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Everything posted by klipsch

  1. It is possible. Oversimplification: The skram follows this concept, except Ricci made the skram slightly bigger (2 skrams are slightly bigger than one skhorn) and Ricci modified the ports to accommodate more tuning options.
  2. Nice. Looking forward to seeing you and your build thread for those Maybe use the cnc to build some Danley Jericho-esque mains for your PA 😁
  3. Try making a skram for an 8ich anarchy woofer. I have 2 of those in 2 tapped horns. They are paired with lsr 308s in my office. Great stuff. Someone model that please
  4. Give those PA a try I was thinking with 2 ports blocked on the skrams that there should be good response in to the 20s. Maybe try running the 3 dual sealed from 5 to 30ish and skrams from 30ish to 100ish. There is a dual front firing pair of 18s too behind the first row of seats (they're good for tactile). I'll need to play around and see how things work out. The 18s are the original stereo integrity ht18s so nothing bad, nothing great. I'll watch movies around reference, usually 5db below. I enjoy music as well and hoping these skrams bring some more fun to that arena.
  5. Will do. There are 6 18" drivers behind the screen right now (3 DO sealed boxes), along with the center SH50. I'm assuming the ports on the skrams are going to push out some air and potentially move the screen. Planning to finish skram 2 over the next couple weeks and then move the skrams in so the ports are below the screen and put 1 of the DO on top of each skram. I'll leave the 3rd DO as a speaker stand for the SH50. I think this is a good idea. The scram and the DO boxes are both exactly 32 inches deep, so hopefully that works out well.
  6. Negative sir. It is an SH50. That is one of "the triplets" as my wife likes to call them. 😉 Ran the last sheet for the 2nd skram. A shot about halfway through...
  7. 1 is done. On to making it a friend.
  8. The dxf that were posted could probably be used to be put in to Vectric (Vcarve or Aspire) or Autodesk (fusion 360 or other), run the nesting tools, and create the necessary toolpaths. That should save several hours of time by using those files.
  9. Sorry for the confusion. I was suggesting the use of melamine sheets to use for the vacuum housing box. Phenolic lined sheets can be used too if they're cheaper in France. Both are usually particleboard middles with lining of both materials on the outside (veneered like you mentioned). The melamine surface is well sealed to keep the multi-vacuum vac box chamber air tight. However, making a box is not necessary. Some just hook 1 vac per zone. The cost of mdf VS melamine in my area is the same. Making a vac box out of melamine saves time and money to seal the vac box if it is made of a porous material like mdf or wood. Metal would work just as well (maybe better) if you have access to fabricate that cheaper. I used 3/4 mdf for the vacuum board and have used regular mdf and umdf for spoilboards. The ultralight mdf may have been slightly better for these motors. I just had a free mdf sheet on hand once I went through the last spoilboard. Each spoilboard has always started out as 3/4". PS There are full phenolic sheets (no particleboard, but full phenolic throughout). Those sheets are several hundred each here in the States. High-end cnc machines use those as the vacboards. They just carve the pattern and need zero sealing due to the phenolic properties. MDF will expand and change with temperature and humidity, but phenolic supposedly does not.
  10. Thanks for the detailed info about the Amps. I only have a dedicated 20amp 240v for the clone, so hopefully that would be enough for a 20k. The xbs folks sent me a picture of a 20 Amp 240v plug they'd use (save me some work of rewiring). 4 sided shapes may work better for vacuum VS an L or other shape with more than 4 sides. I think I remember reading about that somewhere. I do mask the table when the smallest vacuum zone I have is too large for the work material. I have a few small pieces around 6"x20" to put around the work piece to cover the vac zone area. If the work pieces are really small, less than about 6"x6", I need to lower the IPM due to the smaller surface area. I have this image printed from a long while back near the cnc. I think it is accurate based on sea level atmosphere to approximately determine the hold down force. Years ago when I sprayed the duratex, I don't think there was a spray version. I've seen that there are spray and roller grades now (think on parts express). I did not research to see if those grades are marketing or if it maybe is more economical to buy roller grade and thin it to make "spray" grade or any other details.
