first foot, but here is video to see I made for Arlon the owner..I hope Vincent who has #396 post all the build picture's because with out this site we would have been lost and we took a lot picture's and sent then to him.. Each sterling is different it seens..LOL*very frustrated*
http://www.youtube.com/watch?v=-CB_EahzkY8&feature=youtu.be
 
letterman7

letterman7

Honorary Admin
Nice to see a GT under it's own power. The engine is a Cologne 2.8L by the way. The Capri valve covers are a dead giveaway; a 2.8L Ford is slightly different with different heads. The Capri version is a slightly hot-rodded version.

Arlon, I'm jealous!
 
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