Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - Tool-n-Around

Pages: [1] 2
CamBam help (General usage) / DXF Exports from CB
« on: July 30, 2023, 17:24:54 pm »
I'm having a problem using DXF exports from CB. I probably don't have my settings correct in one or both programs but when I export a Polyline to DXF, the arc segments appear as straight lines when I import that DXF file to CAD, in my case Alibre Design Pro. If I reopen the same DXF Export in CB, it displays at it originally appeared as the polyline from which the DXF was created. I'm guessing it's something like the arc fit/number of arc segments selected since each arc in the polyline has only two segments/nodes which are displayed as straight lines in my CAD program, but I can't find where to adjust that setting in CB for that polyline. Any pointers?

Attached is the original CB File, the DXF file as exported from CB, and screen shot of how it displays when imported to Alibre.


CamBam help (General usage) / Copy/Print Console Dialogue GRBL Machine
« on: March 14, 2023, 22:21:32 pm »
I knew how at one point because I have pdf copies of my own console dialogue, but I'll be darned if I can remember how to copy or print the console dialogue from GRBL Machine Plug In. I searched (and searched) and found where I asked the question on teh second to last post at the GRBL Machine plug in thread.............. but I cannot find the answer. Having a brain cramp!


Members Projects / Vintage Automotive Induction System
« on: February 04, 2023, 15:36:30 pm »
Just completed this carbureted induction system. I used CamBam extensively in design, machining the lost foam casting patterns for the intake manifold and air filters, and even some aluminum machining. My little hobby CNC machine leaves a lot to be desired for the latter, but I managed to getter done. I have many upgrades in the works for my machine to address some of the deficiencies. Thanks for the help I received along the way on this forum.

Here's a video of the casting projects and a completion video of the system build up.

Intake Manifold Casting Video:

Air Filter Casting Video:

Machining and Final Assembly:


CamBam help (General usage) / Simple Drilling
« on: January 19, 2023, 15:06:14 pm »
I’ve either forgotten or never knew how to properly use the drill MOP, or maybe I have a problem with my post processor. I use the grbl machine plug in and grbl post processor one of the members here helped provided to me which solved another problemon my machine controller.

I’ve read the documentation, searched and read a number of threads on the forum in the tutorial section and others, and still no joy. When I attempt to execute the MOP on my machine. It immediately fails and returns an error message that “unused gcode exists” and fails in alarm. I havent figured out what I'm doing to produce the error.

In the attached file, I first tried to use the drill MOP with a point list and canned cycle. Now the documentation says this uses either a G81, G82, or G83. Does that just depend upon which of the features you have selected in the MOP as to which gcode is written? Or by not selecting some of the features is it writing multiples to the gcode?

I tried spiral drilling and same thing. I was still using the point list but specified a diameter. Did it need a circular Primitive ID instead of the point list?

I didn’t really want to use spiral, because it was going to be a .125” hole and the smallest bottom cutting end mill I had was .125”. The part being machined was a rather precious aluminum casting and I figured the center of the end mill plunging without movement would instantly gum up and I was too scared to be experimenting and break off a mill in the casting.
I ended up having to place circles on the point list centers and used a point cutter I had to drill centers, but told CB the cutter was and endmill the size of the hole and made the hole .0001” larger so it would accept it (the only enabled MOP in the attached file). Then I manually drilled the blind and tapped the holes in the centers.

I need to make a mating cover plate for the casting from .25” aluminum plate, which is easier to come by then the casting, so I’m feeling somewhat more courageous. I’d like to use a .125” drill and then follow with a spiral drill to slightly enlarge the holes as clearance holes for the screws and have it come off the machine complete.

Drilling is too common of a function for me not to understand how to use it, so if you guys could sort me out, I’d appreciate it.


CamBam help (General usage) / Tracing Edges of Surface Files
« on: December 08, 2022, 17:21:48 pm »
Is there a CB function for detecting and creating lines/shapes from the edges of surface files? Sometime ago a made this part from a surface file I was given and used the polylines above the surface as bounding regions but I'll be darned if I can remember how I generated them. I did a very similar part yesterday.

