Archive for March, 2011

Well I have slowly been making progress with the metal brake. It was time to start focusing on the fingers of the brake, the portion that would clamp the metal and provide a clean edge for the bend. I had chosen to use 2 x 2 x 3/8” angle iron. The idea is this. I wanted to make a box pan style brake therefore I need to allow for different lengths of fingers. I chose to divide the 48” bending envelope into 6” sections. This would allow me to make box pan bends in 6” increments up to a total length of 48”. By building a sequence of figures for the brake I would be able to configure the setup to allow for the 6” increments. By dividing my 48” finger section into two 6” sections, one 12” section, and one 24” section I would be able to mix and match fingers to accommodate a 6, 12, 18, 24, 30, 36, 42, and 48” bend. Got that? Yeah, I know, for the mechanical minded it’s hard to read it and not see it. At this point in time none of this is relevant, let’s move onto the actual fabrication.

 I started with a 4 foot length of angle 2 x 2 angle iron. The factory edge on the iron is too rounded to allow for a clean edge. I decided to continue my milling practice by giving the angle a nice sharp edge. Since I still lack proper tooling I was left with having to engineer something. Since the machining of the angle iron is not very precise I was able to weld a jig together. I needed to be able to stand the angle iron up on end in order to machine the edge of 1 side at a 45 degree angle. I opted to us a scrap piece of angle iron welded to 3 riser blocks made from 2 x 2 x .100” square tubing. I then added a clamping mechanism to each riser block to allow me to hold the angle iron solid while milling. It’s probably easier to just look at the jig picture rather then decipher what I am trying to explain. I added a few C-clamps as added rigidity. Using a ½” 4 flute end mill I was able to shave the edge of the angle iron down to a nice sharp point. I ended up cutting my 48” length in half in order to allow me to complete the machining; I was restricted by my working envelope of the mill. I decided not to cut my figures down to their engineered spec. at this point in time. All they need is a slice on the band saw therefore I will leave the fingers in two 24” sections until I have a need for the shorter configuration.

 Once the fingers were machined I needed to trim off the opposite side of the angle iron in order for it to sit flush with the 3” channel it would eventually get bolted to. A straight edge placed along the channel and a slice with the plasma is all it took to get the angle iron dimensions to specifications. The edge needed to be flush in order to allow clearance for the circular saw; this will become clearer as time goes on.

 It was time to secure the fingers to the 3” channel. This was going to involve bolts. I created a template so that I could drill bolt spacing in such a configuration that it was separated into 6” sections. This way it would allow me to bolt 6” sections, in sequence, along the length of 3” channel. I welded and drilled a jig to ensure that my spacing would be drilled consistently. I clamped the fingers to the channel and drilled them all as one unit. I drilled all the holes to ½” in order to accommodate 1/2” threaded rod.

 Once the holes were all drilled I cut 16 sections of ½” threaded rod and cleaned them up on the lathe. Each section then got TIG welded to the 3” channel. Ok…time to confess to screw ups. TIGing the ½” threaded rod sections in warped out my 3” channel. This is both good news and bad. The bad news is that my 3” channel is no longer straight. I had mentally engineered a spring loaded riser mechanism to allow me to raise the 3” channel up while positioning the metal to be bent. I will spare you the details, it will no longer work. The good news is that the 3” channel warped in such a way that it will clamp the metal to be bent in a more secure manner. The 3” channel warped in a concave manner as apposed to a convex manner, get it?

 It was time to perform a bit more R&D to ensure that my amateur engineering was still on track. I made a few test bends using a scrap piece of 19 gauge galvanized metal I had laying around. The metal clamps down good in the brake. I only used a pair of Vise grips as my leverage; I didn’t have handles fabricated to the bender yet. The 19 gauge bent smooth and even however the bend radius was not great. It worked however it was sub-par in my opinion. There is a bit of flex in the 56” length of angle iron that is doing the actual bending. I am not too concerned about this; I think that a simple truss addition to the angle iron will help diminish the flex. As far as the inadequate bend radius goes I am going to blame it on the brake and finger design however I do not consider this an issue. In fact I consider this a welcome problem. I designed this brake to bend 10 gauge “scribed” metal and not bend the lighter stuff. If I ever have a need to bend lighter gauge steel I have a much better idea of how to build a better brake for that specific purpose, I will spare you the details for now.

 The only other progress I made on the brake was adding some 1” angle iron guides for the 3” channel to slide in. The guides were welded in position to allow for the proper offset between the finger clamps and the angle iron performing the bending.

