Monday, July 30, 2012

Electric Car Model Suspension Starting To Take Shape

A very busy day today at the Tinker's Workshop.  More design work on my 1/6th scale electric car model with tweaking done to the front suspension and parts being cranked out on the Makerbot 3D printer.  Another seven hours onto the design time for a total of 87 hours so far.  Lots of tweaking to say the least.  

This image is a good view of the front suspension and steering setup for the project.  I will need to print out the parts that mount to the upper shocks and the connectors that will hold the rack arm for the rack and pinion steering .  The wheels will mount on to the hubs with internal 10-32 bolts threaded into their centers.  These will hold the wheels, disk brakes and calipers in place on the model. 

Here are the components for one side of the front suspension.  Upper and lower suspension arms, wheel mount  (disk shaped object) and working shock absorber. 

 The parts put together makes more sense as to where what parts go where.  This is the right front suspension ready to be installed on to the chassis once it is printed.

These two photos are of the steering rack and matching steering shaft gear.  The rack is 8 and 1/4 inches long and just fit onto the Makerbot 3D printer. The gear and rack matched up very well and should work great to turn the wheels with the steering wheel. The gear will be mounted onto a 1/4 aluminum shaft directly to the steering wheel.  I have to modify the gear so that it can be easily mounted on to the steering shaft with a set screw.  The steering wheel will be set up the same way.  Also on this shaft will be a spacer mounted on the shaft so that it will not slide out of position once it is installed into the final assembly.
  I plan on assembling the model with hardware wherever possible so that it can be disassembled for modifications or repairs if need be.  The lucky thing with this model is the sheer size of it which makes assembly easier.  Bigger is better and in this case simpler too!  I am still playing around with a design for a fiberglass body for the model and am getting closer with that end of it. Just have not found that perfect shape I have been looking for. Like I said more tweaking to do.... a lot more.

Friday, July 27, 2012

Electric Car Model Wheels In The Making

The 1/6th scale electric car model project continues today with the making of some rather large wheels that are going together well and are time consuming to print. 

 This photo is of one of the front wheel rim assemblies that is just stacked up at this point to show you what it all looks like without the tire sections in place.  There is a small outer rim then the center five spoked hub and then a larger rear rim.  These three pieces took 3 1/2 hours to print on the Makerbot 3D printer.  

This photo shows about half of the components that I printed today.  The white disks with all of the holes are for the disk brakes that will be in the model. The black disk will be in all three wheel assemblies and are spacers to mount the brake calipers in the wheel assemblies.

This photo shows the before and after sanding detail of the center hubs for the wheels .  Once the wheels have been sanded smooth they look very much like a cast plastic part.  

After a short discussion with my brother this afternoon I started printing the tires for the wheel assemblies so that each half of the tire were a mirror image of one another. (there are two pieces for each tire) so that the tread would be correct with a "V" form running through it.  This was more correct than having both sides of the tire being exactly the same.  Just looks a lot better.  Thanks Denny!

This gives you a good idea of how large these tires/rim assembly really is.  The outer diameter of the tire is 3 3/4 inches.  With the parts being this large it is easy to get some real detail in the electric car model.  The lower photo shows the rim cavity that will be filled with the disk brake, caliper and center hub.  The center hub will mount to a full working suspension and front rack and pinion steering. These parts will also allow for mounting of the front fenders. The assemblies are tight enough when put together that no glue is needed to keep everything in place.  The two tire pieces actually hold the entire assembly together.  
  I finalized the design of the front suspension and the tweaked the rack and pinion also today on the computer model.  Hours at this point in just design is around 70 hours so it will be interesting to see how many hours I will have in this model once I have completed it.  
  The one nice thing about this model over the Semi and trailer assembly I did some time back is that there are fewer parts and they are larger.  It got pretty boring building some of the semi just because there were so many parts that were the same and had to be printed over and over again. (22 wheel assemblies!)  Once I get all the wheels printed I will start printing the front suspension and chassis parts.  Should be interesting and fun at the same time.  I am more than happy with the wheels so far as these assemblies alone are quite impressive with the detail that are in them.  

Tuesday, July 24, 2012

New 1/6th Scale Electric Car Model Project Begins!

This past week I have been burning the midnight oil for several days designing a 1/6th scale electric car model.  The tally so far for the design has exceeded 50 hours. This vehicle or something like it has been on my mind for years and I am happily now making a model with my Makerbot 3D printer.  Printing of the first parts for the model started today and will continue for some time in the future until it is completed.  With that in mind here are a few photos of some of the first parts.

