03-11-2012: I thought I?d make a log of my project. I based my design on Retired2?s. I am a novice woodworker. I probably should have made a simpler version but I really liked his design. After months of reading and planning, I started my build. Today I finally had all of the parts made. I did make a deviation from his design. I couldn?t figure out a way to make the radial dados in the rings. So I planned to omit the dados and have the upright spacers butt jointed with counter sunk screws in the rings, screwed into the uprights. Well that was a bad idea. First screw (even though I pre-drilled) split the upright. Another bad decision was I made the upright spacers out of mdf. So my plan now is to remake the uprights out of oak and see if that works. I realized that screwing into end grain is not a good idea, but I hope it works in oak.
03-11-2012: I remade the up-right supports out of oak. It is really solid now. Leason learned.
Here is a pdf of my plan. 2-d sheets 1-7
And a 3-D pdf.
And pdf of round to rectagular inlet I made from RONS' instructions.
I should also mention that many members of this site have helped me. So many. I should have made a list. Like I said I am a novice woodworker, I had no idea how to make the parts I drew. I made all of my parts using pit bull?s circle cutting jig that he shared in his thread: 6" Inlet/Outlet Separator How to with Video. It works great. I don?t have a router bit long enough to cut the parts stacked together. Using the jig, I cut them separately yet they match perfectly.
Doug, You are doing a great job of documenting your Thien TopHat design, keep up the good work, many will be helped by your drawings which are worth thousands of words. I looked over your drawings and didn't see any issues that should impact your build or performance. The transition drawing is very good and detailed, good luck building it.
Bolting the baffel to the bottom with one screw through the center will stiffen it up a lot.
Ron
03-14-2012: I put the polycarbonate in place temporarily with clamps. You can see the mismatch with the slot in the baffle. This was intentional. My plan is to cut the baffle flush with the plastic, while assembled, with a flush cutting router bit. The gap at the top was probably bad planning. The width of the plastic ranged from 6.06 to 6.125. So I made the stack up of my rings and uprights to be 6.25. Why? I don’t really know. At the time I was thinking would be good place to lay a bead of silicone. Hindsight, I wish I would have cut the sheet parallel at 6 inches even and made my stack up like 6.015.
(//)
I was hoping for some feed back. I am wondering if I should disassemble the whole thing. Cut the plastic to 6 inches. Then, cut all of my supports to match. I am thinking then the screws won?t have enough bite. I could c?sink deeper in the rings so the screws can hold. Or should I just run a bead of silicone in the gap between the top of the plastic and the top of the top ring?
Another thought came to me just now. I could run the the top ring (while assembled) across the jointer a few passes. Im not sure how well mdf works with a planner.
any possibility of routing a small grove for the polycarbonate to sit in and put a small bead of caulk/silicone in the grove to seal things? This was my thought during my design phase which is still in progress.
Quote from: Dougp28704 on March 10, 2012, 08:32:29 PM
Here is a pdf of my plan. 2-d sheets 1-7
And a 3-D pdf.
And pdf of round to rectagular inlet I made from RONS' instructions.
Can you please save your SolidWorks as dwg or dxf? I can import those directly into SketchUp. Thanks
I?ll export file to dwg tonight.
Quote from: jgt1942 on March 15, 2012, 09:48:45 PM
any possibility of routing a small grove for the polycarbonate to sit in and put a small bead of caulk/silicone in the grove to seal things? This was my thought during my design phase which is still in progress.
I could put a grove in the top. That is what Retired2 did. But to do that I would still have to take everything apart. Cut the uprights shorter and reassemble. At this point, I want to just finish this. Does anyone out there have an opinion if this gap at the top will hurt the function of the seperator if I fill it with silicone?
Quote from: Dougp28704 on March 16, 2012, 10:57:05 AM
Quote from: jgt1942 on March 15, 2012, 09:48:45 PM
any possibility of routing a small grove for the polycarbonate to sit in and put a small bead of caulk/silicone in the grove to seal things? This was my thought during my design phase which is still in progress.
Does anyone out there have an opinion if this gap at the top will hurt the function of the separator if I fill it with silicone?
My unscientific quesstimation is that sealing the top gaps with silicon will not significantly hurt the separator's performance. I base this upon the thought that the air flow is moving around and towards the base of the separator.
Do I think that it hurts the performance "some", yes I do. I believe that anything that causes turbulence in the ducting or separator has a cost in efficiency. However, is it enough to cause a rebuild? I think that the effect from a 1/4" silicon rough area would be minimal.
Personally, I would continue with what you have and see if the separator meets your expectations. If it doesn't you could disassemble, put in a wider piece of polycarbonate and redo the uprights.
I'm happy with my separator, but am really intrigued with a discussion Phil had in a different post. He talked about increasing the height of the separator giving the opportunity for a high inlet and a lower outlet and the benefit this had when separating fines. If you do end up having to rebuild that thread gives some pretty good food for thought. When I have some free shop time I think that I will explore that with the addition of a round to rectangular inlet using Ron's drawing.