 The next stage will involve fabricating the attachment for the circular saw. The attachment will act as a guide that will slide on top of the 3” channel to help guide the metal saw blade and ensure an accurate “scribe” cut.

 

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…try and set my shirt on fire. I thought I would dedicate a mid-week posting to shop clothing. My garage attire is typically worn worn-out clothing (yes that is 2 worns). My shop shoes are a worn out pair of slip on Merrells from 11 years ago. They have terrible upper ankle protection. The welding and grinding sparks always seem to find a way to burn the tops of my feet. Just look at my socks and the black burn rings are evidence of overheated fabric. Obviously Merrell neglected to take into account the garage junkies in their design. My worn out jeans should have been retired 3 years ago, the hole in the crotch is so big that I have to shield the area with my welding glove when I am using the chop saw, sensitive body parts do not take well to hot flying chips of steel.

Wearing flammable clothing while welding really opens up a persons other senses. When you’re laying beads down vision is obviously a priority however I find that sound is just as crucial. The sound of a perfectly dialed in machine is like a symphony of electrons. You can tell the weld is going to be beautiful just by the crackle. The third sense that starts to come into place is smell.  When your face is buried behind a welding helmet you start to notice things especially when those things don’t smell right. For me I have learned to pick up the scent of burning cotton, it is very distinctive. I suppose this might be a reason to never weld when you are sick and you suffer from plugged nasal passages. I suppose one could argue that it may just be better to wear non flammable clothing. Hey good idea!

The other week I stumbled onto a Miller welding jacket in the discount bin of a local tool supplier. This thing is great! It’s flame resistant, it’s more comfortable then my sweatshirt, and it’s light weight. In summer I will often TIG in just a T-shirt and then suffer the sunburn consequences on my neck and mid arms. This jacket is cool enough that I think I’ll actually make an effort to wear it. Anyway…here’s looking forward to no more potential stop, drop, and role situations.

It came time to put a couple of uncompleted projects off to the side. I have shoved both the gazebo table and the lathe stand into the corner. Trust me, I did it for good reason and not as a result of laziness. It was time, once again, to add to my inventory of garage tooling. The story goes like this…actually before I explain my story I have to first place some blame. It’s the plasma cutters fault. There I said it. The Hypertherm is responsible for my shop tooling issues over the past little while. The reason is that the machine performs so well and it allows my to cut so many different sizes and shapes of metal that it increases the level of fabrication. I have been angry at the machine for over a year now because it has made my Millermatic 135 MIG welder the most under powered piece of shop equipment I have however that is a story for another time.

 The original story goes like this. The plasma has allowed me to start using sheet metal for projects. I am not a fabricator that works well with sheet metal. I visit the metalmeet.com forum to drool over the talent, technique, and tooling there is when it comes to sheet metal work. That stuff is a true art form. The shrinking, stretching, and manipulating of the metal is amazing. I have a great deal of respect for the people how have taken the time to try, learn, and perfect the talent. Anyway…back to me and sheet metal. Both the lathe stand and the gazebo table need some sheet metal added to them and for both projects I need a way to bend it. So as you have probably figured out it was time to add a sheet metal bending brake to the garage family (I do not suspect anyone will get offended with him)

 The dilemma is this, I work by the rule “when in doubt build it stout”. Most of my projects weight is not a factor. We all have fear in our lives, something that scares us. For me it is light gauge sheet metal. It is flimsy, it warps, it is a pain to weld, and I have no idea how to manipulate it the way I want. This leaves me dealing with the thicker stuff. How about 10 gauge? Yeah!!!!! Now we’re talking, that’s man steel. Except it turns out I am not man enough to bend it. To buy a metal brake is not an option; it is not in the budget. Like with most equipment you get what you pay for, cheap brakes don’t cut it (I mean bend it). Even the budget ones that are rated for 22 gauge aren’t great. To get a brake that can do 10 gauge I would have to budget $5000? Maybe $6000 or $7000? I am buying a Millermatic 252 before I drop that kind of dough on a bender.

 So it comes down to having to build one. There are only about 232000 people that have posted their version of a homemade bender on the internet. I spent a very small amount of time snooping around to see what others have done. There was not a lot I found that was of interest to me. Come on…I want 10 gauge. I decided to trailblaze the project.

