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PostPosted: Mon May 21, 2007 11:51 pm
by Tear Les
LittleCritter wrote:This is a very nice design. I have not invested the time into a CAD program, but I wonder what the profile would look like for 5 x 10, 5 feet high? :thinking:


Well, it is 5' wide X 10' long as drawn and 4-feet high (the body itself). Are you trying to fit an overhead bunk or such in there by going to 5-feet high?

Obviously you can't get the identical profile (aspect ratio) by nudging the roof line up a foot but that doesn't mean you couldn't still end up with a nice profile; won't really know without trying.

I only use CAD because the program I have is very inexpensive and I like to mess around with it. Since Andrew has .pdf files on his site you could as easily open that up and print out the profile on regular paper. Set the roof line 1-foot higher and see what you come up with when you blend in the aft and foward curves.

In general I wouldn't go higher unless you've got a special need for the cabinetry or a bunk or such as it will mess with the profile and add generally unusable space (and it will also push it to over 6-feet tall overall). Obviously you have to make it work for you so these are just my thoughts off the top of my head.

Fun stuff, no? :D

PostPosted: Tue May 22, 2007 3:13 am
by angib
lblampman wrote:A question for Andrew if you check in here...I'm assuming that the frame members are 2" X 2" tube stock, is that what you intended on this design? And which wall thickness, I've seen you recommend 16 gauge (or was that 14) in other threads, will that do the job?

I had failed to notice that I hadn't specified that on the drawings! I would say that 2"x2"x1/8" (or 11ga) seems to be a more common size and that would do fine.

14ga would also do fine for a lightweight trailer, particularly as you have a professional welder (it's getting fairly thin) but some folks here may tell you you're skating near the gates of hell with that thickness. Actually Mike may say that if you don't use 3/16" wall tube - if you're going to throw 3/4" ply at the trailer for everything, then 3/16" wouldn't be a bad option.

There is about 260" of tubing in the frame, so the frame-only weights are:
2"x2"x14ga - 46lb
2"x2"x1/8" (11ga) - 66lb
2"x2"x3/16" - 100lb

Andrew

PostPosted: Tue May 22, 2007 3:28 am
by angib
LittleCritter wrote:I wonder what the profile would look like for 5 x 10, 5 feet high?

Image

A bit dumpy? It's nearer to a canned ham than a teardrop. Here are the dimensions:

Image

Andrew

PostPosted: Tue May 22, 2007 8:55 am
by Tear Les
angib wrote:I had failed to notice that I hadn't specified that on the drawings! I would say that 2"x2"x1/8" (or 11ga) seems to be a more common size and that would do fine.

14ga would also do fine for a lightweight trailer, particularly as you have a professional welder (it's getting fairly thin) but some folks here may tell you you're skating near the gates of hell with that thickness. Actually Mike may say that if you don't use 3/16" wall tube - if you're going to throw 3/4" ply at the trailer for everything, then 3/16" wouldn't be a bad option.

There is about 260" of tubing in the frame, so the frame-only weights are:
2"x2"x14ga - 46lb
2"x2"x1/8" (11ga) - 66lb
2"x2"x3/16" - 100lb

Andrew


Thanks Andrew...exactly what I needed! :thumbsup:

Seems like a modest weight gain from 14ga to 1/8" but a quantum leap from 1/8" to 3/16"; I think the 1/8" will do just fine.

PostPosted: Tue May 22, 2007 9:46 am
by LittleCritter
thank ya - thank ya!!! :)

I personally really like this. I still haven't cut the profile out on my TD, so this might be it!!! 8)

PostPosted: Tue May 22, 2007 9:48 am
by LittleCritter
angib wrote:
LittleCritter wrote:I wonder what the profile would look like for 5 x 10, 5 feet high?

Image

A bit dumpy? It's nearer to a canned ham than a teardrop. Here are the dimensions:

Image

Andrew


PS - :oops: Wait a minute before I get all excited here, can I get your permission to use this profile? ;)

PostPosted: Tue May 22, 2007 10:47 am
by angib
LittleCritter wrote:Wait a minute before I get all excited here, can I get your permission to use this profile? ;)

Yes, of course. You can also boast that it's a "custom, created especially for me".

The front and back upper curves are ellipses, not circles and you need to use ellipses if it's going to look right. If you let me have your email address, I'll send you a PDF showing the focuses - the points from which the ellipses are drawn.

