Seeking Advice About Dremel Accessories

[BonzaiDuck]

I wouldn't know where else to ask this question. "Ask a Technical Professional" still seems to include threads that are more appropriate to the computer forums. I COULD ask the question on Computer Hardware and "Cases and Cooling", because some few of us build ducts of foam-art-board and Lexan plate.

IN other threads here, I discussed adding an FM-Transmitter/MP3-player/Bluetooth/hands-free-cell/USB-charging device to my Trooper's dashboard.

To do this elegantly, I need to cut a piece of 1/8" x ~2" x ~7" rectangle of the Lexan polycarbonate, precision-drill eight holes for nylon screws, and cut two rectangular holes that are maybe 3/4" x 1/2" together with a larger 1-1/2" x 4" hole that is not perfectly rectangular, but with curved sides.

Lexan has always been troublesome to work with. You have to use your plastic/wood spec'd 1.25" saw carefully. Lexan melts around the cut. I could actually construct a hot-knife for it with an Xacto blade and discarded soldering iron, but that's a lot of trouble.

Any thoughts about the most appropriate Dremel bit/saw/cutter for this fine Lexan work? I suppose I could use 1/4" x 2" x 7" poplar wood, but the Lexan is preferred for the finished product.

 

[NutBucket]

Do you have a bandsaw? That's what I usually use to cut small pieces of plastic. Maybe use a jigsaw to cut the holes you need before cutting it out of a large piece of material.

Just today I used a circular saw to cut a sheet of acrylic in half.

 

[BonzaiDuck]

I HAD a band saw -- a Craftsman -- but I gave it to my now-estranged younger brother. Only so much room in the garage, only so much in the loft for storage. I took my large workbench apart and got rid of it. I passed a Delta table saw to a friend, and I kept the tabletop drill press. I used to do a lot of woodworking, and then sheet-metal work for building computers.

I think, if using something like a band saw, it would be one of those tiny machines for fine work. But I'm not sure how you get the saw blade through the blank to cut the hole. The blanks, as I said, are approx. 2" x 7", the hole rectangles are 3/4" x 1/2".

The problem with using a cutoff wheel or the 1.25" Dremel saw-wheel -- diameter of the blade is too large for those small sizes. I could see drilling it out -- a lot of extra work. Leave enough in the corners and use a small rat-tail/triangular file.

Parts arrive in intermittent intervals through the next two weeks, and I can't even begin for seven days. But I need to figure this out. For what I want to do, foam-art-board is easy to work with an Xacto knife, but -- seeing how stiff the selected rocker switch is, I'm afraid it might be too soft. You can do a lot with foam-art-board, and you can enamel it.

But my ambitions lean toward Lexan polycarbonate.

AFTERTHOUGHT: I remember now. I was thinking of a scroll saw. That's what it's called. . . . OK . . . Ryobi, $170. If I did more things requiring a scroll saw, it could make sense. But it breaks my project budget. I can afford it -- but it doesn't seem practical for this single project, if I can't find reason to use it again.

I'm guessing that the thin saw blade can be removed, and then inserted into a pre-drilled hole before securing it again to the saw?

I need something to use with the Dremel. I have plenty of small drill bits. I have a cutting tool -- 1/2" diameter -- for shaping wood or plastic. Perhaps I'll try that one. Or order a sharper, new replacement.

I need some ideas, though . . .

 

[herm0016]

You can find scroll saws on Craigslist for around the 50 dollar mark usually. That would be a good tool for this. Yes, drill and insert the blade. A coping saw would be the hand tool equivalent and would also work. Dremmel spins very fast and thus will create a lot of heat.

 

[BonzaiDuck]

. . . So far, I'm looking at bits 199, 115 and 125 -- cutting, shaping, carving wood and plastic. Buying some specialty bits is chump change, but might as well get the right ones.

I also see that they sell a Dremel "mini-table-top-drill-press frame for things like jewelry making and woodworking. Lexan's hardness seems to parallel bits made for woodworking. It's plastic. There are just certain types of things that happen with a plastic like Lexan that you have to accommodate, like the melted waste that solidifies after a cut, maybe keeping the tools clean.

