Building an Excavator

[Newfie_1986]

Hey guys im planning on building a small hydraulic excavator in the future. Has anyone on here built one before ? I dont want to buy plans I would much rather look at pictures of ones already built and re design to my liking...

For anyone who has built one any tips would be appreciated. I dont think I can get any rectangle stock here (at my metal supplier) thicker than 1/8" so I will probably weld 2 pieces of Channel 1x4 1/4 thick together (to make rectangle stock) for the arm. To all those professional welders looking at this dont worry I will make sure to gind down the joint into a V and do a multi pass weld to ensure I get a good solid weld and fuse both pieces together...

Do my first pass with 7018 and cap it with 6010 ??

What thickness steel do you all think I should use for the bucket and the brackets for the Hydraulic rams? 1/4" ?

Oh and I dont wanna hear any of that nonsence that an excavator is too hard to build I was told that by my parents and my brother about my saw mill but that works great. Guess they thought where im only 20 that I couldnt do much of anything !

Darryl

[zapster]

Oh and I dont wanna hear any of that nonsence that an excavator is too hard to build I was told that by my parents and my brother about my saw mill but that works great. Guess they thought where im only 20 that I couldnt do much of anything !

All I'm gonna add is good luck...
And I'll bet 10 bucks you don't finish it..


...zap!

[jknight8907]

Have you compared the cost of the materials vs buying a good used one?

Are we talking something based off of those small, tracked rigs? Like this: http://www.moulton.ac.uk/images/Mech..._excavator.jpg

I'm not sure you're understanding what all goes into one of those. I'm afraid the arm would be the least of your worries there.

[72sporty]

I sat, build away. Any problems you run into are only opportunities to learn. I've got know idea exactly what you are planning. My only thoughts were 6010 then 7018. Good Luck, Adam

[lorenzo]

There is no need to run a cap at all. If SMAW is you weapon of choice then just use the 7018. Good luck to you......

[MicroZone]

I think he might mean one like this:

http://www.harborfreight.com/cpi/cta...emnumber=93167

[Newfie_1986]

Hey Zap thanks for the wishes of Good luck as far as the bet of $10 thats just encouragement for me. By the way is that $10 Canadian or US LOL (if its $10 US im gunna work real hard to prove you wrong LOL)...


jknight8907 here is a link for you to look at im planning to build something similar to this http://www.cadplans.com/821.htm as I said I plan to do some redesigning myself... That one moves by using the bucket to drag it along im debating making mine driveable with tires, no track. Its something along the lines of what I want to build...


and 72sporty thanks for the advice on the rods. That is my plan any problems I have I will deal with it and solve it if everyone shyed away from difficult things we wouldnt have what we have today.

Right now im just looking at getting a rough design in my head and go with it. I dont plan to build the thing for a couple of months because well I need to get some money together to do the build and figure out what way im going to go with the build...

When I looked online at the saw mill designs everyone had things made complicated I simplified everyones designs and modified them to my likeing.
I managed to come up with something simpler in design and cheaper to build.

Darryl

[MicroZone]

Cool, sounds like you know what you want to do and have a long-term plan. Did you ever post pics of your log mill ?

[Newfie_1986]

Lorenzo if 7018 is all I need well thats good I will probably just run that then.

MicroZone yeah that thing is something along the lines of what will be built.

Mine will just be bigger and be able to dig deeper (and may be mobile without the use of the bucket). I think I can build it for $2500 Canadian finished...

Sawmill pics are here. not very good pics but there are pics http://new.photos.yahoo.com/darryl_86/ go to the 2006/09/09 album.
if you look at the pic of the 2x4 you will see the start of the cut was wavy due to a loose blade, The green clap board was cut on the mill as well.. The mill isnt painted and probably never will be now that its in use.... I also have to change the blade guides those bearings were just put there to get it up and running im going to put a set of real blade guides on there...

Thanks

Darryl

[wallythacker]

Go for it.

Here's free plans from another guy. Modify them to suit your needs.

http://www.workshop-projects.com/pro...%20plans-1.pdf

I have some folks pestering me to build one for them. I told them, build me a shop, I'll build your hoe. So far I have no takers.

