Scion xB '06, in-dash Atom 330, Lilliput 889GL; details, pictures, links. Index: pg 1 - Page 11

rdholtz · 07-06-2008, 08:30 PM

Head Unit Support, Version 4

I've made so many refinements to the design of this head unit support that it deserves a new version number, so this is Version 4. Parts are smaller and generally simpler, especially with addition of the hook-and-loop (Velcro) fastening for the DVD unit.

First, I made the DVD support smaller -- it doesn't extend back as far, now -- because the Velcro eliminated the need for a back extension to hold the little 1/2" x 1/2" DVD locater bracket. Then I eliminated the front and back 1/8" flanges; the load on this bracket is very evenly distributed, so it won't sag -- the material has enough strength without flanges. The ability to move the DVD unit up and down relative to the head unit is meaningless for my personal installation -- I'll put mine right down as close as possible -- but I left the capability in the design in case we need a that flexibility in another installation.

Here's the DVD support bracket, seen from the front:

Click images to enlarge.

The DVD guide brackets got a bit more complex when they also became USB port brackets, but that change actually adds only a single bend to produce the front face, plus a little more cutting. Here they are:

They'll be attached by Velcro, too, so there are no holes for fasteners. I should comment here that industrial-strength Velcro is really tough stuff, and it will hold these things in place just fine, especially when we consider that there's no load on them.

If you're considering Velcro, you can also consider good foam tape. Velcro is repositionable, where the foam tape is not, but either is a good solution. The tape is strong, too -- it's what they use to attach wheel weights when balancing tires on alloy rims; I've never heard of anyone losing a wheel weight attached this way. For information on the gold standard of tapes, check this 3M VHB tape link. There are lots of foam tapes out there, including those available at hardware stores and home centers.

The base has remained much the same, but the bend angles on the attachment tabs -- the ones with holes -- have been refined for a nice tight fit:

The side brackets are completely different. While it seemed good in theory to have lots of positioning flexibility, I really don't need that much. So I produced side plates that hold the head unit temporarily in position until I determine where it's going to be permanently; then I'll rivet them in place. The rivets will hardly protrude, and so they won't rub against the sides of the bay where this will be installed. Here's a bracket by itself, and one in position:

There's one change that would be easy to implement: make the side brackets part of the base. If the position stays just where I have it, I may make another base with integrated side brackets, and keep this one for our next installation. It would be easy enough to make slots in the parts if we need to change the head unit's position in the new installation.

Here are two pictures showing everything in place, although the Velcro isn't there yet. The difference between the pictures is the placement of the DVD unit and the USB port brackets, which can vary any way we want:

And here's how it looks from the rear:

Once the weather clears, I'll go out to the car and do a final fit check and get some pix of this system installed. Then I think we can call this good until I determine the final positions of the parts as I build the bezel.

rdholtz · 07-07-2008, 08:45 PM

Adding the Velcro

I stopped at Home Depot on the way home today and picked up the industrial strength Velcro for the USB port + DVD brackets and the DVD unit. I got the kind that comes in 2"-wide strips, which I cut down to 3/4" strips for the brackets and 1/2" strips for the DVD unit. A single 3/4" strip on each bracket and a pair of 1/2 strips on the DVD unit is more than enough to hold them in place. Actually, as strong as this stuff is, a couple of Velcro buttons on each would probably do just fine.

This evening, I made the holes for the USB ports in the brackets. When the touch-up paint is dry, I'll get the Velcro on the parts and get some pictures of the assembly. I wanted to wait and put the Velcro on after making the holes for the USB ports, because I didn't want to dig metal bits out of the Velcro.

I'll put the Velcro strips on the DVD support, but I'll just put Velcro buttons on the DVD unit I'm using for test fitting, because I haven't decided which unit I'll finally use in this installation. I'll put the full strips on the one I install.

Could This Be the Mounting System I Want?

This actually brings up an interesting point: the Velcro seems to have some vibration-damping and shock-damping properties. It's a pretty slick way to mount almost anything as long as it only has to withstand reasonable stresses. I can see using it to retain a PC in the dash or glove box; it would give good retention with relatively easy removal, and it may be just a little gentler when we hit bumps in the roadway.