I also see that they sell a Dremel "mini-table-top-drill-press frame for things like jewelry making and woodworking. The base center has a well that could come in handy. Again -- is it worth it to me to buy that tool? I "Dremel" maybe a few times annually. $50. Gotta think . . . gotta think . . .

. . . Possibly 9901 -- But I have that one, and a shorter one.

I'm not gonna pull the checkout string until I get input here . . . . . Otherwise, to be good-natured about it, it becomes some sort of show and tell if I find success on my own . . . . That's OK too.

Any ideas?

 

[NutBucket]

I'm liking the coping saw suggestion. I've used one many times to make odd size holes as you need to.

 

[IronWing]

With plastic, slower speeds are better. For the drilling, a drill press or Foredom flex shaft with drill press mount would be a better bet than a Dremel as one can run it at much lower rpm. If Dremel is what you have, then the drill press mount is a good idea.

The coping saw idea is good. For plastic, I would look at jewellery blades as they come with narrow, shallow blades (good for curves and corners) and very fine teeth. The coping saws made specifically for jewellery work have more rigid frames for better control and less likelihood of torquing the thin blades.

 

[Greenman]

I wouldn't know where else to ask this question. "Ask a Technical Professional" still seems to include threads that are more appropriate to the computer forums. I COULD ask the question on Computer Hardware and "Cases and Cooling", because some few of us build ducts of foam-art-board and Lexan plate.

IN other threads here, I discussed adding an FM-Transmitter/MP3-player/Bluetooth/hands-free-cell/USB-charging device to my Trooper's dashboard.

To do this elegantly, I need to cut a piece of 1/8" x ~2" x ~7" rectangle of the Lexan polycarbonate, precision-drill eight holes for nylon screws, and cut two rectangular holes that are maybe 3/4" x 1/2" together with a larger 1-1/2" x 4" hole that is not perfectly rectangular, but with curved sides.

Lexan has always been troublesome to work with. You have to use your plastic/wood spec'd 1.25" saw carefully. Lexan melts around the cut. I could actually construct a hot-knife for it with an Xacto blade and discarded soldering iron, but that's a lot of trouble.

Any thoughts about the most appropriate Dremel bit/saw/cutter for this fine Lexan work? I suppose I could use 1/4" x 2" x 7" poplar wood, but the Lexan is preferred for the finished product.

If you can draw the part you need in a simple cad app a sign maker could cut it for you. I would assume the cost to be fairly reasonable.

 

[NutBucket]

Hell if I was going into the office I would 3d print it for you.

 

[BonzaiDuck]

Hell if I was going into the office I would 3d print it for you.

Yeah -- I have a former high-school girlfriend (class of 65) up in Grass Valley, who got her BA at CA College of the Arts (used to be "Arts and Crafts"). She always had a sideline to whatever day job she had. Now she sells an item that helps people knit socks. I asked her if she produced them on a 3D printer -- haven't got an answer back yet. But I was thinking, if she had a 3D printer, I could pay her.

I'd like to draw my little engineering diagram -- I'd probably use Corel Draw or Photo-Paint -- or I could do it in pencil and scan the page. Just don't have the time right now. However, consider your car stereo "head-unit" receiver and its front dimensions.

Under my receiver, there's a space about equal in size and shape. The factory put a little 5-sided black plastic box in there to allow it's use as a shelf for sun-glasses and other paraphernalia.

The item I want to install is this Bluetooth-FM-transmitter-Hands-free-MP3-player .

The pictures are not quite accurate. The male plug meant for a cigar-lighter-socket is perfectly perpendicular to the front face of the item. Its width leaves about 2" on either side of the device. With some 6" USB extender cables, and a small three-pin rocker switch, I can use that space so that USB ports are accessible side-by-side and the switch is installed -- all in a face-plate that fits the shape of the device. Instead of taking the device apart and soldering POS and GRD wires directly to it, I can use a cigar-lighter splitter with 6' wires, cut off one of the female parts with its 6' wire, run it out the back of the black box to an ACC piggy-back fuse fitting inserted into the pass-compartment fuse-box. The female plug with its wires is 1" diameter, and I've drilled a hole in the back of the black box to fit.

