Landscape Rake Build

[GuglioLS]

Larry,
Did you happen to notice any differences in the plasma cut holes from top side compared to the bottom side. ..........SNIP.......

Yes there is a taper, I am aware of that, I've had many project parts plasma cut, several for my friend Rob (3RRL), another friend and for myself. Most of it was 3/8" so the taper effect was not all that bad, any critical holes are undersized then later bored or drilled out. I used 1/2" plate for this rake build, I factored that taper into the index holes of my CAD drawings. Mostly what I wanted from the plasma cutting was the fancy curved parts, then bore or drill out critical holes to remove the taper.

Larry

 

[MJPetersen]

I took the chance for the allmost new 3 cylinder pump. 2 months ago the motor burnt. Its a 4 hp 3phase 400V

A new motor would be 190 euro. Could you explain me what exactly are the parts that you ground smooth ? Maybe my compressor motor suffers the same, and i could fix it myself instead of buying a brand new motor.
I'm not really into electrical devices...

Renze, Our 3 phase motors are nothing like the "wimpy" 220 v motors in the States. I know that here larger (3-10 hp) "comunist era" motors are very inexpensive. I know several places where you can buy them for about scrap price--now that has gone up tremendously so maybe the motor prices also.

Mike

 

[tlbuser]

Larry,


Did you happen to notice any differences in the plasma cut holes from top side compared to the bottom side. The reason I ask is that a plasma stream cuts in a small cone. A laser cuts better, and straighter. With plasma cutting the thicker the metal the worse it gets. I had some holes cut with plasma , and I noticed some difference. Anywhere from 1 to 5 degrees. On 3/4 thick metal, one side of the hole might be 1 inch, and the bottom might be 1 1/8 On thin metal, you will not notice much difference. This is just something to think about. It all depends on the cutting tip, whether it is new or well used.

Not entirely wrong nor entirely correct. Speed and amperage (or capacity) also have a huge effect on the quality of cut. Different tips will affect cut quality too. Hypertherm Powermax1000 Manual Plasma Cutter

 

[3RRL]

Larry, I had no idea that sandblaster you have is that inexpensive? What a great tool to have around for all kinds of general tough cleaning like that.
Thanks for sharing it. I'll have to get one for sure now.

Larry,
Did you happen to notice any differences in the plasma cut holes from top side compared to the bottom side. The reason I ask is that a plasma stream cuts in a small cone. A laser cuts better, and straighter. With plasma cutting the thicker the metal the worse it gets. I had some holes cut with plasma , and I noticed some difference. Anywhere from 1 to 5 degrees. On 3/4 thick metal, one side of the hole might be 1 inch, and the bottom might be 1 1/8 On thin metal, you will not notice much difference. This is just something to think about. It all depends on the cutting tip, whether it is new or well used.

Hi JJ,
Larry got several projects plasma cut for me.
The source he uses did a good job and Lord knows the price was certainly right. There is a taper as you describe and would vary depending. After receiving the first batch, I saw what you are talking about. On future projects I asked for only the cosmetic shapes to be plasma cut. Holes too, but only if cosmetic. I found holes that needed precision were better to get cut undersized, if done at all, so you can drill, ream or bore depending how close you want them. Not just hole size, but positioning also. I was worried about the "one edge" of the plasma cut holes wearing out my pins sooner. Plus they are kind of hard after being cut, so I use carbide to open the holes up since it is a little tough on hi speed. Still easier than starting a big hole from scratch though. And if size and location are not absolute, it's very inexpensive to have everything done.

How accurate, how straight is the laser cutting you talk about? What is the difference in cost, if any %?
Can you get a TRUE straight wall in a hole that doesn't need to be machined after laser?
Thanks,

 

[J_J]

Larry, I had no idea that sandblaster you have is that inexpensive? What a great tool to have around for all kinds of general tough cleaning like that.
Thanks for sharing it. I'll have to get one for sure now.

Hi JJ,
Larry got several projects plasma cut for me.
The source he uses did a good job and Lord knows the price was certainly right. There is a taper as you describe and would vary depending. After receiving the first batch, I saw what you are talking about. On future projects I asked for only the cosmetic shapes to be plasma cut. Holes too, but only if cosmetic. I found holes that needed precision were better to get cut undersized, if done at all, so you can drill, ream or bore depending how close you want them. Not just hole size, but positioning also. I was worried about the "one edge" of the plasma cut holes wearing out my pins sooner. Plus they are kind of hard after being cut, so I use carbide to open the holes up since it is a little tough on hi speed. Still easier than starting a big hole from scratch though. And if size and location are not absolute, it's very inexpensive to have everything done.

How accurate, how straight is the laser cutting you talk about? What is the difference in cost, if any %?
Can you get a TRUE straight wall in a hole that doesn't need to be machined after laser?
Thanks,

This data is from a CO2 laser verses a plasma .

Minimum size of the cutting slit (kerf width)

LASER- 0.006", depending on cutting speed
PLASMA- 0.002"

Cut surface appearance

LASER-Cut surface will show a striated structure
PLASMA-Cut surface will show a striated structure

Degree of cut edges to completely parallel

LASER-Good; occasionally will demonstrate conical edges
PLASMA-Fair, will demonstrate non-parallel cut edges with some frequency


Laser cutting machines are very expensive. You can set up a Plasma cutting station for about $10,000

Oxy-Acetylene cutting is the least expensive.

Water jet is another method of cutting.

 

[J_J]

Larry,

Have you ever used one of those pressure washer sand blaster guns ? They will strip things down pretty fast. It works by sucking the sand into the stream and will suck up just about any size sand. I will try and find a picture.

 

[J_J]

Larry,

Practical CNC made up my plasma cutting table. I have everything ready to go except a place to put it. No garage. no shed, no nothing. I had thought about one of those shipping containers. I need 230 v for the Lincoln Pro-cut 55, and machine torch. Maybe one day soon.

PracticalCNC, makers of the finest plama cutters/routers

 

[GuglioLS]

J.J. -

That pressure washer sandblasting attachment gizmo looks inexpensive enough. I would imagine sand mixed with a stream of water at 2400 psi might make short work out of a tough job. Does the metal rust from all that water?
Where do I get one? Does it fit all pressure washers?

Larry

 

[SkunkWerX]

Larry,

Better check on types of pressure washers it fits, I was saddened to find those types wouldn't fit my Karcher pressure washer.

They do a fantastic job, a friend has one. He took an old implement, i think it was an old disc, in about 15 minutes he had it entirely down to bare metal, took 50 years of rust off like that! Using regular white sand-box play sand.

If you leave the parts sit for days and/or weeks depending on your location and humidity you might get some surface oxidation, but nothing a quick hit with 220 paper or steel wool won't take care of quickly.

 

[GuglioLS]

Larry,

Better check on types of pressure washers it fits, I was saddened to find those types wouldn't fit my Karcher pressure washer. .....snip.....

Bummer, that's exactly what I have, a Karcher. Maybe it could be adapted to fit somehow? Do I see another mod in the works I've got one more huge part to blast, and I do not look forward doing that with my little gun. But will if it comes down to it.

Larry