I have a question. By "brick measure" are you guys referring to the folding rule?
That is what dad used when laying brick and block decades ago. Not sure if certain measurements are highlighted that corresponds with certain brick/block/seam combinations making for a quick check of the run, or what, but that's all I remember him using while laying brick. Never a tape measure.
Handheld 3x21 Rockwell belt sander. Picked up new 50 grit and 120 grit belts today. Yes, indeed, lots of sawdust. Should be fun!!!
The plan: I will be clamping/mounting the donuts in my 45 degree angle sled and bringing the edge down to the guidelines in a total of 5 stages. Double checking the round-over consistency along the way with the templates. When I get close to the final round-over guidelines, my plan is to glue sandpaper to my templates and do the final sanding by hand.
We will need the gratuitous slo-mo sawdust flying everywhere shot for sure Gluing the sandpaper to the templates is a good idea👍
I loaded the donuts into my 45 degree angle speaker building sled (fixture). This made it easy for me to sand the profile from a standing height, and, at the same time, allowed the weight of the belt sander to do most of the work. As I went along, I was constantly checking the profile against my templates, which helped me to start developing a consistent rotational sanding pattern, to avoid flat spotting. I'm about half done now and the donut is really starting to take shape!!
I'd chisel some chunks out. That framing slick of Ron's would work well.
I was going to do this to save time. But after thinking it over, I decided to sand it all down with the belt sander. My thinking was that I needed practice to get a feeling for how the belt sander was working so that I could develop a good rotational rhythm. I also needed to get a feel for how quickly different grits (40, 80, 120, etc.) hit my guidelines. If I started by chiseling out large chucks, I might end up flat spotting the top edge, going too far before realizing that I messed it up. A belt sander is a very aggressive tool and must be handled with caution. I agree, what I am doing is a lot more work and dust, but hopefully it will help me avoid mistakes.
What is Ron's framing slick?
EDIT: Also, one thing that I noticed so far is that this particle board bench-top material (approx. 1-1/8 thickness) has an extremely hard surface layer approximately 1/16" on both the top and bottom surfaces. When the belt sander hits those hard surface layers, the sanding belt is much less effective. The inner surface of the particle board is very soft and sands off quickly. After sanding back and forth in my rotational pattern, I check with the template only to find that the surface layers are bulging up a little. So then I go back and re-sand the bulges to match the template. Seems strange, but true.
If this works, here is an enclosure built by Olson that was at InDIYana 2018.
This enclosure served as inspiration for this build. When I was listening to these, I kept wondering what a pair of smaller donuts with better drivers would sound like.
It was build in grasshopper, using lunchbox plugin, then baked in rhino. It's sort of a mobius surface, machined in 3 axis. There's no write up. Parametric modeling.
A few slo-mo dust flying everywhere shots. I marked the high spots with a magic marker and then ground them down as I went along. I am now very close to the final guidelines.
I'm surprised; accuracy is VERY good, much better than I had initially anticipated. Using 40 grit sand belt type strips glued to my templates, I'm getting an almost perfect 5-5/8" radius all the way around. The taper from 5-5/8" down to 3/4" also looks very good after hand sanding with my smaller radius templates.
Belt sander gear box is started to fail (slipping). I tore it apart and fixed it and am hoping that it holds together until I get done. Looks like I will be in the market for a new belt sander soon. This one dates back to the 1970's, when refrigerators were green.
Marking the high spots:
Dr. Diffraction lost 5 lbs. of sawdust in only 7 days!!! Now weighs in at a mere 13 lbs!!!! (on bathroom scales; down from 18 lbs.):
Big, big pile of sawdust:
I mounted the tweeter to see what it will look like. Kind of goofy looking, but not too bad:
That looks like a real labor of love, with emphasis on the labor.
I wonder if you could mount the whole block on a turntable so you could rotate it, and use a band saw with a big enough throat to rough out the cuts and reduce the amount of sanding to a minimum?
I can't believe you're doing that nasty work wearing such a nice dress shirt. Heck, you're even wearing your wrist watch. Positive points for that. I usually wear my oldest, most worn out Tee shirt, complete with holes under the arms when I tackle anything close to that! I'm glad to see you are wearing a proper respirator but Bill, Bill, Bill.... no safety glasses or leather gloves? Naughty naughty my friend. Positive points removed.