Once the LEXAN faceplate is done -- milled, drilled, whatever -- I can construct a frame with Poly-Zap polycarbonate glue and (using foam art-board for the remainder of the frame) Hold-The-Foam glue to put it together. Or -- I might use a larger strip of 1/8"-thick lexan to make a three-sided frame that just fits snugly in the box. Anytime I need to remove the entire construction, it should just pull out from the recess. But it otherwise appears to be another "head-unit" or receiver, and should almost look like "OEM". The interference fit of the female cigar-lighter extension and a properly constructed art-board frame should hold the entire assembly in the box, allowing use of the switch, the ports, and access to the device's buttons and dials.

Anything metal will screw this up, because it transmits FM signals to the OEM head-unit radio receiver and metal will interfere with it.

The quality of the sound is equal to anything that came with the car. After all -- it's just an MP3 player and Bluetooth gadget for the cell-phone. If it lasts forever, that should be good. I hadn't seen any adverse reviews about it. None of significance.

Those things sell for about $19 -- I see they're out of stock, but they're available everywhere, like EBay. Some outfits are trying to gete $70 for them.

People will say I should just replace the Trooper's OEM head unit, which means getting rid of the 12-CD-changer installed in the cargo compartment. I say -- no. And if the gadget doesn't last forever, another $20 will get me a spare to keep around.

The OEM audio system is top-notch for its day, all in perfect working order. Unless I want HD radio and a bunch of other features, my DIY Rube-Goldberg construction will be just fine. And with that, there was no modification of the car, its OEM audio, or anything else. Nothing but the hole in the back of the plastic-box insert under the OEM receiver.

Topping off, I think I've found the Dremel bits I'll need, and I found a heat-knife for less than $20. If I buy extra tools, I'll be able to use them again later, and I can see that I probably will have many such opportunities.

See -- it's an old car, and I could just wire the device in, still leaving my OEM cigar-lighter free, and "stick it " somewhere. This extra tedium, even so, adds a nicer touch to the project.

Seems silly, but it will work great.

 

[herm0016]

i was at ace today and they had jigsaw blades made just for polycarb. worth a try. i still think a dremel is the wrong tool for the job.

 

[NutBucket]

IMHO what you should consider replacing are the speakers. That's where the OEMs really cheap out with paper cones and foam surrounds. You should pop a grill and see what they look like.

 

[BonzaiDuck]

IMHO what you should consider replacing are the speakers. That's where the OEMs really cheap out with paper cones and foam surrounds. You should pop a grill and see what they look like.

The speakers in that car are fine. The entire point of this . . . tedium . . . is to avoid replacing anything OEM. The head-unit/receiver for that model SUV was at the high end of anything for that year.

Otherwise, replacing the head-unit and possibly the speakers, then the perfectly operational 12-CD changer has to go. See -- for music, I can live without the CD changer with the MP3 device. I could probably live without it with a new head-unit. But it's all "OEM" and it all works fine.

For the Lexan, I'd have to make two straight cuts in a corner of the 12"x24" panel arriving in a few days. Then, a 3/4" x 1/2" and a 1"x1" to either side of the panel. The largest hole for the face of the MP3 device can be done partly with the rotary saw blade, except for the tight corners.

But thinking of a design for sturdiness, I can do the entire initial project with foam board, so that the LExan can be added later just by disassembly and reassembly and otherwise no bother. I had ordered two switches, the first (GAMA) is very stiff -- you'd want to use the Lexan with it. The second switch is solid but it doesn't require much pressure to throw on or off. I can be assured that it doesn't stress the assembly when thrown. So -- Lexan for later, maybe with the smaller GAMA switch.

I just need to make everything precise down to the 1/32" or 1/64". I'm hoping the heat-knife I ordered -- a $20 item -- works with the foam board like customer reviews say.

I might not even bother adding the Lexan plate, but plan to cut the Lexan anyway. Foam-board can be enameled.

 

[NutBucket]

I just use a file for fine work.

Anyway, I can agree on not replacing what isn't broke. But I'd almost bet money your stock speakers are about to turn to dust if they haven't already.

 

[BonzaiDuck]

I just use a file for fine work.

Anyway, I can agree on not replacing what isn't broke. But I'd almost bet money your stock speakers are about to turn to dust if they haven't already.

You know, I thought about what you said earlier about the speakers, and remembered that I told you that one could reach a point where they clip slightly or distort. I had even done an initial search to find replacement speakers for the six of them, and that's neither expensive nor difficult as far as I can see.