If you buy the parts at Princess Auto when they're on sale you might get by with $1500 + the cost of steel. Last week Princess had a decent 6hp motor with integrated hydraulic pump for $400 or so.

[jknight8907]

Ah, I see. I have much more faith in your ability to build that now that I see it's a simpler job than what I'd though. Looks like a challenge, but a fun one.

[Sober_Pollock]

Originally Posted by Newfie_1986

..... I would much rather look at pictures of ones already built and re design to my liking.....Darryl

PICTURES?

I would think the least you could do is go find a couple REAL ones and look at those.

Good luck, I think it "could" be done by the right person. Take my hint and go look at a few real ones.

I just have one question.....What are you going to do with it when you're done with it?

Do you know how to operate an excavator?

[Newfie_1986]

Wallythacker
Thanks for the link. yeah princess auto is where I plan to go thats where I got most of the parts for my saw mill.. They opened there doors here 2 weeks before I started my saw mill Build !

Sober_pollock

The reason I want to see pictures is because no one here local that I know has actually built a homemade excavator in there garage (I want photos of homemade ones) I find in general people who build things themselves tend to simplify things.


Only thing I could copy or use off a real excavator is the arm design and maybe the bucket (I already have ideas for the design of these items) I pretty much have a grasp on the way it will be built just need to decide how I will put on the out riggers for stability.

This will be built with a Plasma Cutter, Stick welder and other hand tools...

I like to keep things simple that makes things easy to build and easy to
repair...

Yes I know how to operate an excavator, have used the small Kubotas many times...

oh and I plan to dig a drive way for my parents new cabin they're building. I was looking at a pic of one guys home made excavator and he used it for exactly that.

Thanks for the tips guys

[jknight8907]

The problem with basing your designs off of homemade stuff is what the builder has done to the homemade one. If he's jacked it up somehow, then you go and modify that design, your end product will be fully jacked up.

[Newfie_1986]

Thats why im only looking at the designs and using what works ! Thats why I brought the idea up on this site to see if anyone has made one they could tell me there machines flaws, and good points and I could modify the design to my liking. Guess no one on here has built one ???

My plan is the same one I had for my saw mill get all the info I can on the subject and try to get it right the first time (I did with the Mill). If its flawed I will cut it apart and fix the flaw thats all apart of building and designing things...

My brother is a Carpenter and I have worked with him a lot, he always told me to stop worrying about screwing what I was doing up because if I screwed it up I could figure it out and fix it up !

[wallythacker]

y dad bought the 6hp hydraulic drive without my knowing and some decent priced cylinders. He's one of the pesterers. I'll pick up the 6 spool control from Princess and some lines and fitting. So far we've got $1300 invested and maybe an other $150 in lines and fittings needed.

Now to scrounge or buy the steel. If I get lucky $200-500 should do it. I should find a bump brake for the bucket and other stuff, maybe I'll make one

Said protable hoes go for 5-7K when complete. Not back for a week or two work.

But I so need a decent shop. Actuslly, 2-3 of the units will be biult termote hence my 120v 140amp mig requirement. Ya, I know, a HH187 might he better buy but damn 240v gets in the way.

[Newfie_1986]

Thats actually the only thing I see myself having issues with is the Hydraulics because well to be honest I dont know much about hydraulics (I have a bit of learning to do before I jump into the hydraulics)..

Wallythacker
did you're dad buy the 6.5 hp hydraulic pack the one that puts out 2 gpm ? its reg $499. The engine on the 6.5 hydraulic pack is what I used on my saw mill. Works well but sometimes hard to start (needs the carb adjusted).

Hmm somethin for me to think about I could probably pull the engine off the mill and use that for the hydraulics when im not using the mill (just switch back and forth). Help keep the costs down on the build...

yeah dads like to pester mine has been pestering me to cut him some lumber !

Good luck on you're build and keep us updated im sure you will have you'res finished before I get to mine.

[jamlit]

It's a great project and a worthy one if you just want to see you built one and maybe save a few bucks. I love projects like this. I helped build one from scratch for the back of a farm tractor. I wish it was still around so I could get some pics for you. It was awhile ago and don't know where the thing is today. May do some inquires for you.

