Translam Subwoofers with 18" Passive Radiators - The Jedi Mind Tricks

[Kevin K.]

I'll leave it on order. Anxious to see how this all works out. If you find you like the straight flute cutters better and end up using this one, we'll square up on it later. If not, just bring it with you to MWAF, I'll pick it up from you there.

[KEtheredge87]

Alright guys, time for another update. I made a test cut on some scrap with a straight flush cutter to see how the surface compares. The straight bit cut much easier than the spiral bit did yesterday, which makes me think I must have boogered up the spiral bit somewhere along the way. I can't imagine Whiteside really would let something that dull out the factory doors, but who knows. I suppose I'll find out Friday when the bit arrives back at Whiteside HQ in North Carolina. Fingers crossed that I didn't do it!

What I can say about this test is the general surface finish with the straight bit was decent. In fact, If I didn't care about the exposed plies, I'd say it's good enough to use on the project. However, when I looked closer I could see little tearouts along the edges of every light colored ply that were not present on the pieces cut with the spiral bit. This makes sense... since a spiral bit is supposed to avoid tearout for better finishes. In the pictures I attached, the straight flush bit sample is the one with the aluminum template attached to it. It's hard to see with my cell phone camera, but the little tearouts are there. I assume I'd need to rub a thin coat of wood filler on the whole cabinet to smooth out those spots if I actually went forward with the straight bit?

Instead of making fully finished pieces with the straight cutter tonight, I just batched out some rough cuts on the bandsaw. Now my Jenga game looks really strange!

Picture 1) Straight bit sample on the left side with the aluminum, spiral bit sample on the right


Picture 2) Straight bit sample on the bottom, spiral bit sample on the top


Picture 3) JENGA!!!

[Gordy]

Yeah I think that spiral bit is done. Finish the project with the new flush trim bit.

[KEtheredge87]

Yeah I think that spiral bit is done. Finish the project with the new flush trim bit.

Man... I hope I at least get to learn what I did wrong with the bit if that ends up being the case. That bit ain't exactly cheap, so If it really is shot, I'd at least want to investigate carbide recycle prices.

Let's assume I do finish the subs with the standard flush trim... if I'm planning to leave the plies exposed with clear poly later on, shouldn't I try to fill those little tearouts, or am I just splitting hairs that no one will ever be able to detect?

[Gordy]

Man... I hope I at least get to learn what I did wrong with the bit if that ends up being the case. That bit ain't exactly cheap, so If it really is shot, I'd at least want to investigate carbide recycle prices.

Let's assume I do finish the subs with the standard flush trim... if I'm planning to leave the plies exposed with clear poly later on, shouldn't I try to fill those little tearouts, or am I just splitting hairs that no one will ever be able to detect?

Once you get it clamped up an glued you will need to sand. I have had the same issue and some sanding with 120 then 220 solved most of it. You can also build the coats and sand betweeen. I built a boombox in translam that was rough. After sanding, I sprayed satin lacquer for the first 2 coats then sanded. Then another 2 coats then sanding and so on... that box is new glass smooth.

[Kevin K.]

There's another option if you don't mind the extra work. Order an oversized bearing (not by much, same ID but .02-.03 larger on the OD) for the straight flush cutter. Run all of your parts with the straight cutter and you wont need to worry about burn marks. Follow that with the Spiral cutter using it's normal bearing and it should cut what's left clean and fast with no burns. Like I said, more work cause you will be putting your templates on twice but maybe cleaner cut parts in the end. McMaster probably carries the bearings.

[KEtheredge87]

There's another option if you don't mind the extra work. Order an oversized bearing (not by much, same ID but .02-.03 larger on the OD) for the straight flush cutter. Run all of your parts with the straight cutter and you wont need to worry about burn marks. Follow that with the Spiral cutter using it's normal bearing and it should cut what's left clean and fast with no burns. Like I said, more work cause you will be putting your templates on twice but maybe cleaner cut parts in the end. McMaster probably carries the bearings.

Hmm... I hadn't considered something like that before. A major step there would be actually getting my spiral cutter back from Whiteside. Assuming things go in my favor, I may have a new bit by this time next week. Until then I can still rough cut on the bandsaw... and Gordy's advice to roll forward with the straight cutter is still floating around my mind. I'm probably splitting hairs to the extreme if I'm worrying about micro-level tearout on individual plies. Unfortunately I challenge myself to do something new on each project, so I never know how it may turn out!

