[amyers]

Buy or make a "protram" can't get any easier than that.

hoss has a nice easy to make one here and demonstrates how to use it, definitely on my must make list. Projects

[mduckett]

Buy or make a "protram" can't get any easier than that.


Originally Posted by BAMCNC.COM View Post

Buy or make a "protram" can't get any easier than that.

Below are the drawings for the ProTram knock-off I built about 18 months back

Regards,
Ray L.

hoss has a nice easy to make one here and demonstrates how to use it, definitely on my must make list. Projects

Thanks all--you're right, that is exactly what I need. Should have made it before I dis-assembled the mill Thanks also for the drawings and project link. --md

[mduckett]

I wanted to try out an idea for the motor covers using a square packaging tube that I had saved to make the X,Y stepper covers. The tube is made from that thin, tough clear plastic material, you know that stuff that makes it nearly impossible to get your merchandise out of the package without a pair of tin snips. The tube I have is 3” square, with .015” thick walls and was the packaging for a window blind. I think the material is vinyl, but not sure. The packaging also had some inner white plastic squares and some clear bevel protectors to support the package and protect the blind. The pictures show the left over tube and the end product--not sure if I’ll stay with these but I kind of like the look and they are very light and durable. Those clear bevel pieces look like they were made to house the rear shaft on the motors, and there would be room for a future encoder inside there. I can always go with my secondary plan using bent plexiglas aka the Hoss design or similar if these don't work out.
By sheer coincidence, the width of the Y bearing block + limit switch came to exactly 3”, so the tubing would fit snugly at the front of the Y-axis with no additional support needed, but required the tubing center line to be offset to the left by about 9/16” (the width of the limit switch housing). With the front of the tubing supported, it only needed a support at the rear to basically complete the housing. To make that, I took one of the white inner square structure pieces and applied Dykem to it, and then located and drilled a ¼” hole for the rear motor shaft through the point that would allow the edges of the square to align with the necessary offset position of the front. The piece was then slipped onto the rear motor shaft and slid tight against the back of the motor so the motor outline could be scribed. This material is about .060 thick and is white, tough and flexible, maybe a polyethylene. It shaves easily on the edge with a razor blade, but is too tough to cut an outline easily with a utility knife, so I used tin snips to rough it out then trimmed it up with an Xacto knife. After some fitting and trimming, it fit snugly onto the rear of the motor. A piece of the package tubing was cut to length by marking, collapsing the tubing flat and cutting with tin snips. The piece was slid over the rear support and up to the front. I marked the location of the two #4-40 cap screws on the limit switch, and the position of the motor cable connector mount, which will come out the side. The offset position and over-size of the tubing allows plenty of room for the motor cable to be routed. I drilled tight holes for the #4-40’s socket heads so the cover would just snap down over those. The motor connector hole in the side was cut with an Xacto as a clearance hole to allow for the panel mount connector to pass outside, where an external plate will be attached and this will then be bolted back to the side of the box with an O-ring between to seal it. In hindsight, I should have put a plastic mounting washer onto the motor cables connectors prior to soldering on the connectors; that way I could have just made the connector hole and then run screws through a mating exterior washer. With everything aligned and cut to length, I plan to use some self-tapping screws to fasten the tube to the supports and fill the voids with clear RTV. As mentioned above, the packing material included two clear bevel pieces that originally cradled the ends of the blind and fit into the white pieces. When placed in the opposite orientation, these make a nice back cover as shown.
The X-axis was treated similarly, except that the tube is centered left/right and positioned about 1/8” above the motor/bearing block. I needed, but didn’t have, one more of the plastic supports to use in the front to provide support for the sides, as this does not have front support all the way across like the Y axis had with the limit switch. For the interim until the mill is operational and I can make a proper piece from plastic or aluminum, I cut a bracket from a piece of 3/4" pine. This slides up to the front over the bearing block and against the table bracket to hold the tube level. Since this end will also need to be sealed, I went on to McMaster-Carr and found some rubber edge trim/seal made to fit over 1/32” material. It fits pretty good as you can see in the pictures. When everything is glued up, the strapping I plan to use will squeeze this down and against the bearing bracket to make a water tight seal. Motor connections will be similar to the Y-axis' described above.
To hold both covers in position, I plan to make some straps out of a piece of the tubing material and use it with a small bolt/nut underneath to squeeze the tubing tight around the bearing blocks and supports.
To make the covers look a little better, I’ll paint all of the white (and wood!) supports black prior to final assembly. Heat build up and ventilation holes are possible issues/needs, but for my setup I think it should be ok given the clearances and amount of aluminum heat sinking available to the motors, but we'll see how it goes.