 So here it is the build criteria. Cheap! I believe that if something is worth building it is worth building well, budget is usually not an issue for my projects. With the brake I am not sure how well my idea will work so I am not going to sink money into the project. 2nd criteria, it has to be able to do 10 gauge (I think I have already mentioned that). 3rd it has to bend lengths up to 48”. 4th it would be great to be able to incorporate a box pan style. And finally 5th it has to easily be stored and not take up useful shop space. Shouldn’t be too difficult.

 Before I continue I need to confess something. I am going to cheat. There is a reason bending brakes cost $5000 and so if I am to think I can build an equivalent in my garage for under $100 I think may be demented. The trick to making my budget build work is to thin up the steel. So although I am going to use 10 gauge it is going to get cut partway through which will actually cut its thickness in about half.

 The concept is this. The sheet metal is going to get clamped down on top of the brake. Then, using my Dewalt DW362 (discontinued) circular saw, I am going to make a cut halfway through the steel at the point of the desired bend. Once the cut is made the steel will get slid over and clamped down again in the bending portion of the brake and the bend will be made.

 In order to have some idea as to whether or not my idea would work it required a little bit of R&D. I mounted a metal cutting 7 ¼ inch 24 tooth carbide tipped saw blade in the saw. The blade is rated at 6000 rpm and the saw spins out at 5800 rpm, should be good to go. I set the depth of the blade to about half of the metal thickness and buzzed it through a piece of metal. The metal was then clamped to the bench and, using Vise grips, I made the bend. First problem, the width of the kerf did not allow me to make a 90 degree bend. I think I may have maxed out at 70 degrees. So I tried again. This time I made a second cut set just slightly off center to the first cut to give me a simulated wider kerf. Now I was able to bend to a perfect 90 degrees. I thought about doubling up the saw blades but 2 blades are a bit too thick. The bend worked out well and resulted in very little bowing. The steel wants to bend at the weakest spot so when I performed the bend it wasn’t being forced it was more like being folded. The strength of the bend, once bent, was good. It held its position very well and was not at all weak or flimsy along the bend seam. The second problem was trying to keep the depth of cut even througout the entire length. When I feed the saw into the metal and when I exit I have a tendency of tilting the saw. This results in me cutting completely through the sheet metal at both ends.

 So the idea is this. Build a brake that allows me to “scribe” the bend line using a circular saw and then perform the bend. The brake will be designed to allow only 1 side of the bend to visibly look good. On the opposite side of the bend, where the cut line is visible, a few tack welds can be placed to help add strength if needed.

 I made a trip down to the metal yard and dug through their cut-off rack. I was able to pick up a 5 foot section of 3” channel, a 5 footer of 5” channel, and a 10’ length of 2 x 2 x 3/8 angle iron. Total cost? $68! Add to that the budget $20 circular saw blade I previously purchased and that puts the build cost at $88. The rest of materials will be coming from stuff lying around the shop.

 I am not going to bore you with the basic concept; you’ll catch on as we go. The only thing I have done is posted a picture of the basic layout of the structure (look up).

 Starting in no particular order I began with building the hinges that will allow the 2 x 2 angle iron to perform the bending. I used a left over section of 1.250” seamless pipe with a .250” wall thickness from the BBQ spit build. I decided to make the hinges greaseable as well as implement a set screw for securing the hinge pin. The overall length of the hinge is 5 inches. The seamless pipe was cut into sections using the band saw. The end and center sections were then drilled and tapped to accept a grease fitting and a set screw. The hinge pin was machined from an old broken section of a slide hammer. The shaft was trimmed down to .725” to allow for a smooth fit into the hinge body. It was pure guess work as to the size the hinge had to be. I’ll have to wait to see if I guessed right, hopefully the strength will be adequate.

The section of 5” channel is going to act as the base for the entire brake. A 5 foot section of 2 x 2 angle iron will be hinged to the channel and perform the bending. The trick was to hinge the angle iron to the channel to allow for the pivot line to bend even with the edge of the channel and angle iron. Both the angle iron and channel got notched at the ends approximately 5/8” (1.250” halved). With the metal notched and the hinge machined it was time to weld the assembly together. The challenge was going to be ensuring that both hinges are welded along the same plain so that no hinge binding will occur during the bend. I set the hinges into the notched sections, spaced them using 1/16” welding rod and then placed a scrap section of 1” angle iron overtop connecting the 2 hinges together. Tack welded the hinges in place and tested the pivot function for smooth operation. 100%! No binding. Good to go, the hinges get TIG welded into their permanent positions.

