Bandsaw Stand

I have had a 4X6 inch horizontal bandsaw from Harbor Freight for years. It works reasonably well. I have cut a lot of metal with it. The stand that came with it however leaves a lot to be desired. It is made of thin sheet metal and has become bent and broken. It is too short to use with my roller stands to support long work. It is also too short for me to use comfortably.  You are supposed to be able to lift the saw and pull it around on the wheels attached to the stand but it drags unless you lift it very high. I got busy building the new stand and forgot to take a picture of the old one. If you have one of these saws I am sure you know what it looks like.

Now that my new shop is operational it is a good time to build a better stand for the bandsaw. The legs of the stand are made with some 1 inch square steel tubing. I made a U shaped frame that fits up into the base casting of the saw and attaches to the saw with the same bolt holes as the old stand. Then the legs were welded to the frame at the same angle as the old stand.

Above is a picture of one of the leg assemblies clamped to the welding table. I made a wood pattern to align the legs to the correct angle.

Above is a picture of the leg assembly being test fit into the base of the saw.

Once the leg assemblies were built and temporarily attached to the saw I welded some 1 inch angle to the legs to serve as bracing and to support a pan to collect the chips. At the motor end of the saw a piece of 1/2 inch rod near the bottom serves as the bracing and an axle for the wheels. At the other end of the saw a piece of 1 inch square tubing serves as the bracing and a place to attach the handle for moving the saw. The old stand had a lift up handle but I made this one a pullout handle. Two 5 inch lawn mower wheels serve to make the saw portable.

Above is a picture of the completed saw stand. I can see from the picture I missed a couple of spots in the final painting. The handle is show in the pulled out position. It can be pushed in to get it out of the way. I used an old bread baking pan to collect the chips. It looks a little spindly but the wheels are mounted out and give it a wider stance. One thing I noticed after using the saw on the new stand, it is much quieter, the old sheet metal stand acted like a sound board for the motor noise. All in all a nice little welding project.

Advertisements
Posted in Machine Shop, Metal Working, welding | Tagged , , , | Leave a comment

Mill Clamping

Now that my shop build is finished I can get on with some projects. Some of my upcoming projects will need a way to hold small irregular parts in the mill/drill. Several home shop machinists on the web describe making a mini pallet system to hold parts in the mill.

A mini pallet is a metal plate that can be attached to the milling table or held in a milling vice. The plate has an array of tapped holes that allow toe clamps to be attached to the plate with screws where needed.

I found a roughly 5″ X 14″ X .75″ 6061-T6 aluminum plate in my stock pile that was just the right size for my pallet. Four counter bored holes at the ends allow the plate to be attached to the mill table with cap screws and Tee nuts. The counter bored holes let the top of the pallet be clear of any obstructions. The rest of the plate is drilled and tapped 10-24 on a 1″ grid. Even with the holes drilled for a 40% thread it was very difficult to tap the holes all the way through so I drilled the holes over half of the depth from the back to clearance size. Even so the tapping takes a lot of time, backing up several times for each hole. My plan is to only tap a few of the holes and tap the rest as needed.

The other thing I needed to make were the clamps. These were machined out of 5/16″ X 1/2″ cold rolled 1018 steel. A tapped hold in one end allows a screw to be inserted to adjust the height of the clamp to suit the part being clamped and there is a slot for the hold down screw. I made two sizes 2″  and 1.5″ long.

One thing I wanted to try out was putting a nice surface finish on the clamps. Something that would help keep them from rusting. I hear a lot about Parkerizing (manganese phosphate)  for firearms but not so much for tools. It seems like most steel tools that are black are black oxide treated. To me manganese phosphate is a good choice for a surface treatment. You can get ready made Parkerizing solution but of course I had to mix up my own. To get the parts ready they were sanded on the belt sander then sandblasted. That was the first use of my new sandblasting cabinet. Then I soaked the clamps in the hot Parkerizing solution for about 10 minutes at a time taking them out to inspect and clean based on several tutorials on the web. There really was not much to clean off the parts and I think it would have worked better if I had just let them soak for about an hour or so. This was my first attempt at Parkerizing and I was happy with the results. I do think a bit more attention to surface preparation and a longer soak would have given better results.

