Showroom Newb's compact 2DOF build - Moving from a commercial unit to a DIY under seat mover

Greetings!!!

Just call me Kranky, though I try not to live up to that name too often.

Having been a long-time lurker to these forums (well over a year), and after initially chickening out of going the DIY route for a motion rig, I have recently become...shall we say "enlightened" to the benefits of doing such.

***Please feel free to skip the rather long winded story below as to why I am re-visiting the DIY option.
You have been warned, LOL!!!
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The reason, my just 6 week old Next Level Racing V3 Motion Platform up and died on me. Even after we had so much fun during our short time together, I guess that it had just had enough.
But not me, I was DEFINITELY bitten by the motion bug, and a static rig would now feel dead to me.

Since it came with a 2 years manufacturer warranty, normally something like that wouldn't be an issue, but it got me to thinking...

1.) While it's a great and compact unit which performed very well, at $4K Canadian after taxes this was an expensive sim-item to have, which I am at the mercy of if something were to go wrong with it.

2.) Even with the somewhat longer than usual 2 year warranty, the fact is that there are no service centers in my part of the world (Canada/USA), and the unit would have to be shipped to Poland for any major repairs (like this one).
At the very least a minimum $200 (probably more) just to ship it to Poland while it's under warranty, but an out-of-warranty unit would also incur return shipping fees plus whatever the repair charges would be.

3.) The design of the unit is completely sealed and proprietary, there's not even an external fuse to check, and the warranty is null & void if the consumer breaks the seals in order to inspect it.

4.) Perhaps it was a one off thing, but with the cost of the unit + a catastrophic failure so early in its life + the only service center being on another continent, this situation was far from confidence inspiring to say the least.

Luckily it was purchased from Best Buy (online special order only, not sold in stores), who were absolute champs with the options they gave to me.
Even though I was 2 weeks past what is normally a 30 day return/refund policy, they do acknowledge that this is a rather unique item. I was informed that as per an agreement in place with their supplier, they handle everything during the 2 year warranty (repairs, shipping, exchanges, etc.)
While that does sound great, and I applaud them for this, it got me to thinking how anything past those 2 years could/would be a nightmare to deal with. I mean, if my car breaks down, I can at least get it fixed locally and not have to ship it off to Europe every time!$!$!$!$$$$

So my options were to return it to the store for a refund, or exchange it (refund + re-order) and wait for one to be delivered.
After thinking about it for all of 1 second, I decided that the best course of action would be to cut my losses and simply refund it, then re-visit the DIY option with (hopefully) a much smaller portion of that money.
The greatest benefit being that if I build it, then I should also be able to maintain and repair it when need be.

So now my journey begins...
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First off, my rig is designed around the concept of a drop-in seat mover for motion.
Obviously from my above tale, that was the Next Level Racing V3 Motion Platform.
Once that was returned for a refund, I began looking at my available options.

A DIY rig was at the very top of my list, but I was still open to a commercial unit if it were to fit the certain criteria, mainly being repairable with off the shelf components.
I had briefly considered going with the new M2 Seat Mover from DofReality @ $799 USD, but after calculating the cost of the unit itself, Shipping ($200USD), Taxes, Duties and $ conversion to CAD, it more than doubled in price.

After spending a week @ roughly 4hrs a day browsing these forums, I figured that DIY was without a doubt the way to go.
You folks have built some fantastic machines, and with such passion that it's truly inspiring to move ahead and attempt to try this myself.
Or, as one might say "Do or do not...there is no try".

So now I must DO !

What I am planning is to build something that is similar in design, concept and footprint of the NLRv3 which I had, so that it can simply be slid into place where that unit once was.
That unit is an entirely under the seat type of mover.
Since my actual rig is already built, I really don't want to have to heavily modify it for a behind the seat motion setup, unless I really have to.

