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Discussion Starter · #21 ·
Budget info for the Bosch Rexroth framing material posted:


Here are picts of 2 shopping carts, first one is what I have in my basement, 20mm x 20mm profile, 3000mm (118") is max length for that, I am making my screen a 2.37:1 on the inside edge of the frame, so I ordered (5) pieces of 1245mm long (49"), this will give me approx 126" diag screen, plenty big enough for me.

With tax (6% in Mich), $173.42 pick-up at their Madison Heights location




This second cart is same screen geometry as 1st, profile is 30mm x 30mm, this is what Itai used. His screen is slightly bigger than mine....

With tax, $231.43 pick-up at their Madison Heights location.



You only save a few$'s if you order longer material and cut yourself, so I figured for the convience why not have them cut to size?


So, the 30mm x 30mm is $60 more than the 20mm x 20mm, I went with 3 inside supports, that may be over-engineered and most likely you could get by with just 2 inside supports, which if you have AT screen and center speaker obviously you don't want a frame member in front of the center speaker, i.e. Itai's design.


I also went with the "big" corner gussetts at all 10 locations, 2 bolts/side, to make the frame very rigid in-plane.


Itai used the "big" 2 bolt gusset at the (4) outside corners, while using a single bolt gusset for the (2) inside frame members of his design.



That works fine for his situation, because I will be warping wood for the curve I wanted a little more margin for the frame rigidity.


Bosch originally shipped my order with (10) single bolt gussette, and when I put that together the did not hold so well for the in-plane rigidity/torsion flex.

Swapped with them for the double bolt gussetts.



Updated timeline:

Looks like June 21 weekend is when this DIY screen project will be done, based on work travel and family weekend obligations ....

(you know, the married with children thing)


So, I have the frame material, the DW laminate, I've been exploring wood options @ HD/Lowes for the curved piece and will post my thoughts here prior to 6/21 to pick others brains.


So far, I've spent $170 frame + $120 DW laminate, round that to $300.

I figure another $50-60 total for wood/screws, and black border material.

Plus, I'll be using 3/8 "super magnetics" for my manual 16:9 masks, I'll have to add that cost as well. So looking around $375 for the total project, we'll see how close that is when done.
 

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Discussion Starter · #23 ·
It's been a while since progress/posting.

As noted elsewhere in this forum, here in SE Michigan area we had bad storms weekend of 6/8 and we lost power for 7+ days, 6/8-6/15. That put me a few weeks behind schedule.


Below is quick run-through of frame assembly, so far I've not tackled the curve portion, that is 2 weeks away still.


Materials:





Sub assemble the corner gussets:

(4 fasteners/gusset, here only 3 shown)



I drilled (5) holes in the top and bottom member for Allen wrench tightening of end screws in the 5 vertical members.



Slid each member to it's position, just slightly tightened the end screw, attach corner gusset, slowly tighten "T", mostly it self-aligns and locks in place.



Once or twice I was not sure it locked correctly, so I used a finish nail to "hold" it while initially tightening it, that worked and ensured 100% correct alignment:



Here is a 126" diag 2.37:1 very rigid/strong lightweight frame.

This will become the backbone for the curved wood portion.

Next time I post I'll have the curve method worked out, I might post some ideas before I tackle it.



By the way, here is my temp "ghetto mount" of my Panamorph U380, seeing scope for 1st time was real neat:
 

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Hey nice work I used the same material accept the 1.5" stuff or my frame some time ago and plan to build a new 10' screen here shortly as the whole room is getting a makeover. I have a supplier local just go down and pickup what I need.


Nate

 

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Scott Horton, techht.com
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Lat to this party, but... FYI, if you use the 30x30 profile (much more rigid), they make some groove covers for it that double as a panel slide. Those are strong enough to "snap" into the grooves and bind a piece of blackout material. I have a test 2.35 screen I made with it for evaluating pincushion on anamorphics. It is free standing. I'll try to take a photo of it.


Scott
 

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Quote:
Originally Posted by mtbdudex /forum/post/13932864


My original post stated (I know tmi):


I expect the rigidity of the 20mm x 20mm frame to be magnitude stronger than the wood, so it will basically stay flat, but honestly until I try it I can't be 100% sure, unless I want to do some Engineering 501 with FEA/etc, and that's too much for me. If the 20mm x 20mm is not enough, then I'll try some countermeasure first before giving up on 20mm x 20mm and moving up to 30mm x 30mm.


