Machining/CAD tech mailbag ZDSPB.com > Tech index > Tech mailbag > Machining/CAD


Subject: Macintosh OS
From: Charlie J.
Are their any CAD programs for Macintosh computers (Sorry I want to sound smart!). You seem to know a lot about these things so that is why I am asking you. Also what are you recommendations for a first time CAD user? I am using for two projects that I need to do. I need to design a bolt for a threshold and ***** gun (Shh... Tell no one about the ***** part!). I need to get the dimensions correct, which I already have, but I am not sure how to use CAD so I want to know what has the easiest interface.
Thanks,
Charlie

Re: Macintosh OS
I'm not really sure of any Mac-specific CAD programs, I don't use any apple systems here so I'm unsure which work and which don't (lol). You can probably find out browsing the programs' websites though. I know Vectorworks is a proud Mac interface type thing, but I'm not too experienced with it, onlys used it for a few specific things a few months/years back.

In terms of an entry-level program, I'd definitely suggest AutoCAD. It's not the most cheap thing out there though, but it's really an industry standard in terms of abilities and compatibility. But if you're a student you can probably get a cheaper copy...I'm not sure how that process works but I hear people talking about it all the time.
There are other cheaper programs out there, or even free ones, but many of them are pretty primitive in terms of the features. I know the program Alibre is pretty nice (and free for the base-version) but I don't know how well it does things in 2d modes. It's mainly a 3d program I think.
Anyway, hope that helps...
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Quest solenoid file (this was in response to a previous e-mail about my Quest solenoid model)
From: Brent M.
I'm not too concerned about the internals.. but do you have the manifold gasket area accurate?
I've been trying to have a special manifold made for a quest that would use the smc (matrix,quest) solenoid gasket to seal it.. but have been unlucky in getting the dimensions correct. So I figured if your drawing is accurate then I could pull the dimensions from that.
But I noticed that you said the drawings weren't accurate. I believe you specified that was the internal components aren't accurate, but I was just wondering.
Thank you for your time
Brent M.

Re: Quest solenoid file
Yeah, that's the problem with the cad file post...some things are accurate but not everything. In this case the DM3 solenoid I modeled doesn't have the bottom ports included in the model, just the exterior of the gasket...so it probably won't help much. But instead I'd suggest heading over to airsoldier.com and looking up the solenoid model in his store, since I believe he has the datasheet posted there which should have the necessary dimensions and such.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Your degree? (response to my Ion bolt strength failure computer model)
From: Zachary W.
Hey this is ***** on pbn and I was wondering what your college degree was in? I was planing on majoring in mechanical engineering and work for a company, is this what you degree is in?

Re: Your degree?
By trade I do contractual design work but I don't have a college degree in it. I just do it a LOT...lol. My trade profession is CNC machining but I'm going back to school right now so I can get a degree in robotics, since industrial environments want people that are well-rounded in many aspects of the production process.

Myself, I would highly suggest a career in mechanical engineering. It's true that the computerized analysis like that video isn't something you'd deal with for quite some time, but there's a huge demand for it in the manufacturing industry, since the proper level of analysis can literally save tens of thousands of dollars. I do fluid engineering these days, which is less important and the software is also cheaper, but still leads onto other mechanical aspects too. Such as when pneumatic parts in paintball markers snap under pressure :)
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Solidworks tools?
From: Daystar
Just wondering if you knew of a good place that would help me learn solidworks. I have the software, along with AutoCAD and others. My problem is trying to draw something that already exists... reverse engineering I guess. How in the world do you do it? Do you draw manually, or have some nifty way of scanning stuff in?
Great site by the way, ive learned tons!

Re: Solidworks tools?
Well, I never really learned solidworks myself, but rather I learned Inventor which works very similar. I had inventor classes in high school back in the day (when it was Inventor version 4), so when the time came to start using solidworks I just had to relearn where the commands were and exactly how they worked. But the two programs are very similar. My suggestion would be to look around for a tutorial book (either an actual book, or a e-book, or anything in between). That's probably your best bet outside of just playing around in the program for a while. I think some versions come with built-in tutorials too although I'm not sure on which ones.

Autocad is definitely a bit different, it's not meant for complex solid modeling, even though it can do it. You can make solid models in autocad but then if you want to make a change to them you can't "go back" and edit the previous commands...like in Inventor or Solidworks.

