DIY - Actuator feasibilty

Hello all,
Excellent site here, full of great info. I am looking at the feasibility of DIY actuators to help reduce the cost of a 2DOF simulator like bvillersjr's. I have thrown together a drawing and a parts list to see if this preliminary design might be a feasible solution.
I have posted a very rough drawing to illustrate what I am thinking. I would hope that tronicGR's dual mosfet h-bridge could control the actuator. My hope is that the design would allow the use of different motors to suit the users weight/torque requirements. I also think the stroke length could be varied easily to taste as well.
picture:


parts list:
12 (.500 OD) acme threaded rod - mcmaster.com $11.29 pn: 98935A721 5/8 - 6
ball screws could be used also, but at a much greater cost
2 pullies with 2:1 ratio - not yet sourced
1 belt - not yet sourced
8 X 2 X 2 aluminum bar stock for bearing blocks and lead nut (2 blocks/1 nut)
1 Miniature Absolute Magnetic Shaft Encoder $36.00 pn:MA3 <a class=postlink href=http://usdigital.com/products/ma3/ target=_blank>http://usdigital.com/products/ma3/</a> target=_blank target=_blank target=_blank (not shown in drawing)
1 12 X .750 round tube 304 stainless threaded to mate with lead nut and spherical rod end (extending arm)
1 spherical rod end - mcmaster.com $9.68 pn: 8405K131
1 5.5 X 2.5 X .250 flat aluminum plate for support plate for dc motor/lead screw

I did this quickly, only to see if I was headed in the right direction so please post all constructive criticism,ideas for improvements, mistakes etc.... Or if I'm just way off.

I have a very complete hobby shop to create the parts. CNC mill, lathe, etc.

Regards,
Devin

The idea of a DIY actuator has been lurking in all our minds for quite some time. I would love to see it happen.

I dont't know where the post is, (maybe egoexpress could point it out?) but if I recall, egoexpress examined this subject in detail and I think the outcome was that an actuator with the same capabilities as an SCN5 could not be built for a price that made it worthwhile.

Also, I'm pretty sure that ACME threads wouldn't be up to the speeds / heat necessary to match an SCN5 (400mm/sec).

I'm no expert on the matter though. To get your answer, you'll need some advice from egoexpress.

@bvillersjr
here is the post I think you're refering to:
http://www.x-simulator.de/forum/post9657.html?hilit= diy actuator #p9657

I was concerned about the acme as well. I found a Ball screw and Nut, that fit this application, that can be had from McMasterCarr.com for under $50.00.

My total thus far is under $200.00 with the motor and ballscrew assembly and encoder.

Thats interesting. Could you please post a parts list with links so I can look over the specs of the individual components.

parts list: price part # source
12 (.625 OD) ball screw $10.00 5966K261 mcmaster.com
ball nut $28.00 5966K16 mcmaster.com
1 sprocket 12 tooth $5.00 6793K17 mcmaster.com
1 sprocket 25 tooth $5.83 6793K4 mcmaster.com
1 chain - $3.24 6261K281 mcmaster.com
8 X 2 X 2 steel bar stock $20.00
1 12 X .750 round tube 304 stainless $15.00
1 linear bearing $20.00 8974T3 mcmaster.com
1 spherical rod end $9.68 8405K131 mcmaster.com
1 5.5 X 2.5 X .125 flat steel plate $11.97
1 12 long 2 square aluminum tube $9.55
controller - tronicgr's dual mosfet h-bridge $15.00 tronicgr/mouser.com
1 Miniature Absolute Magnetic Shaft Encoder $36.00 MA3 http://usdigital.com/products/ma3/
1 250W 24v 13.3A GEARED Motor $50.00 http://tncscooters.com/product.php?sku=106105
I believe a cheaper encoder could be sourced or made.

Had to change to 5/8 ballscrews to get a cheaper ball nut.
I dont think mcmaster.com allows offsite links into their product catalog as none of the links would work.

Well, do to lack of response and me doing the Wiki editing. This project is on hold. I will however pick it back up, however with a different direction.

Devin

Hi,

Just wondering how much is the linear speed for such an homemade actuator ?

For my own study, a quick and dirty math for 200 mm/s actuator means a rotating speed of approx 8000 rev/minute.
Decided to give away for the time being.

OscarH

Hi
Ball screw 5966k261 pitch 13/64=+/-5mm=40x60=2400rpm
Fore Devin to make it more easy look @ <a class=postlink href=http://www.surpluscenter.com onclick=window.open(this.href);
return false;>www.surpluscenter.com</a>
They have a mechanical actuator (ball screw 1/4 pitch) you will find him on MISC.
Miscellaneous/other number1-3074
Regards Ad

I posted before following Adgun's link to the mechanical actuators, so I had to edit my post.
Great link Adgun! I bought one of the actuators to test it. I will post back. I was thinking of heading in a different direction but these are so cheap I have to see if they will work in this application.

Me too.
I ordered 2 * 1-3074 today. This could possibly replace my 2 Renault Clio wipers motors. More design to do...
It is worth spending 10 bucks to have a try. I'll keep you posted.
OscarH

Hi
Please add. some picters when hi arived.
Ad :thbup:

Hi,

The carjack actuator looks good cheap solution but take a look on what I found:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=400018496509

And it looks pretty close to this:
http://www.idcmotion.com/products/cylinders/EC2/index.html


Looks like nice deal... but I'm not sure if they ship to Greece... not cheap at least! :-(

Thanos

that looks nice too bad theres only one.

I was wondering about the quality as well. Even if some of the components are bad, I can probably still use the ballscrew and nut. We shall see.
Anyways, for 9 bucks, you cant go wrong. They also had some other cool stuff I wanted as well, so it was a good find for me. Thanks again Adgun.
Devin

I received the actuator yesterday. I still need to clean it up quite a bit, but it looks promising. It feels very solid, at least solid enough for my purposes. I now need to source a 40 degree helical gear to mate to the gear on the actuator. Depending on how hard it is to source this, I may fab up a pulley instead.

Hi,

Got my 2 units this morning. Time to open the box and take pictures. Here they are...
Look promising. Just need to find out how to stick a motor on it.
15cm activated lentgh. Not a lot, but somehow reasonnable.

OscarH

I am disassembling mine so I can get the old grease out and make it spin more freely. I am also trying to figure out how hard it would be to get the helical gear off so I could put on a cogged pulley and belt setup to fix it to a motor.

Devin