6 DOF Step by Step DIY Project (with blueprints)

Last updated August 15 2016
(Mechanical..Complete)
(Electrical work .... Last Updated May 16, 2016...Need to link some pictures.)
(Tuning work....about 80% done...)
(Motion Software Setup ....about 50% I guess)


Hi All,


I have been lurking and have read a number of threads on this forum and have been inspired.  I have started this particular thread because I could not find a thread that laid it all out for the novice builder.  I also could not find what the exact cost might be.  So this is my journey.  I have designed this project for the novice.  Meaning it does not require to many tools or special skills.  It does require a bit of welding but you might be able to find someone to do this for you.

Background on me:  I have never built a motion platform (I don't really think this counts) .  I have however built many other mechanical things including car(s), so it is fair to say that I am good with tools.  I have over 30 years of computer experience (computers are my day job) so its also fair to say I am good with computers.


In total there are 4 post in this thread that will guide you through the process of building a 6DOF platform. 
1. This one....The physical build
2. Electrical....The wiring
3. Tuning....The configuration of the Hitachi and AMC1280USB
4. Motion Software Setup


The supplied blueprints will let you create a system like this
(insert image....once completed )

Dimension

    Diameter needed without seating position (machine without control case)
    1924mm or 6' 4"

    
    Diameter needed with standard seating position (machine without control case)
        Accounting for movement you will approximately 2543 mm or 8' 4" from front to back.
    

Specification

Yaw	TBD
Pitch	TBD
Roll	TBD
Sway	TBD
Surge	TBD
Heave	127 mm or 5 inches per direction ( 254 mm or 10 inches total movement)

(All measurements where taken one plane at a time with a max travel angle of 60 degrees from mid stroke ...Compound movements will reduce overall travel)

    Power
        Max AMP ... TBD


Q and A:

Q.  Do you need any special skills?
A.  Not really...I assume that you found this forum so you generally have some idea of what your getting into.

Q.  Do you need any special tools?
A.  No.  All the tools that I used in the project will be listed.

Q. Where are you located?
A.  About 30 miles North of Atlanta Georgia (US).

Q.  Can I come see/test your platform?
A.  Don't see why not.

Q.  Will you sell/make me a platform?
A.  No...I really don't want to do that but if your local I would be happy to help.

Q.  Why are some of your measurements in inches and others in meters?
A.  I prefer the metric system but I am in the US which never made the switch.

Q.  Why so many pictures?
A.  Personal preference.

Q.  How long did it take to make the unit?
A.  Basic construction 6 days. Wiring 4 days. Tuning 2 days. (8-10 hour days).

Q.  Where did the blueprints come from?
A.  I created them in SOLIDWORKS.  I will not take credit for the dimensions, I simple used what others had done.  (Really appreciate all that have shared) If there is some dimensions that I did not show let me know and I will be glad to update the blueprints.

Q. Why did you choose to bolt things together instead of welding
A. I assumed that most where not to familiar with welding and since this was for the DIY I felt that bolting everything together made more sense.

Q. Is there any part of the project that you would do differently
A. I would not have painted things UNTIL I had done all the testing with the motion software.  I will need to dismantle and repaint.

Q. Do you think it can be done cheaper
A. Yes! In reality to build a setup like this your looking at 5k-6k spend no matter what.  You can source the motors/gearbox and inverters directly from China which would save you about 1k - 3k from my build list.  There are lots if inverters out there.  So shop around.  Look for sales and used items.  And I would look at the cost below as worst case.

Q. What mistakes did you make that I can avoid
A.  Make sure your positions sensors are 180 degrees.  That was a costly mistake for me.

Q. Does your wife know you spent that much.
A. Yes and No...mostly NO!!! 

The prices listed below are in US dollars as of 2015/2016 and round up to the nearest $5
The * notes high dollar items
If it's not link than I just picked it up at the local store.


            


Tools (I will update this as needed):

Tape Measure



Square

Drill


Drill Bits

1.625" Hole Saw


Dremel tool with cut wheel



Straight Edge

(2) 3/4 Wrenches

(2) 1/2 Wrenches



(1) 5/8 Wrench


(1) 9/16 Wrench


(1) 9/16 Ratchet


Screw and Screw Driver (for Jig)


Spray Adhesive


Threadlocker (Red)


JB Weld


Pencil (   ...Ok to much detail)

Step Drill Bits


Welder (if you don't own one they are rentable)


Metal Chop Saw (see above)


Someway to clean up the welds

Drill press


Saw for jig


Jigsaw

---

Let's get started:

Step one...Build the platform

Materials:

(1) 4x8 MDF board to layout the measurements Cost ~$25


(1) Box of dowels


(3) 20" 1x2 wall thickness .125


(3) 15.5" 1x2 wall thickness .125


(3) 8" 1x2 wall thickness .125

(6) 1/2" ID x 1" OD x 2 1/2 long spacers
(insert image)

---

Using the attached blueprints, start laying at the platform on the MDF.  Note: Do not drill holes yet.