When I make models I simply measure everything out. I try to imagine how the parts were actually created, then replicate it in the modeler. It is possible to 3d-scan objects into CAD programs but that requires a very expensive piece of laser scanner hardware which pretty much nobody uses unless they're a megacompany with money to burn. That said I have used them before, they are quite the cool things (one of my clients is buying one soon for development concepts...I can't wait).
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: ION CAD
From: Ryan N.
Hey, I am reverse engineering my Ion using Autodesk Inventor 2008 to prepare for a CAD Competition. I was wondering if you have any CAD files of a stock Ion board and a Ion Body that you could send me?
Thank You,
Ryan

Re: ION CAD
I don't have a physically accurate stock board, although I have a model for a Tadao Raider board if that helps, but it's just the circuit board itself...no solenoid, trigger microswitch, or capacitor is attached to it, so you'd have to make models for those and add them, or just add the parts onto the board model as one part.
Unfortunately I'm not allowed to send out the exoskeleton model since some of its measurements came from SP. Even though it's not critical stuff they still have their rules.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Shocker frame
From: Gary M.
I'm wondering, what are the extra holes in the top of the Shocker frame used for? I've noticed not all Shockers have them, for instance my old 2003 model (serial 1103) doesn't have them, but the later ones seem to have them.

Re: Shocker frame
The holes are hardconnect points for the robot SP uses to buff and polish their machined parts. The holes are then later used to hang the parts during the anodizing bath.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Buffing bot
From: Ed G.
I thought I read you state somewhere the holes in the Shocker frames were used by a buffing robot to hold the part. Do you know what type of workcell SP uses for this? How much robotics do they use over there?

Re: Buffing bot
If memory serves they're using a Fanuc LRM200i robot, which if you're not familiar is a small-sized 6 axis robot geared for line work like this. They didn't have an actual workcell installed however they do have an enclosure to protect the area from contamination and keep people out (you know how that goes) the buffing wheel is stationary and the Fanuc robot picks the frames out from an organized tray, buffs them, then puts them back in. The tray uses a special fixture that holds the frames a certain space apart so the robot doesn't need to use any super advanced tech like a vision camera system or anything like that.
Besides for that particular buffing application, they don't use robotics too much. Some of their higher-production CNC machines are fed by what they call a robot although it actually isn't...it's a "hive" system where a robotic gantry picks up blank workpieces from a holding area then transfers them to the CNC to be machined via conveyor system. The same loader then moves over to tend another CNC machine if needed. It's pretty high-production stuff, designed mainly for unattended production shifts. Of course there's always a group of people at the factory but for situations like this they don't do much except fix problems should they come up.
It's cool since it helps to really show that not every part of a paintball marker is designed specifically to shoot paint...many aspects are (or should) be made for easier manufacturing, handling, assembly, etc.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Shocker bolt project
From: Phil C.
I'm wondering if I can ask some advise on making a custom Shocker bolt. First off all basically what I'm doing is making a replica HE bolt out of delrin so itll be lighter. I know this won't be as durable and all, but I'm making a lot of them since I have access to the machinery and have a team of guys wanting to use them :) Anyway my problem is the way we're making them right now is taking a very long time since we have to take very little cuts during each pass. I have a chart of recommended cuts at different situations, and it says I should be able to remove much more matieral than I am right now.
I know these things are made by SP and they have some spaceage facilities available, but is there a secret to this so I don't have to take off 3 thou each pass? It's literally taking 15 minutes to make one bolt.
Thanks for any info. Here's a few pictures of the finished bolt.

Re: Shocker bolt project
I may have a suggestion, let me ask you this...are you using a tailstock with a live center to support the far end of the bolt? When I make Shocker bolts what I do is first bore out the whole thing (assuming you're using an open-face design) then hold the bolt supported using a pair of centers. The one on the tailstock is live, and the other is a new mandrell I make from steel at a 30º included angle then chuck it up in the spindle. The bolt gets supported between the two and allows you to move in and go nuts with the outside-diameter turning.

The only downside is that you then have to core-drill or bore (then ream) the inside of the bolt on a second pass, after chucking it up on the outside...so you'll have to be careful about the spindle marring the bolt. But if you're tricky you could probably finish out the inside diameter then use that between the two centers, get it out of the way first.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Solidworks 2009
From: Steve B.
I’ve been reading over the zdspb website. There is a lot of good information on there. I do have a question for you though. I was trying your ‘Threading’ tutorial with little success. I am using SolidWorks 2009. I cannot get threading going on for the life of me. I’ve tried your way to no avail, and I have also tried using the hole wizard and the Cosmetic Thread annotation. What am I not doing right?

