[FTC]: REV Slide

[Jeremy1410]

Hi guys,

So for this year, our team was thinking about using an 80/20 slide for lifting objects, but after doing some research, it seems as if teams prefer REV lifts instead. So, I have questions regarding it, if you have information

1) Does it weigh a lot? I read some people were saying that it still weighed a bit too much, but still was pretty lightweight.

2) Does it have the same strength as an 80/20 lift?

3) What causes different levels to move up? Is it pulley based, motorized, or something else?

4) How would one attach these to TETRIX pieces? Would the brackets work?

Thanks in advance for any help.

Regards,
Jeremy

[MattRain]

RevRobotics just released their FTC line. They have two different models. A 1 inch version (Mainly used in FRC) and a 15mm version (Designed for FTC). The 15mm extrusion bars have been available for the last year, with all of the new attachments being release at Kickoff this year. In the past teams were 3d printing their parts or cutting out similar parts.

I cant say that I have used this line of product yet, but my teams are looking into using the 15mm. We've created CAD models of the lifts that we would like to make, with some modification to the bars, but we're waiting on Andymark and RevRobotics to start selling the parts. We are looking at driving the slides with pulleys through a Cascading lift design with mini v-bearings we found on ebay.

As for weight and strength, I only have a 10inch piece of the 15mm that I got from one of their booths, and it weighs next to nothing. I can stand on it without it bending.

Attaching it to tetrix. I'm not sure how well it will line up with the tetrix hole pattern, as we custom build our robots, using as little tetrix as possible. But the brackets RevRobotics provide might work. If not, a drill and drill bit go a long way. :P

http://www.revrobotics.com/

[RRLedford]

Hi guys,

So for this year, our team was thinking about using an 80/20 slide for lifting objects, but after doing some research, it seems as if teams prefer REV lifts instead. So, I have questions regarding it, if you have information
1) Does it weigh a lot? I read some people were saying that it still weighed a bit too much, but still was pretty lightweight.
2) Does it have the same strength as an 80/20 lift?
3) What causes different levels to move up? Is it pulley based, motorized, or something else?
4) How would one attach these to TETRIX pieces? Would the brackets work?
Thanks in advance for any help.

Regards,
Jeremy

The 1" 80/20 framing is overkill on strength as well as weight. Even with a single set of columns. The concern for strength needs to be focused on the fasteners & brackets, the sliding blocks that interlock the frame columns, the cord, and the cord wrap scheme.

The nylon sliders blocks do make better/stronger engagement with the 1" 80/20 framing than some of the smaller sliders for 15 or 20mm (Rexroth or 80/20) framing. We haven't tried the 15mm REX frame yet and even though it is 7000 series much better aircraft strength aluminum, the 3mm fasteners are IMO just too weak of a size fastener for stiff joints that will not shift or loosen with cyclic loading. We use both 10-32 and 4mm hardware with the 20mm and the 1" framing too. If loading is high, we try to use 10-32 as much as we can.

Last year we had an elevator using only a single set of 1" 80/20 frame elements and the cord was wrapped so that all moving frame elements extended at same time. This made it one of the fastest elevators we saw and it was carrying a sweeper bin using a TETRIX motor with chain and sprockets, and having a servo actuated dump door. With a solid mounting at the frame, this elevator remained very stable even when extended all the way up to the high goal.
It was the best preforming assembly on either robot build by our school's two teams.

-Dick Ledford

[RRLedford]

RevRobotics just released their FTC line. They have two different models. A 1 inch version (Mainly used in FRC) and a 15mm version (Designed for FTC). The 15mm extrusion bars have been available for the last year, with all of the new attachments being release at Kickoff this year. In the past teams were 3d printing their parts or cutting out similar parts.

I cant say that I have used this line of product yet, but my teams are looking into using the 15mm. We've created CAD models of the lifts that we would like to make, with some modification to the bars, but we're waiting on Andymark and RevRobotics to start selling the parts. We are looking at driving the slides with pulleys through a Cascading lift design with mini v-bearings we found on ebay.

As for weight and strength, I only have a 10inch piece of the 15mm that I got from one of their booths, and it weighs next to nothing. I can stand on it without it bending.

Attaching it to tetrix. I'm not sure how well it will line up with the tetrix hole pattern, as we custom build our robots, using as little tetrix as possible. But the brackets RevRobotics provide might work. If not, a drill and drill bit go a long way. :P

http://www.revrobotics.com/

Mixing the slotted framing with Tetrix structural elements is not so much of a problem, but with bigger than 6-32 fasteners you will have to drill the Tetrix holes larger. The infinitely variable position mounting that the slotted framing offers is a big plus when integrated with Tetrix modules that will need to be adjustably tuned or repositioned.

