Can I afford a beveling cutting head? 5 axis?

[weldersandblaster]

Hello gentleman. Nice to meet you. I’m new here and new to the world of plasma tables.

The question is, can I afford a table that will cut bevels?

I’ll give you the background info.
I’m already a welder and sandblaster with my own small shop and mobile blasting rig.

I’m considering expanding into a new market which I don’t know its size yet as I will be the first one in it. Maybe I’ll find a lot of customers, maybe only a few. I’m willing to gamble some. Since I might not find a lot of customers, I’m scared to make a huge expensive jump in with a table I might not end up needing if enough customers do not exist.

I need to cut ¼” (635mm) thick stainless plate into about 1.5” x 1.5” (38.1mm) pieces and one side of it needs a 45 degree bevel to give it some sort of moderately sharp edge. Like a knife edge you might give to your 7 year old.

I don’t need a large table. I buy my plate 4’x8’ (1219.2mm x 2438.4mm) and will cut it into quarters and work with one fourth of it at a time. So a small table will work just fine.

I don’t need a lot of accuracy. My tolerances can be plus or minus .030” or 0.762mm.

The bevel can be from 40 degrees to 50 degrees. Closer to 45 the better. Again, I don’t need a lot of accuracy.

I don’t need a fast machine. 1 minute per piece will be fast in my opinion compared to my cutting and sharpening them by hand which took 3 hours for 6 pieces.

I might only cut 50-200 pieces a week in the beginning. So I don’t need industrial quality and dependability as a job shop would. I don’t need expensive. I can only afford barely functional, I’m afraid.

Here is where most of you might roll your eyes at me and shake your head. Here is the toy I have.
https://smile.amazon.com/gp/product/B07 ... UTF8&psc=1

PRIMEWELD CUT60 60Amp Non-Touch Pilot Arc PT60 Torch Plasma Cutter 110V/220V Dual Voltage 3 Year Warranty.

I’m sorry I have such a puny toy. But my sandblaster cost $80,000 if that makes you feel better. Until now, I only cut with plasma 15 minutes per month.

I do have a table head from a older miller plasma machine. Maybe I can hook it to my machine?

Not knowing if there really is a consumer market for my new product, I can’t invest much into the initial table in case I’m wrong. I can’t begin to assess the market size without jumping in at least a little bit. I can’t jump in at all unless I can cut bevels. I tried sharpening these stainless edges with grinders and other methods, but the time consumption eats up the profit and then some.

So finally my question.

Is there a small table by anyone that can cut bevels, I can afford to gamble on with $3,500? USD

I have a suspicion I want too much and have too little to trade for it. Please tell me I’m wrong, and I’ll forgive you for laughing at me.

I live in USA, Florida. So a Russian or other foreign machine coming through customs might be a dealbreaker. I’m scared to buy a machine from another country. Unless you guys have much experience in it and can talk me through it and reassure me.

Many thanks in advance to you experts for taking the time to read this.

BEWARE!

If you help me find a table I can afford, this post is just the first of many posts carrying my questions I’ll have for you experts. And I’m not in a hurry. It will probably be a month from now before I pull the trigger and buy. Assuming I can afford to buy?

So, the forum says?

Chris

[adbuch]

Chris - For an entry level table, I would recommend one of the Langmuir tables like the Crossfire Pro.

https://www.langmuirsystems.com/pro?gcl ... yzEALw_wcB

crossfire pro.jpg

Others will suggest building a table from scratch to save money. It all depends on if you have more money or more time, and what you value your time at.

I can see building or buying a swivel mount to set your torch to 45 degrees for cutting the bevel. You could cut your bevels first, then rotate the torch back to vertical to cut your straight edges. Or visa-versa.

I can think of numerous procedures to follow.

Cut long strips around 3" wide, then cut bevels on both sides, then cut along center and then cut off individual parts. Or cut your 1.5" squares first, then cut bevels individually on each part using holding fixture. Or ................

But I think you get the idea.

David

[adbuch]

The original Crossfire could certainly be set up to cut bevels as well. Cost is $1495.
For extremely large quantities, you might also consider having these quoted from one of the cnc laser cutters. I personally have many parts cnc laser cut and they can do the entire job including material for what I would pay just for the material.