  11. Haha about avsforum. I can relate - there may be 8 18" drivers in the room where the 2 skrams are going... 😯 I also have an extra b&c 8ohm 152 that needs a home. Build another skram? Buy another 152 and try a skhorn? 1st world problems... What type of clone Amp did you go with? I'm thinking of trying one for the 2 skrams. Maybe I should not have, but I suggested 3 vac motors as that is what I think I should have done. That is awesome that you and your Dad are working together. Congrats on his upcoming retirement. Right now, I have 4 vac motors. Can run either 2 at once or 4 at once. 2 is what I run 90% fof the time. 2 works for full 4x8 sheets. I've run 4 on large warped boards, but that was for material I ran for a few customers. Also run 4 for carving and cutting smaller pieces. For your smaller work area, 2 would probably be great, but for when you upgrade or cut smaller pieces, 3 would probably be a good option. I've never sprayed Warnex, but I've sprayed duratex before. It was not the spray version of the duratex. I watered it down a bit and it sprayed well with a cheap Warner sprayer (maybe it was 5 to 1 mixture). However, I ran a thick nap roller on the sprayed surface after the spray to get the texture look.
  12. A diy vac with 3 lighthouse motors will run around 700 bucks for melamine box (melamine makes sealing easy), pvc, mdf, pvc glue, circuit breaker, etc. I have two layers of mdf (one is the spoilboard). I made something similar to the below. It is based off of a Gary Campbell design: http://www.talkshopbot.com/forum/showthread.php?19556-Vac-box-setup-Complete The two skrams will be going behind a screen in our basement. Probably only to be heard and never to be seen again. There is no such thing as too many clamps Your cabs look great. Really nice job with the design and cnc work. Very clean. Looks like you and Kregg have been really busy too! I hope your design gets you that flat 30hz you're looking for in a transportable form. I'll find your avsforum post when you get to it. I am hoping to have these cabs done and running in the next 3 weeks. Doing some traveling...
  13. Vacuum hold down will change everything :). These cheap vac motors will take 1/2" warped sheets down flat. 3/4" warp sheets will go flat as well, but only if the warp is slight. If these cheap vac motors were replaced with a much more expensive regen vac motor, then there isn't much that wouldn't be flattened. Servos are very nice. Steppers work just fine too. This HSD air cooled spindle is not loud at all. I can hold normal conversations with just the spindle on. The cutting of the material is far louder than the spindle motor and the vacuum motors. However, all of that is no where near as loud as the dust collection system. Water cooled spindles are quiet, but do have more things to do for maintenance and operation. In my experience, for wood, typically I'll use climbing for first pass and conventional for final pass. For dados/grooves/joints, I'll do full axial path in climb and leave a bit on radial. Then do full axial and radial conventional path to remove the remaining radial stock material. For profiles, I'll do climb and leave 0.04" axial and typically 0.02" radial. Then do the final pass with conventional for remaining. This usually yields good results regardless of grain direction. Climb can be less forgiving against the grain. Higher RPM can combat that, but then an increase in IPM is usually needed, etc. The wife wanted me to stain these like the other sub cabinets we have. Current plan is to sand lightly and poly them. No duratex on these two. I really like your joints. They look nice for fit and great for final assembly. Long ago I used to glue and use brad nails, but have just been "gluing" with Pl premium 3x and clamping for years now. With CNC cutting (assuming joints or similar like yours), screwing and nailing has not been needed for me or others. Heck, I've seen people use Pl premium and painters tape instead of clamps with joints like yours. The tape was enough to hold everything in place while the adhesive expands and cures. I've had 4 DO 18" sealed subs running for 6+ years with no issues with the Pl premium and clamp method. I do use kregg's pocket jig and screws for things cut on a table or miter saw, even with that square headed bit Some clamping action: Have any pictures or models of the inside of that cab?