Mike... did you find the 20x20mm strong enough? With a smaller screen (101" diag, 93" width) could I go with the 30x30mm and not use the vertical bracing?


Ron
 

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Great thread guys !


From what I have read both "mtbdudex" & "Iitai" used Bosch T-slot rails, 20mm & 30mm respectively.


Questions for; "cubesys", Nasty N8" & "GetGray";

What brand of T-slot rails did you use in your builds ? What size frames did you go with & did you use vertical supports ?

How did you attach your screen materials to the rails ?

"Nasty N8" what was your screen fabric ?

You guys have any photos of your builds ?


Did you find it necessary / or good to paint your frames black, before adding screen fabric ?


These questions may have been answered already, but since so many posts were lost, I thought I would ask.


Thanks,

John
 

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Scott Horton, techht.com
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HDGTX/John: Here is the 2.35 screen I tossed together with the Bosch 30x30 for anamorphic lens testing. The strings you see in the photos were special markers I was using, just ignore them. I threw this together in a couple of hours from spare 30x30 stock and a piece of blackout cloth. The material is held firmly in place by the Bosch channel covers (not the skinny/flat ones, but the ones that double as a panel holder). You can see I have it stretched tight. What you can't see is there is a middle vertical member. Also, I just used spare small gussets I had on hand. Using the larger ones give some flexibility to stretch the fabric more if needed. It's no Stewart, but for a screen I could literally draw or write on if I wanted (didn't), it serverd it

purpose fine. This one is free standing on 2 30x30 "legs". I took acloser shot of the corner, too so you can see the covers holding the material.


It would be trivial to add a velvet,etc. covered border using the same small gussets, or leave spaces in the black covers to insert a T-nut along the frame.


You are close enough I might sell it if you wanted to come after it. But I might need it for another test soon first.


Rough picture, In an unfinished area, excuse the mess:





 

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Hi "GetGray",


Thanks for the great info & the pics, kind of you to take time to post the info & pics. Great looking screen

& frame, what size is it ? When you get ready to sell, PM me. I may not be ready yet, no projector yet. The BOC screen surface looks very tight & straight. Does your center vertical support show thru at all on the screen surface ? I wondered if one should use the smaller size of vertical T-rails (20x20mm in this case) in the center of the frame to avoid them showing thru the fabric (in case the fabric rests against them) ?


Still in planning stage. Looked at a bunch of stuff on Bosh's web site today -- lots of cool stuff. That top T-slot rail would make a great place to hang & slide a mask assembly from. Thanks again.


John
 

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Scott Horton, techht.com
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Quote:
Originally Posted by HDGTX /forum/post/14441630


Hi "GetGray",


Thanks for the great info & the pics, kind of you to take time to post the info & pics. Great looking screen

& frame, what size is it ? When you get ready to sell, PM me. I may not be ready yet, no projector yet. The BOC screen surface looks very tight & straight. Does your center vertical support show thru at all on the screen surface ? I wondered if one should use the smaller size of vertical T-rails (20x20mm in this case) in the center of the frame to avoid them showing thru the fabric (in case the fabric rests against them) ?


Still in planning stage. Looked at a bunch of stuff on Bosh's web site today -- lots of cool stuff. That top T-slot rail would make a great place to hang & slide a mask assembly from. Thanks again.


John

re size, it's whatever the blackout cloth width is, I forget, 54" I think about 10' wide 2.35. Center post does not touch or show. No need to use smaller posts. That span is too long for a 20mm post anyway IMO. yes, the structural profiles are like an adult erector set. Chop saw and a hex key set and you can build a lot of cool stuff. I use it to make my CineSlide mounts (see "options" link at www.cineslide.com ). But mine are reanodized black.
 

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Sorry I missed the question.