Leather gloves can actually be a bad thing. It leads to less grip by hands, and possibly loose material that can get caught in moving machines. I personally don't like gloves in most cases.
1- no jewelry of any kind should be worn. Including wedding rings. 2- personal protective equipment; glasses/goggles, respirator, hearing protection, smocks/aprons, Kevlar sleeves 3- no loose clothing or dangling hair, etc.
I actually get polycarbonate lenses for my glasses for protection, even if the spectacles are not rated as safety frames. I've had instances where I was glad for that as I used to be required to wear prescription safety glasses for work. Now that I don't have to, I still wear safety lenses.
Sorry for delay in responding, been offline for a few days. You caught me!! I do have two pair of safety glasses sitting slightly out of frame. I keep taking them off because they keep fogging up. I have the respirator tightly sealed around my nose, but there is always a small amount of leakage that fogs the glasses. You almost need a respirator with built-in goggles to solve this problem.
The shirt is several years old with worn collar and missing buttons. The watch has a flexible band, so I should get a few safety bonus points for that! But on an overall basis, I stand corrected and will try to follow better safety procedures in the future.
That looks like a real labor of love, with emphasis on the labor.
I wonder if you could mount the whole block on a turntable so you could rotate it, and use a band saw with a big enough throat to rough out the cuts and reduce the amount of sanding to a minimum?
Thanks. This would certainly be possible, but my band saw is too small to handle this diameter. Both of my donuts are now done, sanded down to a spec tolerance of roughly 1/32." If I ever do this again, I will certainly be looking into getting a bigger band saw.
Wow, that's impressive! Hope the old Rockwell holds together so you can finish the second one.
Made it (and still grinding away).
Thinking that it might burn out before I got done, I went shopping for a new belt sander and found a Porter Cable unit, model 352VS --- that is almost identical to the 40 year old Rockwell. The only difference is the dust port.
Internal dimensions modified to: 32" H x 7.125" W x 11.25" D. Gross volume: 1.48 cu. ft. WinISD standard tuning model: FB: 35Hz. F3/6/10: 32/29/26 Vent: 2.5ID, 5.4" length. WinISD TL port tuning model: FB: 31Hz. F3/6/10: 31/29/26 Vent: 2.5ID, 7.4" length.
This will be an accidental ML-TL with the top half of the line stuffed with denim and the lower half left open as a resonating chamber. Port will be on the rear about a foot off the floor.
Comments
If this works, here is an enclosure built by Olson that was at InDIYana 2018.
I know!
I loaded the donuts into my 45 degree angle speaker building sled (fixture). This made it easy for me to sand the profile from a standing height, and, at the same time, allowed the weight of the belt sander to do most of the work. As I went along, I was constantly checking the profile against my templates, which helped me to start developing a consistent rotational sanding pattern, to avoid flat spotting. I'm about half done now and the donut is really starting to take shape!!
Edge beveled down to the first set of guidelines:
Edge beveled down to the 2nd set of guidelines:
Good agreement with 5 5/8 template so far:
I was going to do this to save time. But after thinking it over, I decided to sand it all down with the belt sander. My thinking was that I needed practice to get a feeling for how the belt sander was working so that I could develop a good rotational rhythm. I also needed to get a feel for how quickly different grits (40, 80, 120, etc.) hit my guidelines. If I started by chiseling out large chucks, I might end up flat spotting the top edge, going too far before realizing that I messed it up. A belt sander is a very aggressive tool and must be handled with caution. I agree, what I am doing is a lot more work and dust, but hopefully it will help me avoid mistakes.
What is Ron's framing slick?
EDIT: Also, one thing that I noticed so far is that this particle board bench-top material (approx. 1-1/8 thickness) has an extremely hard surface layer approximately 1/16" on both the top and bottom surfaces. When the belt sander hits those hard surface layers, the sanding belt is much less effective. The inner surface of the particle board is very soft and sands off quickly. After sanding back and forth in my rotational pattern, I check with the template only to find that the surface layers are bulging up a little. So then I go back and re-sand the bulges to match the template. Seems strange, but true.