After doing a lot of research on the forums I've started ordering what I'll need for my build.
What I've come up with for my parts list is as follows, please don't hesitate to make any suggestions or substitutions:

Major Components, quantities are in brackets

(1) Flanged U-Joint with appropriate mount for proper seat height
(2) PGsaw 50:1 ratio 12VDC 200w motors
(2) Motor Mounts (design to be determined, but likely 1/8" steel plates) [EDIT : ended up with 1/4" steel L-Brackets for the bottom mounts + a 3/8" threaded connecting rod + rod ends for the top motor mounts]
(2) 12mm threaded rods for the motor axles
(2) Motor Arms (drilled with various CTC holes for making adjustments/testing)
(2) 10K 5watt Pots (std carbon, wire wound, or Hall Effect pots) [EDIT : currently testing with 10k 5watt Wire Wound pots]
(2) Polulo JRK 12v12's (original version, but may exchange for G2's if need be) [EDIT : since Pololu has officially discontinued the 12v12's and the chips are no longer being manufactured, I've exchanged them for G2 18v19's in order to future-proof this build and not have to worry about sourcing a critical obsolete part]
(1) Medium sized project box to house the electronics, with cooling fans
(2) 12v 500watt 40A LED/3D Printer-type Power Supplies (with fused power switch on each one)
(2) 30A circuit breakers to install between either the motors & JRK's, or the JRK's & the Power Supplies (protecting the JRK's from anything above 30A)
(2) Emergency Cut-off push switches (for emergency shut down while in the rig)

Various other supplies such as 10-14GA wire, nuts, bolts, brackets, Heatsinks & Fans for the electronics, etc.

I'll most likely build this onto a 3/4" plywood drop-in style platform for a prototype, then later follow up with having a proper metal one welded by my local shop.
As stated earlier, the plan is to build it away from the rig, and be able to bolt it in, much like the NLRv3 does.
This would also make for easy repairs, or even swapping it into a different rig with minimal effort.
Basically a portable motion platform, easily adaptable and bolt-in to almost any rig.

Here are some pic's of my rig both before (leather BMW seat, narrower design), then with the NLRv3 (racing seat, wider cockpit & platform, etc.), and now after removing the NLRv3 (note the unfinished plywood plank under the seat with dual uprights in place of the NLRv3, temporarily a static rig...Yuk!!!!)

The Original Rig:




The Rig with prep for NLRv3 + fully installed NLRv3:







The Rig as it stands now, MINUS the NLRv3, and sitting on an unfinished plywood plank :-( ...but eagerly awaiting the DIY build







*NOTE* As you may have noticed, the seat is mounted to a 3/4 wooden platform which has quick release mounts both left & right for a HOTAS system (pictured) as well as a Thrustmaster Th8A shifter.
It takes about a minute to swap between racing or flight mode.
I plan on keeping this setup and simply bolting it to the top of the drop-in motion platform.

Now I'm looking forward to receiving my parts, and designing/building a drop-in motion platform.

Thanks again for allowing me to introduce myself, and reading about my motivations for joining this community.

Cheers!

Parts have begun to arrive, the first being my order from PGsaw.

(2) PGsaw 50:1 12v 180w Gear Motors (will have to swap one gearbox side to make a L & R pair)
(2) 30A Circuit Breakers
(1) custom made flanged U-joint (thanks Kim!)

Swapped one of the motor gearboxes to the opposite side in order for them to be symmetrical once mounted.




Also found this post mount @ Home Depot, which seems to be a perfect match for the U-Joint + a 3 1/2" wooden post.



Now I'll be able to experiment with different seat-post heights during the prototype phase until I come up with the ideal match and get something welded together.
Later on I can re-purpose this base for something like a joystick/shifter/accessory mount, so it's not going to be wasted.

Still awaiting delivery of my JRK's.
Having a heck'uva time finding a set of rod ends + fine-thread threaded rods, but persistence will pay off.

More stuffs have arrived!!!