[BAMCNC.COM]

They will get to hot.

[mduckett]

They will get to hot.

Yeah, that's my main concern too. I can open up the bottoms with vent holes and allow some air paths out the back if it turns out to be a problem.

-md

[BAMCNC.COM]

I made aluminum covers that touch the motor, it dissipates the heat well.

[bjones]

I made aluminum covers that touch the motor, it dissipates the heat well.

if you have to dissipate stepper heat you don't have them running properly or on a piss poorly designed system. they should get warm but not so that heat needs dissipated. plastic covers should be all that's necessary.

[BAMCNC.COM]

To each his own, not sure who told you that they "need" cooled, but like anything why not add life to the motor while covering it, I mean your covering it to add life to it, why not properly design a cover that plays 2 roles, and looks good while doing it.

[bjones]

To each his own, not sure who told you that they "need" cooled, but like anything why not add life to the motor while covering it, I mean your covering it to add life to it, why not properly design a cover that plays 2 roles, and looks good while doing it.

uh, you are the one implying they need cooled, i pointed out that run properly cooling shouldn't even be a factor to consider. looks good? is that important to you? mine are covered with chips and coolant while the mills working so doesn't really matter how pretty they are under that stuff. keep the chips and coolant off the wiring and coupler and they are doing the job.

[BAMCNC.COM]

His covers trapped heat, nothing more needs said, he completely understood, I'm sorry you can't comprehend that. Do you follow me around to make ignorant arguments for your own pleasure?

[BAMCNC.COM]

K, put yours in a closed up plastic box, I'm sure it will be fine. We'll take you back to the home now....

[mduckett]