One of the suggestions I found on the web was to use a case to store the screws and clamps. I also included an Allen key for the screws in the case.

The picture above is an example of how the mini pallet works. The part is a standard for a Stuart model steam engine. You can see that would be difficult to hold in a vice. The standard needs 4 holes drilled into the feet.

References:

My pallet attaches to the table directly rather than in a vice and has a square 1″ hole grid rather than a diagonal grid.

My Toe clamps a mostly the same as these except for 5/16″ thick instead of 1/4″.

https://www.milsurps.com/showthread.php?t=43247 Contains formula for solution and some how to.

Posted in DIY, Machine Shop, Metal Working | Tagged , , , , | Leave a comment

Eclipse 2017

I was not up to driving over a 100 miles in hope of finding clear sky in the path of eclipse totality. So I decided to make the most of what could be observed at home where we had about a 90% eclipse. Of course it was cloudy.
At my location Longitude: 91,39.26W Latitude: 42,11.90N the eclipse timing was about: start 11:45, max 1:12, end 2:36. There are a number of atmospheric sensors logging data here and it is interesting to see what effect the eclipse had on each of them.

The most obvious thing to look at was the sunlight intensity. This is a plot from my pyranometer which records the total visible light intensity of the sky. The red plot is the calculated intensity for a totally clear sky. The blue plot is the actual intensity. The effect of the eclipse can be seen as the small dip between 12:00 and 14:00. Roughly looking at the plot there is a 10:1 reduction in intensity during the eclipse. The cloud cover stayed relatively constant during that time. Of course just after the eclipse the sky cleared momentarily around the sun.

Above is a plot of the temperature and relative humidity. One would expect the temperature to drop during an eclipse and it did. It is hard to tell how much is due to the eclipse but I would say somewhere between 2 and 3 degrees F.

Above is the UV index plot. The dip in the index is quite clear.

Above is a plot of the infrared sky temperature. The red plot is the air temperature for reference. Comparing the sky temperature with the air temperature will give an indication of the cloud cover. A cloudy sky will have a IR temperature close to the air temperature. A clear sky will have a much lower IR temperature. If calibrated the clear sky IR temperature will indicate the amount of precipitable moisture in the air column. For some reason the IR data gets noisy when the sun is up. The plot shows less noise during the eclipse. The big signal after the eclipse is the sky clearing for a bit.

Above is the barometric pressure plot. I had read that an eclipse could affect the pressure and there is a dip during the eclipse time. But given how much it is bouncing around, who knows.

Above is the wind speed and direction plot. Nothing obvious here but the speed did drop during the eclipse.

Above is the Geiger counter data. I did not expect to see any effect due to the eclipse. There are however two radon washout events ( the increases around 6:00 and 21:00) due to the rain we had at those times.

Above is about all that I could see of the eclipse through the cloud cover. You can see that the sun is not round.

Posted in Amateur Science, environmental monotoring | Tagged | Leave a comment

Grillin’ With Wood

My vintage Weber grill is rapidly approaching the end of its usefulness.

There is a hole rusted through the bottom, one of the vent covers has corroded off and the lid handle is about to fall off. When we lived in town one of the neighbor kids used it for target practice with his BB gun.
I have been looking for something to replace the Weber and I also got to thinking, why am I paying for charcoal to grill?

So I started looking for something that would burn wood. For some reason most everything that burns wood is on the ground like a fire ring or a grate over a fire pit. Now I really don’t like to bend over to grill so this was a problem. Then I thought about the grills you see in parks. I think they are really intended for charcoal but they are open and you can easily burn and tend a wood fire in them.
Turns out there is a company right here in Iowa that makes park grills Pilot Rock.

