Experimenting with options for vacuum clamping - Taibao, Taiwan

[liaoh75]

Hi Gerald and all Mechmate builders, I have been lurking around here for a long time watching and learning over the last several months and have finally decided to jump in and begin my build. I am an American Citizen (of Asian descent) working in Taiwan long term. I think I have it easier than a fair number of fellow builders as this country is quite the manufacturing haven. I have access to all kinds of things here. I hope to build the CNC router I've always wanted. I have to say that I wouldn't even attempt this if it wasn't for the helpful people on this forum who contribute selflessly. I'll be building on the conservative side using mostly recommended components. After building some confidence, I'll tap into the vast resources here in terms of electronic components and the ability to Laser cut and machine steel. I hope to have fun, learn a lot, and hopefully contribute in some way to this great Mechmate community.

[Greg J]

Welcome David,

Just be for warned, this is addictive.

Oh, to be in Taiwan. I agree. It is a manufacturing haven. I wish to visit Taiwan and South Korea. South Korea's ship building industry is something I must witness.

[Gerald D]

Welcome David,

It is going to be useful to have an agent over there!

[hennie]

Welcome David,

Start dreaming your MechMate number!

[domino11]

Welcome David!
Hope you enjoy your adventure here.

[liaoh75]

Thank you all for the warm welcome. I'm in the process of acquiring steel components consisting of 7" (180mm X75mm @21kg/meter) channel and cross support chanels. I asked them about the 60 degree cuts but they don't have the right equipment to cut at an angle at the lowest price place in town. This would mean I would have to either cut the angles myself or take the 10 meter chanel to another place for cutting. Can anybody attest to the feasablity of trimming the angles (final length on my table size is 3070mm) myself with a good cutting disk on a handheld angle grinder? Any advice or words of wisdom would be appreciated as I've never worked with such a large hunk of steel before.

[Kobus_Joubert]

Hi David, I left my ends at 90 degrees. Firstly I was lazy/afraid to try and cut them myself, secondly IF...I plan to put some sort of indexer on the machine, I then already have a flat surface to fit the indexer onto. Just my 'logic' lazy thought. Good luck.

[Gerald D]

David, I don't know how you plan to to make your rails M1 10 1*0, but consider that lengths of channel makes a good work surface for clamping the rails onto.

The angles (both main beams and cross supports) are optional, purely for aesthetics.

Originally Posted by liaoh75

Can anybody attest to the feasablity of trimming the angles (final length on my table size is 3070mm) myself with a good cutting disk on a handheld angle grinder? Any advice or words of wisdom would be appreciated as I've never worked with such a large hunk of steel before.

Totally feasible if you have the patience and are allowed to make whining noise for a while Will ask somebody in my workshop to cut a beam like that today and to record the time and disk wear.

[Gerald D]

Trimmed a cross-support channel 76x38x6.7 that was already cut to length, with this disk. Took 43 seconds and 1.5mm off the diameter of the disk. (if that link does not work, it is a Würth, part# 0664131150)

[liaoh75]

Wow, that was quick. I thought there would be at least a 24hr wait before someone would stumble upon my post earlier.

Gerald:
Because of the fact that these guys are the cheapest in town (by a pretty big margin), they have a large quantity of "standard" sizes but not a large variety of dimensions. They also force you to buy the full length of stock which is unfortunately 10 meters. (We are talking about the main chanels here.) My plan was to get two 3.07 meter pieces and that would leave me with one piece which would be almost 4 meters to clamp and cut my rails with. I will buy all my chanels from these guys. I'll have to buy my rails and other parts from somewhere else as they only sell chanel and flat bar but no angles or square or round tube. After re-reading my earlier post, I discovered that it wasn't very clear. Sorry about that. I was contemplating cutting the angles on the main chanels with the angle grinder. The cross supports are small enough (I think) where I can use my 14" chop saw which I purchased for this project .