Now its time to make some cuts.  All steel will need a 60 degree inward angle on both outward edges

to do this we cut 30 degrees

Layout the steel and drill holes for the dowels.  Dill the holes as close as possible to the steel and near the conners.  The dowels will hold the steel while your welding.




Note: All outside corners are 120 degrees



Moving on to the mount points for the rod ends.  This needs to be done BEFORE welding everything together!!!!

On the 8" long 1x2 steel measure in 2" from the end and drill a pilot home.  This will be done on both sides.  This will leave 4 inches between the mount points (4 inches is ~ 100mm which you may have seen in other peoples posts)


Next use the step bit to increase the hole size

Finally use the large step bit an increase the hole to 1" diameter so the steel bushing will fit


The 1" hole will need to go all the way through so you will need to flip the steel over to complete the process

Insert the 2 1/2" steel spacers

If you've done it right you should have an 1 1/2" exposed.  Note:  Make sure you have the 1 1/2" on the side face out.


 
With the 1 1/2" offset the rod will have plenty of clearance

Sand/grind the inside flat so that the bolt can seat properly
Before

After

now it's time to weld all the pieces together....put all the pieces back in the jig
Check that it's square and weld them up.

---

Next up....Rods

Materials:
I've chosen a high misalignment rod ends.  With the adaptors installed the inside diameter is 1/2".  This will give about 30 degrees to work with.

(6) Right hand thread rod ends
(6) Left hand thread rod ends
 

(6) 19" 1x.133 steel 
 


Once the rods are completely assembled the center to center length will be ~ 630mm long.

(6) 5 1/2" x 1/2" Grade 8 bolts

(6) 6" x 1/2" Grade 8

(insert image)

---

Weld the rod end to the rods and check the rod to the platform

Even at the most extreme angle (which is not technically a possibility) the 1 1/2" offset gives us about 1/4" clearance
View 1

View 2

---

Finally onto the base

For this next part I would recommend make a jig. 

Materials:
(3) 2" x 2" x 50" x .125" (wall)
(3) 2" x 2" x 54" x .125" (wall) 



(6) 2" x 2" X 5 1/2" x .125" (wall)



(6) 2" x 2" x 12 1/4" x .125 (wall)

(6) 2" x 2" x 10 1/4" x .125 (wall)


(18) 1/2" ID 1" OD and 5" long spacers


(18) 1/2" Carriage Bolts 6" long
 

(36)  3/8"-16 x 1 3/4" long rod hex couplers


(24) 3/8" x 1" long bolts
(24) 3/8" Nuts
(72) 3/8" Washer

(12) 3/8 x 2 1/2" long bolts


(24) 3/8"-16 x 2" long rod (I used a long rod and cut it into 2" sections)


(12) 2" inserts with captive nut


(12) X x 2 1/2" bolt

---

On one of the 50" piece layout the side holes

Per the blueprint that would be 2 1/2", 7" and 11 1/2".  These holes should be center from top to bottom.  So the second mark would be 1" from the top or bottom side.

Next drill some pilot holes.

Drill all six pilot holes.

Now onto the masking the jig.  I am going to use some scrap 2x4 I had laying around.

Lay the 2 x 2 steel on top of the 2x4 with the six (6) side holes so the edge is flush and temporally screw in place.



Added a temp 2 x 2  (steel) to the end and a 2x4 top and 2x4 side.  Screw the 2x4 in place.

remove the temp steel and add another piece of wood to the opening to maintain the dimensions.  Screw this into place.

With the screws still in the steel drill the open pilot holes.

Remove the two screws hold the steel and drill those pilot holes.

insure holes in the jig are complete through


I would recommend that you mark the jig on two sides.  You will also mark each steel tube the same way.  This way if one of your holes is not exactly right it will not cause a alignment problem when you go to bolt everything up.


Jig is now complete.



Drill the pilot holes  in the remaining two (2) pieces of 50" steel
Remove the 2 inch stop.

And repeat the process on the three (3) pieces of 54" steel

Per the blueprint we need to add a 3/8" hole 1" from the end and 1" from the top of the 54" pieces



With the step bit enlarge pilot holes to the correct size listed on the blueprint. The inside will be 1" and the outside will be 1/2".  You can see this in the picture below.

Install the 2" square insert with 3/8" captive nut and weld into place.


Only thing left to do is to put it all together.  Note the paint marks.  Matching them this way ensure they will bolt together easily even if the holes where not completely uniformed in the jig (there is also paint on the side that facing the ground).