Their grills are intended to be permanently mounted in concrete but I really want mine to be moveable. Instead of putting the base in concrete I welded the support tube to a plate welded to a truck brake drum. That brake drum weighs more than the grill. The next thing to figure out is where/how to store some firewood and keep it dry.

First burgers on the grill.

Posted in Cooking | Tagged , , , , , | Leave a comment

Simple Scissor Lift

In building my shop I spent some time thinking about how I was going to put the ceiling up. Metal pole building sheets were my choice for covering the ceiling. They are light weight, fireproof and already painted. The problem is the ceiling is almost 12 feet high and the panels are 3X10 feet. So how to get them up and hold them while attaching the panels.
I finally decided that a scissor lift would be a good idea. After looking at a number of commercial scissor lifts on the web I was coming up with all sorts of complicated designs. Then I remembered the saying KISS “Keep It Simple Stupid.
What I finally came up with consists of 8 8′ 2X4’s for the frames and some more bits of 2X4 for spacers. I used screws to attach the spacers making it strong and easy to take apart.

The center pivots are 3/8″ bolts, elastic stop nuts and washers. The end pivots are also used for the come-along to raise the lift so they need to be strong. I used 1 inch steel rod for this. There is also a safety chain to prevent the lift from collapsing completely if the come-along or its straps should fail. Your arms are inside the lift when working the come-along and a failure could easily break an arm or two.

To use it I drag it in place and slide a panel on top of the partially lowered lift. Operating the come-along raises the panel until it is in place. The position of the panel can be adjusted by dragging the lift or pushing the panel around. The panel is then attached to the rafters.

The only inconvenience with the lift is that the come-along is slow and fiddly to lower under tension. It takes twice as long to lower the lift than it does to raise it.  When I am done with the ceiling the lift will be taken apart and the pieces salvaged for future projects.

The lift has done its job and the ceiling is done.

I have posted a video on YouTube showing the lift in operation putting up ceiling panels. https://youtu.be/w5AClCLYUk0

Posted in DIY, Machine Shop | Tagged , , | 1 Comment

CNC Laser Cutter / Engraver Build

I see a number of articles on the WEB about using a blue laser around 2 watts for cutting and engraving. A lot of times the laser is attached to a 3D printer. Now I have a 3D printer but I wanted a cutter that was a bit larger and did not want to bother with swapping the laser for the print head. So I built a carriage for the laser based on  reprap Prusa technology.

The usable area of the bed is about 16″ by 16″ (400 by 400 mm). Unlike the 3D printer the laser is moved in both the X and Y directions rather than moving the bed in one direction and the laser in the other. A piece of 3/4″ plywood serves as the base and it sits on rubber feet so I can get my fingers under it to pick it up. The carriage and gantry move on 8 mm rods with dual linear bearings. I used two steppers to move the gantry in the Y direction to provide even force at each end of the gantry. There is no Z axis as the laser can be refocused for different height materials. There is a piece of sheet metal on the base that serves to protect the plywood from the laser.

Parts like the motor mounts and bearing supports are 3D printed and are based on the Prusa parts. For the electronics I used the Arduino mega with the ramps 1.4 interface. Since I have 2 steppers for the Y axis the Z axis driver on the ramps was used as it has two stepper connectors. To get this to work I modified the pins.h file in the Marlin software to swap the Y and Z axis.

laser1

The laser is turned on by use of the fan circuit in the ramps board. This is really handy as the circuit provides the 12VDC needed by the laser and there is  Gcode functions to turn the fan on and off.

There is a bit more work to do on it. The cables need to be properly dressed. Then there is all the safety issues. It needs a lockout switch and an enclosure to prevent any stray laser beams and control the fumes.