What brand of T-slot rails did you use in your builds ? I used a local company Frame World 1.5" thick


What size frames did you go with? First one was 106" 1.78:1 new one is 10' wide 2.37:1

did you use vertical supports ? No plenty strong

How did you attach your screen materials to the rails ? First one I used a rubber hose pinching the fabric in the groove (kind of a pain) and some super glue in spots. new one not sure may try velcro

"Nasty N8" what was your screen fabric ? First one Da-Lite Cinema Vision Second I have Seymour AV acoustic transparent

You guys have any photos of your builds ? Posted


Did you find it necessary / or good to paint your frames black, before adding screen fabric ? No the frame section was covered with the screen wall


Nate




 

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Good work guys



Mark
 

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Great thread guys. So glad I found it. I tried building a frame for a 128" wide 2.37:1 screen Tuesday night and it was horrible. 2X4's just aren't very straight at 11' long and it doesn't take much of a bow to make your screen bad.


My question: If I use the 30X30 tubing, will I need vertical support bars or will it be rigid enough? I'm using the sheerweave fabric for AT and I'm worried about being able to see the vertical supports through the screen material as well as possible sound issues.
 

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Discussion Starter · #35 ·
No, I've not "given up" this DIY project, other normal life distractions got in the way for a while.

Plus, like others here have found out, the temp primer drywall'd wall screen does a decent enough job so we've been watching that and the "pressure" to finish the "real" screen is less.

Since I want to carpet the HT room over xmas vacation all these little/final DIY projects now have to get done.


Therefore, finally made some progress over Thanksgiving weekend (Sat afternoon and Sunday).


Wood frame making that will become curved and used for attaching DW laminate & screen black border too.

I used base board molding from HomeDepot, it was 1/2" thick x 4" wide, mostly flat with slight router shape on the top edge.

Used table saw to get rid of that for a 3 1/2" wide piece.

The whole wood frame will be mostly overhang the alum frame by 1/4" on the inside and the rest overhang on the outside.


Measure/cut confirm before attaching together.



Wood frame together, used dual corner braces to keep the frame "flat/in plane to itself" when it becomes curved:

(that's my theory at least...)





Getting ready to attach the wood frame to the alum frame.

The alum frame is blocked off ground at the 4 corners and center.



Corner shot and misc hardware to be used:



After debating/different design concepts for the end supports, I decided to use 4 x 4 (really 3 1/2 x 3 1/4) Cedar post. I picked a very tight grain running the correct direction for my mounting.

Using geometry/trig 101, and wiki http://en.wikipedia.org/wiki/Circular_segment , calculated the correct angle.

Notched them for nesting onto the alum frame and attachment method.

This pict shows 6 "identical" blocks that are cut at @ 7.11 degrees, height of 3.67", 3 used per side.



Missed taking some in process shots.

Basically aligned wood frame over alum frame, with 1/4" overhang all round on inside.

Clamped at 4 corners.

Attach at middle.

Attach at mid support. I used same cedar stock, calc correct angle.

Here shows with 1st end support in place roughly during confirm fitting.

Ended up using 2" decking screws to attach the cedar block to the alum frame and also the wood frame to the cedar block.

All mtg screws on wood frame are sunk just below surface for flush DW laminate mtg.



A composite alum/wood frame curve screen in process.

The small block was cut at 3.55 deg with a height of 0.914"







Nothing like some background AC/DC while working...



Stay tuned, I'll be working on this nightly.

I'm going to get the mounting done next and mount w/o screen.

There will be a border frame attached on top of the wood frame once it is laminated.
 

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Discussion Starter · #36 ·

Quote:
Originally Posted by mrlittlejeans /forum/post/14884023


Great thread guys. So glad I found it. I tried building a frame for a 128" wide 2.37:1 screen Tuesday night and it was horrible. 2X4's just aren't very straight at 11' long and it doesn't take much of a bow to make your screen bad.


My question: If I use the 30X30 tubing, will I need vertical support bars or will it be rigid enough? I'm using the sheerweave fabric for AT and I'm worried about being able to see the vertical supports through the screen material as well as possible sound issues.

Do like Itai did, add just two vertical support bars, his is AT fabric and w/o lights no problem for see thru (I was at his home a few months back). Spaced so your RH/Ctr/LH is not in the way.


Without you will get too much flex, the alum 30x30 is not that strong by itself for that length (I've held them at work that big).


