CadDigger 628 build

[glastron23]

Hi Guys.. nice looking units, i think i'm going to build one this winter as the wife will be in going south for a couple of months. I just happened to have some "SPARE" parts left over from the wood processor we built last winter....
can i make one suggestion to mrcaptainbob and ask if he wouldn't mind if removing the brass flow controls from the cylinders and replace them with steel units rated for the maximum pressures that he is running on the digger, the majority of brass fittings and valves are only rated for 800 psi, i would guess that the system pressure on he digger is at least 2000 psi, the brass will hold for a while but it can not be trusted to last when it's most needed..... this holds true for black iron also, every time i see this in my shop i normally scream at the owners of the equipment.. sorry about this but i've personally seen what the consequences of doing this and it was not a pretty site...Jim

 

[mrcaptainbob]

Glastron23, thanks for the suggestion! The system mis close to 2000#'s. I purchased them on suggestion from an hydraulics shop. I was purchasing some other stuff from them and one of the items we spoke of were a way to slow the boom speed. They started out with the flow meters, but I could not afford them, even when I was working! They gave me these. It's many, many years and many, many h0ours with them in place, but am not willing to push my luck. I'll check on the steel ones as you suggested.

By the way, I like the name....can't wait for the ice to melt!

 

[Richard61]

Hi, I really like the 628, but I take the point regarding the swing cylinder, are the other functions easy to manage? or does the boom tend to drop rather hard when there is a full bucket? There are in line flow restrictors made that restrict flow one way but are full bore when flow is in the other direction. I remember these being retro fitted to prevent the early JCB 806 boom dropping like a stone unless the operator was extremely careful. I am thinking also a longer stroke swing ram set at a greater radius would take more flow per degree of swing. This may give the problem of increasing swing torque to a level that could bend things. A cross line relief valve would bypass the cyl either way at a preset psi - thus bringing the torque back to the design value.
I am interested in these machines, they used a multi pin hole bracket to allow the 130 degree swing to be used 90 left & 40 right or move the pin for the mirror image. http://www.oilyhands.co.uk/images/Powerfab_180C_Brochure.pdf
Wondered if this idea could be used with the cadplans machines?

 

[notme]

interesting concept Richard...seems u would only need the full swing to one side most of the time anyway.. if you fig'd out how it was done anyone that has built a caddigger would prbly want to know! the 628 is an old rig now with the 821/841 being biggest and the newest also having 2 swing cylinders..

 

[chad22]

If I may ask. What size of plate did you use to make the swing assy? It looks like 1/2" ?

I ask because I'm thinking of building A backhoe to mount to the back of my Garden Tractor/loader sometime.

Thanks

Chad

 

[notme]

they are 1/2"

 

[Krookz]

How in the world did you build this for ~$1500? Lots of parts laying around?

 

[chad22]

they are 1/2"

Thanks.

Chad

 

[uncleaddy]

Here's my Caddigger 728. Shown in the towing position and with the small 9" trenching bucket. All the cylinders are the same size.