David

https://www.langmuirsystems.com/crossfire

crossfire.jpg

[adbuch]

Chris,
You might also consider buying or building a bevel guide for manual plasma cutting. For proof of concept, this would be much more cost effective than buying a cnc plasma table to get started. I would use one guide for cutting the bevel on long strips, then another guide (fixture) for the straight cuts and cutting off your finished parts. Much faster than your current method, and most likely much better results.

David

https://flangewizard.com/plasma-beveling-cutting-guide/

flangewizard.jpg

bevel guide.jpg

[adbuch]

Here is another approach half way between full cnc and hand operation.

https://hackaday.com/2018/06/22/linear- ... nd-simple/

hackaday 1.jpg

[weldersandblaster]

Chris - For an entry level table, I would recommend one of the Langmuir tables like the Crossfire Pro.

https://www.langmuirsystems.com/pro?gcl ... yzEALw_wcB
crossfire pro.jpg

Others will suggest building a table from scratch to save money. It all depends on if you have more money or more time, and what you value your time at.

I can see building or buying a swivel mount to set your torch to 45 degrees for cutting the bevel. You could cut your bevels first, then rotate the torch back to vertical to cut your straight edges. Or visa-versa.

I can think of numerous procedures to follow.

Cut long strips around 3" wide, then cut bevels on both sides, then cut along center and then cut off individual parts. Or cut your 1.5" squares first, then cut bevels individually on each part using holding fixture. Or ................

But I think you get the idea.

David

Hi David
Thanks for the reply.

For some reason this forum did not send me a email notifying me I had any responses to my post. For 2 days I thought my post was too insignificant to the group of experts to justify a response from them.

So I kept researching and brainstorming and found Crossfire and became intrigued by their little tables as my shop is very small. I kept wondering without the ability for cnc angling torch head, how could I make a Crossfire work? I came up with some interesting ideas I will tell you about shortly.

So I came back here to do a search on Crossfires on this forum.
To my amazement, I found your response to my post I thought no one responded to.

At the top of the page, there were NO NOTIFICATIONS showing. How can that be I wondered? Maybe some setting was out of whack I wondered?

I go into my control panel profile settings and find “notify me of replies by default” was turned off. So maybe that’s why I was not emailed to be aware you replied? But why did your reply not show up under NOTIFICATIONS when I came to this forum to check to see if my post had replies, I wonder?

You reply and I ignore you for 2 days and you think what a jerk.
I post and find no replies, and think what a forum.
And we’d both be wrong.

Anyhow on to your reply, which I thank you again for.

I would be interested in researching what can be done to mount a beveling torch head to a Crossfire. 2 Days ago I thought that a beveling cnc was the only solution. Now I have some other ideas to achieve the desired results, and beveling cnc may not be needed.

I was delighted to read your reply was right along the lines of my latest brain storm. If I give you more details about the pieces I am making, your advice will become much more valuable.

So here goes. I want ¼ circles like pie shapes, and the curved side beveled to make a modest blade. The 2 straight edges will NOT be beveled or sharpened.

A 4 inch circle could make 4 quarter moon pie slices.
4 inch is about the average size. However as I receive orders, the size can change slightly with each order. One order may need 2 pie slices at 1 ½ inches, and the next order may need 6 pie slices 1.75” and the next 2 pie slices at 2”.

So that makes it challenging to have a laser cut me 400 pieces in advance since I don’t know the sizes in advance and they change from order to order.

Also one of the straight edges of the pie slice, will have a minor wave cut into it, so when I weld it on, it’s a tight fit with no giant gaps to fill. That minor wave pattern will change from order to order. I’m thinking I can free hand cut that minor wave and any gaps, I just fill with weld. So that’s not my big concern.

So while you were writing your reply to me, I came up with this.
Use a cnc plasma to cut the circle diameters and quantities I need for that order. And use it to punch a hole in the center of the circle as if I had drilled that hole.
Then I have 2 perfect circles cut, ready to receive a bolt through its center.

Now I take something like a vice held hand drill, or rotating welding fixture spinner, and grab that bolt and spin the circle plate as a stationary torch holder holds the plasma torch at a 45 degree angle as I spin the circle and cut my bevel.