[Gordy]

There's another option if you don't mind the extra work. Order an oversized bearing (not by much, same ID but .02-.03 larger on the OD) for the straight flush cutter. Run all of your parts with the straight cutter and you wont need to worry about burn marks. Follow that with the Spiral cutter using it's normal bearing and it should cut what's left clean and fast with no burns. Like I said, more work cause you will be putting your templates on twice but maybe cleaner cut parts in the end. McMaster probably carries the bearings.

If you are looking for bearings that are hundredths over, I would try Stewart Mac. They sell 19 different bearings sizes that are to be used with a 1/2" rabbit bit for guitar bindings.

For example, add a .520" bearing to a 1/2" flush trim bit and you get .01" gap in the material being routed. I have used these bearings for speaker recesses with a 1/2 rabbit bit. I can flush mount a PS95 with zero gap around the edges and with a snug fit. Before Stew-Mac, I looked at McMaster and they did not have anything close. Due to the ID of the Stew-Mac bearings you may need a shim which is readily available. I needed one for my Freud 1/2' rabbit bit.

If you do the math, you can route out the hole for a speaker and just use a 1/2" rabbit and bearing to get a perfect fit. It takes some trial and error but if you want a snug/no gap perfect recess there is nothing better. With the bearings graduating in hundredths, you can really get exact recesses and mitigate the small differences in converting from millimeters to inches.

Bearings
http://www.stewmac.com/Luthier_Tools..._Bearings.html

Shim
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[KEtheredge87]

Tonight's update starts with a fun fact. In legends and myths, a common trope is naming a weapon or object like a sword if it is special or is supposed to have magical powers. After tonight's adventures, I'm about THIS CLOSE to re-naming these subwoofers "Tool Breaker." After trimming a total of 40 wall pieces, my Timberwolf bandsaw blade broke at the weld!!! Thankfully I noticed the sudden imbalance as the blade started to crack, and managed to turn the saw off and investigate before things got out of hand.

...If you want to move through the wood in a hurry, use a 1/4" blade with 6 teeth per inch. If you cant find a blade like that for your saw, let me know, we have a company pretty close to us that makes custom blades and the price is not bad.

So Kevin... still got that bandsaw info handy? I suppose I'll be installing the stock bandsaw blade and running that until I get something else. It should suffice for the bulk trimming I'm doing. Timberwolf has a warranty of sorts, but by the time I pay to ship the blade back and get another, I could have just bought another $20 bandsaw blade.

Otherwise, I did receive the flush trim bit you kindly had shipped to my house. I'm considering rolling forward with that while the spiral bit saga continues. I did a 120 grit and 220 grit hand sanding on the inside face of one spiral cut piece and the straight cut piece I made yesterday. Both turned out pretty darn smooth, so I'm inclined to believe that I am (once again) overthinking things. I may exercise a little more patience to at least see what Whiteside has to say on Friday. If they'll replace the spiral bit, I may wait. If they say I'm up the creek, then the straight bit is my huckleberry.

[Kevin K.]

Sorry to hear about you blade Keith. Where did you purchase that one, local? If you need the information on my source, I'd be glad to hook you up but you would be looking at a couple of days before you'd be back up and running due to the freight.

[KEtheredge87]

Thanks Kevin,

I bought that Timberwolf blade new off Amazon. I'm considering buying a new one and ship the first one back to Timberwolf for repair while I wear out the stock blade that came with my bandsaw. I'm curious to hear who you know and what kind of prices they offer.

Either way, I'm not totally dead in the water, just operating with a sub-par blade. Thankfully I don't need a great finish on these bandsaw cuts!

[Kevin K.]

Thanks Kevin,
I'm curious to hear who you know and what kind of prices they offer.

It's just a local industrial supplier here close to us called Richards Supply. They make the blades in house and usually the same day. Just need the length of your blade and I can get you the price today.

[KEtheredge87]

Oh, duh... would have been smart to include that info already! My bandsaw takes a 72 inch blade. Thanks for the help. I can contact them directly unless you've got a man on the inside and get a better than usual price.

[Kevin K.]

I'll have you a price here shortly.

[Kevin K.]

$9.10 each. How many do you want Mr. Tool Breaker?