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View Full Version : Die spring suspension verses bungees?



Glenn5ft19
02-03-2005, 07:04 PM
I am just in the process of building my gear for a Wag P18 Replica. I like the looks of the die spring gear. Does anyone know what the spring size and rates are? What are the advantages and disadvantages of each system? Appreciate all opinions.
Thanks
Glenn

Tim
02-03-2005, 07:36 PM
I've had both on my 2+2 and much prefer the diespring gear.

Tim

Laz
02-03-2005, 08:47 PM
Tim,
I am building a 2+2 and was wondering about the diesprings? There was a thread aways back, but I can't seem to find it again.
Where did you get the springs and what are the specs. on them? Did you "preload" them when building the struts? Are you using Hydrasorbs? Thanks, Laz

Tim
02-03-2005, 09:48 PM
Laz

I used Danly die springs, cat.# 9-3232-36. I preloaded them about 1inch.. I don't use Hydrasorbs the springs are all you need. I made mine from a set of plans I got from an engineer who designed them for his 2+2. They are a little different than what you see at Wag. or Aircraft Spurce. I've been into some rough places with them (about 800 hours worth) and so far so good.

CptKelly
02-04-2005, 12:59 AM
My Smith Cub uses a die spring suspension. I had thought that I would prefer the bungee type, but after using the die spring gear, I have changed my mind. The die springs are just fine, and one never has to worry about the bungees.

Mike

supercubc37
02-04-2005, 04:03 AM
Hi Laz

How are your wings coming along? Just thought I'd drop a hello. Si plans on being up to the AA show. We'll be sending a care package for the hospitality last July.

Matt

Glenn5ft19
02-04-2005, 04:59 PM
Laz,
Any chance you could post us a digital image of the plans??
Thanks
Glenn

Glenn5ft19
02-06-2005, 05:52 PM
The dies springs are 6'' x 2" x 1" spring rate is 0.7"/1000lbs.

Hyrdflyr
02-07-2005, 03:06 AM
Could anyone post a plan and specs for the spring struts? I'd like to try them on X-12.

Thanks, Hyrdflyr

Tim
02-07-2005, 08:52 AM
PM, me your address and I'll send you a copy.They are on paper and I have no idea how to get them into the computer and on to the site.

Tim

Laz
02-09-2005, 02:04 AM
Hi Matt,
Good to hear from you!
I'm still welding tabs on the fuselage! Can't seem to get them all yet.
Laz

Laz
02-09-2005, 02:07 AM
Tim,
Thanks for the info.!
Could you also send me a copy of the drawings??
I'll PM my address.
Laz

supercubc37
02-09-2005, 04:03 AM
Hi Laz

Keep at it will get done. Si sold his 2+2 project to a friend of ours during Oshkosh and I'm in the process of helping him build it. He bought a set of Smith wings and we have them covered and shooting dope on the second one right now. Fuselage build up will come next.

Matt

Al King
02-26-2005, 05:47 PM
Hi Glen,
Die spring gear works well, I have it on my Northstar. However be carefull of the design. Mine broke, but it was because of a combination of design and a lot of hard off airport landings.
My die springs are a 2" dia.spring 12" long. Theoretically they can support 1700 pounds each. My plane weighs 1260 Lbs. empty which is probably more than most cubs.
Anyway when you add a couple of guys some fuel etc. and it is often at about 1800 ( gross is 2450).
You have to preload the springs roughly equal to half the weight you want to carry. If you don't the gear will splay out as soon as you put the plane on it.
In my case this means a preload of about 1 1/2" , . The problem is a 12" spring only has a travel of 3.5" before preload.
When you clobber it hard two things happen for sure, and maybe more that no-one will ever understand.
The springs bottom and the energy goes into the airframe, causing it to be hard to grease it on.
The energy can also be destructive, my struts broke between the spring and the axle. I fixed the problem by increasing the thickness of the strut tubes and making some changes to the strut design.
I made a Cadd drawing of the strut I made and will share it.
You can find listings of die springs and the pressure they will support at various web sites. Anchor Lamina have a site where you can download a chart.
In the near future I plan to study the use of urethane rubber in place of the die springs, with the intention of getting more travel without bottoming the suspension.
Let me know if you want that drawing

Marty57
03-04-2005, 06:13 PM
Laz,
I saw your post about the springs on the 2+2 you are building, I am also interested in the springs. I am just beginning a Wag Aero 2+2. Any hints or suggestions before I start? I am currently setting up the jigs for the fuselage. I am welding mine up from scratch. I am going to buy some of the parts from Univair or Spruce, such as gear and wing fittings, screw jack tower, tail post, etc. I have been looking at the many threads on this site, and plan on adding the popular mods I have seen. I also plan on adding flaps to the project. What has been your experience so far, and how far along are you? I must say, the plans are lacking in many areas, some additional pictures would be nice. I am also using drawings from Cub Club to help figure some things out.
I haven't come across many 2+2 builders yet, good to find your thread. Any help or advice you can give me ( or other readers) as I start would be very helpful. This is my first building project however I am not new to this kind of thing. I have been teaching Industrial Arts for 25 years and have experience in all the different building areas. I must say, the info I have found on this site and the help I have received has been great. This site has a wealth of information and great members.
Marty Feehan
mafeehan@earthlink.net

Bugs66
03-05-2005, 01:27 AM
Laz,
...
I haven't come across many 2+2 builders yet, ...

Look up username Dan2+2 on this board. He's building a 2+2 with D&E wings.

Also there is a Wag Aero builders Yahoo group:
http://groups.yahoo.com/group/wagbuilders/

Marty57
03-05-2005, 04:11 PM
Thanks for the tip! I went to the site and again, some great info. Each time I find an answer to a question I have, it clues me in on something else I have not figured out yet. I guess this is why expairamental aircraft are for "education" as the FAA likes to say.
Thanks again,

Marty

Laz
03-12-2005, 07:54 PM
Marty,
Sorry it's taken so long to get back to. I've been away from the computer (working on the fuselage).
The plans are a little "thin" on details, and what I did was " mine'supercub ,org. for info on the best modifications (great site by the way!) as well as purchase the PA18 CD from Northland. There were a few dimensions in error on the plans also, so verify everything! I am getting ready to hang the engine and work on "firewall forward". Please PM me and we can chat about details if you like?
Laz

Pilk
03-12-2005, 11:03 PM
Glenn i have the die spring they work great if you would like i could send adigram how idone mine