I will have to, and can build, that rotating cutter setup. And I’m open to advice on what components to cobble together to make it work. And as with all my previous prototypes, it will need tweaks, changes and adjustments to get it perfect. I realize speed of rotation will determine quality of cut and slag. So somehow that will be accounted for and accurately controlled for good repeatability.

But building that is better than buying a $80,000 beveling industrial plasma table I might not have the market to for.
I can put in my time as I take a chance and gamble a market does exist. If I’m wrong, I’m not $50,000 in debt. I can throw away some prototype and build time and I’ll live.

So now I have the two .25” thick, plate circles perfectly beveled. I drop them back on the table, back into the plate they came out of, back into the holes they came out of, and the cnc goes back to the same place, and cuts each circle into 4 quarters thus giving me 8 pieces.

Now if I did this right, I have 8 pieces that cost me about 10 minutes or less. That keeps me in the high profit margin.

My first barbaric test run, made 6 pieces in 3 hours. THAT WAS A DEAL BREAKER!

Now 2 more minutes, and I hand cut the minor curve or wave into one flat side of each quarter.
12 minutes and the pieces are ready to weld on. 3-4 minutes of welding, and I’m done. Yesterday my goal was to be done in less than 30 minutes as much longer than 30 minutes is too strongly watering down my profit margin. At 45 minutes I quit and won’t build them. I would go spend my time elsewhere.

But now with today’s thinking, I might be done in 15 minutes. Now my interest is VERY STRONG.

I have never used any associated cnc design software yet, but I’m wondering if I took a picture of the curve, then import it into the program, and tell it the length of the curve, could I create code to also cut the curve when it cuts the round circle into 4 pieces?
That might save me another 3 minutes.

So David, what are your thoughts?

Then as the business grows, and I determine which sizes are standard and most duplicated, maybe I can swap out the torch for a engraver head and write part numbers on them before plasma cutting them. I expect to find 10-15 sizes cover 99% of my orders. Then with part numbers printed on them, I can make 100 pieces at a time in advance all at the same batch sitting and stock pile them.

Thank you for your reply David. Your ideas are really good. I like them.

If/when you reply again, please make sure you mention the word CROSSFIRE again. Now if I can’t find any replies, in a day or two, I will search the whole forum for what new posts have that word in it.

Chris

[weldersandblaster]

David, based on your Ebay page, you're a man not to be underestimated. You seem very capable. I'm impressed.
Chris

[adbuch]

Hi David
Thanks for the reply.

For some reason this forum did not send me a email notifying me I had any responses to my post. For 2 days I thought my post was too insignificant to the group of experts to justify a response from them.

You will need to subscribe to your original post in order to receive email notifications. You can also change your personal settings to automatically send email notification for every post you author or comment on.

David

[weldersandblaster]

I was just emailed and informed you did this reply. Which surprised me. Maybe I am now being informed of replies. I will look for the "subscribe to your original post" button and click it if and when I find it.

[adbuch]

Hi David
Thanks for the reply.

For some reason this forum did not send me a email notifying me I had any responses to my post. For 2 days I thought my post was too insignificant to the group of experts to justify a response from them.

Chris - the heading you have posted in is "Various Manufacturers". Not a lot of activity there, so it won't be too hard to find your post.

https://www.plasmaspider.com/viewforum.php?f=73

new posts.jpg

Or just bookmark your post.
https://www.plasmaspider.com/viewtopic.php?f=73&t=34520

David

[adbuch]

square with bevel.jpg

[adbuch]

The first thing would be to give a complete description of your part. I now assume it is a pie shaped piece from your description. But you photo does not look that way. You photo looks more like a rectangular shape with a curved bevel on radius and blending into one of the sides. Then you have what I assume is a straight curved cut (no bevel, but shape is curved to match the part you are welding it to).
David

[weldersandblaster]

square with bevel.jpg

Hi David.
Yeah, by reading your reply I realized my description of the pieces was inadequate. So thats why I wrote more description describing the circles and included pictures for clarification.