For the front Y-axis way cover, I’m using a traveling solid plate similar to what others have done. Most I’ve seen are metal, but in keeping with this emerging “visible V-8” theme on this build—thought it might be neat to be able to see the ball screw and ways when the machine is running, so I used a piece of Plexiglas and bent it into a shallow U-shape. The bracket for this cover will be temporary until I get the new X-axis limit switch housing made, but I will be able to re-use the cover and just re-make the bracket when the time comes. To get started, I settled on using a length of 1” aluminum angle to hold the cover to the saddle. Cut a piece 6 1/2” long, and then marked the two screw holes provided for the original front rubber bellows way cover. I had a couple of spare pointed-end 6mm set screws that I bought for the gibs, so I threaded these into the holes backwards to serve as pin centers to locate the holes on the bracket. I needed some clearance for the bracket above the base, so I put a steel ruler down, set the angle on top of that, and used a hammer to tap the aluminum against the set screws to mark the hole centers. I also made sure there was clearance for the gib nuts to be adjusted above the bracket. The clearance holes were drilled and they aligned perfectly. Next the cutout for the X-axis limit switch housing needed to be marked on the bracket. I left the set screws in place, actually threaded them out pretty far to use as studs to hold the bracket, and marked the cutout. Used the band saw to make the cuts through the back and down into the front leg of the angle. This left the horizontal interior part in the front to be cut. Got out the old Dremel with abrasive wheel and slotted it until it could be bent back and forth and snapped off, being careful to not bend the now-fragile bracket. With the bracket complete, the Plexiglas was centered and the same cutout marked and cut. I used my regular band saw to cut the plastic. Next up was to mark the holes in the bracket used to bolt the cover to the bracket. I had some #8-32 socket screws, and after a search I found some nuts and washers, so went with those. The bracket holes were located and drilled first, then the cover holes were marked and drilled. I must interject here that I bought one of those automatic center punches at Harbor Freight on sale for $2.99—it works really well on aluminum and plastic, really helps to make accurate punch marks. I used the largest recommended clearance hole, as Plexiglas (acrylic) and polycarbonate (Lexan) have large thermal expansion properties, and will stress crack under relatively normal temperature swings if confined, so leave ample clearance and use washers when bolting through these materials. To complete the cover, I wanted the edges to bend down to form a side shield/drip edge with some overlap with the base. My scrap plastic piece provided about ½” of overlap, which seemed nominal to prevent swarf or coolant from splashing in there. To make the bend, I marked the bend line with a Sharpie, then put a piece of plywood on my table top edge and clamped the plastic down, aligning the bend line with the edge of the plywood (later, I would learn that I needed to compensate for 1 thickness of material when making 90 degree bends). Used a heat gun to heat evenly along the line (Hoss has a video for making his motor covers on his web site that shows the process) until the panel eventually sagged down. I used a piece of wood to help it along and smooth it out. I must have overheated the plastic because it got all bubbly and a little rough. Takes a little experience to know when to back off the heat and make the bend. I had a piece of angle aluminum to use to press/cool the piece also. The second side repeated the first, but required the stack of wood to be tall enough to accommodate the clearance for the completed bend. Did better on this side, although still a few bubbles. Re-attached to the bracket with the bolts, nuts and washers. To make this bracket water tight along the interface with the saddle, I cut a rubber gasket from some .050” sheet rubber, to put behind the aluminum bracket. For the area around the X limit switch housing, I used some rubber gasket pinched between the housing and the bracket, and plan to use a little bit of silicon to make a bead around it just to make sure—this is out in the open and easy to peel off the silicon, so why take a chance? When the new X limit switch housing is done, I’ll re-visit the whole bracket/gasket and try to improve it. Bolted the cover into place using the two 6mm bolts and the front cover was done.
For the rear, I’m using the stock rubber bellows. The original was pretty dirty, so I soaked it in hot water with detergent, but after getting it cleaned up I found it had worn pretty badly in the valleys. I had a new section of the rubber bellows material from LMS so I made a new rear section from that. I estimated it would need to be about 3 sections longer than the stock original. As I was getting ready to mount the brackets, I realized I had forgotten about the addition of the new rear limit switch. The original mount for the bellows was too low and would hit the switch. After slapping forehead, I thought about using some 1” angle aluminum for the front mount, as it would ride high enough to clear the limit switch when fastened with the original screws. I cut a piece of the angle to the width of the rubber bellows and used the same trick as above to locate the screw holes. I jacked up the bracket by about 1/8” using a steel scale and marked and drilled the holes, then decided to turn the holes into slots so the bracket could be removed without removing the bolts. I always worried I would drop one into the saddle. I experimented with folding the bellows over the angle and tightening it down, but it made the angle tilt, so I added washers at the bolts to compensate, but then it wouldn’t tighten up against the rubber. Decided to just add a gasket to the bracket and attach the bellows to the top of the bracket with the original bracket strip. About this time I realized that the angle would clear the limit switch vertically, but would collide with the angle supports on the round column bracket. Another forehead slap, and then thought about cutting back the top leg of the angle to let it clear. Marked the angle and free-hand cut on the band saw. When finished, the flat strip that resulted was almost exactly the same width as the original flat bracket, but this piece was the full length of the bellows so I drilled it to match the original bolt holes and used it instead. I could have added more bolts but it didn’t seem necessary. I scrounged up some short #10 bolts and realized I need to get holes made in the rubber. I don’t have a set of gasket punches, but remembered a trick—use a short piece of tubing in a drill to cut holes in soft materials. I found a piece of 7/32” aluminum tubing, cut a piece of #10 screw to fit the middle so it wouldn’t crush, and chucked it in the cordless drill. Held a file while spinning it to sharpen it up. Using the holes in the bracket as a guide, pushed it against the rubber with a piece of scrap wood behind—Voila, perfect holes. You can see the little cutter in the picture in front of the scissors. Bolted the rubber to the bracket, and then over to the mill to attach the back first, then simply slide over the loosened front bolts, and tighten down. I really wanted some side shielding so I experimented with making a couple of plastic brackets that mount to the front aluminum bracket. They turned out ok, but I didn’t get a picture. I may re-make these with a little more thought.
I’ve been giving the Z-Axis way cover a lot of thought over the past couple weeks. That is the next main focus with a few other nagging details still on the todo: list, which is getting much shorter, albeit slowly.