Just my $.02
Steve
Quote from: Dougp28704 on March 16, 2012, 06:09:07 AM
I?ll export file to dwg tonight.
Sorry. I thought SW's could export to dwg. It can, but only the 2-d drawings. Can sketchup import other 3-d files? I can export to iges, step, parasolid, acis.
I don't think that filling the gap with caulk/silicone will impact the performance of your Thien TopHat at all. I would smooth the caulk/silicone as much as possible to reduce any turbulence.
if u go with the silicon u might want to rough up the area to be glued so the silicon ca get a better bond. i had a few leaks and had to take my apart and sand it but i used tape to protect the plastic
Quote from: Dougp28704 on March 17, 2012, 10:10:46 AM
Sorry. I thought SW's could export to dwg. It can, but only the 2-d drawings. Can sketchup import other 3-d files? I can export to iges, step, parasolid, acis.
Thanks for trying! I'll just recreate in SU using your PDF.
Doug, Per your message, here are some pictures of the way I bend the Sheet Metal for the transition. The bends are only about 15 degrees so take it easy when you make a bend. The biggest issue, as you work around the transition it becomes rounded and hard to get it under your bench top I just forced it. I originally used to pieces ok angle, but the flat piece makes it easy to keep one end clamped when moving to the next bend line.
Picture 1 and 2: Angle and flat piece of metal (AL) clamped to edge of bench, with front edges aligned, as "Break". SM to be bent is placed between the two pieces with the bend line aligned to the front edge and clamped place.
Picture3: Make your bend
Remove clamp align your next bend line repeat until done. Try not to bent into the round and rectangular extensions any more than necessary. You can use the same setup to make the 90 degree bends for the rectangular corners.
03-24-2012: Making the transition intake. The first half of the diagonal bends went really well. The second half is giving me trouble. As Ron said, the curve ends up hitting the bottom of the bench.
After a short break, I went back to it. Finished off the diagonal bends. It looks pretty good.
03-25-2012: Today I made an assembly jig for the round to rectangular intake. It is two .75 thick 5.06 diameter pieces of mdf screwed and doweled together. Two .75 thick pieces of 3.58 x 5.95 pieces of mdf screwed and doweled together. The round and rectangular parts are screwed and doweled to an 8 inch long 2x4. The rectangular end of the sheet metal fits the form fine. But I can?t get the round side to wrap all the way around. I quadruple checked my ?round to rectangular transition drawing?. Ron advised to try not to have your diagonal bends go into the round section. Well, I couldn?t help it, the creases did. I figured I could flatten them out once I got it on the jig. I just can?t get the round part to be round yet. I think a sheet metal shop has a device that has two rollers that clamp the sheet and you push it back and forth to take out the crease. Obviously I don?t have that. Trying to figure out a way. I gave up for tonight and decided to post my status.
Its hard to believe that the creases would take up so much space on the circumferance. But like I said, I am sure my drawing and sheet metal cuts are correct. Any ideas out there?
Maybe a large enough hose clamp that will pull the thing closed around the form?
Doug, To help straighten the small bends just place the round end on a flat surface (edge of bench) with the form installed and tap the creases with a hammer.
How much of a gap do you have on the round end?
From your drawing I see you were trying to fit the uncrimped end of 5" pipe inside of the round end. If you are off to far you could go with the crimped end which is about 4.97.
If you have a 4" to 5" or 5" to 6" round transition try and fit the 5" end over the round end of your transition and see if that closes the gap. If it does you could just leave it there.
Good idea Phil. I put hose clamps on and it clamped round to the form.
Ron, I still have about .5 inch gap. Tapping the remaining creases out with hammer may close the gap a little more, but not enough to fasten. I cant figure out what went wrong. My plan was for spiral pipe to fit inside the inlet. It has a 5.03 O.D. I think I will be able to forget the spiral pipe and use the crimped end of regular duct.
I have been thinking about this. Over thinking probably. My drawing was for the inside dimensions. While folding, I needed to see the lines. So, the inside became the outside. Does it make sense that the material thickness offset multiplied by all the bends caused the gap?
Anyways.... I plan to cut a sheet metal strip, from the scrap left over, and rivet it in place to close the gap. And Tape the seams with foil tape.
Doug, Good idea using a SM strip to cover the gap. I think that will be ok.
If you put the out side dimension's ( your ID 5.06 + 2* your SM thickness) into the spread sheet you should be able to see what the difference in the short/long tic marks would be.
I looked at my transition and all the bend markings are on the inside.
Yeah, down the road I may remake my trasition. This thread should help me remember my mistakes so I dont repeat them. And hopefully help others that plan to make a similar Top Hat.
I riveted it together tonight. Thanks Ron. It is very satisfying to make a custom round to rectangular transition from a $10 sheet metal piece from Lowes. And I still have a good size piece left over from sheet to make something else.