These wheel module blocks used the last 2 years mount to 20mm framing with (2) high strength alloy 10-32 button head screws going into the frame slot's T-nuts. The 5" long hardened alloy socket head :cap screws serve as our free spinning axles after polishing them down where they engage the sleeve bearings. McMaster Carr sells them. Axle driven or motor shaft direct driven wheels rarely work well. We mount the drivren element directly onto wheels when possible. We countersink holes in hubs, gears sprockets as much as needed to use flat head screws for staying flush on one side when possible to locate rotating parts clocer togeyher and reduce bend forces on axles & shafts..

http://i489.photobucket.com/albums/rr259/RRLedford/FTC2013-14/20131203_205650_zps54f5c514.jpg (http://s489.photobucket.com/user/RRLedford/media/FTC2013-14/20131203_205650_zps54f5c514.jpg.html)

http://i489.photobucket.com/albums/rr259/RRLedford/FTC2013-14/20131203_205641_zps8c58367e.jpg (http://s489.photobucket.com/user/RRLedford/media/FTC2013-14/20131203_205641_zps8c58367e.jpg.html)

[Greg Needel]

Wow, not sure how I missed this thread....Anyway...Matt is correct that we now have 2 systems. The 1 inch system is very much overkill for FTC and is really designed for FRC. The difference is that those use ball bearings with eccentric bushings for a preload on the lift allowing for higher loads.


The new linear motion system for FTC around our 15mm line uses molded Acetel (Delrin) sliders. These provide a similar experience to the plastic sliders for 80/20, at a fraction of the cost. They also allow you to use a smaller profile than you can get with drawer slides or other linear motion systems.

In terms of strength, they are able to adapt for each application. For light duty applications you can just use the center connections, and as you need more strength you can use the sides.

Our slide kits will be available early next week, and we will also be releasing a video on how to assemble and use them.

In terms of connecting extrusion to tetrix, it is very easy. Similar to what
RRLedford said, you just bolt them together and it works. I'll make some photos or video to show how the two interface.



http://www.revrobotics.com/wp-content/uploads/2015/09/15mmlinearmotion.jpg

[Greg Needel]

We haven't tried the 15mm REV frame yet and even though it is 7000 series much better aircraft strength aluminum, the 3mm fasteners are IMO just too weak of a size fastener for stiff joints that will not shift or loosen with cyclic loading. We use both 10-32 and 4mm hardware with the 20mm and the 1" framing too. If loading is high, we try to use 10-32 as much as we can.




You are right 7000 series is a stronger series for aluminum but unfortunately it comes with a much higher price. We chose 6063, because it is cost effective to product and is strong enough for the application. We take the price vs performance evaluation very seriously and try to make the best decisions which will work for widest group of teams. If there is interest in a High strength version of our profile, we can always make one out of 7075 ;)

The other note is about our choice for 3mm screws. When I was working on the profile design more than a year ago, we discovered the really great relationship between a 15mm profile and how well it works with the size of the 3mm nut (5.5mm). In my experience building sample robots and testing we have never had a problem with 3mm screws, but I do understand your concern. We do use rated steel screws in all of our kits and recommend the same on all of our product pages. Again this one came down to trying to make the best decision for the mass number of teams where 3mm will be good enough.

I do appreciate the feedback and we are always open to discuss our decisions and listen to new ideas. We do our best, but can always improve.

[RRLedford]

Wow, not sure how I missed this thread....Anyway...Matt is correct that we now have 2 systems. The 1 inch system is very much overkill for FTC and is really designed for FRC. The difference is that those use ball bearings with eccentric bushings for a preload on the lift allowing for higher loads.


The new linear motion system for FTC around our 15mm line uses molded Acetel (Delrin) sliders. These provide a similar experience to the plastic sliders for 80/20, at a fraction of the cost. They also allow you to use a smaller profile than you can get with drawer slides or other linear motion systems.

In terms of strength, they are able to adapt for each application. For light duty applications you can just use the center connections, and as you need more strength you can use the sides.

Our slide kits will be available early next week, and we will also be releasing a video on how to assemble and use them.

In terms of connecting extrusion to tetrix, it is very easy. Similar to what
RRLedford said, you just bolt them together and it works. I'll make some photos or video to show how the two interface.



http://www.revrobotics.com/wp-content/uploads/2015/09/15mmlinearmotion.jpg


Andy mark is still showing the delrin slider blocks ae OUT OF STOCK.
Any update on when they will ship?

-Dick Ledford

[Greg Needel]

Andy mark is still showing the delrin slider blocks ae OUT OF STOCK.
Any update on when they will ship?

-Dick Ledford

Dick,
The parts are now in stock at AndyMark. http://www.andymark.com/product-p/am-3246.htm

Thanks,

Greg

[MattRain]

Greg, Do you have picture or videos of how you would make muilt-teir lifts out of the 15mm Rev. We created a CAD model with multiple slides, by combining two bars into 1 for the middle sections, but would just like to see what you recommend.

[Greg Needel]

Greg, Do you have picture or videos of how you would make muilt-teir lifts out of the 15mm Rev. We created a CAD model with multiple slides, by combining two bars into 1 for the middle sections, but would just like to see what you recommend.

Yes.... We will be releasing a bunch of documentation soon for this, we are in the process of putting it together in form which is easy to understand. If you want the preview "rough version" send me a PM