OF course you could do the Mechanical static load analysis, all the parameters are in the Bosch info, if you like doing that stuff.
 

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Discussion Starter · #37 ·
Few more picts of activity tonight.

Made 4 more blocks to give added stability on the corner along the top and bottom member.

That 4 x 4 cedar sure is good wood to work with, nice grain and does not split.

These were cut on 5.78 deg, 2.42" height, 2 RH and 2 LH's made/installed:




The one on the floor were installed tonight:



Curvature is now consistent w/o any flat spots, success so far!!



Here I took a square and ran it across the top/bottom along the width of the screen frame, constant gap confirms no flat spots.

I could measure the chord height "h" and reverse calculate the screen curvature, for a chord length of 2', to see if it is 39.7' radius, I just might do that tomorrow.




Tomorrow I'm going to work on the wall hanging and see what part of the frame needs to be painted flat black. I'd like to set this at the same height as the drywall viewing was painted, plus give me 2-3 adjustment's up/down in 1" increments, just in case for future proof, so now is the time to make that.


I'm taking Thursday off work, my son has a school field trip, when we get back @ 2pm my goal is install the DW laminate then.

And of course hang it up, re-calibrate the PJ to the DW laminate, and watch the 1st Blu-Ray on it of possible the night.

Finally, light at the end of the tunnel.

I will be working on the black velvet border this weekend, I'm going to the DIY screens forum to see how others did theirs.
 

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Discussion Starter · #38 ·
Wed 12/3 progress.

-Making & hanging cleats

-1st frame hanging

-rough pincushion check

-determine what on the frame needs painting prior to laminate install (via paintbrush hand apply, not spray paint)


Hanging DIY cleats, I tell you that $39 laser I bought from HomeDepot 7 years ago is one of my favorite tools.

It sticks onto walls via small pin needle extension and you can barely tell afterward.



Frame up and level!

Cleats worked like a charm, and I could easily adjust the frame side-side.

And yes, I do plan on rope back lighting, that is why you see the recessed 120v access, the other gang box houses Cat5e for future screen masking controls if I ever go that route.



Close up of cleat, one each side, nesting into the alum framing.




Side profile, I'm stoked. Can't with for the laminate to be done, which I am attaching via contact cement to the wood (not the center piece).



Pincushion grid study:

My PanamorphUH380/SonyVW60 combo need fine tuning obviously, I put it up there months ago and now will dial it in perfectly after the screen is done.
 

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Discussion Starter · #39 ·
Ok buddy, you are going to become my screen!


This is a 5' x 12' sheet of HomeDepot special ordered DW laminate.



Measure/score/cut/little "oops"
on one side, that's why you give 2" overhang all around for "oops" while cutting and install.



Pre-check, getting ready, kids waiting/watching.



My wife and I did a few dry trials, can I tell you it really is a bear taking a 127" long x 61" wide sheet of laminate and flip it over and expect a good install?

Coordinating hands, having them crossed when the sheet was upside down and then while turning over they became correct, little details that needed trials before actual.

I had to put my Manufacturing hat on to error proof the install process as much as possible.

I came up with these install guide jigs, 3 on the bottom side to center the sheet and line up one edge.

The edge of the center one was the dead center for the laminate, I put a mark on the white side to line up with that.

The other 2 jigs I spaced 1' apart from center, that was about how much of the bottom laminate was there when sagging prior to the center actually touching the wood frame.

We trialed with the jigs 3 times and felt very confident to do this with just us 2 adults.



Glue applied first to laminate, then the wood, in my past experience the wood dries faster because it soaks some of it, so the laminate is best applied glue first, then the wood. I actually turned the fan to the lamiante to get it the same tacky state as the wood, then turned it facing out of the room to remove the fumes, it's winter here in SE Michigan!




It worked!!

Those guide jigs helped so much, easy to line up the center point and have confidence the laminate is where it should be, we gently lowered the laminate (Imagine it is curved, which it is), center touched, then as we lowered it touched from center to sides w/o any gaps. I then took the "J" roller and applied pressure.





I'm going to let it dry tonight and router the excess tomorrow.

That screen is being hung and viewed tomorrow night, time to celebrate getting this far.


I'll be working on the border and post that progress later.
 
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