Vertical Tracks for Forklift

[asid61]

Originally Posted by BBray_T1296

So when your elevator is in a lifted position, you aren't simply supplying continuous electric current to hold it off the ground, but instead mechanically hindering gravity. Saves battery.

I was under the impression that it was a heating issue- if you're holding a stack of totes, it could burn out the motor due to the weight and lack of rotation.
And yes, RS-775 18v run at 12v.

[cadandcookies]

I realize this is a little bit outside the point of this discussion, but...

I actually find the argument about 6061 versus 6063 aluminum a bit funny. 2220 has used 6063 2x1" for years on their drive trains without any significant issues. This includes "Aerial Assault" where our frame held up with no major bending.

I realize this might be a bit of a "you don't realize how bad it's been until you get out" but 6063 served me quite well when I was on 2220.

[Bryce Paputa]

Originally Posted by asid61

I was under the impression that it was a heating issue- if you're holding a stack of totes, it could burn out the motor due to the weight and lack of rotation.
And yes, RS-775 18v run at 12v.

It's two sides of the same issue. Stalling motors uses a lot of power, and therefore creates a lot of heat. Fan/Air cooled motors (rs775/550, am9015) are more likely to burn up without the spinning fan, while high thermal mass motors like CIMs and mini CIMs will probably survive, but only after using large amounts of power. Holding large motors like CIMs and rs775s at stall (even with less than 12v being applied by the controller) will also lower the battery voltage available to other motors while it is holding the lift, in addition to draining the battery. All of this said, we don't plan on having a brake initially.

[Munchskull]

Our team is planning on using some high performance linear rails that ended up in our possession after the local HP plant decided to cut their full size printing presses resulting in literally tons of scrape. Some of which happened to be linear rails that we decided could work this year.

[GeeTwo]

Originally Posted by MrRiedemanJACC

So to hijack the thread a bit what is everyone powering their lift(s) with?

We're using 1 CIM in a KOP-equivalent gearbox (so we only have one gearbox type to keep as a spare) at 8.45:1. A 15-tooth sprocket on this axle drives a 32-tooth sprocket on the lift axle, (now down to 18:1) and 15-tooth sprockets all around on the lift chain. Theoretical lift at 40A (before losses) is 125 lb.

We're planning more of a pawl than a brake - it'll be up to the motor to bring the load to a stop. We'll probably going to use a 1/2" ratchet wrench on the gearbox shaft and use a servo to move the toggle back and forth. If that's too finicky, we have several brake designs to choose from.

[apm4242]

2 CIMs on a toughbox mini with 10.71:1 reduction. After that, belts/pulleys provide further reduction to a final ratio of around 42:1. lift is a chain driven carriage with delrin roller sliders on tslot rails. Going to try counter-weighting the carriage so the motors are only lifting the game pieces.

Still not sure if we need a brake.

[z_beeblebrox]

MiniCIM in 50:1 (25:1?) VersaPlanetary driving 2" 3-D printed pulley. Bicycle disc brake.

[pfreivald]

Originally Posted by z_beeblebrox

MiniCIM in 50:1 (25:1?) VersaPlanetary driving 2" 3-D printed pulley. Bicycle disc brake.

Is the 3D-printed pulley strong enough? We use 3D-printed spacers, but don't trust PLA and ABS for most torque applications.

[BeardyMentor]

Originally Posted by FrankJ

In terms of the elevator masts 6063 has the same stiffness as 6061. I don't thing you will come close to the yield strength of either. Of course some one somewhere will be the exception.

I was wondering if anyone else had done any sort of loading calculation to see if the 6061 vs 6063 really mattered for most applications. Unless you are skeletonizing your tubing and using terrible fastening practices, I don't think most of us are going to come close to the yield stress.

[Mike Marandola]

Originally Posted by MrRiedemanJACC

So to hijack the thread a bit what is everyone powering their lift(s) with?

We are using a Cim with a 27 -1 versa planetary and a 12 tooth 35 chain sprocket .

No brake yet...

We are using a harbor freight drill gearbox, similar to the DeWalt XRP with a RS775-18. The box is ~15:1 and since it is locking we don't have to worry about adding a brake.

[GeeTwo]

Originally Posted by apm4242

2 CIMs on a toughbox mini with 10.71:1 reduction. After that, belts/pulleys provide further reduction to a final ratio of around 42:1. lift is a chain driven carriage with delrin roller sliders on tslot rails. Going to try counter-weighting the carriage so the motors are only lifting the game pieces.

Still not sure if we need a brake.

Unless you have an enormous drum/sprocket that is pulling your lift, you can probably disconnect one of the CIMs, even before counter weighting.

[BeardyMentor]

Originally Posted by pfreivald

Is the 3D-printed pulley strong enough? We use 3D-printed spacers, but don't trust PLA and ABS for most torque applications.

With more extra shells and a higher infill density, it will be fine. The key is to keep tension along the layers and try and keep all other loading as compression. Also ABS and PLA are not your only options. I have a mallet I made from 3D printed nylon 6 and it is plenty strong. I have been abusing it for the last 4 months with very little indication of wear.

[mdituri]

Since the original post was from Long Island, I suggest you use:

Yarde Metal
999 Motor Parkway Hauppauge NY 11788
Phone: 800.333.2024
Fax: 631.232.3200

I am in NJ and they have a location within a half hour of us that we use all the time.

First, there is a delivery minimum most likely, however, if you own a pick up truck you can just make the drive and get your order. It takes one - three days depending upon where the particular item you want is located. The 6063 C channel we wanted was in the CT location, took 2 business days.

Realize that you will likely be picking up metal in 16 to 20 ft lengths. Bring a hacksaw with you and just cut it in half or for our purposes we needed it in 6 ft ish lengths so we cut the first 6 feet off and the 10 ft fit fine in the truck.

Their sales people are wonderful and they can find almost anything for you. I have used them for 10 years. They do not, however, have an online catalog, which is annoying, but they emailed me the 2 pages of 6063 channel options so I could tell them exactly what I needed.

I am not sure who mentioned delivery into NYC, but I don't see why Yarde won't deliver to you. They have locations all throughout NY, NJ, CT.

http://www.yarde.com/

[Chris is me]

We're using 2x2 tube for our elevators.



Pretty much ripping off 973's bearing and gusset setup; it's really simple to manufacture and strong enough for what we are doing.

[pfreivald]

Originally Posted by BeardyMentor

With more extra shells and a higher infill density, it will be fine. The key is to keep tension along the layers and try and keep all other loading as compression. Also ABS and PLA are not your only options. I have a mallet I made from 3D printed nylon 6 and it is plenty strong. I have been abusing it for the last 4 months with very little indication of wear.

Cool, thanks.