CadDigger 628 build

eazyduzzit · Dec 31, 2009

Hey, great post!
The write up and pictures are great. I like seeing other folks out there who build rather than buy.

Scotty370 · Dec 31, 2009

With only 8 posts, and talent like that, where the **** have you been hiding? Come out of the 'shadows'!!! Nice work!! ~Scotty

Verticaltrx · Dec 31, 2009

Scotty370 said:
With only 8 posts, and talent like that, where the **** have you been hiding? Come out of the 'shadows'!!! Nice work!! ~Scotty

lol, thanks. I hope I can add a little to this forum and hopefully learn a lot myself.

simplicityguy92 · Jan 1, 2010

cool backhoe what size and thickness tube did you use

mrcaptainbob · Jan 2, 2010

Great job on your 628! I built one with the help of my then son-in-law. It has done hundreds of hours of work. Just like yours, the swing cylinder ended up with a bent shaft, due to over swing. I turned the shaft 180*, did it again to the straighten-it-out point, then welded in a limiter. I've dug trenches, dug out rocks, dug out 8" dia. trees (with roots), dug a half basement and a 12 x 12 x 8 pit for a dry well. It's a real work horse. Make sure to keep that swing point well greased. The pin seized on mine, had a most difficult time removing it. In the mean time it elongated the base holes. Adding grease fittings all around makes sure that won't happen again! What size engine are you using?

Verticaltrx · Jan 2, 2010

simplicityguy92 said:
cool backhoe what size and thickness tube did you use

Its been almost a year since I built it so without looking at the machine or the plans I don't recall exactly. I know there is 2", 2.5" and maybe 3" square tubing in it in 3/16" and 1/4" wall.

mrcaptainbob said:
Great job on your 628! I built one with the help of my then son-in-law. It has done hundreds of hours of work. Just like yours, the swing cylinder ended up with a bent shaft, due to over swing. I turned the shaft 180*, did it again to the straighten-it-out point, then welded in a limiter. I've dug trenches, dug out rocks, dug out 8" dia. trees (with roots), dug a half basement and a 12 x 12 x 8 pit for a dry well. It's a real work horse. Make sure to keep that swing point well greased. The pin seized on mine, had a most difficult time removing it. In the mean time it elongated the base holes. Adding grease fittings all around makes sure that won't happen again! What size engine are you using?

Yup, the threads on the clevis end of the swing cylinder loosened up causing it to over swing. I think it will hold up for a while till I can replace it, I had a bent cylinder on a tree-puller I built and used it for hundreds of hours before the seals finally got torn out. Glad to hear your CadDigger is working great as well, they are fairly under-rated IMO. I grease every joint on mine about every 10hrs, so hopefully that will be enough. In really abrasive conditions I grease the bucket pins every couple hours. As for the engine, its a 5hp Honda GC160. I may eventually upgrade to a GX160, but for now this one is working great.

Renze · Jan 2, 2010

How many feet per minute can you trench with that ? and is force, or speed the limiting factor ? If its speed, using more horses and a bigger pump will uprate its capacity (tractor hydraulics put out about 10 horse nett, which equals a 12hp gas engine that powers a pump) but if force is the limiting factor, it will require heavier (more expensive) steel to get this to work behind a farm tractor..

I have too many things on my to do list, but a backhoe might end up on the bottom of it.. I'm surprised what this machine can do...

Verticaltrx · Jan 3, 2010

Renze said:
How many feet per minute can you trench with that ? and is force, or speed the limiting factor ? If its speed, using more horses and a bigger pump will uprate its capacity (tractor hydraulics put out about 10 horse nett, which equals a 12hp gas engine that powers a pump) but if force is the limiting factor, it will require heavier (more expensive) steel to get this to work behind a farm tractor..

I have too many things on my to do list, but a backhoe might end up on the bottom of it.. I'm surprised what this machine can do...

There are a lot of variables with how fast you can trench, the depth and type of soil are the two biggest factors. The trench pictured took about more than a minute per foot, but I'm not sure exactly how long. The machine will dig to 5', but really 3-4' is the practical limit. The curved excavator style boom would help speed things up, (don't have to move the machine as often), and I may build one in the future. Another limiting factor is the swing speed is too high in relation to the other controls, which makes it touchy trying to get lined back up with the trench, this wasted a little time too. A flow limiter on the lines running to the swing cylinder might also be coming in the future. Another factor, maybe one of the largest, is the operator. I've spent many hours operating a backhoe, but this was the first one I've run with out swivel sticks, so getting used to the 4-lever system is a bit of a challenge. Bottom line is that this isn't a fast machine, but it does get the job done. I'm sure the larger CadDigger models are a lot faster.

mrcaptainbob · Jan 3, 2010

Sure agree with with it being a slow process. I was doing about ten feet an hour in sand with occasional rock. About that over swing. The limiter I added was on the right side where the pivot assembly touches the frame spine. I think it was about 5/8 or 3/4 long. As you mentioned, the swing speed was WAY too fast. Actually could be dangerous. I added brass valves in line on one side on each of the cylinders. The bucket I usually leave full open, boom and boom extension are about 1/2 open and the swing is maybe 1/4 open. No restriction on pressure, as it's just an orifice controlling the amount going through. Neat thing is that they can be tweaked for personal preference as well as job specific.
Don't mean to hijack your thread...just sharing similar experience. Here are some pics on Flickr of my 628:
Dirt Digger info--- - a set on Flickr

Verticaltrx · Jan 4, 2010

mrcaptainbob said:
Sure agree with with it being a slow process. I was doing about ten feet an hour in sand with occasional rock. About that over swing. The limiter I added was on the right side where the pivot assembly touches the frame spine. I think it was about 5/8 or 3/4 long. As you mentioned, the swing speed was WAY too fast. Actually could be dangerous. I added brass valves in line on one side on each of the cylinders. The bucket I usually leave full open, boom and boom extension are about 1/2 open and the swing is maybe 1/4 open. No restriction on pressure, as it's just an orifice controlling the amount going through. Neat thing is that they can be tweaked for personal preference as well as job specific.
Don't mean to hijack your thread...just sharing similar experience. Here are some pics on Flickr of my 628:
Dirt Digger info--- - a set on Flickr

I like that control pannel you set up, I wish I had put an hour meter on mine. I think I'll start with a flow limiter on the swing cylinder, but adding them to the boom and boom extension cylinders is something I might eventually consider too. It would ceartainly make operating it a little smoother.