Andrew
email: angib (at) blueyonder (dot) co (dot) uk

PostPosted: Sat May 26, 2007 8:24 pm
by Tear Les
angib wrote:There is about 260" of tubing in the frame, so the frame-only weights are:
2"x2"x14ga - 46lb
2"x2"x1/8" (11ga) - 66lb
2"x2"x3/16" - 100lb

Andrew

In the interest of updating this for others (and to make sure I'm comprehending this correctly) I've come up with the following:

2 frame sides @ 101.75" each; 203.5" total
2 tongue pieces @ 47.75" each; 95.5" total
1 rear crossmember @ 58" each; 58" total
1 front crossmember @ 54" each; 54" total

Total 2x2 tube = 411 inches (34.25 feet)

Weight for 1/8" wall thickness at 3 lbs/foot = 102.75 lbs
Weight for 14 gauge at 2 lbs/foot = 68.5 lbs

Do I have this right? :roll:

PostPosted: Sun May 27, 2007 8:59 am
by angib
Yes, I agree.

Anyone who wanted to reduce the weight could change the cross-members to 2"x2"x1/8" angle which would save 13lb.

Andrew

PostPosted: Mon May 28, 2007 4:48 pm
by glassice
Andrew great looking as always . did you do any cabinet drawings

PostPosted: Mon Jun 25, 2007 11:52 pm
by Alphacarina
I'm 'late to the party' too, having just discovered the Grumman - After looking at nearly every teardrop design out there, this one just jumped out and said 'I'm the right one', so I'm gonna give it a go

Not sure yet about the half in/half out wheels but I have decided to use Fexiride half axles, but mounted to the top of the frame and set for as much above angle as possible to try and get the frame lowered down to around 7 or 8 inches off the road . . . . so that it won't be any taller than my 55 inch high car. My width will be somewhere between 55 and 60 inches, again to match the car and the final number will depend on whether or not I decide to tuck the wheels in. Sure wish there was a commercial source for the 'half fenders' as that would make the decision very easy

Another big vote of thanks to Andrew for the excellent design - Far and away the most pleasant tear shape to my eye . . . . and I'm pretty fussy about such things

Don

PostPosted: Tue Jun 26, 2007 12:46 pm
by angib
Alphacarina wrote:I have decided to use Fexiride half axles, but mounted to the top of the frame and set for as much above angle as possible to try and get the frame lowered down to around 7 or 8 inches off the road

Sounds a good plan, Don, but it might be worth checking with Flexiride to see if their axles are symmetrical and so are happy to work upside down - I think they are, but it would be good to check....

One problem you may have is the half-axles sticking up through the cabin floor - from the Flexiride sheets, it looks like the fixed part is 3-3.5" high - and then you want to put a box around it make the cabin watertight. With luck, this will be down under your knees not your backside and you can just make a recess in the underside of the mattress.

Andrew

PostPosted: Tue Jun 26, 2007 7:30 pm
by Alphacarina
Yes Andrew - They may bump up the carpet a bit. I had planned to notch the floor around the axles and leave about 1/8th inch all around to bed in some flexible sealant. We'll put some shag carpeting with a half inch pad on the floor and hopefully notching the pad around the stubs will about make the axles flush with the bottom of the carpet - We'll have a 2 1/2 inch memory foam mattress on top of the carpet most of the time and it's pretty forgiving so I doubt we'll notice the remaining irregularity when sleeping . . . . it will be near our knees anyway. We can roll up the mattress and use it as a seatback to lean against when watching TV or reading. I'll have a built in A/C in the rear, so we can make good use of the extra length in your design

Already asked Flexiride if there was any built in camber or toe on the half axles . . . . haven't received a good answer yet, but even if there is, I can counteract that by welding my mounts so that it compensates for it

I saw somewhere where someone had carved and sanded a positive 'mold' out of some laminated foam sheets to make fiberglass fenders with and since I've got lots of experience with epoxy I may make my own set of half fenders - I REALLY like the half in/half out wheel wells on your (and the original) design and since I'd hate to lose that, I'll need to solve the 'fender problem' . . . . without cutting up a $300 pair of fenders

Gotta see if I can find a local source for sheet aluminum - I could save more weight by using 1/8th inch ply skins inside and out and clad it with the aluminum - Looks more traditional too

Can't rave enough about your rendition of the original - It's the perfect design for me!

Don

Ooops!

PostPosted: Wed Jun 27, 2007 10:11 am
by Alphacarina
Just got word back from UCF (the makers of Fexiride) and yes, there is some camber built into the half axles, so they don't recommend mounting them upside down - I'll have to redesign things a bit

Another interesting tidbit of new information is that they now make the smaller 935 and 550 axle pairs with adjustable arms too - Used to be only the 1400 and larger axles had adjustable arms

Don

PostPosted: Wed Jun 27, 2007 10:24 am
by madjack
Don...source of aluminum sheeting...Aluminum and Stainless Specialties..a division of Reliance Metal...they have outlets in Lafayette La. and used to have one in N.O...before Katrina...check on 'em...they have free delivery within 100mi of their stores...oh yeah, they have the best prices on Al sheet goods that I have seen or come across.......
madjack 8)