I wanted as much detail in the model that I could make and so have decided to have a full suspension complete with working shock absorbers.  The puzzle to figure out in the design of the shocks was how to hold it all together.  This was accomplished using a small press fit 3/32nd diameter steel pin.  The pin is slid into the upper portion of the shock through the slotted inner lower piece.  This holds the assembly together without the need for glue. With the 3/4 inch long by 1/2 inch diameter spring and the slot in the lower portion of the shock assembly makes the shocks fully functional.  I made the press fit pins by cutting them from a piece of steel rod that I had left over from the Gyrokite project.  I used a carbon fiber disk and my Dremel tool to cut the pins to length while they were held firmly in a table vise. (A two second job for each pin.) 

The first two of four shocks needed I completed today. They are 2 1/4 inches from mounting center to center (uncompressed) and are 1 and 7/8th inches compressed.  I would have completed all four shocks but the hardware store only had a couple of springs that I needed so the other two will have to wait until I can acquire more.   All four shocks took three hours to print on the Makerbot.

Here are a couple of good computer images of the electric car model (without a body).  It is complete in scale right down to the correct electric motor and lithium battery packs. The model as I said earlier will have a working front and rear suspension and also will have a working rack and pinion steering system.  The model will be 24 inches long and 13 inches wide.  Overall height will be 7 3/8ths inches.  Being this size it will be an impressive model comparable to my Makerbot Semi and trailer and allow me to put nice detail in the building of it. I have a wooden figure of a person that will fit exactly into the model.  It (Him? or Her?) stands 12 inches tall and would be six foot tall in real life if and when this model ever becomes a real vehicle some time down the line here at the Tinker's Workshop. 

Monday, July 16, 2012

Gyrokite Project Completed

This past month or so I have been working on the Gyrokite project.  Today I put the finishing touches on it and am happy as usual that it turned out as well as it has with all the tinkering that needed to be done to design and build it.  First off for those of you that have not been following my blog for that amount of time this gyrocopter is a remake of an old design from the 1960's I came across and decided to update and build.  It is a kite so the name Gyrokite was born.  (My idea).  The finished gyro stands 19 3/4 inches tall and has a 19 inch long fuselage.  The dual counter rotating main rotors are 36 inches from tip to tip and the tail structure is 9 1/2 inches across.  

The fuselage is constructed of fiberglass and it has at least fourteen coats of primer on it.  This was primed and wet sanded, primed and wet sanded over an over again before five coats of banner red paint was applied.  As you can see from the photos it was worth the effort to get this kind of finish on the Gyrokite.

 Doing the final assembly of the Gyrokite turned out to be  a comedy of errors.  I had assembled the main rotors and top vane on to the main rotor shaft assembly only to find out that the top rotor hub was assembled upside down.  This caused the top main rotor to tilt down instead of up and collide with the bottom rotor.  Not a good idea at all. Also the top wind vain was completely backward in the assembly.  I had to remove the main steel 3/32nd rotor shaft and had to make a new one to replace it to correct the problems.  This only took about ten minutes or so but at least everything was made right very quickly and it is now ready to fly. 

For more information about the construction of this little beauty go back to the blog here over the past month as I have posted all information about how the Gyrokite was put together from the main rotors to the landing skids.  I will have to get a good windy day to test fly my latest project and hopefully I can get a hand with shooting some video of the maiden flight.  If I can I will post the video here when I do.  My brother who was visiting me over the weekend hopes that it will fly as good as it looks.  I wish for the same but even if it does not turn out like I hope and believe it will this project will in no way be a failure in my eyes if it does not fly well or if at all. (But I am still keeping my fingers crossed for the first flight!) I learned a lot about finishing fiberglass so that I can get a near perfect surface for painting because of this project.  That alone was worth the effort and something that I will carry forward in future fiber glassing projects.  Your never to old to learn new things, especially here at the Tinker's Workshop.

Wednesday, July 11, 2012

Gyrokite Fuselage Almost Ready For Final Paint

  I've been busy today making adjustments and modifications to my Gyrokite project.  One of the main changes that needed to be made was the replacement of the landing skids.  The original design for the skids was to short in length to support the fuselage correctly.  The tail of the fuselage ended up sitting on the ground when placed on a flat surface.  