[mduckett]

I really wanted a good solid solution for the Z-axis way and ball screw cover that would be effective yet not cost a fortune, so I kept looking around thinking about the different options. I narrowed down the choices to 3 that I would consider further:
1) The easiest method would be to put a “curtain” using some of the rubber bellows or other materials. I already have a new section I bought from LMS a long time ago anticipating using it for this purpose (I’ve since used some of it for the rear Y axis). The benefits are that it is relatively quick and easy to implement. Cons, needs extra supports to keep it from moving into the balls screw when collapsing, doesn’t completely cover the screw/way all around to keep out dust.
2) Make a custom box-bellow using either the rubber bellows material, or some other material. I did some research on this and made some paper models to help work out the folding. I think a vacuum process using one of the many thermoplastic films could yield a pretty decent box bellows, but it would probably need a folding or telescopic support system to keep it running straight.
3) Make a custom overlapping shield system using metal or plastic panels. I’ve seen quite a few of these made from metal panels, especially on larger machines (G0704’s, RF-45’s, HAAS—almost everything’s bigger than the X2 ). I haven’t searched all of the X2 threads, so someone may well have implemented such a system already but I didn’t find it.
In the end I picked option #3, although I may return to option #1 for a quick fix if I can’t make option #3 work. I really want to try option #2 sometime, as making a vacuum table and doing thermoplastic mold/forming looks really interesting. To get started I’ve been making some 3D models to explore the possible designs. It’s harder than I thought to make a system with sliding panels that ends up at the right length expanded and fully collapsed. A number of times I had what I thought was a good design, only to find that it did not actually function properly. Finally, I narrowed down to two designs, and picked the simplest. This design uses four overlapping U-shaped covers with the largest at the top, and smallest fixed at the bottom. In keeping with the “see-the-moving-parts” theme, I decided to try to use bent Plexiglas for the covers, although aluminum panels could certainly work well. One important element of this design is using the column dovetail ways to act as retainer/guides. I understand from an earlier post that the G0704 bellows cover uses the column dovetails to retain it, so that seemed like a good approach for this also. To get started, I made some shop drawings of the covers to help in making a wooden mold/press to form them. I also ordered some Delrin (acetal) plastic bars and some fasteners from McMaster-Carr, and also bought a sheet of 0.080” Plexiglas from Lowes. The pictures are some of the 3D model renderings of what I’m trying to build.
Construction details: I needed to make the covers first, which requires 4 bends per cover, and the bends must be such that the pieces fit closely together, and I needed a total of 4 covers. I could have used a square form for the covers, but chose the angled design to make a lower profile, and also to make the connection with the way guides easier to fabricate. With this design, the way guides can be simple Delrin strips cut to a 60 degree point. When put into the way, the piece simply needs trimming to length to fit against the cover, which is at the matching angle. Being lazy, I decided to make a half-form profile and adjust the clamping position for each cover rather than making individual forms. I cut a piece of 2x4 lumber and a matching piece of ¾” scrap plywood and screwed the two together. Next, cut a 30 degree angle along the side on the table saw to the required depth of the smallest cover. I made the mold long enough so I could add some hold-down pieces using a screw on each side of the material being bent (I used ¼” plywood strips for this). Next was to cut the stock for the covers by ripping Plexiglas strips, about 3” wide. The first piece would use the mold as-is, so I clamped a piece centered on the mold top, heated and bent it down against the beveled edge. Flipped it around and bent the other angle (I added a small strip to the top surface to act as a square alignment guide also). Now I had a truncated “A” shape, and proceeded to make the final vertical bends that would engage the column sides. The first piece came out nearly perfect to my surprise, so on to the next. These pieces need to fit over the previous piece, with a target tolerance of .015” (4 sheets of printer paper). I marked the center on the next piece and made the first angle bend, then using the paper spacer(a sheet folded twice to make 4 layers) between the first piece and the first bent angle, I carefully rolled the new piece around the radius of the next angle to bend. When at the midpoint of the first piece’s bend, I marked that point on the flat piece (in math terms the flat piece is tangent with the first piece’s bend radius). This line is then put exactly onto the bend line on the form and clamped into place and bent. Using this method I was able to make 4 telescoping pieces with some variation in spacing but close enough to achieve the desired slide/fit. With the pieces made, I proceeded to make the Delrin guides. I’ll put that in the next post along with some pictures of the completed prototype cover.

