CadDigger 628 build

[Verticaltrx]

Thought some of yall might be interested in the 628 CadDigger I built. I wanted a small backhoe for small trenching jobs, light excavation, and other jobs I encounter in my agricultural construction business and the CadDiggers seemed to fit the bill. At the time I didn't have my B3200, and I wouldn't have spent $7000-8000 for a backhoe attachment anyways. Plus with the 628 I can tow it quickly to a small job with my Tacoma without bringing one of my bigger trucks and trailers.

I built this in my farm shop using basic tools such as a chop saw, drill press, 4.5" grinder, etc. Welding was done with my Lincoln SP175-T MIG welder (.035 flux core) and Lincoln 225AC stick welder (1/8" 7018.)

Here's the main frame, hydraulic tank, stabilizer assy.

Next was the main swing assy. (prior to welding)

Main boom

This is the shell of the 12" bucket I made

More forthcoming...

 

[Verticaltrx]

I used Hercules 2A bucket teeth which were about $8 each, but the tooth holder assemblies were over $20 each. So I fashioned my own out of two pieces of 1/2" plate welded back to back (didn't have any 1" on hand.)

Here's a picture of the nearly completed CadDigger, pictured are the cheapo tie-rod type cylinders that I used. At $55 each they seemed like a good idea, but I'm beginning to regret not spending a little more on better cylinders, more on that later.

This is the completed 12" bucket. The cutting edge was made out of a 16" plow share. I also have a 6" bucket, and will make a 15" bucket in the future.

Fast forward a few weeks:

Specs:

5' digging depth
8' reach
2600lbs ripping power

5hp Honda GC160
2gpm Dynamic pump
Prince SV series 4-spool valve
2 Grizzly 2"x8" cylinders (from Agri-supply)
1 Grizzly 2"x10" cylinder
1 Grizzly 2.5"x8" cylinder

Total cost for the machine was about $1500

I'll post some pics of it on the job when I get them uploaded.

 

[tnhomestead]

Well just drop off those cheap cylinders here and I will take care of themfor you, might as well leave that there contraption too! LOL
I want one, first I have to learn to weld much better -- SWEET JOB, Kudos man!

 

[Army grunt]

outstanding!
thats a freat looking job. I am involoved reworking a arps 80 back hoe.along with several other things.(saw mill,dump trailer)
Grunt.

 

[GE222]

Nice posting, both with the comments and the pictures.

The workmanship was outstanding.

There is a lot to be said for using small easy to transport machines.

 

[Verticaltrx]

Thanks for the replies. I'm pretty pleased with the performance of the machine, it definitely beats a shovel or spade.

Here's a few pics of one of the first jobs I did with it:

Was installing an automatic waterer, dug a couple of 4' deep holes for the connections and trenched 300' about 3' deep in red clay. Took about 8-9hrs which is a while, but saved a couple hundred dollars and half a day to go rent a trencher.

I've done several other jobs since then and the machine has worked great. I replaced a 20' culvert, cleaned out a couple of creeks, cleaned up about 200' of ditch line, and done a few other small drainage projects. I've run numerous larger backhoes, everything from a B21 to a full size Allis-Chalmers TLB, and although it takes a little different operating technique, the CadDigger has really surprised me with what it will do. Of course it's not as fast as a larger backhoe, but once you figure out how to run the machine it can do a lot of work.

The main boom cylinder has started to leak a bit, and the pump has started to leak a bit. Also the swing cylinder got slightly bent. I'll probably replace the cylinders eventually with some nice welded cylinders, and use these for another project.

 

[Diamondpilot]

Very nice build. Now that you have the 2 tractors are you considering making it into a 3 point BH? You could lose the engine and hydro pump and run it off the tractors hydro's. I would think you could do a little more work that way having a stable platform to work form.

Chris

 

[Iplayfarmer]

I've run numerous larger backhoes, everything from a B21 to a full size Allis-Chalmers TLB, and although it takes a little different operating technique, the CadDigger has really surprised me with what it will do. Of course it's not as fast as a larger backhoe, but once you figure out how to run the machine it can do a lot of work.

When I saw the picture of that trench I figured you must have run a backhoe before. It's good to hear a glowing review from someone who has used "real" machinery. I'm planning a backhoe attachment for my tractor in the near future that will not be much bigger than a cadDigger. I'm glad to know that a simiilar sized machine is appreciated even by someone with prior experience with heavy machinery.

 

[Zick]

Awesome project!
Always wanted to do the same thing whenever I get some free time and extra money.

Btw, what reason did you have for wanting to swap out the cylinders to the welded units?
I've thought about using the same ones you did just for cost wise.

 

[Verticaltrx]

Very nice build. Now that you have the 2 tractors are you considering making it into a 3 point BH? You could lose the engine and hydro pump and run it off the tractors hydro's. I would think you could do a little more work that way having a stable platform to work form.

Chris

Most likely I will build another larger unit to go on one or both of my tractors. Not sure what size I would build, maybe a 708 CadDigger (7' digging depth), and mount it on the B3200 with the Kubota sub-frame. I do really like having the 628 for small jobs though, I can go dig up a broken water line or other small quick jobs without tying up one of my tractors.

When I saw the picture of that trench I figured you must have run a backhoe before. It's good to hear a glowing review from someone who has used "real" machinery. I'm planning a backhoe attachment for my tractor in the near future that will not be much bigger than a cadDigger. I'm glad to know that a simiilar sized machine is appreciated even by someone with prior experience with heavy machinery.

Yup, even a small machine when operated properly can do a lot of work. Plus, when I envision how people would have been digging that trench 100yrs ago (spade, pick and a tile hoe) it seems to really go quick.

Awesome project!
Always wanted to do the same thing whenever I get some free time and extra money.

Btw, what reason did you have for wanting to swap out the cylinders to the welded units?
I've thought about using the same ones you did just for cost wise.

The tie-rod cylinders I got were just cheap ones. To be honest I didn't want to spend too much money on this unit because I had no idea if it would really work. Now that I know it does I'm willing to buy some better parts.

There are some good tie-rod type cylinders out there, but the welded type are cleaner, more compact, and often are sturdier. Plus, the welded type generally have a cross-tube at both ends instead of a clevis type end, which with a grease fitting would make things last longer.

 

[eazyduzzit]

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

 

[Scotty370]

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

 

[Verticaltrx]

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]

cool backhoe what size and thickness tube did you use

 

[mrcaptainbob]

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]

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.

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]

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]

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]

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]

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.