Foam tape can be used much the same way, or Velcro and foam tape could even be used together. If I mount a small sheet metal base plate in the car with some heavy foam tape, and then mount the PC (or amp or whatever) to the plate with Velcro, I can easily get the unit in and out, and yet it's held in tightly and has vibration-damping and shock-damping built into the mount.

Hmmmm -- maybe this will change the way I decide to mount the PC. I'll work on that idea.

rdholtz · 07-09-2008, 09:57 PM

Velcro Results

I was interested in where Velcro came from, so here's a little information on Velcro Industries, found on Hoover's:

"Velcro hook-and-loop fasteners originated in 1948 as the brainchild of rambling Swiss inventor George de Mestral, who became curious about cockleburs that stuck to his clothes. The resulting trademarked invention VELCRO (named for the French words "velour" and "crochet") can be separated and reclosed 10,000 times and can hold up to nine pounds per square inch. VELCRO has been around for more than 40 years".

So, how does the Velcro work in this installation? Well, there's good news and bad news. The good news is that it works as advertised. The two strips of Velcro hold the DVD very well -- as I expected. Actually, because it's a temporary installation, there are two 3" x 1/2" strips on the DVD mount, but only four buttons of it on the DVD unit itself. It still stays right in place.

But the brackets are a lot less successful. They work, but the brackets are relatively narrow -- 7/8" -- and so they can roll somewhat on their long axis, and they move around: if I push a USB plug into one of them, I can feel the Velcro flex. The brackets aren't going to fall off, but they're never really grabbed tightly, either. I'd like them to hold the DVD in place better laterally, too. The brackets just feel loose -- definitely not OEM.

I tried removing the brackets and repositioning them, putting them back on so I had to push the DVD down into place, but there's still too much wobble in the brackets, even though the DVD is stable.

There are other, somewhat-similar kinds of fasteners that hold more tightly, but they're not as easy to reposition, and that's one of the benefits I hoped to have with the Velcro. In my spare parts bins, I have a couple pieces of a plastic Velcro competitor. Although it's unlabeled, I suspect it's 3M Dual-Lock.

So maybe it's time to re-think this.

There are a few solutions I can see:

go back to Home Depot and get the low-profile Velcro buttons that would move around less; I think it would be better, but the brackets would still flex with pressure, so they wouldn't feel OEM.
keep the Velcro, but make a channel that goes over the DVD unit and connects the brackets into a single unit; they'd have much greater effective width, and that would provide stability; they wouldn't rock as much.
scrap the Velcro on the brackets and modify the existing brackets by making slots in them and drilling matching holes in the DVD support; keep the Velcro for the DVD.
do the same as above, and use the connecting channel, too; keep the Velcro for the DVD.
replace the Velcro on the existing brackets with the Dual Lock; keep the Velcro for the DVD.

My first inclination was to just go with the third choice: modify the existing brackets with slots and fasteners; that's an easy choice because I know how to do it.

But I like to try new stuff, so, before I revert to slots and fasteners, I'll try the Dual Lock. It's available at Amazon; current price is $12.10 for two strips 5/8" x 10 feet. It's available by the yard at iTapestore, where price varies by quantity (it's expensive in small quantities). It's also available at Radio Shack as item 64-2360, but it's far from cheap: online or in the store, two sets of strips (under the Superlock name), 1" x 3" each, are $3.99. Ouch! Despite that price, I bought it at our local Radio Shack, so there was tax, but there was no shipping cost and I didn't have to wait for delivery.

I'll get it installed on the brackets to see if that resolves the feeling of instability.

rdholtz · 07-11-2008, 02:57 PM

Dual-Lock Results

Here are the brackets in position:

Click image to enlarge.

The brackets hold the DVD tightly on each side, and the Dual-Lock holds the brackets in place as if they're screwed down. Looks like this is the fastening system of choice where we may want to move parts around later on.

The Velcro is still fine on the DVD unit, but The DVD could also be attached with the Dual-Lock; after I pick the unit I'll use, I could do that with the spare strips I have in the parts bin. But the Dual-Lock definitely doesn't have the shock-damping and vibration-damping properties that Velcro does. That may not be much of an issue here, because the brackets hold the DVD unit so tightly that it's probably going to feel every bump through the brackets.