Now we need to make a jig to drill the holes for the gearbox(s).  So more scrap wood.  Basically a piece of plywood with 2x4 stops 


Print out the gearbox template (Use a tape measure or calipers to make sure your printer did not change the overall dimensions) 


Line up the template onto the jig per the blueprints and glue into place


and drill pilot holes. 




We also need pilot holes for the risers.  They will be 1" from the ene of the 50" long pieces and 3" for the end of the 54" long pieces.






Increase the pilot holes on the top side to 3/8"

and increase the pilot holes on the bottom to a size the will allow the washer to pass through

Now were ready to create the gear box spacers

The easiest way to get the 3/8"-16 x 2" long rod sections ....is to cut up a long rod commonly found at the hardware store



Insert the 3/8" x 1" bolt into the hex coupler


Apply thread locker to the open end of the coupler and a 2" piece of rod


and thread together


remove the bolt.  It was there to act as a stop and let the thread lock dry. Placing the coupler up so the thread locker pools on the rod threads
 
Note:  Do not leave the bolt in place as thread locker will have most likely reached so of the threads accidently


Make sure to clean the thread locker off before it dries

Once the thread locker dries its time to put it all together


Apply thread locker to the 3/8" x 1" bolt and the open end of the hex coupler.

using the ratchet pass the 3/8" x 1" through the oversized hole 


loosely tighten the hex coupler spacer

repeat until all 8 hex couplers are installed

using some 2x4 wood place the gearbox approximate the distance per the blueprints

now place the rails onto the gearbox install the nuts and tighten everything down

now bolt on the risers


flip over after everything is tighten up

install motors

one down two to go


Cut a 30 degree angle on the 2" x 2" x 10 1/4 and the 2" x 2" x 12 1/4" steel



Weld 2" end with captive nut to the 2" x 2" x 10 1/4" pieces


Drill a 1/2" thought the 2" x 2" x 10 1/4" pieces 2 1/4" from the 90 degree side



Weld the 2" x 2" x 10 1/4" pieces together insure there is a 120 degree angle

Weld the 2" x 2" x 12 1/4" to the bottom of the 2" x 2" x 10 1/4" pieces and install in the conner with the X x 2 1/2" bolts



The base in now complete

---

The last piece of the puzzle..... Levers (Option 1)


Materials:

(6) 3" x 1" x .803" wall x 10" 9.5" long


2" x 1/8" thick flat steel (for gusset)


3/4" x 1/8"thick flat steel (filler)




(6) POWER DRIVE H X 1-1/4 Bushing

(6) 1" Outside x 1/2" inside x 3" long spacers



(12) 3/16" x 3 1/2" long bolts

(6) 4mm x 25mm (or longer) screws

---

Print out six (6) copies of the lever.pdf (Measure the distance between the holes to make sure your printer did not change the dimensions)


Now cut around the outside edge and glue the template to the steel (simple jig)



Now it's time to drill

Drill 1.625" hole

next drill 1/2" hole


last drill the 5/16" holes


Cut a compression relief 


Optional:  Cutting a half circle on the arm will give it a more finished look


Insert the H drive into the hole and tack weld


Insert the 3/16" bolts
Insert the shaft and let it protrude 1/4". Important: Not more than 1/4" or you will have clearance problems



Tighten the compression bolts


weld H drive in place




Cut the 2" flat steel into 12 pieces with a 45 degree angle


Insert the 1" spacer and tack weld into place




Weld in the support gusset


Before placing end cap weld spacer to bottom


Weld up ends with 3/4" flat stock







Clean welds and trim drive shaft



This next step is specifically design to work with the position sensor listed in the build.

Drive the opposite end of the shaft so that the 4mm screw with slide in


Fill the hole with JB weld and insert the screw


Once cured, cut the screw so that approximately 5mm is protruding from the shaft


Temporally install the R/C U joint to make sure you remove enough to the screw.  The U joint should sit flush on the shaft

  
for a finished look. Cover with body filler/sand/paint

---

Sensor Mounting (Option 1)
After thinking about it the sensor mounting really belongs in this part of the build

Materials:

(6) Output Drive Covers



(6) Position Sensor


(6) R/C Joints



(6) 1 1/2" x 1/2" PVC reducer

 

---

Dill a hole in the center of the cover large enough to replace the POT should it become defective.



Install the cover and U joint.


Using the step bit on the side that has the "stop".  You will need to drill deep enough so that the POT shaft is approximately 11mm from the bottom
 





Drill access hole to tighten the R/C Joint.  I went with a 1/2" but it really does not matter



JB Weld PCV to cover insuring that it is exactly centered.

---

Sensor Mounting (Option 2)

In the downloadable zip file you will find "Cover with position holder.stl"  this is a 3D printable file.  If you don't have a 3D printer and want to use these option you can get it done here

Once printer they will look like this




Need more detail?  Let me know.

-GA Dawg