M.E. Advice -- 3-point Hitch

[jpanhalt]

Thirty years ago, I designed and built this door (50'X 18'):
View attachment 64797
using only equations in Mechanics Handbook and a calculator (i.e. pre-PC days). It has withstood many Minnesota Winters and thunderstorms without a problem. Generally, I use L.A.R. when designing something. But now, I want some other opinions.

I am faced with converting a Lesco compact sprayer:
View attachment 64798
to a 3-point hitch. The hitch will be on the long side of the tank. The sprayer tank is 200 gal (1600#) max. Assume the motor + pump are about 100# and the reel is also 100#.

Given this hypothetical structure:
View attachment 64799
for one side of the 3-pt hitch, what size tubing/channel should be used? I prefer tubing for looks and ability to weld both sides; although, a mixture of tubing and channel is no problem. My gut tells me that 2X3X1/8 or heavier will be fine. The 3-pt attachments will be 3/8 hot-roll plate.

Is there a good online calculator for cantilever beams?

John

PS: I've gotten older, dummer, and lazier in 30 years. L.A.R. = looks about right.

 

[tcmtech]

As long as the tank is closest to the supporting end nearest the tractor I dont see much of a problem with it. However I tend to overbuild for durability so if it was me I would be inclined to go with at least a 2" x 4" x 3/8" channel iron or a 2" x 4" x 3/16" rectangular tubing as the base frame work.

Water likes to slosh and tractors tend to hit hard bumps which can create rather large shock load events that can momentarily multiply the weight of the unit by a factor of 3 - 5 times!

 

[jpanhalt]

Thanks, tcmtech. I have faith in your experience.

The 3-pt will be on the side with the vertical black bars shown in the Lesco picture. Imagine using a pair forks from the side, except it will be the 3-point.

Travel with the tank full will be very limited, if ever. In fact, the tank is unlikely to be more than half full. More typically it will have 60 to 80 gallons. This is mostly for spraying around the house for carpenter bees and weeds and my driveway for grass. For the field, I have a 200 gal Hardi with 24' boom already on a 3-point. It is a tall, narrower tank.

With fresh morning eyes, I looked a little harder and found this site: https://www.engineersedge.com/beam_bending/beam_bending8.htm

I assumed a 2000# load equally distributed between two lifts, X3 for "bounce" and safety (i.e., 3000#), and values from here: https://www.electro-tech-online.com/custompdfs/2012/06/HollowStruct.pdf to find that a 4X2X3/16 will give a deflection of 0.25" while a 3X2X3/16 will be 0.5". So, 4X2 it will be.

Just curious, what do you pay on average for hot roll and tubing? My local distributor charged $0.85 to $0.87 per pound for some hot roll shorts, which seemed a little high. But, I haven't bought steel in a long time. Thirty years ago, I was paying $0.35 to $0.40 for full tubing lengths (delivered), and $0.10 for clean drops at the distributor -- I know today the price is higher.

John

 

[duffy]

Is there a good online calculator for cantilever beams?

I bookmark online calculators, here's the ones I have for that -

**broken link removed**
https://www.efunda.com/formulae/solid_mechanics/beams/casestudy_bc_cantilever.cfm
https://civilengineer.webinfolist.com/str/sdcalc2.htm

 

[tcmtech]

Just curious, what do you pay on average for hot roll and tubing?

I have a good friend with a salvage yard that gets tons of odd brand new metals every day from a few big manufacturing places so for me I just trade a bit of service work for what ever I want.

As far as cost goes locally if I cant afford to use the right material I cant afford the project.

 

[jpanhalt]

As far as cost goes locally if I cant afford to use the right material I cant afford the project.

That's true. But, a penny saved is a penny earned. Most important, one doesn't have to pay income tax on that penny earned.

4X2X3/16 is 6.9#/ft or 166#/length. It is not going to break me, but most of us can find something to spend an extra $20 on.

@duffy, Thanks for the links. I will check them out when I get back later today. I am already late leaving.

John

 

[shortbus=]

I hadn't bought any steel for couple of years until last month. WHAT A SHOCK!!!

 

[tcmtech]

Most important, one doesn't have to pay income tax on that penny earned.

No wories, our governments are working day and night to find ways to fix that.