And there's one other important consideration with the Dual-Lock: once these brackets were installed, they were hard to get off. I used the whole 1" x 3" strip on each side; I had to pry them apart with a flat-blade screwdriver when I decided to move them. I could probably have used a 1/2"-wide strip and had the same result, or mounted two 1/4"-wide strips at the outer edges of the bracket. That would mean I'd have gotten the same result with half as much material, and allowed for easier removal. If you use this product, remember that it holds on like a bulldog.

If frequent repositioning is the plan, then Velcro may be easier to work with than Dual-Lock. But for this particular application, and any other where rock-solid positioning is required, Dual-Lock is perfect.

This material would be a great way to mount a dash camera because it would stay accurately positioned, but the camera could still be removed for other uses. It's going to take some more experimentation with Dual-Lock to determine just how much or little to use so the device will be solidly mounted, but will still come off easily.

If I were just buying one product or the other, I'd take the Dual-Lock, even though it's significantly more expensive.

I'll get a picture showing it from the back so you can see how the brackets sit. Then I'll get it installed in the car.

rdholtz · 07-13-2008, 12:11 PM

DVD Support System

Here's a rear view of the DVD mount and brackets, using the Dual-Lock material (there's a front view in the previous post):

Click image to enlarge.

If I had this to do all over again, I'd use half as much of the Dual-Lock, probably just 1/2" strips down the middle of the brackets, so they'd be easier to remove and reposition as needed while I'm designing, building and fitting the bezel.

I'll get it installed and get an in-vehicle picture.

rdholtz · 07-14-2008, 05:50 PM

Final Head Unit Support Installed

I've temporarily riveted the base and side brackets together with a single rivet on each side. When I get ready for the final installation, I'll drill those rivets out, mark their final relative positions, and install two rivets on each side. For now, the system fits and works just as I wanted it to. Here's the head unit installed in what should be somewhere close to its final position:

Click image to enlarge.

There's no bezel installed here; it's further down the list of projects. I'll have to decide how the USB ports will integrate into the bezel, but I'm leaving that decision until I'm actually building that part of the bezel.

The first version of this head unit support was really, really stout, and probably would have been just fine through some very rough roads and even an accident. But it was way over-engineered -- I was driving a thumbtack with a sledgehammer -- and it lacked a place for a DVD unit.

I prefer this redesigned system because

it's lighter and simpler, but strong enough to do the job well
it can be duplicated with relatively simple tools
it's far easier to make and install
it gives more positioning flexibility
it includes space for the DVD unit

It was a long road getting to the point where I can say this: I'm satisfied with the result.

The one change I'm considering would be to build a slight angle into the USB faces on the brackets, so they'd align with the curved face of the head unit. That's an easy change to make, although it means making the brackets again. I'll incorporate the change into the part drawings and, if I decide to make the change while I'm fitting the bezel, I'll make the new parts then.

rdholtz · 07-15-2008, 02:04 PM

How Do You Make Slots?

When I was building the sheet metal parts to move my head unit, I was able to do all the shaping, drilling, slotting and filing in the flat; then, after a trip through the bender or the vise -- or both -- the parts were done.

The biggest dilemma was cutting slots in the sheet metal. With my current equipment, I use a drill press to drill the end holes, and a rotary cutoff tool (much like a Dremel) to cut out the space between them. It's almost the last process in building the parts, and one slip makes a lousy-looking part; it isn't unusable, but it has a nick or cut that shouldn't be there, and I want my parts to look as close as possible to OEM. It's not a very precise method. I've also tried an air-powered nibbler, but it isn't very precise, either.

Is there a better way to make slots than this? I'm not ready to buy a milling machine. I guess a milling attachment for a drill press is one option. I'm open to suggestions.

Do you know any slick, low-budget ways to make nice, clean slots in sheet metal? I'll post a similar question in the Fabrication forum, and cross-report any answers I get.

rdholtz · 07-16-2008, 09:37 PM

Slot-Making Update

I got a couple of answers to my "How Do *You* Make Slots?" question in the Fabrication forum. As promised, here they are, with my replies:

Quote: Originally Posted by kibble

I just do what you do but I make the openings a tiny bit smaller than actually needed. Then I get a smooth file and carefully remove material until I get it to the size/shape I want. Haven't come up with a better way to do it without the big tools, yet. :-(

I agree. My standard technique in metalworking is to go a bit oversize, and file to the dimension I want. On holes, I go undersize, like you, and file to the size I want. A set of miniature files make the fine work a lot easier.

