6 DOF from scratch

Aie! J't'avais vu avant, mais je savais pas que t'etais de Quebec!

Man, another Quebecer. Where are you from? Me, as you probably already seen, I am from Drummondville. But only on weekend as I work at Frima Studio in Quebec City during the week. This is why things go so slow. I only work on it the weekend.

When I'll have something to show, we might do a get together.

Last week I did my first screw up. I wanted to bring part of the ball screw with me to find the right screw to fix it. So I unscrew it all the way. DON`T DO THAT, it is stupid. I was fool enough to think it was a simple screw.
This is when I saw a small ball fall on the floor. I was fortunate enough to find it back. My first reflex, screw it back together. Second mistake, it got stuck. After many tries, I could get it out.



After I stopped to curse at my self, I decide to get over it and walk all over my ego by ordering a new one right away. Since then, I found a picture of how it work, and I might try to put it back together.


But at least, Christmas time is there almost every week end. There is an enormous box. What could be inside?



You see the little rail on the top? Well, that was what was inside. No joke. All that for a free sample.



There was an other box and a mystery bond. We will only know next week what it will provide me from the mail. So exciting!



So this is it for now. A Igus plastic guiding rail slider as a free sample and the new couplers for my up coming motors. Oh! could it be what's waiting for me at the post office? Next week folks!



This is mother's day weekend. I don't expect doing much work on it this week.

I suspected the bearings would fall out but wasn't sure and haven't read any warnings not to do this on the forum and so thank you for sharing your experience so hopefully others can avoid the same mistake!
I believe that in the manufacture/assembly of the ball screw the ball bearings are inserted through the hole in the side of the bearing housing which is then plugged once all the bearings have been inserted. On yours you have two orange plugs, I'm guessing that there are two raceways for the bearings.
Good luck reinserting the ball bearings and re-plugging, I'm not sure if this can be done.

youtube is your friend here, I have re-packed one of these after curiosity got the better of me. Its not that difficult, but it takes a steady hand, patience and sticky grease.



Nice job on the linear actuator build, it seems like these 6DOF builds are popping up all over the place.

I have redone all of mine at least once, its easy enough once you know what your doing That's why limit switches are a must on these actuators, me being me ran it for a while with out any which was a stupid school boy mistake

RandomCoder: I was so mad at my self that I almost decide to not tell anyone and go under the radar with it. But, if you don't get over your mistake and accept them as a learning curve, you won't go far with this kind of build. Every things I do (and I am not doing much yet) is: "Am I doing the right thing? Am I taking the right decision? How do I do that?" I hate to do mistakes and do things over again, but it is faster than hesitate all the time on how to do it right the first time. Another thing that I learned.

Hodden: Thanks for the video. I was on the hunt for one of those, but did only find something about how to grease the bearing of a linear rail. It will be helpfull.

SilentHill: Glad to know that it can be done so many time. I just have to be patient and good in mechanics... Damn, I'm screw (pun intended).

I'm from Mirabel.

My current work on a 6dof system is not even worth creating a thread atm. We are still testing some motors and made an actuator with ABS tube (yeah for testing purpose of course).

Well, don't worry about progress speed. I have a lot of parts, but nothing assembled. I am even destroying my ball screws.

I passed by a lot of time from Mirabel when I worked 10 month at Hybrid in Piedmont.

I got it back together! Yeah. Does it run smoothly? No, but I think it got more to do with those damn plastic seal on each side. He doesn't show in the video how to set those back, as it is straight forward. Well, for me, it was not. But with the help of my friendly hammer... Maybe with a bit of running, things will get to there places (or everything will fall apart). Sure thing, it will be good enough for testing.



I also did some drawing and punching in prevision to drill the holes. I don't have the tools to do that. My brother does, but now, it's time to go to bed.

I never succeded in puting 100% of the ball inside, it never went smooth again ... +1 don't do it :/ I had to buy 1 more at the end ...