With stage one complete it was time to move on. Again, in no particular order, I directed my attention to the 3” section of channel. The 3” channel is going to be the top side of the clamp which sits on top of the 5” channel that is going to secure the sheet metal for cutting. It will also act as part of the guide for the circular saw. The channel needed a slot run down the center ¼” wide and 52” long to allow for the carbide saw blade clearance. I could plasma it, I could cut it with the angle grinder but I figured it was time to break in the milling machine. I clamped the channel down on the table, squared it up, and with a ¼” 4 flute HSS end mill I carved a slot down the channel. Due to the length of the steel the milling machines working envelope was a limiting factor. I ended up having to reset the channel 3 times in the machine in order to achieve the 52” slot. I measured the accuracy of the slot from the start of the cut to the end. It turns out I was only off .015”, not bad for a first try. The .015” will have absolutely no affect on the function of the brake.

I feel an explanation may be required at this point. As I mentioned earlier I need more than a saw blade kerf in order to bend 90 degrees. The saw blade has a carbide tooth thickness of .080”. Until I do some more R&D I will not know exactly what width kerf I will need however I am fairly certain double the blade thickness to a .160” will be too much. The slotted 3” channel is going to act as the guide for the saw. Right now the guide slot runs exactly down the center of the channel. The idea, if all goes as planned, is to off set the saw approximately .030” in the guide. I will start by making one saw cut one direction down the guide and then flip the saw and run it done the guide the opposite direction. This should give me a .100” kerf. If I need more or less kerf all I need to do is adjust the saw on the guide. If this is confusing I apologize, it would be easier if I could just scan my brain and post the image.

 As the bender sits now the hinges are built and welded. The 2 x 2 angle iron now pivots freely on the 5″ channel. The next stage will involve having to mill a sharp edge on the upper 2 x 2 angle iron that will be performing the clamping. The factory round edge on the angle iron is not sufficient for giving the metal a clean, crisp bend. Milling one side will give the bending edge a sharp clean edge. It’ll give me a chance to get more familiar with the milling machine. I need the practice.

With the feet completed last week it was time to start cutting and welding the metal which will, eventually, resemble a lathe stand. I didn’t have a plan drawn up for the design I simply started to work off some basic critical dimensions.

 The main structure was simple. It was all welded from 2 x 2 x .100 square tubing, the same stuff that I built the milling machine stand from. It was nothing more then a rectangle boxed frame with extended rear legs to accommodate the back splash.

I wanted to try and maximize the amount of space on the lower portion of the stand. The lower section was going to house the tool chest and a couple of shelves to hold my turning stock. For about a week straight my mental planning process was fixated on somehow incorporating the top section of the tool chest as useable space. I came up with some elaborate designs but decided that, in the end, using the top storage section was not going to work out. So the plan is to mount the tool chest as high in the lower stand section as possible and sacrifice the upper storage section. This meant getting rid of the tool chest lid. What was the best way to amputate the lid from the rest of the box? The first plan was to drill all the spot welds out on the piano hinge. After I counted about 20 welds I figured forget that! Then I thought I could slide the hinge pin out of the piano hinge. Well it turns out the hinge pin was peened into the hinge in about 20 spots as well. Ok…looks like its going to get done the fun way. Got the plasma cutter out and in about 20 seconds I had the lid sliced off. With the lid off I was able to lose a couple of inches off the overall height of the chest. If anyone has any suggestions as to what I can do with a tool  chest lid just send them my way.

 With the chest test fit into the stand I could now determine my shelf spacing for the 2 lower shelves. I only had 10 inches to work with. 2 of those inches were going to get lost to the 1” angle iron frame for each shelf. I wanted to ensure that there would be enough space between the shelves for me to get my hands, and eyes, into so that I could scrounge around for miscellaneous turning stock. I figured 4 inches per shelf was too tight. I opted to build a rear pivot into the middle shelf. This way I could mount the center shelf lower which would gain me more room for my hands. The lower shelf now did not have useable space above it however I could now lift my middle shelf up so that I could access my lower shelf. The turning stock will roll towards the rear of the middle shelf when it pivots up but oh well. I’ll build a back to the middle shelf yet so that the turning stock won’t roll out and fall behind the lathe. I made the shelf pivots from a couple of nuts and socket head bolts I had kicking around. If you view the pictures the design is self explanatory. The nuts were simply a way for me to screw the pivot pins into the main stand frame. The shelves will get lined with expanded metal.