So I'm wondering, what's the easiest way to hold and spin the circles with controlled adjustable speed while the torch burns a bevel?
I can afford the Crossfire as my jumping in investment. My needs are basic, and it seems more than capable of cutting circles, and then quartering them.

[adbuch]

square with bevel 1.jpg

[weldersandblaster]

Hi David.

The first thing would be to give a complete description of your part. I now assume it is a pie shaped piece from your description. But you photo does not look that way. You photo looks more like a rectangular shape with a curved bevel on radius and blending into one of the sides. Then you have what I assume is a straight curved cut (no bevel, but shape is curved to match the part you are welding it to).
David

The pictures of my protype peices I made are much more accurate of what I'm hoping to achieve. But that puts me towards a 5 axis (is 5 axis the correct terminology? ) so I can bevel the curved side that is not a perfectly round circle in my prototypes. And thats leaning towards big money.

Now if I'm willing to sacrifice some on the radius of my curve, and settle on more round, more circular, then a low-cost solutions seems within my reach.

Fortunately for me, tolerances allow me to adjust my curve towards perfectly round, for the gain of a lower cost solution. I think the end results of the modification should probably achieve adequate results of this tool in operation for my customers.

I am the first in this market, so my customers have no alternate solutions, except what I give them. I have no standard I must live up to.

So tomorrow I will use a wood template and cut a circle, and drill a hole in the middle. My Milwaukee hand drill spins slow in first gear and I will attempt a bevel on a perfectly round piece. I will build the tool with the round quarter moon, and test its function.

Then I will know if proceeding further down this road is worth our time.
Chris

[adbuch]

So which one are you planning to make? The pie shape or the shark tooth? Both are possible without need for a 5 axis machine. A simple torch guide will do it either way. The bevels are cut with hand torch/guide. Straight lines cut either by hand with torch guide, or inexpensive cnc plasma table.
David

[weldersandblaster]

square with bevel 1.jpg

Yes, you have it. Your picture is perfect. You understand clearly how I am adjusting my wishes to a pie. Seeing it drawn as you did, now has me thinking that by altering the angle of the curve I must cut along the straight edge, could bring the quarter circle closer to my prototype beveled edge.

Dam, I was right. You're smart. I got lucky meeting you.

Ah, shark tooth. What a perfect name.

I could settle for the pie, but more prefer the sharks tooth.

Cutting bevels with a hand torch guide makes for a sloppier cut, which means a lot more grinding to clean it up. Grinding stainless is slow. This is not mild steel.

[adbuch]

square with bevel 1.jpg

Cutting bevels with a hand torch guide makes for a sloppier cut, which means a lot more grinding to clean it up. Grinding stainless is slow. This is not mild steel.

No. Not if you use the correct torch guide. This would not be the ones available as I showed previously from Hypertherm or the other one. This would be custom build for your application.
David

[weldersandblaster]

square with bevel 1.jpg

Cutting bevels with a hand torch guide makes for a sloppier cut, which means a lot more grinding to clean it up. Grinding stainless is slow. This is not mild steel.

No. Not if you use the correct torch guide. This would not be the ones available as I showed previously from Hypertherm or the other one. This would be custom build for your application.
David

Am I reading you right?

Ok, build a clamp to hold the piece and the clamp can rotate. Build a track to control cutting speed. The track engages the clamp and rotates it at a precise speed while it's cutting the bevel?

The clamp rotates in a cam motion and not perfectly circular?

Or what middle ground can be had between the shark's tooth and the pie, by adjusting the weld curve cut? The sharks tooth does not have to be that long as in my prototype. I can probably get the same result with .75 of its length, or maybe slightly less.

[weldersandblaster]

The high rear of the sharks tooth does not have to be so high. I need a low front tapered cutting edge that gradually increases in height. Once the max height is achieved, the remainder of the high end adds nothing further. So the remainder of the high end can be sacrificed and removed if necessary. With that alteration, and altering the location of the welding curve, how close can we get a quarter circle to my sharks tooth configuration?

I ask because I'm considering the manufacturing ease of altering the sharks tooth, verses building and using mechanized cutting guides, because I think hand cutting cant control the cutting speed accurately enough to make smooth clean bevels that don't need grinding to clean them up massively.