[mduckett]

With the 4 covers completed, I started making the Delrin guides that would ride in the dovetail ways and hold the covers in alignment. These also serve as the place where the push/pull mechanism for the covers is supported. The Delrin I bought was a strip 3/8” x 1.5” x 12”. I made the first cut using the power miter box set to 30 degrees. This makes half of the way angle, and for the inner-most covers the miter box can be used to make the needed 60 degree triangles. I just put the pieces in place and marked and cut to fit to the inside of each cover. For the outer covers, the guide pieces get a little more complicated, as I needed some space to hold the connecting rods in addition to the way guide triangle. I could have made these in separate pieces, but wanted to keep the fastener count small so I combined the needed pieces into a single block. These pieces were generally about 1.5” long, and the first cut made on the miter box at 30 degrees, then the rest of the cuts were made on the band saw. I just moved from each cover cutting and fitting until all pieces were fitted. The covers in this design are connected by a series of solid round bars that capture the section below through the Delrin guide/blocks. I chose to use 1/8” brass bar for this because it is easy to work with, locally available at Lowes and won’t rust. I went back and forth on how to make the ends of the rods captive on the Delrin blocks. The easiest would have been to solder a cap to each end. This would work but then the cover could not be easily dis-assembled. Finally, I decided to just drill and tap the ends of each rod for a #2-56 button head cap screw. Tedious, but an elegant solution, and I only needed a total of six rods, so 12 total drill/tap operations. I got to it and knocked out the first 4, which allowed the top 3 covers to be connected up. I located holes and drilled the holes in the blocks, being careful with alignment and using each section as a guide for the next. When complete, each section pulls up the immediately lower section, and when collapsing each section’s rods collapse through the lower sections. Sections not being pulled have over-sized clearance holes to ensure no binding occurs. This all probably sounds complicated, but it’s really a simple mechanism. When collapsing, each section simply pushes down the lower sections, and when extending each section is pulled upward when the rods pull up on the Delrin blocks. I attached some pictures of the completed prototype. In the process of building this up, I discovered a few things that caused a lot of rework effort. First of all, after playing with the covers, I found I had forgot about the column braces and the need for the covers to ride down past them. Fortunately, only the lower two covers needed to be cut. Next, I found that the covers were too long and need to be trimmed in height by about ½” in order to allow enough down motion when collapsed. As an aside, I’ve known for some time that the maximum down travel allowed by my ball screw implementation gets the spindle to about 1” above the table, and without resorting to another rework of the covers, this will actually work out to be about 2” or so. I didn’t see this as a big deal as most work I believe can accommodate this. The real problem was cutting the covers, as the bent shape is hard to navigate on the band saw, and improper support can cause a grab and shatter event as I found out. In the end, I did most of the work by hand using a hacksaw and X-acto razor saw, aka PITA. My once nice, clean cut covers now have pretty lousy looking bottom edges, but at least it’s done. I cleaned them up some on the belt sander too, but this is as good as these are going to get. I may try to fit some of the rubber edging I bought a while back if there is enough clearance. About this time I also realized I don’t really need the bottom cover either. The pictures show the covers pushed into several positions and the extended/collapsing action. On the todo: list, I need to make top cover for the top and then attach that to the bottom of the carriage to complete the installation. Since there is already a 10mm hole left over from the torsion spring attach point on the left side, I’m going to drill/tap a smaller hole on the right side (probably #8-32) in about the same position and use some 1” aluminum angle to attach each side of the top cover to the carriage. I will also need to make an upper cover to shield the ball screw when the spindle is lowered, but it will be relatively simple square U-shape. I’ll post some more pictures when I get these things done.

[BAMCNC.COM]

Very very....VERY cool! Great work!

[gcofieldd]

Very creative, I like that z-axis way cover!

[mduckett]

Very very....VERY cool! Great work!

Very creative, I like that z-axis way cover!

Thanks!