To produce the bounding regions I enlarged, hand placed a lot of points along the edges looking down on the surface in XY plane, connected the points with a spline, converted the spline to polylines, and joined up the shape. It worked but was laborious and messy. When I looked at the XZ plane, many of the points I selected on the edge of the surface were assign a Z value, not 0. I had to go into the point table, change all the Z values to 0, and reconstruct the spline and polylines.

I looked at the plug-ins page but didnt see an applicable PI. Is there a better way?


CamBam help (General usage) / Switching Drawing Units
« on: December 03, 2022, 16:24:26 pm »
Sometimes it's the simplest things.

I just want to toggle back and forth between working in inches and mm but when I switch the units to mm in the tool bar, all existing and new dimensions remain displaying and measuring in inches irrespective of which option I select for default on new drawings. What am I doing wrong?


Members Machines / Contemplating some upgrades to my CNC Router
« on: November 28, 2022, 17:06:08 pm »
I’ve been kicking around some machine upgrades. All comments and input are welcome.

90% of what I do with it is machine polystyrene foam patterns for lost foam casting, so the machining loads are light and desired feed rates high. The machine is fairly lightweight so the smaller steppers do ok. It’s a relatively large work envelop but I need more Z travel (more on the z-design later) for pattern work and will be modifying that  to 8”+ under spindle. To get the additional height I plan to just raise the entire gantry system and for work where I need more rigidity I’ll build a platform that minimizes Z extension and may build wet cutting fluid retention/return features into the platform for harder materials.

Here’s the machine as it stands. There are of course likes and dislikes about the machine but all things at a price point. IMO, It’s a decent hobby grade machine and at the time I bought I have about $2000 into it. It’s the larger XL model. There’s pictures at the link and you can take in whatever you have the appetite for.

Some of my future pattern work may have very long run times. I need to get the machine to the point where it can reliably and at relatively low risk run unattended. I’m looking at replacing the POM rolling wheels with HGH linear track and SFU ball screws on all axis. Although I’ll likely pick up some accuracy, another major reason is debris tolerance. The v-grooves gather statically charged foam which can accumulate to the point to cause loss of steps. The rack and pinion has a similar issue to a lesser extent with foam but worse when collecting hard materials. The wipers on the linear rails and screws seem to do a good job, and as they collect a little foam dust even better. It may also reduce rolling and actuation friction a bit which can’t hurt with my smallish NEMA 23 steppers but may actually be needed with the increase Z-axis travel and weight due to not only the larger travel but also the possible addition of a spindle instead of the router.

The manufacturer of my machine more recently has offered what they call a “pro-version” that has similar linear rail approach but retains the rack and pinion drive. I’d replace the R&P with ball screws. Here is a link to that machine.

I can buy import versions linear rail and ball screw the such to do the entire machine for about $350.
I’m also looking at upgrading from the smallish DeWalt 611 VS Router to a spindle. I don’t think I need a lot of power, but I do want the ability to handle ½” shank bits and ER20 collet spindles seem to be minimum 2.2kw or better and quieter running would certainly be welcome. There’s also the matter of air vs water cooled. Of course, I’m looking at the 4-bearing Chinese imports which can be had with VFD for under $300. I’m very leery of purchasing the Chinese sourced VFD without first seeing a manual first to make sure I can understand it. I seem to recall a thread somewhere (cnczone maybe?) that covers this very well. Any reference sources would be appreciated. Any opinion on water versus air cooled?  Water is just more overhead but not that big of a deal to engineer.

While I had everything apart, for added rigidity I’d fill the gantry aluminum extrusions, at least the stationary two, and maybe the traveling one, I’d use the existing extrusions because they are very easy to retrofit. I could replace them with steel but at that point about the only thing I’m using from the original machine are the steppers and controller, which also could be better. I know the extrusions are not as straight/true as you’d want for linear rail but I see it done all over the place with apparent success.
On the z-axis, it seems the practice is to mount the rails on the stationary Z-plate and bearings on the travel portion. To get the under gantry clearance the router would have to be mounted significantly below the lower linear bearing packs. I was going to mount the rails on the traveling plate and make the traveling plate a stiff as possible, that way it would remain quite stiffer in the retracted position where heavier cutting could be done on platform. When extended, I’d probably only be cutting foam so the loads would be very low and inconsequential. Any other pros/cons to the two approaches?