(2) 12v 500w 40A Power Supplies (with 3 year warranty)
(2) On/Off switches with fuses for the Power Supplies
(2) Emergency Cut-Off Switches

I can feel it getting closer.

Well isn't this just a typical Friday night...a couple of J(e)RK's show up and want to start a party!!!






On a more serious note, today I've received my pair of JRK 12v12's, but ironically it's somewhat of a melancholy moment.

Do I use these tried and proven motor controllers which are now being discontinued by Pololu , or do I return them, pay the extra $50, and order a pair of G2 18v19's in order to be more current???

I believe that "yobuddy" mentioned that the new SimTools v 2.3 (possibly being released by this Monday) will officially support the G2 lineup of JRK's.

It might be worth it in order to be more future proof, and replacements would be easier to get than the 12v12's which may run dry due to the chips no longer being manufactured.


If anyone happens to read this, I'd love to hear their thoughts/opinions with regards to this.

Have people been successfully using the G2's with SimTools recently?

Sunday Funday!!!

No new parts nor build progress, but rather new equipment.

Taking the build to the next level, and (hopefully) learning a new skill in the process.



Been putting off getting a welder for too long now, but this is the project which has prompted me to do it, as has a few of the comments/conversations from forum members in other threads.

By no means do I expect to just magically become a pro welder and have a commercial-grade motion sim in the next month by using this, but as my sim rig is always a WIP, this will come in handy over time as I learn to use it.
After my initial prototype build in order to get back into motion, I can then refine it over time with help from this unit by making upgrades...or entirely new projects .

Pretty good deal on this combo which I couldn't pass up @ $299 CAD.
When not on sale, the 3 main parts alone sell for around $900 CAD combined (MIG/FLUX CORE WELDER (gas compatible) = $570, STAND = $170, and the HELMET =$170).

Each piece was even in its own individual retail box within the one larger combo box.



OK, there are skulls on the helmet.
That's either a Bad Omen, or I'm gonna look like a badass dude while playing with molten metal.
Hopefully the latter of the two.



That's it for today.
Still deciding whether or not to return the pair of JRK 12v12's which I received on Friday, and exchange them for a pair of JRK G2 18v19's.
Will see if the latest public release of SimTools v2.3 has official support for the G2's, then make a decision.

The 12v12 JRK's have been exchanged without issue, just waiting for the replacement G2 18v19's to arrive by Tuesday.

This combined with yobuddy's SimTools v2.3 update today is perfect timing!
Talk about the planets being aligned or what??!?!?!
Lucky me, I should buy a lottery ticket!


While I was out running errands today I stopped by the local metal fabricators to grab some off-cuts to practice my welding on.

Among my findings I managed to grab a short piece of 1/4" thick 2"x2" L-bar, perfect for brackets.

Being a fairly thick metal to work with for the weekend hobbyist, I asked if they would cut it into four 5" lengths, and they did without issue.

Ended up with the four brackets plus an additional ~3ft length left over for other uses.

Will drill 2 holes for the bottom motor mounts, plus a threaded rod between the top motor holes, joining them for rigidity.
This should prove to be a very solid motor mounting solution.


Once properly mounted to a base, I don't think I'll need to worry about any flex.

More stuffs have arrived recently:

* Two Pololu G2 18v19 JRK's (in exchange for the 12v12's since they are now discontinued)
I feel much better about switching over to the G2's, since they offer more headroom for both voltage & amperage, plus better support/replacement for the future.

* Pack of 3-pin wiring harnesses for the G2's to the feedback potentiometers (I'll have to cut/solder the ends to the pots)
https://www.robotshop.com/en/3-pin-jumper-cable-10pk.html

* 10-Pack of XT60's connectors for quick-release connections from the JRK's to both the motors & 12v power, good for up to 60A.
(Helpful in the event of having to swap out components in the future, or testing for faulty components)

* An assortment of 10k pots, both wire-wound and standard ones (I have a feeling I'll be going through a few of 'em )
https://leeselectronic.com/en/product/71651.html?search_query=10k+potentiometer&results=35

* Various steel bits such as 12mm threaded rods + bolts for the motor axles, 1/4" steel bars for the levers, pot brackets, top motor stabilizer rod, etc.