[mduckett]

Been busy the last few weeks but still plugging away on the ToDo list. The Z-axis motor is pretty safe and out of the way, but needs at least a dust cover of some sort. I made a cover from bent Plexiglas to fit around the motor (I know—heat—but the bottom is open and I’ll install some vent holes at the top. Plenty of heat sink into the Z bearing block too). After fitting the cover it also needed a stiffener at the bottom so I made a U-shaped bracket from scrap plexi and secured to one of the column mount bolts. The motor connector hole was drilled near the end and slotted on the band saw to allow the motor cable connector to slide in and tighten down with the panel mount ring/nut.

[mduckett]

Finally got the proper sized hole saw (1 3/4") and drilled the hole for the motor cable and switch wiring cable pass-through conduit into the cabinet. The conduit is 1 ¼ PVC and a couple 90 degree elbows. One end of each elbow was trimmed back about ½” to make a more compact U-turn. The scrap from these cuts was used to make a collar to help stabilize/seal the tube in the hole. The bottom end of the tube is cut at 45 degrees and has a single screw holding it against a wooden member underneath. The two elbows are joined with a short piece of pipe, but not glued so they can be removed. The resulting U-turn is a little tight for the connectors to pass through, so allowing the pieces to separate helps in threading the cables through. The ideas is the down-facing tubing should keep out any incidental coolant splashes and dust.

Finished attaching the Z-way cover to the spindle carriage using a couple angle aluminum pieces. They attach to the top delrin slides and to the spindle carriage with a single #8-32 hex cap screw on each side. I made a 10mm plug from a bolt and drilled/tapped it for #8-32, and plugged the hole on the motor controller side. Used some blue Loctite to keep it in place. The cover was binding a little, but enlarging the holes in the brackets allowed for a little alignment adjustment and now it runs smoothly.

Made the X,Y motor connectors for the motor covers. These are made from a piece of scrap round Delrin. I turned an inner solid ring about 1/8” thick, and an outer ring that was split with the bandsaw so it would make a tight fit on the motor connector. The two rings were drilled/tapped for #4-40 flat head socket screws, then installed into the boxes. The inner was glued with plumber’s GOOP. When dry, the hole was cut out. The hole is large enough to pass the connector through, and then the split ring is held to the connector by the connector ring/nut, then the whole thing is screwed onto the box-side ring.

[mduckett]

Rescued a metal box from the trash at work and used it for my E-switch housing. This box will mount to the front of the bench with the E-switch horizontal. Since the box is fairly tall, I decided to use the top surface for some additional controls. I have two 12 Volt items that I want to control, so I installed wiring for a 12-Volt, 2.5 Amp wall wart (also salvaged) into the box for power. Also wanted an LED to indicate when the E-switch is engaged, so the box has the normally open side of the E-switch wired with to a red LED. When the switch is activated (and power is available) the red LED will light. The rest of the power to the box runs through the flush Lamb switch. Went ahead and wired up the switch LED so when the switch is on and power is available, the switch ring is lit. The two switches are for flood coolant on/off and for a 21-LED angel eyes ring that will be mounted around the spindle to provide some built-in lighting (see this posting: http://www.cnczone.com/forums/bencht...ere_light.html). I’m designing a holder for it (yet another CNC project!), hope to get that done in a couple weeks. Wanted to get on with some actual CNC cutting so I finished up the power switch and E-switch cabling and closed up the box. Tested the E-switch with Mach3 and it works fine. To this point all I had was the Mach3 buttons for emergency stopping, and although my E-switch is still only through Mach3 (software safety), it’s much better than fumbling with the mouse if something is going wrong. I will work on getting more robust safety features built up in the future, including for spindle control.

Finally got around to armoring the limit switch cabling with the clear tubing. This turned out to be a little harder than anticipated as the cable sheathing tended to be grabby on the tubing. Ended up using silicon to make things pull through easier. I won’t have to worry about those cables though, as that tubing is tough stuff.

Did some testing with the X and Y limit switches (none on Z yet). All are working well, although there is a problem with the X switch wiring sagging down into the path of the front Y switch, so it sometimes activates on the cable. The front Y cover will need to be removed and a bracket made to hold that cable clear. Never seem to get finished with the little gotchas. Also found that the table interferes with the rear Y-axis way cover bracket. Installing the gasket behind the bracket should move it enough to allow the table end covers to pass by. To support some preliminary testing, I moved the X axis stop blocks inward to reduce the travel and proceeded with testing.