Kobus:
Can you draw me a simple diagram of the placement of such an indexer? Have you put one on your machine yet and if so could you send me the link to the post with some pictures so I can better understand what this indexer thing is all about as I am very curious. I've read in many places about builders who plan to put one on their machines but haven't seen a picture of one yet.

[Kobus_Joubert]

David, try talking to Uncle Art ...http://turningaround.org/4_axis_mill.htm .
Or search on this forum for ART...you should find some answers.
Still in the future for me.

[Gerald D]

Pictures of Indexers

Also wanted to cut a scrap of main beam with a small angle grinder as a test, but we don't have any here now. It should take about 5 minutes and one disk. Completely feasible. Part of the trick would be to cut only the web at 60 degrees, and cut the bottom flange at 90 degrees (The other flange remains 90 degrees as per your supplier's cut). Cutting the bottom flange at 90 degrees makes it easier to fit part 1010324

[liaoh75]

Gerald, thank you for the link to "Pictures of Indexers". That was way cool. I think I'll put that on the back burner until I'm ready for that. My immediate challenge will be the kitchen table project and working with steel. I'll have a go with the cutting of the main chanel with the angle grinder. I'm heading into the laser cutting shop tomorrow morning to submit the DXF files for cutting. I have a friend comming back from a trip home (U.S) with the following goodies:

(4) PK296A2A SG7.2 Oriental Motors Steppers (man, are those steppers EXPENSIVE),
(4) Gecko G302V drivers (with a set of extra fuses as recommended on this forum),
"Mechmate Kit" from Superior Bearing including 14 vee wheels and 6 eccentrics,
35VDC 500 VA Power supply from Antek

In mid July, I will have two whole weeks to do nothing but work on this beast. I can't wait. In the mean time, I'll begin the "kitchen table" project and continue to get necessary parts.

[liaoh75]

Hi Everyone, sorry about the long delay before getting back to posting something. I have included some pictures to show my progress. I know I have gone against the grain as far as the control box being mounted on the machine, but I think this is the best configuration for me. I will fit a large shopvac filter to the intake. I will be using 2 - 6 inch 220vac fans for ventilation. One fan will draw air into the control box and the other one on the other side will pull air out.

One strange thing - When I got my 20 tooth pinions, the guy I got them from didn't know much about what he was selling. Anyway, can someone identify this thing? It is 33 mm in diameter. I doesn't appear to be metric or U.S. inch stardard. Can anyone shed some light on this weird pinion?

If anyone see anything wrong with my build, please let me know. It's been a fun ride and I look forward to seeing this thing move. Comments and suggestions are greatly welcomed.

[Alan_c]

David - very nice, I like it, especially the intergrated control panel - keep us informed as to how well it works and if you experience any "problems". Very sturdy looking table.

[Greg J]

David,

Nice work!!!!

It's interesting to see the different configurations.

[Gerald D]

A nice surprise David - very good work!

Before we guess which gear that is, how wide and tall is the rack?

[Gerald D]

That could be a metric module 1.5 with the rack being 17 x 17mm?

[liaoh75]

Thanks Gerald, Alan, and Greg for the feedback and comments.

Gerald, the rack is measured at 16 X 16mm. The place I went to buy it specializes is making custom pullies (maybe custom belt drive?), pinions, gears, racks, and sprockets. They acutually have the equipment to cut a blank from round stock and make whatever gear you need on-site. However, I was surprised when the man told me that the pinion I wanted was a standard, but he didn't know anything else. Believe me, I was scratching my head on the way out with four pinions and eight 1-meter long pieces of rack.