Repetier-Host works well for testing and for sending the Gcode files to the cutter. The manual mode lets me move the carriage around and turn the laser on and off.  The first test I did was using handwritten Gcode to cut a 20 mm square. For generating more complex designs I have settled on using Inkscape for drawing and have tried both Gcodetools and J Tech Photonics Laser Tool extensions to generate the Gcode. So far I have had better luck with the J Tech tool.

Here is a short video showing cutting the fabric.

I did a number of tests to see what materials could be cut with this laser cutter and what cutting speeds to use. Regular paper cuts very easily. The cuts don’t even have a burnt looking edge like thicker material. Card stock cuts nicely with a slightly slower cutting speed. Cereal box cardboard would take a slow cutting speed and several passes to cut. Normal thickness cotton fabric cuts easily. I haven’t yet tried other types of fabric. Cricut vinyl cuts and you can adjust the cutting speed to cut just the vinyl and not the support material. It will mark wood with nice clean lines.

2017a

Above is Cricut vinyl cut with the laser and below is after it has been weeded.

2017b

Below is a piece of pine that has been engraved with the laser.

exit

I see many interesting uses for this laser cutter especially once I get better at using Inkscape.

Posted in 3D printing, CAD, CNC, Crafts, DIY, Electronics, Machine Shop, Software | Tagged , , | 2 Comments

DRO for my MIll

Like most of my blog posts this is not meant to be a “how to” but rather a “how did” in hopes that someone will find useful ideas for their projects.

It has gotten a bit frustrating using my milling machine recently and having to deal with the leadscrew backlash and counting turns to get the table positioned. A digital readout  would make using the mill much easier. A full 3 axis DRO for a mill costs almost as much as the mill. I did not want to spend that kind money for a full 3 axis readout so I found some individual scales and ordered them.

millX1

The X axis scale was the easiest to mount to the mill. The front of the mill table has a T slot for adjustable stops. I had never used the stops so I figure I would not miss that function. With the readout is is easy enough to just stop at the correct position. The scale is mounted with some T nuts to the slot on the table and the sensor is mounted to the front of the mill using the mounting holes for the stop. An aluminum bracket and spacer connect the sensor to the mill.

millY1

It was necessary to drill and tap some holes into the mill to mount the Y axis scale. In this case the sensor is attached to the moving part and the scale is attached to the base of the mill. It is tucked away under the table mostly out of harms way.

millz1

The Z axis took me some time to decide how to mount. I did want to retain the depth limit function for the Z axis as I do use that frequently. The bottom of the scale is attached to the mill with two holes drilled and tapped into the mill. For the top of the scale I used a couple of disk magnets as drilling under the belt guard would have been difficult. The magnets make it easy to remove and adjust and they are up out of the way of any chips that the magnets might attract. I could have used a separate rod to mount the sensor but it looks better with the sensor attached to the depth limit screw. This made things more difficult because the screw still has to turn to adjust the depth limit. I added a wave washer where the screw attaches to the spindle and another wave washer where the sensor is mounted.  This eliminates any backlash that would cause error in the scale readings. The sensor is mounted to an extension of the screw to allow the depth adjust to still function over its whole range.

millz2

The original plastic cover was replaced by some aluminum angle. Not really necessary given the digital readout but I added a pointer to the depth limit stop nut and a piece of stick on ruler left over from another project.  This is handy for quick and dirty drilling that does not need to be very accurate.

milldisplay

I am still trying to decide how to mount the readouts for the DRO. Right now they are attached with their magnets to a steel plate sitting on the mill table. This is not a very good place for it as the chips fall on it. Many DRO displays are mounted near the top of the mill but I normally sit down to run the mill especially when doing careful work. Maybe not the safest thing to do but it is a lot easier for me to do careful work sitting down.

Recently I discovered information on the web about using an inexpensive android tablet for a DRO readout. This would let my setup have all the functionality of a 3 axis DRO for less cost. That might happen in the future but right now I want to get back to milling.

Posted in DIY, Machine Shop, Metal Working | Tagged , , , | 2 Comments