Shopmaster Patriot VFD Owners, Your Thoughts?

I've got a BP manual mill, a smaller import manual mill and Sherline mill I converted to CNC running Mach3... the Sherline does surprising well for what it is prototyping in everything up to aluminum. The rub is I do mostly steel work and I really need a steel capable CNC solution so I can prototype and do several small parts in a shorter period of time. Recently the Sherline did cut the first sizable steel part I've ever dared to throw at it, but it took 26 hours with a 1/8" endmill to do it, lol.

I've got more tooling, setup, R8 toolholders, etc, etc than I'll probably ever use, and I've been machining on a hobby level for quite a long time, so this is just about the machine value, not the big picture value/investment. Oh, I also have a manual lathe and also mini CNC lathe (Sherline converted to CNC) so the CNC lathe feature will a nice bonus on the 3-in-1 but not my primary need because I don't have a large need for CNC lathe work. =)

The issue I have is I can't seem to find any videos of the new Patriot VFDs that have the newer features, ballscrews, etc cutting steel so it is hard to know how it performs and make an assessment on the value of the machine based on performance. No doubt it is a great price point at under $6k, but if a Tormach for instance is 2x or 3x the milling machine in terms of accuracy, feed rate, ability, longevity, etc than I would probably be better ponying up a little more since my initial plan was to do a retro on a old production CNC mill if I could find a good candidate, but reality is I may not ever find the candidate for the price I want or the time to do it, so I'm probably going to buy a machine in this class.

With all that said, can some owners give some examples of steel milling ability... like what size cutters they can at what feed rates, including depth of cut and stepover or full width without pushing the machine to the limit. And/or, possibly post a picture of any steel parts you've done on one and how long you estimated it took to complete it.

And, now that you've had the machine for a while are there any glaring issues or problems that have arisen, would you buy another one?

I'm on a budget for this upgrade so value is the most important thing... and not value meaning cheapest, just what is the best bang for the buck in this class of CNC.

Thanks in advance for your feedback!

Good day. I'm BRAND spanking new to the Patriot as well. I do not find or see much dialg on this or any boards for that matter. If it helps- The Precision Mathews PM45CNC is a real solution for what you describe. It's about the same cost as a new Patriot. Hardened ways, one-shot, coolant, and 3axis CNC, heavy stand, etc.... I was about to pull the trigger when my used 2010 Patriot deal rose up and snatched me.

I have everything setup on my unit and am about to go into 1045 steel w/ some imco M525 class cutters. I'll post Vid or you can PM me on the side here and we can swap some notes and such. When you say "steel" Do you mean the usual 36 stuff or Medium carbon, or Tool stuff? I guess for your setup it all comes down to feed, speed, power and rigidity..... Keep us posted. Ask away. There is a love / hate w/ these combo setups. I really don't understand it yet being so new. But folks either love them, or hate them. Most posts will generally note that the Patriot is a very good machine for the class and range. I did not need anything more than this. So I'm very happy I made the choice I did. btw/ What CAM software do you use? Just wondering. CG

I should of clarified, I meant average mild steel, like 1018, but sometimes I work with 40XX but I don't usually see a big difference in machinability when I do it. I see plenty of demos for these machines in aluminum, which is great, but aluminum doesn't give me a good idea of how it will perform in steel and all my work is steel work.

If you could post or PM me a video of it in action on steel that would really help me know if it can handle my needs, would really appreciate it. Even just showing how much material it can face off per pass using like 1/4" - 1/2" end mill would tell me most what I need to know. I can't believe that these vendors do not have comprehensive demo videos showing both steel and aluminum. I don't know if it is because they don't think their machines do well in steel or what.

I have evaluated several CAMs over the last several months and I keep going back to DeskProto. It is easy and has all the features I'll probably ever need and it is cheap.

I'll get something to gether and send it to you. On thre cutting pass, I follow the Tool Mfrs Feed & Speed for the material. Do you use that type of parm to set depths. I anm so new that I'm not the person to instruct on much of anything. ( runb Plasma CNC) But the basics as I have learned upon them is to get a particualt tool type (Carb/HSS etc) Find the material you wish to cut, And use the suggested speed and feed parms. (parameters). That said, My IMCO 525 list as follows: class of cutter http://www.imcousa.com/EndMills/ByProductFamily Ratres: Per Catalog - 3/8Sq end cutter .0748 to .1379
So that's the range I'll stay in. Just asking for any comments back as well. Are these values 'bumped around' as needed? Possibly.

How deep to you want to go? Or expect to go? PS- I am just having a BLAST as well!

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I don't use standard feed calculations because I've never had CNC capable of using them. I those calculations are more for what is optimal for the cutting tool, and what it can handle, but your machine may not have the rigidity to max out the cutting tool. For manual mills I used to use them to get an idea of the optimal RPM, but essentially I just do it by feel and experience gained over time of what the particular machine/cutter can take in terms of how much it can bite out of the stock before you start getting chatter, machine is vibrating or other tell tale signs you're going too fast, and for what RPM I need.

Since this machine is new to you also I would suggest using the Mach 3 wizards to do some simple tests to feel out the limits. There are basically 3 factors that create the limit of what the machine can handle (assuming the endmill can tolerate more than the machine).

Depth of cut, width of cut and feed rate (how fast the table it moving, so how fast the cutter is moving through the piece). All of this adds up to the surface cutting rate, but I'm not familiar enough with the equations to know what the benchmarks are... kind of all of them start with knowing what the machine and cutter can take as far as Feed Per Tooth IIRC.

But something I can relate to for the kind of work I need to produce would be a test like this... using a 3/8 endmill set to a depth of .125" and experiment how fast it will make a cut going down the work piece doing that full 3/8" width cut. I would set the RPM around 900 RPM and adjust up or down as needed... higher if it runs smoother/faster that way and you're adding coolant or cutting fluid to keep the cutter cool.

Then, using the same endmill cut at a depth of .250" and use a step over of .040" (remove .040" of material via the side cut at each pass) and see what type of speed it will handle. If it chattering even at low speeds then reduce the step over to take less out of it. If you don't have a 3/8" endmill just whatever the closest size you have to it would be fine.

Like I said, you can use the Mach 3 wizards to do some simple tests to give you an idea of how it will cut steel. It would be prudent to chuck up some pieces of 2x4 just to feel it out the first time you use it to make sure everything is dialed in right using wood. Instead of using the wizards you could also just set the max feed rate in Mach 3 to something very modest (5 IPM?) and use the manual controls (TAB key) to easily take straight passes at various depths and over riding the feed rate higher and higher until you're noticing the upper limits of the machine. You can do the same thing with some simple G-code, but I would just set the feed rate and manually control it.

The machine looks good so let me know when you are able to get some tests in steel and ideally a video showing what it can do. I'm sure after playing with it for about 30 minutes you'll have a good idea of where you are getting close to maxing it. Looking forward to seeing one cutting steel!! =)