That's good you've run a simulation. 20" x 2.5" is not a strategic cross-section for the loading a gantry experiences. Gravity load is the easiest and should be of little importance, once the...
Type: Posts; User: dmalicky
That's good you've run a simulation. 20" x 2.5" is not a strategic cross-section for the loading a gantry experiences. Gravity load is the easiest and should be of little importance, once the...
It's great you are using FEA to analyze the component stiffnesses, and improve the design based on that.
As others have mentioned, you have some aims that will strongly compete with each other: ...
That's good to hear you two did not have any problems with Mic 6. I didn't find it bad, but it tended to stick to tools in some ops. Probably need a better process, or maybe the Mic 6 I've had...
Thanks, Louie -- I found some distributors, will check them out.
Thanks, Louie, I hadn't thought of phenolic. Do you know what kind is usually used as countertop material and available for low $? (I'm only familiar with the black type used in chemistry labs, but...
Certainly, machining can be done to lighten a solid Mic-6 plate. Consider 2 things, though:
- Mic-6 is dead soft, so it's gummy to machine.
- Pocketing will reduce weight and bending stiffness...
Thank you for clarifying. 8020 does indeed have a wide product spectrum, and that's helpful for many apps. For larger CNC routers, though, Misumi has the best gantry option, with their GFS8 100200...
I'm sure 8020 has very good QC and yes it can be successfully used in most DIY CNC routers. But I'd caution against alluding to Misumi as low quality because it is "foreign". Misumi is not cheap,...
Good addition by hanermo. I see the 542 drives have come down in price since I last looked, now approaching 6600 territory. So I'd say a 'best' drive at various prices would be:
<$5: DRV8825, but...
fretman, You're welcome! The TB6600/THB6064 chip is rated for 50V absolute max. Most of the boards recommend 40-45V max supply voltage. Voltage can spike during decel (motors act as generators),...
Glad to hear it's helpful!
fretman, there are a number of versions of it. Don't get those labeled HY-DIV268N or Rattm (red circuit board) -- those have many issues.
The best implementation appears to be this one (used to...
Nice job on the updates and improvements. The gantry beam and dual spindle mount will be much more rigid. I think the main flexy spot now is the Z car. When raised up, it will be stiff; but when...
The TB6600 or THB6064 are far better than the 6560. And TB6600 drives are $10 - $20 each on ebay, now. Few decisions in CNC design are a no brainer. This is one.
It's great you're exploring alternate gantry designs and drive systems.
It sounds like you've only done a little research so far. There are some techniques gain expertise, and this is essential...
As I understand it, US law has 3 categories to process import shipments, based on declared value:
1. under $200: there is no duty or delay -- these sail right through.
2. between $200 and $2000:...
The Ix and Iy (Moment of Inertia) of the 9090 is 300 cm^4, or 300*10^4 mm^4.
Two 9090s bonded together will have an Ix of 600*10^4 mm^4.
Two 9090s bonded together will have an Iy of 2200*10^4. ...
I don't know the 5083 alloy, but it appears this is a cast product similar to our Mic-6. The main issue is the temper designation. If it is condition "O" (annealed), it will be stress-free and...
Good work on the updates.
Cold rolled may be flat enough to use as is, so long as you aren't looking for high accuracy. But it cannot be milled flat: it will warp more as you mill.
Hot...
Thanks for the pictures. Yes, the old design is not really upgradable, except the table is salvageable. I can see your tool and die background in your new design.
OK, I understand you have an...
For the risers, I'm pretty sure you could use their standard HFS 100x100, with very minimal loss in stiffness compared to GFS. The GFS is for the gantry itself since it flexes the most by far. For...
It's important to know the critical tolerances that the users will need. Else the customer requirements cannot be defined, and the machine will likely fail to do its job. The engineer's first job...
Thank you, that's very helpful info. To be honest, I'm concerned about the match between project scope (this is a very ambitious project) and project resources (1 person and 1 month to do all...
This set is to try more stiffness improvements, and check different Z car positions. Recall Case 57 numbers:
Deflection = 0.00131", Stiffness = 76k lb/in.
Case 58: Thicken Y plate to 3/4"...
Good work on the updates. I'm realizing I gave you incomplete advice earlier -- sorry. For your frame design, I see the X and Y rails have to cross over a tube joint at each end. This joint will...
Good advice from Louie. And thanks, that's good to know they use both thru-coolant and glass scales.
Thanks for sharing more of the machine's purpose -- that's very helpful to know.
It's...
Good to hear you have the budget. You probably also know that Misumi offers pre-machining of the rail mounting surfaces -- that's highly recommended, unless you have access to equipment to do that...
A single 425 oz-in for X sounds reasonable for this app. I don't know what voltage supply and drives you have; there are 2 versions of the 425; one is 3.8mH and the other 6.8mH.
- The 6.8 has...
Good story, Wizard, thanks for that!
I agree steel and cast iron are ultimately better for a 'real' machine tool, but there are some things I like about aluminum for DIY machines...
- To get...
I agree with Louie, I think it would work well. For the X motor, I'm assuming you would use 2 idler pulleys to achieve a good wrap angle around the motor pulley. Just fyi, most dual screw machines...