i always thought cast iron, but then something made me think possibly concrete or steel punch blanks etc. so what in the world are inside of counterweights on say a 20t machine ? pj
The dreams of unsuccessful contractors.
This is what I have seen in my lifetime. 1. Poured and finished concrete, usually on lattice cranes and draglines. 2. Formed steel fabrications filled with concrete or stamping drops. 3. Lead formed, older machines. 4. Cast iron 5. Cast steel 6. Just your basic weight bunker filled with whatever could match the mfg. recommendations.
I've seen excavators with either a steel box filled with concrete or solid cast steel. I recall an old Bucyrus crane parts book calling for the cavity under the motor to be filled up with so many cwt of scrap steel punchings....
My Cat 14 & 21 tonne machines are plain steel plate formed to take the OEM shape out back … what we commonly called a counter weight …. as if it were an added extra add-on …. my 21T is a RTS machine, it's mostly a geometry thing …. other brands vary I guess …..
do you get along alright with your 321? i have a 228 and like it so much i have been looking for a good used 321. pj
Most modern counter weights are a thin, stamped steel outer shell filled with high density concrete. Can't even bring them into the scrap yard, they won't take them.
I've seen a steel box filled with dirt on the back of a crane. Complete with green grass.
Concrete and steel mill slag.
A Cat 215C is thick walled steel box, filled with concrete mixed with steel shot.
I don't think that's a stupid question at all, unless I'm stupid. I just learned that a year or so ago, I always assumed they would be solid steel. Apparently not. Still surprised the heck out of me to learn they were concrete. It does make since though being filled with concrete.
what got me wondering was that i noticed a dent on the back of my 315C one day, and i did it i cant blame it on anyone, i swung into a roll-off during a demolition and it was kinda on the upper side of the CW so i wasnt real suprised it dented but it got the ole gears in the head turnin pj
Sand and saw dust they sweep up off the floor!Also body puddy.
I wonder if it had a winter and summer chart
Our 06 270 hitachi is concrete as well. Same deal as you. Saw a dent in it and got to wondering. Only it wasn't me that put it there. lol.. I would imagine it's easier to maintain a standard weight that way. Ryan
Scrap from the planograph, punchings ( especially fine ones from electrical boxes etc ), used balls from ball mills, used sand from the sandblast shed (fills between everything else). We even dumped in the nuts and bolts that were shoveled up off the floor in front of the bolt bins. I recall somebody had the bright idea of dumping in the used oil from around the plant but don't recall if it was ever done. Regards d.d.
The newer Cat hoes, 300 series, are a steel shell filled with concrete. Some are not full to the top, only to the point the weight is proper for the machine. I have seen 330's with the concrete showing on the corners because the metal had been worn away. It is not even 1/4" thick.
I painted the counterweight on our 330 last year. Its been done a few times. Whoever did it the last time had so much body filler on it, I just sanded all the dents smooth that were in it and painted. Made for an easy job.
Sugar and spice and everything....., oh wait, that's the girlfriends counterweight.