This enclosure served as inspiration for this build. When I was listening to these, I kept wondering what a pair of smaller donuts with better drivers would sound like.
Is there a write-up or thread showing how this was done? I'm trying to visualize the manufacturing process.
A few slo-mo dust flying everywhere shots. I marked the high spots with a magic marker and then ground them down as I went along. I am now very close to the final guidelines.
I'm surprised; accuracy is VERY good, much better than I had initially anticipated. Using 40 grit sand belt type strips glued to my templates, I'm getting an almost perfect 5-5/8" radius all the way around. The taper from 5-5/8" down to 3/4" also looks very good after hand sanding with my smaller radius templates.
Belt sander gear box is started to fail (slipping). I tore it apart and fixed it and am hoping that it holds together until I get done. Looks like I will be in the market for a new belt sander soon. This one dates back to the 1970's, when refrigerators were green.
Marking the high spots:
Dr. Diffraction lost 5 lbs. of sawdust in only 7 days!!! Now weighs in at a mere 13 lbs!!!! (on bathroom scales; down from 18 lbs.):
Big, big pile of sawdust:
I mounted the tweeter to see what it will look like. Kind of goofy looking, but not too bad:
InDIYana Event Website
Wolfy's Photobucket
That looks like a real labor of love, with emphasis on the labor.
I wonder if you could mount the whole block on a turntable so you could rotate it, and use a band saw with a big enough throat to rough out the cuts and reduce the amount of sanding to a minimum?
1- no jewelry of any kind should be worn. Including wedding rings.
2- personal protective equipment; glasses/goggles, respirator, hearing protection, smocks/aprons, Kevlar sleeves
3- no loose clothing or dangling hair, etc.
I actually get polycarbonate lenses for my glasses for protection, even if the spectacles are not rated as safety frames. I've had instances where I was glad for that as I used to be required to wear prescription safety glasses for work. Now that I don't have to, I still wear safety lenses.
InDIYana Event Website
Wolfy's Photobucket
Sorry for delay in responding, been offline for a few days. You caught me!!
I do have two pair of safety glasses sitting slightly out of frame. I keep taking them off because they keep fogging up. I have the respirator tightly sealed around my nose, but there is always a small amount of leakage that fogs the glasses. You almost need a respirator with built-in goggles to solve this problem.
The shirt is several years old with worn collar and missing buttons. The watch has a flexible band, so I should get a few safety bonus points for that! But on an overall basis, I stand corrected and will try to follow better safety procedures in the future.
Thanks. This would certainly be possible, but my band saw is too small to handle this diameter. Both of my donuts are now done, sanded down to a spec tolerance of roughly 1/32." If I ever do this again, I will certainly be looking into getting a bigger band saw.
Made it (and still grinding away).
Thinking that it might burn out before I got done, I went shopping for a new belt sander and found a Porter Cable unit, model 352VS --- that is almost identical to the 40 year old Rockwell. The only difference is the dust port.
https://www.homedepot.com/p/Porter-Cable-8-Amp-3-in-x-21-in-Belt-Sander-352VS/100022581
Amazing. I could buy one of these new Porter Cable units and use the old Rockwell for spare parts!!!
I have to resist the temptation to paint ears, mouth, etc., around the mid/tweeter flange.
I could try hydro dipping the donuts, that would probably look cool.
Lower box glue up and modeling:
Internal dimensions modified to: 32" H x 7.125" W x 11.25" D. Gross volume: 1.48 cu. ft.
WinISD standard tuning model: FB: 35Hz. F3/6/10: 32/29/26 Vent: 2.5ID, 5.4" length.
WinISD TL port tuning model: FB: 31Hz. F3/6/10: 31/29/26 Vent: 2.5ID, 7.4" length.
This will be an accidental ML-TL with the top half of the line stuffed with denim and the lower half left open as a resonating chamber. Port will be on the rear about a foot off the floor.
https://www.diyaudio.com/forums/printthread.php?t=231951&pp=10&s=144d8484378ade2fd3a39e65d86e84e6