[liaoh75]

Just to give you guys a good laugh, I want to share a funny story. It wasn't funny at the time, but now I chuckle as I think about it. If you look carfully at picture 4, you can see the top of a large fan just above the Y-car. The fan was abandoned in a building where I work. I took it home and fixed it up and noticed that it was driven by a 1/2 horse power motor. When I turned it on, the fan was so strong it pushed itself on the wheels I mounted with wheel locks engaged. Well, that isn't the funny story but just background information so you will understand what happened. Here goes. I had not mounted the stops on the gantry yet when I turned on the super fan and walked away to get a clean rag from another room and heard a thunderous bang. I ran back to see what happened to find the gantry on the floor, two cracked section of cable chain, and a BENT Y-rail. I almost had a heart attack. With the gantry riding on the X-rails so smoothly, the fan had blown the gantry right off the table. I had to re-drill, cut, and grind the y-rails. Obviously, I had not put in the stops on the gantry yet but I couldn't believe the wind from a fan could move the 100 lb + gantry and y-car. Luckily, there wan't any other damage and the motors had not been installed at that time. Gerald, my hat's off to you for designing such a tank. No twist in the gantry or anything else outside of a scratched-up paint job. Sorry, if you don't think the story was funny but I am certainly laughing AFTER re-making the y-rails. That is why the Y-rails are not painted in the pictures.

[Greg J]

David,

That is a good story. The best lessons and experiences come from the day to day work.

[Gerald D]

Hi David, that's a good story!

Your gear pitch is definitely metric module 1.5. In the spreadsheet (Gear Speed Steps Freq Calculator.xls) you downloaded, change Module Number to 1.5. It should work quite well.

[hennie]

I like that box mounted under the table, nice!

[Robert M]

Nice work David
Guess you must of sleep in the shop to make this happen so quickly
I can see why your laughing now that it is over, but my hart can only sympathize...
Thanks for sharing this
Robert

[javeria]

WoW David, thats a nice build.

[liaoh75]

Thanks for all the compliments guys. I will post more pictures as my build continues. I had two and a half weeks of vacation time where most of the work took place. I think I'll have to slow down a bit now because I gota go back to work now and only have weekend time and occasional early mornings and late evenings. Boy, has it been fun. I think I got the CNC itch some of you guys have been talking about. Definitely addictive!!

Gerald, thank you for the info on my rack and pinion numbers. Have I got the wrong rack and pinions? Should I go back to get "Module 1" instead of using Module 1.5. Will there be any difference in the performance. Will my machine run rougher?

[Greg J]

Originally Posted by liaoh75

only have weekend time and occasional early mornings and late evenings. Boy, has it been fun. I think I got the CNC itch some of you guys have been talking about. Definitely addictive!!

David,

It only gets better.

[Gerald D]

David, I think your machine will run pretty well with that module 1.5 rack/pinion. Anything less than 20 teeth starts getting a bit rough.

Most of us are using around 30 teeth, and we then have the option to go to a smaller pinion for a finer/smoother cut (you don't have that option with the 1.5 module).

You are lucky in that you have the OM motors with the 7.2 gearboxes. If you had direct drive motors, that module 1.5 would not have worked.

You do have the benefit of a bigger/thicker/stronger/deeper gear tooth than the rest of us. In fact, I think you have a slightly better technical solution.

[liaoh75]

Gerald, thanks for the input on my rack/pinion. I read up almost every day and I don't know how you run a business and answer everyone's questions so quickly.

[liaoh75]

I've been so busy figuring out the CAM portion of this endeavor, I forgot to update my personal thread. I've been cutting away (mostly testing) using Vectric Vcarve trial and Cut3d trial versions. Gerald, would you please be so kind as to move my personal thread to Machines already cutting. I'll be posting some pics after I decide on which CAM application I will end up with. I'm cutting mostly rubbish at the moment but pretty amazing rubbish.

Right now, I'm very busy researching CAM stuff and Eastern Spindles. Man has it been a great ride. What a rush to think the average Joe Blow like me can build and run a CNC router. I used to think stuff like this was reserved for equipment from multi-million dollar companies. Thus far, I have to say the Mechmate has exceeded every expectation. It runs more smoothly than a commercial machine made in Taiwan I checked out on September 16, 2008. I am blown away. For those that are still hanging out wondering if it is really as good as people on this forum say it is, get started; you won't be sorry. The education you get from Gerald, the people on this forum, and the experience of doing it yourself is worth more than words can describe.