In addition to my original purchase price, +$650 for ball screw and linear rail along with a spindle seems like good value for money, compared to $7.5-$15k to buy another more rigid machine with similar features……and yah I suppose the upper end of that could potentially buy a used (up?) real cnc machine, but I don’t have the space or appetite for that.


CamBam help (General usage) / Machining Polycarbonate
« on: November 23, 2022, 23:48:26 pm »
Hi all. Been a while but I’ve been busy with cb. I haven’t had to pay very close attention to feed/speed machining foam patterns but not the case here.

Looking for a little feed and speed guidance for machining polycarbonate. I previously made a post about another polycarbonate lid I made, but I’ll be darned if I can find it. Before I post the cb file, thought I’d just start with the piece I machined, and describe some of the issues I had, and see if I can get a nudge in the right direction.

The part is a display lid for an automotive air filter. The stock size is 21”L x 8”w x .5”t.

I’m seeing a lot of chip welding. I don’t have cut data for the bits, but in general they are carbide woodworking bits unless I say otherwise.

First op was the logo. I had machined it before on a previous project (also polycarbonate) with pretty good results. I set the lowest speed on my router (about 14krpm). It’s a single flute .031” ball nose cutter so it can fit through the narrowest regions of the letter pockets. The feed rates are 15in/min. The depth of cut was .020” and final depth .031. I cut a test plaque and thought it looked good. When I cut the logo on the actual part the chips melted/welded around the bit and scarred the surface around the ellipse. I’m thinking I need to back off to a smaller depth increment to help clear the chips and keep compressed air on the cut. The problem is the darn chips tend to hang on the surface edge like a stringy burr so they can’t always be cleared. Not sure which direction I need to go on feed/speed. I’m at low rpm limit. Coolant/mist is not really option.

The ornamental grooves cut pretty well.

The perimeter chamfer (.5”D double flute 90 degree vee). Depth increment was .15” and final depth .2”, 16krpm. It was a total mess with chip welding on the conventional cut side only. I did a .005” clean up climb cut and the chip welding switched to the waste side, and the part finish looked OK.

The filter gland is cut with a .5”D dish cutter. I didnt post a picture and it has some tool marks in part from the piece being inadequately secured (a screw in each corner and two in centrally in the part). I’m not too concerned about this because the gland turns visbly black when the filter element is installed and I'll never achieve optical clarity on my machine or without polishing.

The .25”D double flute spiral end mill perimeter cuts were a mess. The feed rate 60in/min, depth increment was .25”, and .35” cut width, 16krpm, which for sure was too aggressive for my router and probably so for my hobby cnc machine, especially in the initial two-sided plunge cut. I had a final .5" full depth finish cut of .010” which after observing the chamfer cut, I chose to climb cut. I didn’t post pictures because probably same issue here. The perimeter finish is not so great but why does climb cutting seem to be producing a better result?

I can post additional info as needed, but had to break the cb file up for tool changes and made in-process mods to those files so will need to update the consolidated file before I do so. I can probably salvage this part with some elbow grease but looking to do much better on next pieces.


CamBam help (General usage) / Some Qs on Imported CAD Files
« on: September 15, 2022, 19:49:28 pm »
Hi fellas. It's been a while. I've been happily motoring along with CB and more recently bought some CAD software (Alibre Design) to solid model my projects. As you may recall, I primarily use CB to machine polystyrene foam patterns for lost foam casting, primarily automotive parts.

Attached is a Camotics simulation picture of my first CAD modeled part. It’s an automotive intake manifold flange. I saved the solid model as an STL file for use in CB and that file is 15MB. When I import it into CB and set up several scanline 3D Mops to machine it, it becomes a 75MB CB file so I assume too large to upload here. The actual part is roughly 20”L x 3.5”W x 1.25”H. I simulated in Camotics and it looks ok. I haven’t tried to optimize the run time. This model is not filleted. The filleted version is even larger but I figured it wasn’t necessary since I use a 1/4D ball end mill as the cutter and it happens naturally without the filleted model.