I did a little update on my design, trying to get closer to reality. Because, at home, there is a big heavy box waiting for me, and I know was is inside.

Just and observation but how are you going to stop the top end plate from twisting ?

Yeah, I am still missing some stuff in the design. Since I have no idea on how to fix the carbon tubes to the top plate, I will run a threaded rod all the way from top plate to the one below the ball screw. I will use the tube only as guide support for now. Then, I will have to figure out how to set up the potentiometer (when I`ll receive my parts) and the guide rail.
The more I look at my design, the more I think I might add an extrusion like most people do and use v-wheel to guide it instead of a rail. We "wheel" see. (I'm so funny).
To attach my tube to the ball nut screw, I had the idea to order a 30-28 tube to fit on the nut screw, then another tube to go from 28-25 and insert my 25-23 into it. All should fit nice and tidy. Waiting for the parts (and SeatTime to tell me how to work with carbon ).
But today, my friend, who's a racer, told me there was a great racing seat sells at a rebate price. I was not ready for that but it was a good deal. Usually, they would sell $460 and it was at $300. I could have save on the shipping, but it would have been an hassle. So I pass the rebate in a 60$ shipping. Taxes and everything: $413.99. Thank you credit card. But it's nice.
It weight 11.34 kg and the foams under the thighs are attached with velcro. You could easily insert moving plate under those.

Some people might thing that I spend without thinking. Trust me, I weight every spending decisions and it scare the hell out of me.
I always have the impression of loosing control over this project, but when I calm down, I don't regret any moment or money spent on this build.

Very nice seat and quite lightweight too good choice.

I was the same with spending and just let my budget go out the window it costs what it costs and when it's all done it is easily worth what's spent and is still a fraction of a commercial sim.


Look forward to see some building taking place

@Pierre Lalancette
The correct way of removal of ballnut from ballscrew is to us a tube.
The id of the tube is 10mm and od around 12.7-14mm to fit over the bf12 machined end.
The function of the tube is to stop any balls from falling out and doesn't need to be threaded.
Slip tube over 10mm screw end and wind ballnut off the end of the screw on to the tube.
Don't let tube fall out nor leave a big gap between threaded end and tube.
Once ballnut is completely on the tube you can flip the ballnut and tube and rescrew the nut on.
Job done.

You can find cardboard tube from a cash register docket core or 1/2" ACR copper tube.
You may need to build up the od, the easiest way is to use duct tape to wrap the tube or drill id.
2-3" length of tube would be plenty long.

You can also use the tube to reload the balls in the ballnut.
It will make it a lot easier as you can load the balls directly and move tube up as you fill and you can push the balls so that the return tubes are full. No more left over balls.

Yeah, I say it in the video. He was using a tube to keep the ball in place while screwing the rod inside.
It turned out that I have a Slush Puppy straw exactly the right size that I could use to do the job. I used that to keep the ball in place while I was inserting the rod.
My problem was those 2 plastic nuts that are on each side. Probably to keep sand an dirt out of the screw. They screw all the way to the nut, but then, they have to be press into the hole, while still screwing them. A tool probably exist that you screw with them until you press them in. But I don't have that tool, if it exist.

Guess what? Christmas time!



The hockey pucks are there because I had an idea. The other package was not what I expected at all. It is an arduino with a touch screen. I ordered those 3 months ago, I was not expecting them anymore.



But what could be in the other package? The wait is nerve breaking.



Here they are!



A quick inspection, a little picture, and they go back to there box until needed. Things start to get together. Still, so many things to buy.



Unfortunately, I don't have the tools to start building it. I may have to invest in that area. I can only have a preview for now.



Here's my idea with the pucks. I could drill a hole with my hand drill, not an ideal solution, but just good enough to see that i could work. If I can make it fit on top with a big hole in it, it would be even better. Once fixed, I can cut it as I want, and attache other things to it, like v-wheel for stabilization. It's cheap, not that hard to work with, and can help to temper any over run in that direction. I think it is a great idea.



