Pull Test Machine!

[George Albo]

I was over by the Tulsa Gluedobbers Control Line Club website and saw this cool pull test whizbang. Drawings are available for download in PDF format. lower right hand of the page-no charge

Thought I'd share.   
George Albo

http://www.tulsacl.com/Pull-Test-Machine.html

[frank williams]

I built one.  Best pull tester around.  No chance of over pulls.  Used for two team trials.

[Dave Harmon]

I had the pleasure of operating the pull tester at the Team Trials last year.
It is a lot of effort to fabricate and install one of these units but definitely worth it.
As a 14 year old....my bellcrank had been pulled many times but this time an adult that didn't know that he didn't know what he was doing did not calculate correctly and my day (month) was over.
I never made THAT mistake again.

[Dave_Trible]

I'd sure like to see a couple of these made for use at the Nats to replace what we have there..........

Dave

[Joseph Patterson]

        Brent Rogillio of the Baton Rouge Bi-Liners built the Bob Reeves  pull tester also this year. They are the way to go if you have the time and a few dollars for the material.
        Doug 

[Bob Reeves]

And if anyone has any questions I would be happy to help if I can. PM or email probably the best as I don't check the forum as often as I did when I was active.

[Bob Reeves]

I was over by the Tulsa Gluedobbers Control Line Club website and saw this cool pull test whizbang. Drawings are available for download in PDF format. lower right hand of the page-no charge

Thought I'd share.   
George Albo

http://www.tulsacl.com/Pull-Test-Machine.html

Just noticed the links in the PDF file are no longer good. I will get together with the Tulsa web master and see what we can do to get everything on the tulsacl.com site. Might take a while I'm not moving very fast these days.

[BillP]

My anti virus software is blocking that link...actually both pdf links. 

[Peter Nevai]

For those of you having problems getting the PDF files, they are attached below. All rights go to the Authors

[Tom Vieira]

you guys should check out how Navy Carrier does it... pretty slick.

[Bob Reeves]

you guys should check out how Navy Carrier does it... pretty slick.

Well don't just leave us hanging. Give a few details and a photo or two. Always open to new ideas, I have never competed in Carrier at the NATS but have at several local contests and at Brodaks. All I ever saw used was the old spring scale.

[Tom Vieira]

I need to find a picture, but, it's pretty much just a saw horse with a bucket and pulley. 

The bucket gets filled with pre-weighed and labeled sandbags to the required load.  The pulley is mounted to the sawhorse and used for the direction change of the rope.  The other end of the rope has a hook on it to grab the saftey thong (wrap the thong around the handle grip), and once hooked up, pilot pulls on the plane while the official watches the bucket.  Once the bucket lifts, you're good!  No more over or under pulls.  The bucket lifts or it doesn't.  Plus, the sawhorse also makes a handy spot to keep your clipboard and mics for checking legality of lines.

[Dave_Trible]

That isn't too far from what is used at the Nats except some combination of steel weights are loaded.  Then when it does lift a battery operated light goes on (when they work).  It's just pretty slow and cumbersome to load and reload for every pull and you have to transport these weights around.

Dave

[dale gleason]

The "sawhorse" must have a system that keeps it from moving at all under the stress of the pull. The NATs puller has a steel cable attached to a steel rod driven about 5ft into the ground. ClassII pulltest can be in the neighborhood of 96 lbs.

dg

[Tom Vieira]

The "sawhorse" must have a system that keeps it from moving at all under the stress of the pull. The NATs puller has a steel cable attached to a steel rod driven about 5ft into the ground. ClassII pulltest can be in the neighborhood of 96 lbs.

dg

of course it is also anchored due to the heavy tests...  i was giving the eagle eye view of how it works....

[Tom Vieira]

https://www.flickr.com/photos/modelaircraft/48309182536/in/album-72157709707060741/

[Bob Reeves]

OK thanks for the info. Same deal as the ones that use different weights and one of the things we didn't want when we designed the sliding weight machine. It uses a single weight that is adjusted for the desired pull. Takes about two seconds to adjust it from one pull to the next. 100% reliable, no cable or pulley for the cable to slip off of, was aware of the design and didn't like it. Heard horror stories about machines that used a cable and chose not to take the chance.

[Brent Rogillio]

Bob we could put a limit switch on your design pull tester to put a light on. But the draw back is keeping up with batteries every time you go to use it.

[James Holford]

Having got the chance to use 1 of those pull test machines in Tulsa in 2018. They work absolutely great!!!!!

Sent from my SM-G965U using Tapatalk

[Bob Reeves]

Bob we could put a limit switch on your design pull tester to put a light on. But the draw back is keeping up with batteries every time you go to use it.

No reason to make it more complex than necessary. The flag that drops is easily seen, besides that even if the pilot over pulls once the flag break point is past the pull gets lighter. Impossible to over pull... Well if some idiot went to the point of dumping the weight on the ground and pulling against the anchor he could break his airplane. That would take moving about two feet back while pulling Ha.