Now for some input. Your going to need a bigger GPM than 2. you are most likely going to need 4 - 8 gpm and even than it might be a little low. You will need this flow so you can work more than one cylinder at a time. I have an old farm tractor I replaced the hydraulic pump on. Since I did't know what flow rate I went with a Conservative 6.4 gpm from princess auto. Bad move, it needs allot more and this old traction uses no more and maybe even less than the excavator you want to build. Remember the units you are looking at are made more for wood splitters with a single cylinder and you most likely seen how fast they move. I think you would be very upset if you can only work one cylinder at a time the speed that a wood splitter works. Find out what cylinders you are going to use than size the pump a little bigger than the largest cylinder you are going to use. The guy at princess auto's hydraulic dept should be able to size you up properly. And make sure the spool valve is matched.

Now the fun part is setting the cylinders in place so that the force is applied right and you get full stroke. this can be tricky and you may need to do some trial and error. since the designs you are going to see and will most likely come up with, will not show you the mechanical leverage points that will make your machine work properly. Its not rocket science but will take a little work.

One thing to make sure you do is build a good size hydraulic tank and return all the cylinders to it and have the pump suck from this tank. This will allow proper cooling and flow rate stability. The bigger the tank the better for the most part. add a good return filter as well, sized a little bigger than the flow rate on the pump.

7018 rods is all you will need and since you have a plasma the project should look great.

Well this is all I can think of at the moment. I will watch this post for further developments as I am interested to see how you make out.

Nice to see a fellow east coaster doing a job like this. My father is from Bishop falls.

[wallythacker]

I won't get started on much of anything until I see grass (lawn, not the other stuff)

Jamlit, thanks for good info. Yep, maybe the pump my Dad got is a tad small. I think it's 8-10gpm low pressure, 2-4gpm high side? I need a refresher on hydraulics, it's been a long time since I tinkered with them.

The good thing is the free plans are based on Princess Auto parts (the designer is a Canadian) and he worked out all the mounting points (I hope)

And funny thing, my Princess Auto has a girl as the hydraulics expert. Too cool, and she seems pretty sharp.

All this snow is such a downer when there's no shop to work in Sears has an 11x21 metal shed for $1700. I don't think my bylaws allow sheds that big. Crazy, I have three sheds totalling about 325 sq. ft but you can't have a single shed bigger than 112 sq. ft.

Oh well, at least I have an excuse to head to Princess again and talk hydraulics

[FANS]

Sounds like a great idea.

If I might add a suggestion. Use a rear axle from a pickup (or rear drive car) for your axle and wheels. Keep the ring and pinon and fabricate a mount for a hydraulic motor. Use the hydraulics from the motor to run the motor on a separate circuit forward and reverse 1 or 2 speed you decide - I'd pick single speed. You'd be able to position the thing without using "bucket limp" method.

Another thought is to use the front axle off a 4wd truck for the machine's axle and then you could steer as well at the same time.

[jamlit]

You would need to weld the gears in order to make this work or have a posi rearend.

[jknight8907]

Should be no problem to weld it up. Not like you're running at very high speeds with it.

[wallythacker]

I don't know about the car axle. I want to make the first one KISS.

If, big if, I build one and it turns out OK, I have a bookmark somewhere for a crawler backhoe (another homebuilt and it's awesome) I'll consider an axle for it.

[Newfie_1986]

Jamlit

Thanks for the advice I will see about getting a 12 GPM pump or bigger (the biggest I can justify cost wise). I will probably do a cut out of the arm in card board for referance just as a guideline to help me with the placement of the cylinders.


Wallythacker

Thats pretty much the same plan I have make it simple and then decide if I want to make is driveable... I wont be able to start this project for a few months though because my brothers garage is tied up for a while and well I need to get some $$$ together for the build...

Thanks guys for the input

[Planewelder]

When looking for your hydraulic pump, make sure you don't get a 2 stage pump, which is common on log splitters. The resevour needs to be large as in gal ons, not quarts. The oil will get hot plus you have to have the volumne of all the cylinders extended plus a large reserve. Also make sure the spool valve is not the "float" position model, which is common to a blade type device. You probably know all that but hydraulics are expensive and you don't want to buy them but once.