Where can you buy hockey pucks all year long? Canada. Where are they from? Slovania. Go figure.
If you wonder why they are blue, it is because the are light weight. 4 onces instead of 6.

Santa Claus was busy this week. Many gift. We know what is inside the big box, but what could be the other ones.



The seat is no surprise, still look nice though, and quite confy.



The rest is not much of a surprise either. Tubes and 1605 replacement.



The tube fit nicely on the 1605. The intermediate tube is not as precise and it will be tight. It may need some hammer love, but it should be straight.



I am still missing some holes in my wood pieces for the motor. First thing tomorrow morning. Trying to find all the right screws and bolts to set it up turned out to be more challenging than I thought. Store don't have all sizes, and maybe not in the right amount that you need. It turned out that I bought many part that I may not used (for now). I hope to have a basic structure proposition by tomorrow night.

Note to my self. All the things I still need to get:
- gears for the potentiometer and the guide rail (all ordered, waiting for arrival).
- 5 other potentiometers.
- 5 other igus bushings.
- 2 arduino uno
- 2 sabertooth 2x60 (ouch!)
- 6 bottom joints for the actuators. Don't know those parts. Open to suggestions.
- 6 top joints for the actuators. Don't know those parts. Open to suggestions.
- Wire gauge 4 (will order booster cables)
- Fans, lots of fans!
- Good power bar.
- USB booster.
- Wheel and pedals (if I decide to drive).
- Aluminum extrusions?

I am probably forgetting a lot of things, but I think the major parts are listed.

@SilentChill , do you have a link on where I could get those 25mm reducer. I look in store around here, and I think that most of our pipelines are imperials. It looks like a perfect fit. Did they work well for you?



Still a long way to go. One step at a time.

Mmm. This is how I mounted my carbon shaft to my Ballscrew. You can see the couplers that I made out of pipe and threaded bolts welded on, in the top left hand corner



The carbon rod, coupler and ballscrew are then place on an alignment jig and mated together before being bonded with carbon fibre.



You can see the bonded finished product below, which can be removed from the ballscrew if required by undoing 4 nuts.



Hope that helps - The above images are straight from my thread - unfortunately not so straight forward to follow, but there is allot of information there.

Yeah, I remember those pictures. Not the first one though. You packed a lot of stuff in there.

I have so many questions, I`ll try not to annoy you too much. The fact that you can detach your tube from the ball screw gave me the idea that I could do something similar if I can attache the fitting tube only to my hockey puck. Nice idea.

First question out of ninety-nine. Just kidding. What are the screw you use on top for your 8-10 mm tube? Do you just force them in or do you glue them somehow? I am running a rod all the way through and I thought I might reduce weight if I only use screw at ends. Maybe it's not worth it, but I would just like to know.

I guess you use epoxy glue, but I don't recall mention of which one. Do you recommend any for carbon tube?

As for my construction, its getting on its way. My carbon cutting skill are lame, but fortunately, it is not an issue for how I use it. Next time, I will use 2 metal collars to guide my cut.



The 28-30 into the puck. The 25-28 into the 28-30. Then, the 25-23 into the 25-28. All fit and align nicely.



The I slide the results over the ball screw nut. I can now attach the puck to the nut. If I glue only the puck with the tubes, I could detach it from the nut if needed.



Attach the BK12 and the coupler before attaching everything to the woods, otherwise, nothing can be reach and tided up inside the hole.


I did not bother to cut the long screws yet.



Fixed the motor. I did not test it first, which is pretty stupid. But it is more a design test than a running one.



Now, thanks to forgiving wood and bendable threaded bars, I could fit it with the ball screw support. My alignment is resumed to only: "a few hammer here, a few hammer there."I need more precision in my life.



So here it is! Missing the align wheels, the glue, the potentiometer system and the limit switches.



I can turn it just using my thumb, no major blocs. It might actually works!



Waiting for parts. I should start ordering some others.