This photo shows the Gyrokite with the new skids installed.  They are two inches longer than the original design and have additional bracing for strength.  They actually look better and will give the Gyrokite a better footing when sitting on the ground. This is where the new Makerbot 3D printer was a big plus as the skids now are eight inches long.  On an earlier Makerbot printer I was using in Davenport you could not make parts any bigger than three inches in length on a good day.  

I also got the tail section of the Gyrokite mounted onto the rear of the fuselage today.  All the primer has been wet sanded smooth and is now ready for final painting of the fuselage.  This will happen in the next couple of days along with the final assembly of the main rotors, vertical wind vane, and mounting hardware to the internal mast support. Once I complete this portion of the work for this project I will post the final photos and be ready to test fly it once we get a good windy day. Just will have to keep my fingers crossed that it flies as well as it already looks!

Monday, July 9, 2012

Makerbot Replicator Extruder Centering Solution

The past couple of weeks I have been enjoying my new Makerbot Replicator 3D printer but have noticed something that was not to my liking.  When I loaded a file to be printed on the Makerbot I would center the part and save it but it would not print in the center of the machine even though the software showed the part was in the center of the build platform.  This is really not a problem on this 3D printer as long as you do not try to make very big parts.  Other users online have tried and the parts will fail simply because they are not centered and will run off the edge of the build platform. I did not want this to happen so with this post I will show you how I solved this problem quickly and simply without a hassle.

The image above is the ReplicatorG software screen that I use to set up files to be printed on the Makerbot Replicator 3D printer. This software is the standard used to making 3D parts on any home use  3D printer. The display screen helps me rotate, mirror, scale and view the computer designed part that I wish to make.  In this view is a very small part that is used in the Gyrokite project that I am currently working on.  I used this small part for testing to get the calibration figured out on the Makerbot.   
  I did some research online to see if I could find a solution to my problem of parts not printing at the center location even though it shows that it should in the software setup.  Turns out that a lot of other guys are having the same problem. The only true piece of advise that was any help was a procedure I found to do a calibration set up for centering the printer.  I thought "Great, This will be perfect!"  I ran the software but could not get it to make the corrections I needed on the machine.  
  The procedure for making the correction needed is to click "File", then "Scripts", "Calibration" and lastly click "The Replicator Calibration.Gcode" selection.  This will set up a Gcode file in  the ReplicatorG software screen.  Press the run button and you will get a menu that says "Move the extruder carriage until it lies in the dead center of the build plate. Then press "Yes" to continue.  I moved the extruder carriage to dead center and the platform exactly the thickness of a sheet of paper from the print nozzles.  Then I pressed "Yes" to finish the procedure. After finishing this procedure I thought "Now my prints will be centered perfectly" No so.  I ran another test part and it had not done anything.  I measured the position of the print and found that it was printed 3/4 of an inch to the right of center.  Then a brainstorm hit me.  Why not just adjust the centering of the machine to 3/4 of an inch to the left.  Worth a shot I thought.  So before I ran the procedure again I aligned the print heads to the center to start and then readjusted them to be 3/4 of an inch off to the left.  Then I ran the procedure again. 

  These two photos show the before and after start of the simple part that I was testing.  The single circle is what was printed before making any changes to the printer extruder heads center location which is the incorrect location for the part.  The double circle is the correct location (dead center) after adjusting the start location by 3/4 of an inch to the left. 
  Since making this adjustment I have ran at least a half dozen more parts and all are centered perfectly on the build platform. Why the procedure for making the correction in the first place failed I have no idea.  But with that failure I found a simple solution that works.  Can't find any fault with that for sure.  So hopefully a lot of other people who own the Makerbot Replicator will read what I have  posted here and get their machine centered and printing just the way they want also.  Let the large 3D printing begin!

Friday, July 6, 2012

On The Skids!....... In A Good Way!

With all the heat that we have been experiencing here in the Midwest it has forced many people to stay indoors.... me included.  Luckily this is not a bad thing here at the Tinker's Workshop where my progress on with the Gyrokite project continues.  Here's what has been happening with the project over the past couple of days.

 This is a good shot of the internal workings of the Gyrokite project.  The white rim on the outer edges of the fuselage is a micro-balloon putty that stiffens the structure but is still very light weight.  In the upper center of the photo you can see the horizontal tail structure ready for mounting.

The black tail section for the mounting of the horizontal tail stabilizer was printed on the Makerbot and still will have to be tweaked a bit in order finish the assembly.

  This is a good shot of the main rotors temporarily mounted on the fuselage with the landing skids.  A  vane on the top of the structure still has to be constructed and assembled for the final assembly.