Maybe I said -- I have tinnitus, maybe for not protecting my ears during rock-concerts -- Doors, Quicksilver, Airplane etc. -- 50 years ago. But I've always like my music loud enough. I'd discovered that I could turn up the volume all the way on the OEM receiver and I would hear what seemed to be clipping and distortion from a front left speaker in the door. Listening to it some more, I thought there might be a better than 50% chance that it was the mountings, because the noise seemed to be coming from the door panel and not the speaker. I WILL find out.

However, what I meant about the speakers in conjunct with the MP3 player -- I get almost full volume using the player, or very close to the full volume, just short of reaching that point I mentioned.

If I find that I'm wrong about the speaker door-mounts, I will certainly replace them. As I said, I'd done a preliminary search and matching speakers for that car are available. What kind would you suggest? Jensen? JBL? I"ve forgotten who makes car speakers. . . .

Took the ride out for an excursion today to pick up a $7 tool at Harbor Freight. Turned on the MP3 and FM preset -- played a Stones album. I can see where some people in customer reviews have complained of minor static -- only noticeable between tracks of music. It's the EFF-ing power lines and wires along the highway! Also noticed that I could move the power cable now loosely resting in the passenger seat until I finish up this foam board switch and port tedium, and the player or the wire disturbance would generate some static. I don't think I'll have that problem once the wiring is neatly completed.

Anyway, it's a "step up" -- an experiment. If it's less successful than I planned, I just wasted some retired-person time. I've got plenty of foam board, extra wire, switches, glue. It wouldn't be a major loss. But I'm optimistic!

ADDENDUM: For NutBucket or anyone else . . . . I'm looking at speakers at some reseller sites. One site just automatically matches my 95 Trooper and speakers that "fit". There are other wattage and RMS specs. Or I'd like to get the most powerful speakers that can take advantage of the OEM receiver. They don't have to be "out of spec". Not sure where I'm going on this. One reseller just pops up a list of speakers. "This fits your Trooper". For the front lower door, for instance, there are both 5.25" and 6.5" speaker options. Probably same with the rear pair.

 

[NutBucket]

For speakers your number one concern is sensitivity. Since you're not adding an amp you want something with minimum 90db. It will make the most of the power you have available.

 

[BonzaiDuck]

For speakers your number one concern is sensitivity. Since you're not adding an amp you want something with minimum 90db. It will make the most of the power you have available.

Since I was going to remove the door-panel punch-outs to look at them anyway and verify that the mounts were loose, I'll first measure whether they're 5.25" or 6.5". Then, use the reseller's compatibility listing to pick them. It is not a pressing priority at the moment. I suppose if certain lines and models have ongoing availability, I could do the replacement two speakers at a time over several months. the spec you cited -- is that called "sound-to-noise-ratio"?

I once installed a head-unit and 6"x9" triax speakers in my Honda Super-Civic. In this case, I'm not starting from scratch. I'm more careful about balancing the fact that the car is 25-year-old against a major sound system investment. I'm confident it will run without any major repairs for another ten years, but moderation makes sense. Otherwise, I wouldn't be doing this DIY shit. Time and money for someone like me are two different things.

UPDATE: I'm not buying now -- just looking. I see a pair of 5.25" JBL's for the front lower doors, and some 4" JBL's for the rear pillar. That only leaves the front tweeters. All of these speaker pairs have 90 to 91 dB "sensitivity."

I'll also pretend to be a total novice, although I can determine certain things on my own when I get to it. I am assuming that there are shovel clip connectors on or near the old speakers, and I should only need to remove the old ones, plug in and install the new ones. Does that make sense to anyone?

 

[NutBucket]

No, SNR is an amplifier spec. Sensitivity is a speaker spec. Basically says how loud the output is for a given input power. Higher is better when you have limited input power.

 

[BonzaiDuck]

No, SNR is an amplifier spec. Sensitivity is a speaker spec. Basically says how loud the output is for a given input power. Higher is better when you have limited input power.

And so I assume that 90 to 91 dB is good? I can keep on looking at these things. Do I need to cut and re-solder the wiring connected to the old speakers? Or do they likely have shovel/spade connectors? I mean -- it should be nothing for me (eventually) to investigate by pulling off the pop-out vinyl panels to have a look, but any advance intel is helpful.