It seems easy to cut bevels on a perfect circle. Just spin/rotate it. Then it's easy to cut the weld curve by hand, because that can be sloppy, because it's being welded over. Verses, making what type of cutting guides that are not hand speed controlled?

I'm currently scared of the speed of cutting being controlled by my hand, because I'm so bad at consistent speed. So mechanized speed control seems mandatory to me if we can come up with a cutting guide, which you can see in your head and I can't yet see it in my head.

[adbuch]

First thing to do is to put some dimensions on it so we know exactly what we are dealing with.

view 1.jpg

view 2.jpg

view 3.jpg

One way to do it would be to bevel the 4 inch diameter disc first, then cut in quarters and add curved cut to match mating part.

view 4.jpg

Step 1. cnc plasma cut discs of about 4" od
Step 2. mount disc on motorized (speed controlled) diy cutter to cut 45 degree bevel.
Step 3. cnc plasma cut straight backside and curved bottom side. Qty. 4 pieces cut from a single 4" od beveled round disc.

[weldersandblaster]

First thing to do is to put some dimensions on it so we know exactly what we are dealing with.

view 1.jpg
view 2.jpg
view 3.jpg

One way to do it would be to bevel the 4 inch diameter disc first, then cut in quarters and add a curved cut to match the mating part.
view 4.jpg

Wow David.
You are so good at drawing. I guess that maybe it's some, cad/cam drawing software that I will be learning in the future.

View 1. 40-50 degrees of bevel. My guess is 45 might be the ...
It's a fast moving axe that does not hit the tree head on. It cant hit and stop. It must hit and glance off as its momentum is not allowed to be stopped. To stop it is to break it. When it hits, it is supposed to cut deeply enough into the wood that a significant gash is achieved on that one pass. Then, through hundreds of quick passes and repeated gashes, it chips away until it's cut through. It has very high impact power, and very high impact rate, about 3,000 times a minute. So its sharpness is not critical as it has so much brute strength and high repetition cycle rate. It will half beat it up and half cut it. End result is a severance cut, and ugly is fine. It probably hits with a 20 lb impact, 3,000 times a minute. The angle is justified by the end results obtained. Does it chop its way thru or not? And if it's only 90 percent efficient, that's 90 percent more than my customer had before they met me. That's a 1,000 percent improvement to them.

View 2. I know my prototype showed a 90 degree rear end, high end. But that does not have to be so. The rear end has a lot of flexibility for being altered if it gives us some gain in manufacturing.

View 3, looks like a perfect mix between a round circle and a sharks tooth. The front cutting edge is much lower than the middle or rear cutting edge. (Which is great) Unlike my original sharks tooth, you're not carrying the rear cutting out further than is needed. Longer cutting edge with no height gain adds nothing.

In view 3, you wrote, 90 degree curved cut to match mating part. That is correct. That's what I'm calling my welding curve. View 3 looks like a perfect mix to me, or ease of cutting a bevel on a perfect circle, and ending up with the benefits of a sharks tooth.

As far as numbers go, the proportions of my hands and the blade components being held, is all I have tonight. Tomorrow I can put a tape on them and produce more accurate measurements. But the measurements are not overly critical. Is a 15 oz axe so perfect you would throw away a 13 oz axe? Or refuse to buy a 13 oz axe even though that's the only one for sale?

View 4, or 4 inch circle. That's my best guess at this stage of the game. We can alter the size of the circle as we see fit. One factor that is a landmark anchor, is the high height of the cutting edge, needs to be between 1 inch min and 1.5 inch max. My prototypes I built had 1.5 inch cutting height max, and when tested in real life doing real work, worked perfectly, good as hoped for. I have not tested 1 inch height to see if it works equally, or less.

It is my pleasure to meet you. You're so smart. I live in a very small pond. I'm the big fish in my little pond. I am so sick of only meeting minnows. I love meeting people smarter than me because then I finally have the option of learning things the easy way. From a teacher.

Instead of my typical fashion of beating my head against the brick. I have amazing stubbornness and the bricks eventually always shatter, and I figure it out by being my own scientist. Learning things, by being the scientist, is the slow way. It's so much faster having a teacher that already knows.