 

[ronsimpson]

I have something like this:
**broken link removed**
and
**broken link removed**
The first link (hope it works) is rated for 1000 pounds. I know it will not lift 1000 pounds out on the ends of the fork but I know if the weight is on a pallet or at the back it has lifted 1000 pounds. I often move a 50 gal drum with it (or two at a time).

If you can tie the forks back to the top (near the top link) (making a triangle on each side) it is much stronger. Keep the forks short. The top link should not get as much force. I would beef up where the bottom arms tie in.

I am making (and sold 10) wagons for moving pianos. I can not afford metal so I an using old bed frames. The metal is brittle (hard) but works.

Use not 2 but 4 forks and shorten the length from 4 feet to 2 feet, and double up the metal at where the side arms connect. I would make it from a bead frame or two.

 

[jpanhalt]

Hi Ron,


There is a TSC about 20 miles away in Amherst, OH and I looked at the two versions. I think the first is a little light, but the second would probably be fine. Unfortunately, my frame is quite rusted, so it would need some repairs anyway. The Hypro pump (3 diaphram), Kawasaki motor, and reel work great.

View attachment 64822

It has been a long time since I have done any serious welding, and I need to get back into the groove anyway.

John

 

[strantor]

Why don't you just sell that mig fighter jet and pay somebody else to spray for pests & weeds?

 

[jpanhalt]

That MiG 21 belongs to a buddy.

John

 

[ronsimpson]

You don't have to weld. I have been using square piping with holes every inch. The county uses this metal for stop signs. When a sign gets run over they throw the sign in the recycle been. Then I grab them and build things.

 

[jpanhalt]

I like to weld, particularly with TIG. I find it relaxing. MIG is a bit more frenetic. After all these years, I found the old eyes weren't working with my trusty helmet the way they used to work. I couldn't see anything after striking the arc. So, I got myself a Father's Day gift. A Lincoln Electric 3350 ("Viking"). Now that is nice. I am hoping to take it with me so I can fix St. Peter's gates, if I get there.

If you are not retired, you won't know what I mean. If you are, maybe you will. After about one month, I couldn't stand getting up every morning between 4 and 5 AM as usual with nothing of value to do -- nothing that had to be done. I volunteered teaching for a couple of years, now the "farm" fills that void.

John

 

[jpanhalt]

Update

Wow, a whole month has gone by. Too much to do. Changed the design and simply repaired the sprayer frame. Removed all of the bottom. Electrochemically removed the rust from the vertical 2" channels, followed by wire brushing and grinding, then welded on a new bottom using somewhat heavier 2" tubing. Loss less than 1/4" in height -- had to do a little rebuilding and grinding of a couple of the verticals. Finally cleaned, primed, and painted (Nason acrylic enamel). You can see the before picture (post#10), and here is the after picture.

View attachment 65548

For the 3-point, I will make a sled with the same spacing as the sprayer frame for it to sit on. Then use U-bolts to keep it from sliding. That way, I will have a spare, heavy duty 3-pt lift made from the 2X4X3/16 tubing. I will be spraying only a few times a year, I hope.

John

 

[jpanhalt]

Update #2

Here is the finished 3-pt hitch for the sprayer. The reinforcements are 5/16" hot roll plate. The lighter gray area on the top crossbrace is where I heat straightened it before assembly. Today, I heated the lower crossbrace to make the long pieces parallel (they were off by 1/8" at 48"). It is purely trial and error.

View attachment 66629

Now for the part I dislike the most. Cleaning, priming, and painting.

John

 

[jpanhalt]

The project is complete. Here are a couple of photos of the painted 3-pt attachment and the complete attachment with sprayer. Today, I sprayed about 100 gallons of poison (glyphosate) on my driveway and on the weeds around the pond. It took 5 hours. I am sure glad the hose reel is powered. Nothing broke or bent. Thank you tcmtech for recommending going heavier on the steel.

John

View attachment 66970View attachment 66971

 

[ronsimpson]

Good job. I have a bad starter on the little tractor and a flat that will take $1500 to fix on the big tractor and no money. So I am spraying by hand.

 

[jpanhalt]

Those tires are expensive. I assume the flat is due to aging rubber and is not a simple hole. If it just happens to be a hole, I repaired a front tire a year or so ago using a rubber plug like the ones used for automobile tires. The hole was in the tread, not sidewall. It has held up well.

John

 

[Mikebits]

Thats a cool looking quad.