NEW SHOPMASTER VFD

[bowman1964]

Well mine finally arrived yesterday after a long wait. I thought I would share some pictures of my newest toy as I sat it up in my shop. I hope to get a plug today to actually power the motors tonight.

[bowman1964]

more pictures

[bowman1964]

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[gearhead dan]

Congrats, Bowman!
I've got some great mods to show off, but I just need to stop working them and take some pictures.
I'll post soon.

Gearhead Dan

[bowman1964]

well i have already been using mine. was really surprised how well it worked. i have been used to a bridgeport and i must say it ran smoother than the old bridgeport i was running. i still have to make a dro bracket and hook up the cnc. i did find its easier to adjust the bed with the stepper motor belt off so i can feal the drag better.

[gearhead dan]

Hey Bowman,
Good to hear you're happy with your system. Here are a few pics of mine. I couldn't keep my mits off it and had to do some mods. Fortunately these are simple things. I beefed up the bridge by replacing the flat stock with C channel. I also added a stronger upright. The most clever thing was to add a gas strut to both ends. This took the weight of the far end and helped to keep the mill head level. The effort to raise and lower the mill head is a fraction of what it was.

Gearhead Dan

[bowman1964]

Originally Posted by gearhead dan Hey Bowman, Good to hear you're happy with your system. Here are a few pics of mine. I couldn't keep my mits off it and had to do some mods. Fortunately these are simple things. I beefed up the bridge by replacing the flat stock with C channel. I also added a stronger upright. The most clever thing was to add a gas strut to both ends. This took the weight of the far end and helped to keep the mill head level. The effort to raise and lower the mill head is a fraction of what it was. Gearhead Dan

great mod, i was looking at stiffening the back plate. the c channel is sure the best way to do it. i was going to stiffen the outer end with out pulling the entire plate. and add a angle to stiffen the head from back to front movement.
hey what color paint did you use? i was thinking it was close to safety blue like i use in my shop now. but i havent opened a can to check..

now that shock. do you think it helps on the outer end? i wonder if you can measure the deflection of the head with and with out to see if it does keep it more of a level head or not.

but i am impressed. great work.

[gearhead dan]

Hey Bowman,
That is Safety Blue. Good call. I thought about using a piece of angle iron too, until I happened upon that chunk of C channel. The angle would work too, no doubt. As it is, that flat stock is more like a leaf spring, so adding any amount of rigidity is a huge plus.
On the gas strut. I went a bit crazy figuring that one out. I ended up leveling the whole machine so I could get a reference point of where the mill head should be. I then put a block under the Z axis screw and leveled the mill head by using the Z axis screw itself. You can easily dial in the levelness this way. I leveled off of the pulley since this is the only good flat surface on the mill head. Once I got the mill head leveled I threw a scale (like the one in your bathroom) under the end of the bridge head and gently wedged a stick in there. I then let off on the Z axis and watched as the scale took on the weight. I got about 125 lbs with my setup. To get a sense of the deflection I again leveled off the mill head and then tightened up on the bridge head hold down. I then let off on the Z axis so the hold down took all the weight. I marked the position of the bridge before and after I loosened the hold down. It drops a substantial amount. The sag also registered on the level.
So...after I added the gas strut I did the same measurements and I got no sag. It also doesn't raise it either, so I think I got it right with a 125 strut.
I'm guessing that with the stock setup about 70-80 lbs is what is hanging out on the end of that bridge head. If you consider this strut idea go and check out McMaster Carr. They have a great assortment of struts with travel/weight charts. They go for around $19.

Gearhead Dan

[bowman1964]

dan,
well i like how you went about checking the deflection. good idea there. i am going to mount a piece of 5 x 2 box tubing i have on the back of mine from the motor out and run a box tube from the top of the factory support to the rear corning of the table. i noticed alot of flex if you pulled it foward and back.
i have my dro mounted on a adjustable arm i had. and did get the cnc up and tested the movement last night.
i am thinking about adding the limit switches.... what are you doing concerning using or not using the limit switch?

i am going with your idea on the stut.great idea there. will help alot in keeping the head straight.

[aisrad]

Dan, good idea on the struts. Just to make sure I understand. From the photos it appears you put a struct under both ends. Where they both 125 lbs gas struts?

andy

[gearhead dan]

Bowman, I see your vision. I like it. Its a good use of the existing material to bolster that top end. It will add alot of rigidity for sure.

Andy, both struts are rated at 125 lbs. Adding the one on the near end to the columns takes some of the weight off of that acme screw. For the stock setup do consider a lower weight strut.

For the limit switches I will definitely go with them. I got a great tip from Dan at Camtronics (the designer of our cnc system). He suggested mounting the limit/homing switches on magnets so that they can be moved around from the mill to the lathe. i haven't gotten that far yet, as I'm still waiting on my computer. He advised mounting the switches to a piece of aluminum plate and securing this to a magnet.

I'm interested to know how the software download went for Mach III. From the manual it sounds like there's alot of things that can go wrong. I've also realized why the ball screws are a good investment for the CNC setup. Silly me to think that the DRO would be providing feeding back to the CNC controller...you have to own the big expensive bridgeports for this feature.

I'm currently working on a really nice upgrade mount for the Z axis glass scale. I'm almost finished with it and will add pictures soon. it has been a great first project for the Patriot. So far I couldn't be more pleased with how its performing.

Gearhead Dan

[bowman1964]

i have been playing with the cnc in mach, its alot to learn.
yea i noticed my cnc box appeared to be from camtronics. i ordered a tachometer for mine.
o one thing you should know. it will not cut threads yet. the machines are missing a encoder to measure the spindle speed. john told me this and says they will be shipped as soon as he gets them.i think they are coming from dan.
i may just order my limit switches from dan ,proberly just as cheap. and yes good idea on the magnets for limits. i am thinking i would need 4 anywaysfor the mill.2 for x 2 for y. so i dont see having to move them.