  14. Making a vacuum table is not too difficult. It may not be something you would want to do, but underneath an mdf or ultra light mdf spoilboard is a vacuum board with a pattern cut by the cnc that looks similar to the below. The vacuums connect from underneath to the hole cutouts in the vaccum board via pvc pipe. Different zones can be made on the vacuum board and then can control the vacuum to the zones with blast gates in-line with the pvc. The vacuums lower the barometric pressure beneath the surface of the spoilboard which creates push down force on the material resting on top of the spoilboard. It has worked very well for many (me included). Without knowing the torque vector of your spindle or router, rigidity of your machine, etc., what works best for you and your machine is all that matters and chipload calculations and calculators can be a nuisance. If it will help and you want, I attached a decent chipload calculator that could be used as a reference point. With my main 4.2 hp spindle and machine, I would start with a new material around the chipload recommended in "aggressive". With a router (not a spindle) around 3 hp for Baltic birch plywood, I would have started around a 0.004 - 0.006 chipload. chipload calc.xls This may not be your goal, but in order to extend my bit life, I like to be able to touch the bit after a job and it feel cool to the touch. The speeds I want to cut at and the material finishes have worked well with that cool touch bit as well. Ran another skram sheet last night for the second skram. Here are some chips from the hatch (2 flute 1/4 inch compression bit, ~12,000 rpm @ 240 ipm climb leaving .04" material - nearly full depth profile cut - bit cool) : Added a quick 1st coat of wet stain on skram number 1 last night too:
  15. I really like BB too. The Janka score can be around 1200 and I think as low as 1000. I think that's a decent range to account for when cutting. Over the years, there is a sound I've learned from others and my own work which helps figure out if the cutting rpm and feedrate are not good. Anything high pitch like a screech is typically not good. Visually speaking, if there is dust and not chips, then that is also usually bad (even for mdf).
  16. I ran a while without a vacuum hold down. There are motors here in the US for about $160 that last about 1200 to 1500 hours. 2 or 3 of them with 2 sheets of melamine for a housing will get you over 5 hg if that is something you choose to pursue. Not sure what you have available in your part of the world. Prior to the vacuum hold down, I would make tabs of .25" wide and .0625" thick. They worked well, but took work when finishing like you've mentioned. I then went to onion skinning from tabs and had much better results. Using a down cut bit helped keep the material on the table without a vacuum, but meant any plunge cuts were not too clean (more of a burn than a cut). To work around the plunge cut issues, ramps were used where they could be. A compression bit gave me the ability to do plunge cuts cleanly and still have decent down pushing pressure on the material without a vacuum and using tabs. Is the straight bit causing some "chatter"? 20,000 RPM at 150ipm for a single flute bit should produce a chipload around .008. Is that about what you are making? I only ask as when I was first starting out, I was running too high of RPM which made more heat and dulled my bits (was also using cheap bits). When that happened, the onion skinning and tabs both suffered as the wood was being pushed more than cut.
  17. Hey peniku. Yes, that is my cnc. I added, what may be, extra detail which made this a longer reply. Hopefully adding some detail helps to better answer your questions. For each of the sheets, no holding tabs were used. Instead, about 5 hg of vacuum hold down was used. For a few of the pieces requiring 2 sided work, the vacuum hold down was bumped up to 10 hg. Onion skinning can work better for rigidity and finish in my experience vs tabs when working with quality plywood sheets. What are your experiences? Your eyes are good. A 1/4 inch 2 flute compression bit was used throughout at about 250 ipm and ~12k rpm. Single climbing passes were used for all pocket/groove/slot/recess cuts. Two passes were used for the inside and outside profile cuts: one climbing pass at about 98% depth and 1 conventional pass at 100% depth. Those settings worked well throughout and I do not plan to change them for the 2nd skram. I thought about using a 3/8 inch bit for most of the cutting to be able to run > 450 ipm, but that used a little bit more material and would need a slightly different layout. Since I'm not mass producing these for profit, I stuck with the cheaper 1/4 inch bit. Looking back at my rough notes and machine logs, the following should be approximate cutting times for 1 skram: 12 mm baltic birch sheet: ~18 minutes 18 mm baltic birch sheet1 with the left and right side...: ~40 minutes 18 mm baltic birch sheet2 with hatch, bottom, top..: ~20 minutes 18 mm baltic birch sheet3 with single driver cutout: ~2 minutes Each second side cutting for the parts that have handle recesses took less than 5 minutes total for set up and cutting for each. There are 4 parts with 6 handle recesses, so I think a conservative estimate of 20 minutes total is accurate-ish (5 minutes x 4 parts). The second side cutting for the back part which fits the hatch part took less than 10 minutes for set up and cutting. Total time with setting up the sheets, parts, tooling, machine, and cutting for one skram is probably around 2 hours and 10 minutes with the 1/4 inch bit. How long did it take you to cut one?
  18. Thank you on all accounts! Same to you!
  19. Finally had some personal time to make some chips. Dry fitting the first one before moving on to cut the second one. Thanks for the design Ricci! Are you all using any acoustic foam inside the skrams? pictures or it didn't happen:
  20. Any chance you could throw the 18sound driver in there?
  21. Thanks! The Eminence really models closely to the IPAL and should be much easier to drive. Price VS modeled performance is an interesting decision
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