RoboSavvy Forum

RN-1 Bulding Tip

2006-04-12T12:59:21+01:00

I'm not sure if during the screwing process, you happened to use the wrong screws. That is, you may have used the tapping screw (PH/T) instead of the required machined screw (PH/M) at the hip. Because, it happened to me and I only realized it at the end when I ran out of PH/T. Only it did'nt occur at the hip but somewhere in the upper body parts. Anyhow, I managed to locate it and put the right type of screw to where it should go. Also, I was sure to screw the parts tight enough to withstand the anticipated aftershocks.

Well at least, should my RN's leg ever came loose one of these days, your experience and the suggestion here is quite handy for me to follow.

But please, don't replace the screws of those parts that are not affected. Just tighten them a little bit more. As the saying goes, if it ain't broke, don't fix it.

Statistics: Posted by Lomruz — Wed Apr 12, 2006 12:59 pm

RN-1 Bulding Tip

2006-04-12T03:39:32+01:00

I went with the threadlock solution for now.

My next challenge is - replacing most of the philips screws with hex/square screws. I've already come close to stripping some of the screws...not good...I wonder why they didnt go with hex in the first place

I wonder if I can get away with a direct replacement...yes the heads will stick out a bit more than the current screws - but not by THAT much more. The benefits seem to outweigh the potential problems at this time. Anyone have a differing opinion?

I also need to prepare to install the new grippers. I wonder if I will be able to color match and plate the metal with something similar to the rest of the robot. Chrome is too bling

Statistics: Posted by gsferrari — Wed Apr 12, 2006 3:39 am

RN-1 Bulding Tip

2006-04-12T03:20:57+01:00

Crap! I forgot to log in
...hope it helped anyway!

Statistics: Posted by bauermech — Wed Apr 12, 2006 3:20 am

RN-1 Bulding Tip

2006-04-12T03:19:11+01:00

Your parts are falling off? That's no good.

The parts I want to "rivet" together are the main joints that are basically held together with 4 screws. Thread-Lock is ok but still not sufficient on load bearing joints IMO.

Rivets are okay, but they too can become deformed and loosen up to the point of annoyance. Permatex makes a blue and red version of their thread-locking product. Blue's your medium automotive grade and may work pretty well for you. Red... oh the red bottle... they'll never come out. Seriously... never-ever! If you were planning on going with something as permanent as a weld, then I would suggest using the red stuff. (NOTE: be sure NOT to use thread-lock on plastic parts) Are you sure you want to make it permanent?

OK - I have approached a few metal workshops to ask about spot welding for aluminum. They said it would not be possible and suggested riveting instead.

I consulted our expert aluminum welder "Rusty" at work today and the following is a summery of what he had to say:
A standard shop's spot welder is usually around 7kw - 10kw. The welders used to spot aluminum are huge... 200kw! A lot of shops may not have that kind of set-up.
Second, the robonova is anodized. Having gone through that process, it's no longer conductive. Anodizing bonds to the aluminum about 10 thousandths of an inch (about .25 mm) under the surface. So even if you were to get all the coloring off, the metal underneath would remain impure. It is possible to weld at this point, but don't expect anything pretty. For the best results, you'd have to take it down further. Meaning, you'd be left with a flimsy piece of bracket that's half as thick.

Hope this helps.

Statistics: Posted by Guest — Wed Apr 12, 2006 3:19 am

RN-1 Bulding Tip

2006-04-10T12:24:14+01:00

I want to seen RN-1 in the compitetion

Statistics: Posted by Morbeious — Mon Apr 10, 2006 12:24 pm

RN-1 Bulding Tip

2006-04-10T09:35:46+01:00

gsferrari wrote:
Petition to put Robonova on the moon!

If you're serious about that, you better hurry up. Here's what's happening over here in Japan-

http://www.robo-one.com/sp/movie/robo_one_str1_1m.asx
8O 8O 8O

Statistics: Posted by tempusmaster — Mon Apr 10, 2006 9:35 am

RN-1 Bulding Tip

2006-04-10T07:05:50+01:00

gsferrari wrote:
Is there anyplace where I can purchase the brackets alone just to experiment with the rivets?

http://www.robonova.de/store/home.php?cat=250

I might just have to re-manufacture these parts out of steel...shouldnt be too hard to do this and it will be a helluva lot stronger.

And a lot heavier.[/url]

Statistics: Posted by Gil — Mon Apr 10, 2006 7:05 am

RN-1 Bulding Tip

2006-04-10T03:13:08+01:00

OK - I have approached a few metal workshops to ask about spot welding for aluminum. They said it would not be possible and suggested riveting instead.

The parts I want to "rivet" together are the main joints that are basically held together with 4 screws. Thread-Lock is ok but still not sufficient on load bearing joints IMO.
Is there anyplace where I can purchase the brackets alone just to experiment with the rivets? I might just have to re-manufacture these parts out of steel...shouldnt be too hard to do this and it will be a helluva lot stronger.

Statistics: Posted by gsferrari — Mon Apr 10, 2006 3:13 am

RN-1 Bulding Tip

2006-04-08T00:43:23+01:00

Seconded...My legs came loose on the first day!! 8O

Once you do the cable tie-downs - taking the robot apart becomes a HUGE hassle so use thread-lock when you do the assembly for the first time...I learnt from my mistake

A FEW TIPS:

Dont use the cable-ties on the servo cables. The cable insulation is too delicate to handle the sharp edges of the ties. If you want to tie cables together - use a soft cable-tie made of fabric/velcro.

The last bracket in the legs (the part that attaches the legs to the pelvis) has to be installed with the taller flange closer to the pelvis and the shorter flange closer to the legs. If you dont do this and if you install it the other way around - the tall flange will cut into your servo cable when you bend the robot into a foetal position.

Cheers!

Statistics: Posted by gsferrari — Sat Apr 08, 2006 12:43 am

RN-1 Bulding Tip

2006-03-29T17:32:20+01:00

I recommend you using Blue Thread Locker 242 on the screws at the Hip, for a reference the screws shown on the last picture at this link.

http://robosavvy.com/Robonova/3

I've notice after several moves the 8 screws in total, 4 on each hip, seems to come loose. It sucks having RN-1 do a karate kick and his leg goes a flying off lol..

Statistics: Posted by Morbeious — Wed Mar 29, 2006 5:32 pm