Quote: Originally Posted by Bazza_84

is there no way of getting a punch style tool put ur work in a vise, place the punch where you want it then either press it or the prefered meth of bang it with a hammer

not got to this stage yet, just an idea

The problem with most of those manual techniques is aligning the punch and the die well enough that we don't destroy one or the other when we tighten the vise or whack them with the hammer.

I did search for "sheet metal punch", and I ran into some light duty portable punches, like this $24 hand-held punch from JC Whitney. It looks very similar to this punch from BrandsOnSale.com. Neither company lists the source, but they appear to be like units from Roper Whitney, which has a webpage here showing punches and tooling, including slot-forming tooling, plus a low-cost bench-mounting base for the portable punch. This could be a pretty good alternative to hand-forming. Roper Whitney lists the price on the punch as $55, the kit with tooling and a case at $80, and the base at $28. I couldn't find a price on slot tooling, but their price for a 3/16" round punch and die set is $11.

**EDIT:
I modified the text to show that the punches from JC Whitney and BrandsOnSale.com are NOT from Roper Whitney, but are apparently copies. There's no way to know if Roper Whitney's slot tooling will work in the knockoff tools, so it's probably best to just buy the Roper Whitney tool if we buy this to make slots. The slot tools are available from Roper Whitney distributors.**

rdholtz · 07-18-2008, 11:50 AM

Slot-Making Update #2

(posted in the "How Do *You* Make Slots?" thread I started in Fabrication)

More on Punching Tools

The sheet metal punches seem like an interesting approach for making slots, especially if slotting dies are available. The Roper Whitney tool can definitely punch slots, but it's not a low-cost solution. I don't know if the tools from JC Whitney and BrandsOnSale.com can use the same die sets as the Roper Whitney tool. Until I discover otherwise, I'll have to assume they're just good for punching round holes.

But, even if the punch only produces round holes, it has advantages of over the drill for making the end holes; it's quieter, produces a cleaner hole, and leaves just a slug for waste. I could still use the cutoff wheel, or perhaps a series of overlapping holes could be filed down to make a slot.

I did some more research on the WWWeb, and we can add to the list of similar tools the larger 3-1/4" throat depth Deep Throat Metal Hand Punch from Harbor Freight, which costs $25. The base for it is $10. That looked like it could be a $35 solution, plus the cost of shipping.

It's interesting how things work out. I happened to be close to our local Harbor Freight this afternoon, and went in to see what they had in stock. Their Deep Throat Metal Hand Punch was on sale for $18, and the base for it was on sale for $5. I just couldn't pass it up.

I'll test it this weekend.

roflcopter · 07-18-2008, 11:57 AM

Looking forward to how it turns out.

rdholtz · 07-19-2008, 07:57 AM

Slot-Making Update #3

(posted in the "How Do *You* Make Slots?" thread I started in Fabrication)

Quote: Originally Posted by Curiosity

For metal, I'd try another piece of metal with a straight edge as a guide and clamp it on, cut along the edge with a dremel. Thin aluminum might work as a guide for plastic that's curved, but molding a faceplate in might work better for small things like memory cards, and you can mess it up more.

Actually, I was referring to slots in sheet metal parts, where I think you're talking about slots in bezels and the like. But you bring up an interesting point: it may be possible to simply build a bezel without worrying about slots, and machine the slots and edges of the openings we need. I hadn't thought of that, and I think I'll try machining edges and slots in my bezel plastic to see if that's a possible production path.

I suspect the high speed of the Dremel-type tool might simply melt the material. A lower speed, as with a mill, might do well. Because the material is soft, a drill press could probably be used to mill plastic without tearing up the drill press bearings, but I think it would add a lot of side load on bearings not designed for side loads.

The "Dremel" that I have is actually a Ryobi 18V system. It works well, but isn't mountable like a true Dremel, and there's not a flat surface to run along a guide. An inverted Dremel in a work table might be a good idea. The way those little whizzers throw chips, though, I think I'd like to build a clear shield into the system somehow, or wear some really good goggles.