The top view shows the two counter rotating main rotors. Each rotor assembly is 36 inches long and 1 an 1/2 inches wide made from bass wood and Makerbot printed center hubs.

A couple of more internal shots of the Gyrokite with the landing skids installed and mounting parts to mate the left and right sides of the fuselage. The blue in the photos is just tape to hold the mounting nuts in place while the assembly is being put together. 

This is a good view of the fuselage primed in gray paint.  I will paint the fuselage red with a white accent and a gloss black windshield which should set the assembly off nicely.

   I just could not resist getting this post out to let everyone know how the project has been moving along.  More updates in the coming days as I get farther along. Hope your staying out of the heat like I am and have the time to work on something you have been dreaming of. Enjoy.

Sunday, July 1, 2012

New Makerbot Replicator Enclosure!

The last couple of days I have been busy in the workshop developing this latest creation for my Makerbot Replicator 3D printer.  A lot of information I have been reading about the Makerbot Replicator over the past couple of months has given me a starting point for this project.  The enclosure that I created here will help the Makerbot retain the heat better for making parts.  A cool breeze is not a good idea and as most enclosures I had come across were created using a laser cutter for the clear acrylic I decided to go another direction with this design.  Not that I would not like to get my hands on a laser cutter but it is out of my reach for now due to lack of either funds or plain and simple a place to put it if I did get one for the shop.  So here is what I came up with.

Here is the Makerbot Replicator complete with side windows, front removable window, and hood assembly all made out of 1/4 inch clear acrylic plastic.  I went with the 1/4 inch material simply because I had some of it in the shop just waiting for a project like this and I wanted to make everything here as simply as possible using just my drill press and band saw and of course the Makerbot.

The hood assembly is held together using 10-32 x 1 inch machine bolts and nuts.  The black pieces that you see here are printed on the Makerbot and are various shapes and sizes. They hold the clear acrylic parts together. Each hole in the various parts or panels are 1/4 inch in size and allow for tolerance in the assembly to be built into the design.  This makes for easy assembly when I wanted to put it together.

The front window of the enclosure is held in place using three clips that slide over the top edge of the Replicator and the top edge of the front opening. To remove the front window for servicing, adjustments, or removal of completed parts you simply have to lift the front window up 1/4 of an inch and it pops off of the machine.  To re-install the window you insert it and drop it down 1/4 inch and it's in place.  Just that quick and easy.

Here are the inside and outside views of the lower clip that mounts to the front window.  The nuts used in the assembly are recessed into the part for ease of assembly and you only need a screw driver  to put everything together.

The side windows of the Makerbot panels are made of clear acrylic which were cut to fit into the openings of the machine and are held in place using panel clips. Two are on the bottom of the panel and one on each side.  The clips are rotated 90 degrees to install the panel and then rotated again to lock the panels into the openings. 

Here are a couple of photos of the two top clips used for the front window assembly.  The clips are mounted to the panel themselves and have a 1/4 inch gap at the back surface of the panes so that the clip can straddle the front upper lip of the Makerbot front panel.

Here the front window is removed so that you can see the shape of the complete assembly.  The odd top shape of the window was required so that it would clear various bolt heads that stick out of the front face of the Makerbot.

 The assembly of the top hood is done right on the machine and starts with the corner mounts. These parts are made up of two sub assemblies for each corner and then slid onto the top of the Makerbot using slots to ride over the top outer edge of the machine.  This locks these parts into their correct location so that the outer acrylic panels can be aligned and bolted to each other.

The last pieces that are put together in the assembly are the inner corner mounts and the top front window and upper clear acrylic panel.  The fact that all of the nuts in the assembly are recessed into the black Makerbot parts was a big help in putting everything together.  No tools had to be used inside the machine so it was quick and easy to assemble.  

The Makerbot Replicator is now more high tech looking. This is cool but what is better is that it now can make even better parts no matter what the air is doing outside of the machine.  Nice to know as it can be a real pain to work on a 3D print and have it fail.  Eliminating bad air flow and temperature swings is a couple less things I have to worry about now with this new enclosure.  
  For those interested the machine now is 18 3/4 inches wide, 17 inches deep (with filament spools installed in rear) and 22 inches tall with acrylic hood installed. 

This illustration gives you a good view of the placement and parts that are in my design. 

  If you would like to make an enclosure for yourself go to my Thingiverse site listed below to get all the drawings, and files you will need.  Happy 3D printing!