But being my own scientist allows me to travel the roads less traveled, and or blaze my own trail slowly and stubbornly.


I am so tired, I am seeing cross side. I'm going to bed.
Good night David.

[adbuch]

Here is the approach I would use.

step 1.jpg

step 2.jpg

step 3.jpg

shark tooth dimensions.jpg

[adbuch]

First thing to do is to put some dimensions on it so we know exactly what we are dealing with.

view 1.jpg
view 2.jpg
view 3.jpg

One way to do it would be to bevel the 4 inch diameter disc first, then cut in quarters and add a curved cut to match the mating part.
view 4.jpg

Wow David.
You are so good at drawing. I guess that maybe it's some, cad/cam drawing software that I will be learning in the future.

View 1. 40-50 degrees of bevel. My guess is 45 might be the ...
It's a fast moving axe that does not hit the tree head on. It cant hit and stop. It must hit and glance off as its momentum is not allowed to be stopped. To stop it is to break it. When it hits, it is supposed to cut deeply enough into the wood that a significant gash is achieved on that one pass. Then, through hundreds of quick passes and repeated gashes, it chips away until it's cut through. It has very high impact power, and very high impact rate, about 3,000 times a minute. So its sharpness is not critical as it has so much brute strength and high repetition cycle rate. It will half beat it up and half cut it. End result is a severance cut, and ugly is fine. It probably hits with a 20 lb impact, 3,000 times a minute. The angle is justified by the end results obtained. Does it chop its way thru or not? And if it's only 90 percent efficient, that's 90 percent more than my customer had before they met me. That's a 1,000 percent improvement to them.

View 2. I know my prototype showed a 90 degree rear end, high end. But that does not have to be so. The rear end has a lot of flexibility for being altered if it gives us some gain in manufacturing.

View 3, looks like a perfect mix between a round circle and a sharks tooth. The front cutting edge is much lower than the middle or rear cutting edge. (Which is great) Unlike my original sharks tooth, you're not carrying the rear cutting out further than is needed. Longer cutting edge with no height gain adds nothing.

In view 3, you wrote, 90 degree curved cut to match mating part. That is correct. That's what I'm calling my welding curve. View 3 looks like a perfect mix to me, or ease of cutting a bevel on a perfect circle, and ending up with the benefits of a sharks tooth.

As far as numbers go, the proportions of my hands and the blade components being held, is all I have tonight. Tomorrow I can put a tape on them and produce more accurate measurements. But the measurements are not overly critical. Is a 15 oz axe so perfect you would throw away a 13 oz axe? Or refuse to buy a 13 oz axe even though that's the only one for sale?

View 4, or 4 inch circle. That's my best guess at this stage of the game. We can alter the size of the circle as we see fit. One factor that is a landmark anchor, is the high height of the cutting edge, needs to be between 1 inch min and 1.5 inch max. My prototypes I built had 1.5 inch cutting height max, and when tested in real life doing real work, worked perfectly, good as hoped for. I have not tested 1 inch height to see if it works equally, or less.

It is my pleasure to meet you. You're so smart. I live in a very small pond. I'm the big fish in my little pond. I am so sick of only meeting minnows. I love meeting people smarter than me because then I finally have the option of learning things the easy way. From a teacher.

Instead of my typical fashion of beating my head against the brick. I have amazing stubbornness and the bricks eventually always shatter, and I figure it out by being my own scientist. Learning things, by being the scientist, is the slow way. It's so much faster having a teacher that already knows.

But being my own scientist allows me to travel the roads less traveled, and or blaze my own trail slowly and stubbornly.


I am so tired, I am seeing cross side. I'm going to bed.
Good night David.

[adbuch]

Here are some videos showing some different approaches for building a motorized rotary table for welding/plasma cutting.





You could also do a scratch build using a stepper motor. I am thinking something like Nema34 stepper motor with grbl/Arduino for control. I would add a torch control cable to your plasma cutter so that the torch will fire under computer control. So you will be able to set your cut speed, pierce delay time, torch firing, etc. under computer control. This could be direct drive, belt drive, etc. There are some good ideas about building an adjustable torch mount in the video above.

David