Now I'm just mapping out the component placement on the bottom platform, it's getting close to the actual assembly!!!

Hopefully in time for some ACC VR!

Thar she blowwwwwwwws!!!!!!

Finally, I've found my white whale, and it's in my possession....rod-ends + a 3' fine-threaded rod for my motors to seat connection!

Easily the most difficult parts to locate, and even then I had to go to two different retailers to source the parts.

They were the last four rod-ends from my local Princess Auto (Harbor Freight for you Yanks) and the last fine-threaded rod/nuts/lock washers at a local construction supply store which I found by accident.



This is a great start to a long weekend here in Canada, and I'm hoping to get going on the assembly of my seat mover.

Now the fun begins.

compliments! very solid and massive realization !.
do your rod ends also have a little hole for greasing?



complimenti! realizzazione molto solida e massiccia!
le tue estremità stelo hanno anche un piccolo foro per ingrassare?

No, these don't have grease fittings.

They are of decent quality and were reasonably priced ($13.99 CAD each) though, with a PTFE liner.

My old Next Level Racing v3 Motion Platform didn't have any grease fittings on the Heim joints either.

These ones can still be lubricated if needed, simply by spraying a light duty lube (garage door roller spray lube works well) onto the contact points and PTFE liner.


My previous main hurdle was locating a fine-threaded rod, the joints were fairly easy to source, but a matching rod was the issue.

Now I know where to buy one locally if needed.

With this being an under-the-seat mover design, a 3' length of rod should be more than enough since I'll probably only need a few inches (6"-12") for each side.


Will begin the build today, starting with cleaning up, drilling & painting the motor brackets.

As I'm waiting for the paint to dry I'll solder the XT-60 connectors to the motor wires, G2 JRK's, and the power supplies for easy connections and future swap-outs if need be.

Following that will be mounting the motors to the platform, adding the axles, motor levers and feedback pots.

Then the testing with SimTools begins...

Hmmmmm.......

Now I'm considering switching the rod-ends over to this style.



They have more range of movement (less chance of binding on the bolt), and I won't need to buy any bolts / studs / misalignment spacers / etc.
I already have the matching fine-threaded nuts & washers.

Only $4 more than the ones I grabbed yesterday, and they're from the same store.

They seem like a better option, and I can simply bolt them straight into the motor levers & under the seat brackets.

Went for another shopping trip today, and I think this may be the last one needed for a while (ya rite! ), or at least for over the weekend.

The haul:



Decided to go with this other style of end-rod which I mentioned in a previous post, since it offers a greater range of movement due to the less restricted smooth ball side vs using a traditional bolt.




I also found these neat fuse holders which I can use with some 30A fuses, perfect for in between the motors and G2 JRK's (which have a max 30A rating).

The LED will help when troubleshooting...as I'll see if there is power going to the motors or not.

These could also be useful between the JRK's and the 12v Power supplies.



Does anyone have any thoughts as to where in-line would be the best place to place these 30A fuses?

Would they prove to be most useful between the 12v PGSaw 50:1 Motors & G2 JRK's, or between the G2 JRK's & the 12v 40A Power Supplies...or even both scenarios (4 fuses in total)?


My local Home Depot also gave me a fantastic selection of 3/4" thick large plywood off-cuts for free, perfect for prototyping the base + seat platform...or even for a semi-temporary build if they turn out well.