 

I had an evening where I thought I would give the stand some personality. I had bent a piece of 1” square tubing for my metal bending video but I never actually had a use for the bent length. The arc has been kicking around the garage and taking up space (it’s hard to store bent steel). The chunk of steel shone in its debut performance of the video and now it was time for it to reappear in a new act and star in a different role. The arc got sliced up so that it would fit between the 2 rear legs. I had some 304 stainless steel 5/16” round bar left over from the BBQ grates so I cut some sections out and created a decorative top trim section for the stand. The trim serves no purpose other then it allowed me stop tripping over the poorly stored 10 foot bent 1 x 1. I did the original mock up of the trim on the bench but then did the entire SS rod welding when it was mounted to the lathe stand. The SS round steel got TIG welded to the steel using an ER309 filler rod. The tops of the rear legs got capped with a couple of decorative post caps I have had laying around for years. I think the trim touches worked out well, my wife thinks it makes the stand looks like a bed. I can see her point.

 The backsplash is nothing more the 11 gauge steel plasma cut to fit. The backsplash then got stitch welded in from the back side.

 With the main structure completed it is time to focus on the base chip tray and the upper shelving. This is going to lead me into another project. The problem is this. My brain does not always mentally design projects according to what equipment my hands have to work with. My hands continually argue with my brain. The brain wants something a certain way, it’s real stubborn. My hands, as capable as they are, still need certain equipment to perform the tasks my neurological side is insisting on. It’s like my brain has a mind of its own and is oblivious to the fact that just because it sits at the top of my spine it still has other appendages it needs to consider. Anyway…it looks like another project will need to be completed before the lathe stand gets finished.

 

…and going to repurpose it. Actually it goes something like this. There has been some unrest in the garage this winter. It started with the chop saw and plasma freakin’ out on the band saw and just as they all settled down and started getting along the lathe decided to throw a hissy fit. It turns out that it can’t understand why the milling machine ended up getting a stand built for it with an integrated tool box when he, the lathe, has been stuck doing all the machining and he only rests on top of the useless factory stand. I couldn’t argue; the lathe had a point. His factory stand is completely useless. The stand is about 4 inches too low, there is a center section with a big hole in it that takes up cubic inch shop space, and the two side cabinets make for very poor storage space. I had been watching for a deal to come up on an extra wide tool chest and final one emerged. I managed to score a 40 inch wide upper tool cabinet with ball bearing slides. So the lathe is going to get a new stand and the old factory stand will get taken apart and repurposed. I think one of the cabinet stands will get turned into a belt sander stand, we’ll see yet.

The idea is this; to build a more useful lathe stand. The criteria are as follows; raise the height of the stand up probably 4” to help save my back. The new tool chest is going to get the lid cut off and then mounted into the stand just below the lathe. I’ll see how much room I end up with between the floor and the bottom of the tool chest. I plan to add at least 1, if not 2, shelves to hold my turning stock. The chip tray will be built similar to that of the milling machine. It will be water tight in case I decide to add coolant sometime down the line. An addition I am desperately looking forward to is an integrated back splash; I am tired of making a mess of the wall behind the lathe from the cutting oil that gets tossed around. If my mental design pans out then the stand will also get a 2 foot double florescent light fixture as well as an upper shelve to hold some supplies.

I started the build with fabricating the adjustable feet. Since the height of the feet will play a factor in how high the stand is built I needed to determine foot height first. The design for the feet is the same as I use for all my other hockey puck feet. I start by drilling a 1” hole 90% way through into the puck. I like to keep the bottom of the hockey puck sealed to the floor just to keep the moisture off the threaded leg. The legs all get chopped out of a 3 foot section of 1” threaded rod. The threads then all get cleaned up on the lathe. I usually use 1” washers to weld onto the threaded 1” rod however I don’t have any plus I don’t think they look very nice. I still had some 2” seamless pipe with .5” thick walls leftover from the metal bender project. I trimmed off 4 slices and cleaned them up on the lathe to use as the support washers on the hockey pucks.

The base of the stand where the threaded hockey puck feet will get screwed into was made from 2 x 2 x .100” square tubing. I took four 1” coupler nuts and cut them to length so that they would fit inside the square tubing. The nuts then get tack welded in place and will act as the threads for the adjustable feet. The square wall tubing then gets capped, welded and ground to finish them off. Now that the time consuming feet issue has been dealt with I can start on getting the main frame of the stand mocked up as well as plasma off the top of the tool box.