I've also wondered if I could run a milling tool in my router -- mounted upside down under a work table -- to make slots. My router operates at a single high rpm; I'd have to bring it down to the proper rpm for plastic or metal milling. Also, I don't know that its bearings -- which handle sawdust just fine -- are set up to handle hot metal fragments. When I was only thinking of sheet metal work, I couldn't easily resolve either issue, so I abandoned the idea. I might have to revive it for machining plastic, if I could control the speed.

I want a better way to form slots because I want to take less time and less effort, and I want better slot quality and consistency.

But one of the secondary reasons is that the current method involves lots of metal chips. I was wondering if there's a way to do "instant" slot forming -- like punching -- that only produces a slug, or a few slugs. I end up having to take off my shop shoes every time I walk into the house, because I don't have a housekeeper (except me), and I'd rather work in the shop than run the Roomba or a mop. If I can make less mess, I'll get more done because it'll be easier to clean up after myself.

rdholtz · 07-19-2008, 11:57 PM

Slot-Making Update #4

(more of the ongoing conversation from the "How Do *You* Make Slots?" thread I started in Fabrication

Quote: Originally Posted by rdholtz

I suspect the high speed of the Dremel-type tool might simply melt the material.

Quote: Originally Posted by kibble

They actually have some wheels that are made to cut through plastic. They look like the big metal cut-off wheels. I use them myself and they work pretty well, but you have to make sure to not stay in one area too long or it will start melting the plastic.

I'd bought a kit of Dremel tools, and there's a mini-sawblade in there. But I was thinking of something more akin to a milling head, where we could simply machine a slot in the face of a plastic bezel. That would save a huge amount of finishing time. I believe the primary issue will be matching tool speed to the material; the softer the material, the slower we'll want to run the tool. Controlling the tool speed is probably easier in a 110V machine than a battery-powered one like mine, so I may have to invest in another Dremel-type tool (for research purposes, of course).

Unfortunately, I'm going to have to delay experimenting with plastic machining, because I'm leaving in the morning for an unexpected week or more on the road.

The good news is that today I got pictures of the punch and its results, and I'll get them posted as soon as I can write it up. I use GMail and Google Docs, so everything travels with me. Shouldn't be more than a day or so . . .

Quote: Originally Posted by kibble

Having a variable speed rotary tool doesn't compare to a fixed speed one. Get yourself one, you'll be glad you did!

The Ryobi seemed like a great compromise when I found it. I've had excellent service from all my Ryobi tools. But this rotary tool is struggling to find its place. I think you've highlighted a major weakness in its lack of variable speed, and it may force me to get a Dremel-branded tool.

There are a couple of other reason to get the Dremel brand. At Home Depot, I saw the #220-01 WorkStation mount for Dremel tools that looks really slick. There's also the Dremel #231 Shaper/Router Table, which might be a nifty slotting device.

There may be a Dremel in my future.

rdholtz · 07-21-2008, 04:30 AM

Slot-Making Update #5

(more from the "How Do *You* Make Slots?" thread I started in Fabrication)

Quote: Originally Posted by kibble

Post some pics after you try it out! I'm curious to know how it works out for you.

Punch Testing

I've been playing with the Deep Throat Metal Hand Punch from Harbor Freight. It appears to be a knockoff of the Roper Whitney No. XX seen on this page. If the tooling for the Roper Whitney model fits this tool -- and pictures suggest that it might, then this tool may be able to punch slots. So far, though, I've only punched round holes.

I'm glad I bought the base; it makes it easier to use, but it needs to be mounted to a board; without it, the tool just tips over onto its nose. I attached the tool to the base, and the base to a piece of 5/8" plywood 5" x 8" with some 1" screws and fender washers. I didn't do any finishing to the base board other than file the edges to knock off the splinters. Here's how it looks mounted:

Click images to enlarge.

For size reference, the slot on the depth gauge is 3" long.

The manual assures us that everything we need is included, but there's a 2.5mm Allen wrench needed to tighten the set screws; it's not in the box, nor is it on the parts list. If you go to Harbor Freight to get this, buy a set of metric Allen wrenches at the same time.