This build will most likely be tweaked over the coming Winter months, then hopefully in the Spring I can ditch all of the wood pieces and weld up something nicer...but I do need to practice my welding first.

in my opinion, it is convenient to mount the fuses between power supply and bridge H. the geared motor is subject to strong current peaks due to continuous reversal of rotation and if you use the software / firmware smc3 you also have the electric brake. the fuse is a specially weak component of the supply chain, it would lower the internal resistance offered by the H bridge (driver) mosfets, risking burning at some instantaneous peak, or during a violent reversal of travel. Hello Marco

Hi Marco, and thank you for the input & suggestions.


FYI, I'm using Pololu G2 18v19 JRK's (they can handle up to 30A), which means that I'm not using an Arduino nor SMC3.

I believe that with the Pololu configuration software it will still be much the same as your configuration, which I think also includes the electric braking feature.


I'm tempted to use the 30A fuses between the motors & JRK's specifically to protect the JRK's from possible power peaks over 30A's (doubtful, but never say never).

As well, since a defective power supply could also fry a JRK, it seems like there should also be some form of protection there as well, say another 30A fuse or resetable circuit breaker.

I do have two 30A circuit breakers (they auto-reset when tripped) which I can use in place of fuses to protect the JRK's, which may be an option between either the motor or the power supply.


It's the motor power peaks which you mention, or even a short circuit which I'd like to protect against.

The LED's are also a nice feature in aiding with a quick visual as to whether or not there is power going through the circuit.

certainly a fuse is used to protect when everything is correctly sized, due to accidental short circuits or faults.
you can if it makes you feel more secure to protect both the engine and power lines, the automatic fuses IMHO personally I do not like mistakes sometimes intervening on some strong peak.

however, if you can 'interest, my 2dof simulator with front engines handles 100kg players as if it were weightless or almost, using a common cinese psu 29A ATx for all 2 engines 16: 1 step.
I believe that 30A estimated by you are sufficient and abundant.


in edit on the other hand, use of the big 500000uf supercapacitors so as not to stress the power supplies from the inductive currents of the motors

I do see your point.

Perhaps I'm overthinking it, but if the JRK's can take up to 19A without extra cooling, I figured it was a good match for the 30A fuses.

Like you say, there could be the occasional false trigger due to motor reversal etc, but I generally subscribe to the "better safe than sorry" camp.

I don't see any info on the max amperage, only the mention of 19A continuous..so now it's got me thinking that I may have confused the max 30v rating and assumed it was also the same value for the amperage.


If for some reason you may be interested, here's the info page on the Pololu 18v19 JRK motor controllers:
https://www.pololu.com/product/3146

They do mention this, which I believe is the same as your setup's electric braking feature:
"Configurable hardware current limiting on higher-power versions – the motor drivers on the Jrk G2 18v19, 18v27, 24v13, and 24v21 use current chopping to actively limit the motor current when it exceeds a software-configurable threshold."

If that's the case, then as you suggest, the best match may be to configure the electric braking in the software for protecting the JRK's from erratic motor amperage output and NOT use any fuses there.

Then simply use the 30A fuses (or a more appropriate rating) between the power supplies and the JRK's in order to protect from a power supply failure or glitch.


Thanks for your input, it's really helping to figure out an appropriate solution.

LOL!!!

Oh man, I must REALLY be overthinking things.


I'm planning on using two 12v 500watt 40A power supplies, one for each motor side.

If I could get away with just using one for the build, then it may be a good idea just to keep one unused as a spare or return it for a refund.

Your design may be more forgiving though and one power supply is enough, with 16:1 motors and lifting the front vs under the seat and my fat ass.


I'd post a link to my power supplies, but for some reason Amazon links don't work on this site (perhaps a forum rule or something????).

Well....out with the old stationary seat.

Time to make some measurements between the mounting holes in order to start building the motor/U-joint mounting platform.

This is being built with the intention of being a self-contained motion platform which can be unbolted from the rig's deck, making for quick & easy adjustments or repairs.

I may also incorporate some seat-sliders on the bottom of the motor platform in order to slide the entire assembly fore & aft, keeping it's COG same.