I recently acquired a CNC mill (TM-3P with a 4th axis). I’m thinking about starting a service dedicated only to machining aluminum tube. Keeping a consistent set up would allow me to keep the lead time pretty low. I’d like to come up with a predictable pricing model so that when you’ve finished your part in CAD you can calculate the cost to manufacture based on area removed and minimum bit size.
I realize that there are a good number of teams on CD that probably have access to awesome CNC mills so it may not be the best place to be asking for this. But here I go anyway, any feedback would be appreciated.
Is anyone aware of other FRC specific machining services? I know there is Xometry and Anchor labs that will make anything but I’m more interested in services that are tailored for FRC teams and processes (similar to AndyMark’s waterjetting service)
Do you think this service would be valuable? Either to reduce the bottle neck on your machine or to give access to machined parts that teams may not have otherwise.
What would you feel is a realistic but awesome lead time?
What tube sizes are important to you 1x1, 1x2, 2x2, 3x3?
What would you expect a normal longest tube to be? (~37" is my max before pushing into a second set up.)
Would having the ability to see your parts get machined make the service more valuable to you?
Would everyone having the ability to see your parts get machined make the service less valuable to you?
6061 or 6063?
I’ve also toyed around with the idea of having date ranges of specific availability; ie chassis and tube for the first 4 weeks of the season then plate and/or rotary something for the next 4 weeks. really just to keep consistent tooling/flow in the shop. Those of you who have machines how have your set up’s typically evolved over the build season?
Again any thoughts or comments would be appreciated.
-Darrel
I think a lead time of a few days for a handful of parts is reasonable. That’s comparable, if a bit longer, than what it would take for a team with a CNC to machine them in-house. I’d say anything over a week for all but the largest of orders would be a deal breaker for a lot of teams
Pretty much everything in FRC can be done with 1x1” and 1x2” tubes. I’d try to stock two wall thicknesses of each, one thicker (~1/8” thick) and one thinner (~1/16” thick). If the customer needs something else they can have the raw stock shipped to your location
37” should be long enough for the majority of tubes in FRC. The main exceptions I can think of would be elevator or arm verticals on tall robots
Would it be cool? Sure. Would I want it if it slowed down my parts being made even a little bit? Nope
6061 all the way. 6063 is a PITA to machine and no stronger (weaker even IIRC)
Maybe? I think it would be beneficial to many teams, but I think my team probably wouldn’t use it. We value the learning experience of students machining parts themsleves, and take pride in being able to say every part on our robot was student-machined. But I do think teams that don’t have precision machining capability would value it.
On my last team, before the CNC router, they used to send parts out to sponsors to be machined, and a week was the typical lead time. If we were paying money for it, we definitely would have expected a shorter lead time.
1x1 and 1x2 are by far the most used on my team. We rarely use 2x2, and I don’t think we’ve ever used 3x3.
36" would feel reasonable to me. That would be enough for drivetrain framing. There will always be some demand for longer stock for things like elevators, but I think a service that offered machining for stock up to 36" would be very useful. Up to 24" would still be useful for a lot of mechanism components. If the limit was less than 24", that would limit the usefulness significantly
6 & 7. It’d be fun to see them be machined, but not valuable in the sense that I would be willing to pay more for a service that included it
Last season, we invested in a high-end CNC router and we’re about to purchase a new tube setup. Unfortunately, I don’t think we’ll be a customer of yours but I wish you the best of luck and will gladly share my input.
Again, probably not worth it for us, but certainly if we weren’t in the position to do it in-house.
In-hand in 4 business days.
I agree with @AriMB on stocking 6061 1x1 and 1x2 in 1/16 and 1/8 wall.
That should cover all but the longest pieces for most robots. Like the situation with the stock, you can’t be expected to do everything and this seems like a fully reasonable compromise.
This would only be valuable from a fun perspective, not transparency or anything of the ilk.
Nah.
Only somewhat relevant, but these laser tube cutting machines are mesmerizing and incredibly overkill for FRC purposes. https://youtu.be/QoF1nxKW0vw?t=6
Laser cutting tubes creates a heat affected zone which is a big deal with 6061-T6 or 4130. Machining is the best way to go for more “high performance” structures
Consider the electrical power usage / environmental impacts also… To cut 1/8" aluminum with a decent edge quality you’d need to deliver a few kilowatts of heat to the material. Say the laser power supply is ~25% efficient. For the same electrical energy input, you could run a 1 HP (750 W) router/milling machine 10-20 times longer, at full load, than you could run the laser.
To sell the service you would have to be a legitimate vendor. Not really hard to do, but you should read the rules so you jump through the right hoops.
It would be a good service if you stocked the common shapes in 6061 which can be hard to find. (My choice would be 1x1, and 1x2 in .050 ish and .100 ish. thickness.) Maybe something for the chain in tube teams as well. Having the stock will cut the cost of teams having to ship the stock to you to cut.