To date I’ve done most of my CAD within CB and not imported objects. What is the preferred type of CAD file to import and use within CB? For the STL file, I have a bunch of options about the faceting parameters, surface deviation, and coordinate system as described here in the Alibre documentation. I have no idea what is necessary/adequate for my use in CB and probably chose excessive parameters. Any rules of thumb or advice in this regard?!alibre-help-v25/stl-export-settings

Ultimately, it seems this part would run much faster as a 2.5D part excluding the angled bosses, followed by some 3D MOPS for those bosses, but even with the run time, just running it as one surface would be quite attractive. Run time isn't me-time when you’re only making one or two parts :-)


Members Projects / Commemorative Carb Parts Storage
« on: April 09, 2022, 18:30:45 pm »
Hi all,

I use CB to make lost foam casting patterns. I make a lot of automotive and machine parts and receieve a lot of help from the forum. I have a several pretty sizable projects involving intake manifolds and custom induction systems for Inline Autolite carburetors. One of those projects is winding up, so I thought I'd make a couple commemorative gifts for the participants.

In a seperate project, I had made a number (14 !!) of working copies of 2-barrel version of the original Inline Four Barrel. So I took the work from that project made a few mods, and decided to make these commemorative parts storage kits for a couple of the other guys that have invested a lot in the project. They are aluminum cast aluminum present and appear to be a 2-barrel version of original carburator but actually store parts and related tuning tools. They also have a couple of additional features that mesh with their other hobby interests.

I did the personalizing by engraving the foam pattern as opposed to the casting. I think it may have been crisper to engrave the castng but the cast aluminum can be kind of gummy and load up cuttters, especially without coolant/cutting fluid and on fine details like this.

They're essentially done but I need to flock the inetrior storage compartments. Sort of like and Inline Four Barrel Autolite Carb and a Jewelry box went on a date and had twin love-children. They should be a nice conversation piece for their coffee table or man cave. I think they'll like them.


Members Projects / Automotive Scoop Adapter
« on: April 03, 2022, 15:11:30 pm »
I'm a lost foam caster and use CB to make lost foam patterns. Here's a recent project to make a carburetor to scoop adapter for a blown 41 Willy's Coupe. I'm still a bit of a hack when it comes to CB but I get by.


CamBam help (General usage) / Question on 3D Profile
« on: March 08, 2022, 02:24:59 am »
Hi all,

I was modleing some revolve extruded profiles and this one seemed like it would be ideal for waterline finishing. Why does the waterline finish method seem to ignore the bounding region and cuts the innner groove shown in the attached picture when waterline roughing or scanline methods do not?


CamBam Shop Feedback / Site Security Certificate Expiration?
« on: February 13, 2022, 22:35:21 pm »
I haven'y been on the forum for a couple days but every browser I try to access the site with starts screaming secutity warnings at me. https is displayed as https in the forum address line and I can't navigate the forum without getting kicked back to the security warnings. Anyone else having that problem?


Members Projects / Custom Automotive Timing Cover
« on: February 05, 2022, 23:44:25 pm »
Hi all,

I'm a lost foam caster and have been using Cambam to machine polystyrene foam patterns for evaporative casting. This pattern was machined in several pieces and assembled. Attached are a couple pictures foam pattern and resulting casting, and a YouTube video link describing the project.


CamBam help (General usage) / Machining Logo on 3D Surface
« on: December 15, 2021, 17:26:05 pm »
Hi All,

I was experimenting for another potential project that would require machining a relief on a 3D surface. I made a shallow sperical surface using revolve extrude and then projected the logo onto that surface. I just used a rough and finish waterline to machine the spherical surface but per David's recent tutorial, realize a cmbination of waterfall and scanline near the top o fthe dome will be better. -I can work on that.

I'm having trouble figuring out how to cut the logo into the spherical surface at a given depth of cut below the surface. Do I need to define a region below the surface at depth of cut? What is the best 3D profile method for the logo? See attached.


Pages: [1] 2