Re: Solidworks 2009
hmmm, really once you get the hang of it, it should be pretty fast and easy. I even used it a couple times in this solidworks video I made a while back www.youtube.com/watch?v=_F9EpSM2Z54 (starts at 5:46)
The most important thing is to get the helical axis correct...once you have that it's just a matter of sweeping along a profile.

One thing that usually fouls me up is the triangle shape you need to draw for the threads has to be JUST three lines, the closed shape only. You can insert construction lines in order to get measurements, but you must switch them from regular lines to construction lines before you finish the sketch. If you don't do this then the sweep feature pukes out on you. I run into this often since I'm used to Inventor which is a little more forgiving about the 2k sketch.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Going rates for freelance design
From: WH
Hi Andrew, I'll be doing some on-the-side design work soon for an aftermarket paintball company. I'm excited to get started, but I'm not sure what to charge!
Time-wise, my first project has an 8wk delivery, including reviews and prototyping. I figured 3 weeks might go to reviews and proto, working half time the other 5. That's 100hrs, but what's a fair hourly rate? $30/hr seems high enough, but $3000 to bring a product to market seems awfully cheap! Have you had any experience that you might share?

Re: Going rates for freelance design
Well, personally I don't go by an hourly rate, just because it's too "honors-system"-y. The only times I do that is when I have to physically punch-in for the work, so pretty much local only. At the moment most of what I do is indeed local like this, but still whenever I do work over the internets it's often a different story. But of course the other problem with doing hourly stuff is, the better you are, the cheaper you make. You could be a super prodigious expert and have the task done with the snap of your fingers, and get paid less for it as a result!

Most of the contracts I've done for paintball start out as a one-time payment of whatever the work is worth, and if the item gets sold I try to land a few (not really in the contract, but hey) more expensive things I get a small percentage profit, though to be honest it's just little shaving from the price that I just want to have my address on for the sake of it. But the bottomline is, I charge depending on the amount of development needed. For instance if it were a machining print of a trigger I'd charge a hundred or so, but if it were a bonified functional part then chances are it'd be more. If it's an assembly it's even more than that. If it involves extensive design work and/or CAM or machining work, I typically charge around $60/hour and roughly estimate how long the project will take.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]


Subject: Question on producing a custom frame
From: Trevor
Hi Andrew- long time. I have a question for a paintball ninja like yourself... if I wanted to have a small quantity of custom marker frames machined (just a simple single finger 45 grip style with standard trigger/sear slot and pivot holes); is there anyone specific you could recommend? I would need a high enough quantity to warrant CNC.

I have a few CNC vendors that I use, but none have made parts for markers. I'd imagine someone who's made frames before would have some pre-made fixtures for their machines reducing cost to me. ...or do you know of a readily available frame like that besides the RAP T68 (to gen 4) or the Arrow precision Inferno?

Re: Question on producing a custom frame
Well, I know a few people that have done one-off or prototype frame machining via CNC, but the fixturing they used ended up being pretty non-production (ie. just screws threaded into some scrap material, holding the frame down) so you might actually not run into many problems in terms of fixturing and the like. It depends on the level of hollowed-out-ness that the frame undergoes. If it's walls are paper thin then you need to get a little creative with the fixturing to keep it more rigid. But otherwise it's nothing too difficult.

Personally whenever I've made simple frames (those that don't have crazy deep internal pockets through the top, etc) all I do is fixture the frame on each side necessary then work on it one side at a time. With a more intricate frame design the order of operations is more specific, though. What I've done is something like this:
setup 1 - preliminary pockets in the side of the frame placed to give chips a way out (not required, but helps to keep the cycle times up)
setup 2 - cuts in the top, all of them in one shot. I do this early because the large billet of metal is the most rigid in this form, fixtured in a regular vice.
setup 3 - External profile cuts on one of the frame's sides. I then move to a toe-clamp holddown method and machine all side pockets like for the trigger and battery/grip area
setup 4 - Flip over and finish the opposite side
Any other setups are just for the front, bottom, back, or any other machining angles you need to use to finish any supporting holes or whatnot.

All in all it's a long process but then again frames tend to be a reasonably intricate item. They're not hard to make, just intricate.
-from Andrew "Ydna" DuBuc - [ZDSPB.com]