Predicting the stock you will need for a season will be difficult. Just ask Vex and Andymark. One thought is you could have teams pre-order a raw stock before the beginning of the season.
It is a really interesting idea. I wish you luck with your adventure. If successful, don’t plan on sleeping during build season.
Yeah I think the bottom line may be that you’ll need a few routers and some assistants if you actually want to make this a profitable business. We run our CNC router nearly 24 hours a day for a about week with operators working on shifts in order to make parts for two robots. If you get even a half robot’s worth of parts from a handful of teams at a time, you’re going to struggle to get them done in a reasonable amount of time being just one person operating one machine.
I’d recommend offering the fewest variation of tubes possible… At most do 2x1 and 1x1 (Inventory is expensive).
Stock the least amount of material you can assuming you have a local metal supplier than can deliver within a few days (inventory is expensive).
The request in this thread from people for less than a week lead time for custom machined tubes is likely infeasible unless next to no teams are ordering from you and/or this is a full time job for you (I’m assuming this is part time).
You’ll likely find teams are unwilling to pay enough for you to actually make money as well. I recommend pricing out a few example tubes based on costs for all overhead, electricity, consumable tools, machine cost, material cost, shipping materials, your time, etc…
Yes, this. Cost and lead-time are probably the biggest factors that are going to influence if teams find your service worthwhile. The sooner in the process you can pull together approximate pricing, the better your market validation will be and the less time you would waste if it turns out to be unprofitable.
There are a pile of laser and plasma tube cutting services out there to support programs like FSAE and Baja SAE at very reasonable costs (such as a whole FSAE frame cut from steel for ~$2k including the material).
@Andy_A and I have PCNC 1100 sitting in our shop with a 4th axis… I’d still look to have a laser cutter do this sort of work if it were more than a couple pieces.
It’s just so fast and clean compared to anything you could do on a mill…
You could probably do a good bit of business just stockpiling 1x1 and 2x1 1/16 wall extrusion during the off season and reselling it to teams come build.
I think at this point Onlinemetals.com has caught on to FRC and is stocking more of that thin wall goodness, but it does still seem to be a common sell out item.
None other than 221/AM’s waterjet. Tube machining makes me think of https://vr3.ca/ which is an AMAZING service for planes/racecars. But (almost) nobody makes round tubeframes. I can see that a “kit” format would be more appropriate- “I have a ton of tubes, please make my entire frame for me.”
Not so much with tubes. Waterjet, sure- things you’d make out of plate are hard. Tubes, less so… usually, I just want holes- and I can knock those out by hand or bridgeport and have them same day which is usually what’s most important with how we build things.
Same day isn’t realistic, even for one-offs But for a “kit”… one week from submission to parts-in-hand would be awesome. (Trouble is: you’ll have two weeks where you’ll be SLOGGED, and nothing special beyond that)
1x2… 2x2… I think that’s it? I don’t put fancy holes in 1x1.
30"
No.
No.
6061 and/or 7075. Maybe 4130 if we start talking tubeframes
Other thoughts:
Stock items could be neat. I wonder if there’s a “standard” WCD setup you would offer, that way you can have items in stock and ship immediately. Or even “stock + custom” where you just need to punch in a couple extra holes. (Vex, take notes?)
This has definitely been on my mind. I think suppliers don’t do it because it cuts out all of the little accessories you can sell. I could see how it limits teams flexibility vs a custom designed chain in tube chassis but compared to and AM14U2 I think it would be a huge step up in ease of design/assembly.
which I suppose makes me pivot to this:
3 versa blocks are ~$90 and versa rail for 1 side rail is about ~$20. I’d think $110 for a simple side rail to be on the high end of the spectrum of what I could do.
I have seen those laser cutter videos before and TBH I’d kinda copy their work holding a bit. I usually just run tube in a vice but would much rather run an entire tube in one set up on a 4th axis. I’ve been thinking of supporting the work either with a floating steady rest similar to the rotational axis in those videos or with a set of clamps that lock/unlock after I index the part.
I love coming up with setups and workholding its a bad addiction.
I think you’ll definitely have a lot of demand - too much, even.
Wanna get a bunch of my money? Sell lengths of 2x1 and 1x1 6061-T6 aluminum tubes (1/16 and 1/8 wall) with 0.196" diameter hole patterns cut into all faces. 1 row of holes centered on the 1" faces, 2 rows of holes on the 2" faces that are either 1" or 1.5" apart (1.5" preferred), 0.5" spacing between each set of holes. I can upload pictures if you want, pretty much the style that 1323/973/4414 does. Simple inventory and no need to do custom orders. Doing hole patterns is already most of the work when it comes to these tubes.
If you sold that for a reasonable price we would buy 98% of our tubes from you.
But for a “kit”… one week from submission to parts-in-hand would be awesome. (Trouble is: you’ll have two weeks where you’ll be SLOGGED, and nothing special beyond that)