Dr4B Speed


I’m currently running a 2M 1:7 HS Dr4B and it is too slow relative to our top four-bar (1:1 Torque) and makes for some problems as its slowing our fielding and loader time down. I’m using only one by L on the top and Gearbox and am NOT willing to add 2 extra motors or switch my intake to a passive intake. Are there any tips I could have to make this faster?


  • Evan

Aluminum screws and thin nylocks help a lot it you aren’t already using them. robosource.net (I was not paid for this shilling.) We use them and we have a 1:5 speed lift on two motors. Not willing to give away any more secrets… :wink:

@Aponthis just curious how much total weight reduction you think those did. I am debating buying them

We’ve gone through about 200 aluminum screws, and each is about 1/3 the weight of a steel screw (big difference!!!). Thin nylocks are about half the weight of the nylocks, and we used 200 and really could use more. I’d say we saved at least a pound and a half total on our bot. It’s pretty insane.

@Aponthis thanks! I think I will be ordering some now lol!

@Aponthis thanks for the tips. I will go buy at least 500 aluminum screws and thin nylocks now. Should I invest in more 1 by L?

Yes, and purchasing an angle grinder makes making your own much easier. Reduce your ratio to 1:5 and run torque. Here’s my robot https://youtu.be/FzKPYCJnxnk
Don’t do what I did and make the entire lift 1x L, make the bottom stage full bars please. This lift was run at turbo 1:5, the fastest I’ve seen a competition robot go to date.
EDIT: just noticed that you’re running 2 motors on the lift noob the only reason I was able to get mine so fast is because of my 4 motor lift.

Additionally, proper rubber banding is CRUCIAL. Spend a lot of time properly tuning your robot’s rubber bands. Also, check every single pivot on your lift and tune it with a screwdriver to make it as low friction as possible

Swiss cheese it! Try to use half c-channles on the output bars, it lightens up the load a lot. and

In my experience, rubber banding and build quality are more important than (extreme) mass reduction.
At one point our DR4B was 2M 5:1 turbo with full 2x25 C-channels.

Don’t buy aluminum screws, use zip-ties on your bearing flats, 4 each. ideally, the axle will be going through the center hole, and you’ll have 2 zip-ties on each of the other wholes, Its the META weight reduction tactic

Even if you do that craziness (please don’t, for your sake), you still need aluminum screws for structural connections.

Of course, it’s up to you and your build style, not to talk down on any other members preferred methods, but zip-ties have worked very well for us, 98% of our bearing flats are zip-tied.
Also, I would be careful using aluminum for things like joints, or any weight bearing structure (for example, I would not suggest attaching your towers to your drive with aluminum screws) that could lead to bending in the screws and that can often lead to subtle problems like supports not being squared correctly, causing your lift to go up and down crooked. But then again I don’t have any cross supports other than my secondary towers, (another way to shave weight, If your lift is built correctly, you don’t need any “X-braces” or cross supports. totally overrated)

If you aren’t comfortable with zip-ties, then yes, aluminum screws are the way to go.

I had a 2m 7:1 HS lift that used 1x1.5’s on the bottom and then 1x1’s (cut from a 2x) on the top half and never had any problems with stuff snapping. The bars of the dr4b should pretty much all be 1x1.5’s (halfcutting a 3x) just cut down the middle of the 3x and then shave off the excess of the hole so that you have one edge of the 1x that is smooth. That is plenty strong for all parts of the dr4b be it the lower half middle gearbox or the top stage. Make sure that when you mount the bars you have the longer side vertically to utilize the extra strength.

For me it’s nowhere near 98%, but I can attest that ziptie bearings work well. I wouldn’t use them on the drive, but they are great for weight reduction on a lift, or intake (we use them on rollers/4-bar).

Same. My only cross support is a 2 wide c-channel. I know lots of people would say this is stupid, but I’m not having any problems with leaning or tipping, even when being pushed, so why change it?

Exactly! My dr4b doesn’t need any supports to go up straight, and but I haven’t had any problems with it