Hatch Gas Spring/Strut Calculator

[danlott]

I have made a calculator to help determine the proper gas spring length, placement and force required to properly open and support my galley hatch. I searched the internet for formulas and recommendations for the proper placement of gas springs. This is what I came up with to use. I have not actually used it on my own trailer yet, but I figured I would throw it out there and hopefully it will help someone.

If you do use the calculator please post your results on this thread to help determine if it is accurate and useful.

Here is a picture that goes along with the spreadsheet below.

View attachment Gas Spring Calculator.xls

Hope it helps.

Dan

 

[Micro469]

This is going to be VERY usefull. Saves making a whole bunch of holes in the walls. But one thing confuses me.... How do you convert a number like 28.88 inches into a measurement I can use...such as 28 3/4 "???? my tape measure doesn't have a .88 of an inch mark, and when I try to convert, it never seems to come out as a fraction . I seem to run into this in a lot of building plans, but since I failed math since Grade one.............( I recut a lot of boards......)

 

[Fyddler]

Just multiply the .88 by 32, round the number, and that gives you the /32's. In this example .88x32=28.16, so it would be 28/32 (or simplified to 7/

 

[treeview]

I needed to do a layout to divide a space equally. The divisions were easy to calculate but came out, like yours, in a number that wasn't sixteenth friendly.

Simple solution...go metric!

I have one tape with metric divisions on one edge, imperial on the other. I don't like using it though because I risk measuring on the wrong edge. When I use metric I grab the metric tape measure or scales.

Tom

 

[danlott]

I updated the drawing and description in the calculator to help clear up some confusion on the spring attachment locations.

Dan

 

[MtnDon]

Thanks for that. Saved it as ya' never know when it could be handy.

 

[danlott]

I updated the calculator due to an error in one of the formulas. This was causing the force of the struts to be twice of what they should be. I am sorry if this caused anyone to get the incorrect struts.

The calculator is now corrected and re-uploaded. If you had previously downloaded the calculator please delete it and download the new file.

Thank you to member ssample (Steve) for helping me determine that there was an error in my calculator.

Dan

 

[ToyWorksMt]

I have made a calculator to help determine the proper gas spring length, placement and force required to properly open and support my galley hatch. I searched the internet for formulas and recommendations for the proper placement of gas springs. This is what I came up with to use. I have not actually used it on my own trailer yet, but I figured I would throw it out there and hopefully it will help someone.

If you do use the calculator please post your results on this thread to help determine if it is accurate and useful.

Here is a picture that goes along with the spreadsheet below.

Hope it helps.

Dan

Thanks so much for posting this Dan. It works very well. It saved me a lot of time in calculating.

 

[danlott]

Thanks so much for posting this Dan. It works very well. It saved me a lot of time in calculating.

I am glad it worked for you. Thank you for letting me know.

Dan

 

[ToyWorksMt]

It works just like it's supposed to. When I close the hatch, it compresses until you get about the last 10%, the when it close, the springs actually push it the other way to hold pressure in the closing position.

 

[danlott]

It works just like it's supposed to. When I close the hatch, it compresses until you get about the last 10%, the when it close, the springs actually push it the other way to hold pressure in the closing position.

That is great news. I hope it works as well for mine when I get to that point.

Dan

 

[ToyWorksMt]

The only thing with mine is my springs are too strong. I have 100# springs and they're too strong. My hatch came out far lighter than I had figured it would be. One spring actually works about right for lift. I have some 45# ones coming.

 

[Hogdaddy]

Thanks for posting this Dan, I'm sure I'll use it in a week or so.

 

[matthewp-TNT]

This is an awesome calculator, thanks!

 

[ctstaas]

Thanks, one of the coolest things ever explained. When I built mine, I had no clue of tnttt or how to figure the complexities of a gas/spring strut, so I built my strut of 1/2" steel round stock. I was going to use a similar design on my next build, but now I think I know enough to scrap that plan. It's not that my idea was bad, the gas/spring struts are slicker looking. Better?

 

[Gunguy05]

Awesome, awesome!

Thank you! After tugging on my 93 lb (at the midpoint) hatch.. THIS worked like a boss!

I had to "fudge" things a bit as the calculation for a 56.5 in hatch, 93 lb, gave me that I needed 33.9 in struts, 133 lb, The longest struts I could find were 30.9in, and 150 lb. So.. I figured a little shorter, a little more force might work well, and it did. I still have to put the luan on the inside of the hatch, but that should be in the 6-10lb range, and I have to give a good tug on it now to get it down. Definitly feel stable and safe above my head.

BTW: A great source on ebay for longer struts and brackets is http://www.ebay.com/usr/strut-your-stuf ... 7675.l2559

The spring I used, http://www.ebay.com/itm/371303887887?_t ... EBIDX%3AIT

The brackets,
Hatch : http://www.ebay.com/itm/391109960046?_t ... EBIDX%3AIT
Galley wall: http://www.ebay.com/itm/391035825660?_t ... EBIDX%3AIT

I will try and post a short video/photo set later. They were much easier to install than I had thought they would be.

 

[danlott]

I am glad the calculator worked for you. 150 lb struts are a little more than you needed, but you still have to add the inside plywood and whatever else you end up putting on the inside of your hatch. Sounds like it should work well. Thank you for the feedback.

Dan

 

[DougN-TNT]

Hi Dan, thank you for making this calculator! Question, if I reverse the mount points so the outer mount point is on the hatch and the inner mount point in the galley, will the calculations be the same? Any reason not to do it that way? I read somewhere it makes the hatch more stable, especially in wind.

Thanks,
Doug

 

[dales133]

Hey Dan could you please check that link it seems to have died

 

[danlott]

Hey Dan could you please check that link it seems to have died

The file attachment is still there and works. Not sure why you are not able to download it. If you PM me your email address I will send it to you.

Dan