I installed the 3/16" die set. I tried the punch on scraps of the types of steel I've been using for parts -- some .022" galvanized steel, an old computer case (.028" steel powder-coated on both sides), and some .031" stainless steel. The punch went through all of them. The force required depended on the material. The painted steel was easiest, probably because of the paint acting as a lubricant. The galvanized was almost as easy. The stainless steel was tougher, and I don't think I'll want to use this punch on that material. The stainless steel may have dulled the punch in a single use, because holes were just a little tougher after that. I confess that the instructions say "mild steel", and stainless isn't mild steel. Any damage done to the die set is clearly my fault for pushing it beyond its specified use. But that's just what research does.

There's a locator point on the tip of the punch, so I can locate holes precisely; once the punch is positioned, I just a push on the lever arm, and I have a hole. "Push" means "apply some pretty healthy pressure".

Here's a picture of the resulting holes in the test pieces:

The material on the left is .031" stainless steel; in the center is .028" powder-coated steel; on the right is .022" galvanized steel

I also tried punching 1/8" polyethylene, and it did just fine. The hole was smooth and very clean.

The dies come grease-coated and packed in clear wrap, which makes me suspect they need corrosion protection in the humidity of south Florida. I made a small container for them in my tool chest and I'll keep a grease rag over them so the atmosphere in the box is oily air.

The punch takes more initial setup than just slipping a drill bit into the drill press. But if I'm using a standard size hole -- I generally use 3/16" -- then I can just leave the punch set up with the 3/16" die set in it. It can sit on a lower shelf, ready to pull into action whenever I need holes.

I like the cleanup; there isn't any. I guess when I've punched enough holes, the slugs will start to fall out of the bottom of the die, but that's still almost no mess. I'll brush a little dab of grease on the punch and the die when I'm finished each time to keep them lubricated and rust-free.

If I just use it to make the holes at the end of slots, it's an improvement over drilling. The resulting holes are very clean and smooth-edged, and don't need any filing until final cleanup of the parts.

I made a quickie bracket for a temporary system I was building, and needed holes in a piece of bent sheet metal. I marked the holes with a center punch, stuck the metal in the punch a couple times, and BAM!, BAM!, there were holes, perfect holes, right where I needed them, with no finishing required. I've never made holes so quickly and easily in my life. Oh, I like this tool.

The verdict so far? While this is a handy tool for surprisingly low cost -- especially on sale -- it isn't the total answer to making slots. With the standard tooling, I'll still have to use the cutoff tool to complete the slots. The punch makes the process easier, but it doesn't produce instant slots, so I'm not ready to call it the "solution".

If it can accept the Roper Whitney tooling and punch slots, it could be the answer I wanted. I'll research that this week.

Even without that capability, it's a keeper.

rdholtz · 07-21-2008, 11:39 PM

Slot-Making Update #6

(more from the "How Do *You* Make Slots?" thread I started in Fabrication)

Quote: Originally Posted by kibble

Hmmm I like the fact that it's not messy like drilling stuff. I may get one myself! Another thing I don't like about drilling is that the holes are sometimes not really 100% round because of the way the drill bit bites into the material.

I've punched enough holes with it that the slugs are falling out of the bottom, now. They just drop onto the workbench. When I'm done with the punch, I put it away and sweep the slugs into the metal scraps bin. I wish all my tools were as neat and easy to clean up after.

Hurry, if you're going to get one on sale -- it ends July 22, I believe. But, even at its full $37 price, this is a really good tool, terrific for quick holes. And, now that I'm used to it, changing the punch only takes about a minute.

I still have to check on getting the Roper Whitney slot punch and die to see if they fit.

rdholtz · 07-24-2008, 05:34 PM

Slot-Making Update #7

(more from the "How Do *You* Make Slots?" thread I started in Fabrication)

Quote: Originally Posted by golfguy

If you can use plastic, a router would be the way to go. Simply clamp a straight edge to your piece and plunge a router bit in to make the slot. You might even be able to do it with metal if you found the right bit.

For plastic, a router would be good, but mine is a single-speed router. I'd need to control the speed so the tool doesn't melt the plastic; just the friction between the spinning tool and the material would cause melting, so the tool couldn't stop until it got to the end of the cut. That makes a variable-speed Dremel-type tool seem pretty attractive.

I guess a mill could do both the plunge and the slotting in steel, but it would take some experimentation with material that thin. I'd also guess it would demand pretty low plunge and travel speeds to keep from bending the sheet metal.

User Name		Remember Me?
Password