Just offhand, it looks as though I could spend about $150 for all three pairs or six speakers. That's not so bad -- perhaps an upcoming birthday gift from me to me. Ease of replacement -- that's the key.

 

[NutBucket]

For ease of replacement go with Crutchfield. Even for your jalopy they should know what fits and they usually provide all the adapters and such free of charge. So you pay for more for the speakers but there's nothing else to buy.

 

[BonzaiDuck]

For ease of replacement go with Crutchfield. Even for your jalopy they should know what fits and they usually provide all the adapters and such free of charge. So you pay for more for the speakers but there's nothing else to buy.

Yes -- thank you! Among the three web-sites that offered compatibility filtering for my Trooper LS, that was the outfit to whom I was giving my final attentions.

NutBucket, this has been a very productive exchange for me. I started the thread looking for ideas about shaping a piece of LEXAN, and I come back with ideas for replacing my speakers!

 

[BonzaiDuck]

NutBucket? or Anyone?

If the Crutchfield site shows both 5.25" and 6.5" speaker pairs for my Trooper -- say -- for the lower front doors, suppose I find one or the other originally installed. Better, suppose I find 5.25". What are my limitations for choosing 6.5"? And what benefits would I possibly achieve, ordering larger speakers?

Again -- I'm not planning to do this very soon, but it's something no different than the RIGID fog-lights I installed. I'll plan to do it in so many months, or even make it "next year's project".

 

[NutBucket]

I think ultimately you'll have to remove the door panel and see what you've actually got. In some cases the OEM speaker has a large frame or something meaning you can physically fit a larger speaker in the same spot with a spacing ring of some sort. Or, it could be that different trim levels had different speakers and Crutchfield just hasn't distinguished between them.

On the note of hearing loss...I've been to plenty of concerts too and probably should have been wearing earplugs for some of them. But so far, so good!

 

[BonzaiDuck]

I think ultimately you'll have to remove the door panel and see what you've actually got. In some cases the OEM speaker has a large frame or something meaning you can physically fit a larger speaker in the same spot with a spacing ring of some sort. Or, it could be that different trim levels had different speakers and Crutchfield just hasn't distinguished between them.

On the note of hearing loss...I've been to plenty of concerts too and probably should have been wearing earplugs for some of them. But so far, so good!

They say some large percentage -- maybe between 30 and 50% of the population -- have tinnitus. Some say diet or things like drinking coffee or taking prescription drugs may cause it. I just suspect that some damage was done 50 years ago. I used to know two guys who wrote reviews for Rolling Stone during my first tour of DC. They didn't have a car between them, but I did. I got free promotional albums, and tickets to Baltimore Civic Auditorium. We were able to go back-stage to visit with the performers like Jethro Tull or Emerson-Lake-and-Palmer, and we also got to hob-nob with all the whores. Chicks dressed up like Good-and-Plenty candy, with 35mm cameras around their necks. CAll them groupies, but what were they doing backstage? One just has to assume . . . .

The speakers have pop-out panels for access without taking off the entire door panel. I'll just have to take a look. I may just opt for the best 5.25" speakers I can get -- within reason. AGain, it's an old car, but it's worth the restoration efforts to a point or limit.

I have to attend to the most tedious part of fitting the MP3 player and cutting the art-board for a frame. I may just wait for the heat-knife to arrive in the mail over the next couple days. I need to make precise (really precise) measurements. Once completed, the assembly will just slide into the dash snugly. It will need something like wire-tie "Pulls" to extract. If I can fit both USB ports on the front panel, I won't likely need to pull it out until the MP3 circuit-board fails.

 

[mindless1]

I don't get it. Lexan is very easy to machine, very forgiving. I don't see why you need a dremel tool at all. A drill (better still a drill press) and fine tooth sabre saw blade should get that done fine, then if you want to file, even sand and polish the edges, do that too. Lexan is hard enough to make that possible unlike a lot of other plastics, but even better than acrylic in not being easy to chip or crack.

The two main things not to do to lexan is try to grind it, or motorized sanding tools, either of which create too much heat. A saw usually isn't remotely close to that unless it is extremely dull.