Chopper could you show a picture with the entire part? How long did it take to cut? What did you use for coolant? Very cool stuff, thanks.

J.R.,
here is a picture of the complete part, as far as coolant I used a stream of air,
and a little silicone lube once in a while, the air seamed to make the biggest difference, I didn't time it but as I recall it took around an hour to cut each piece, but some of that was wasted screwing down the parts and cutting air because I wrote the program a little deeper than the part, so it could have been done faster, but I wasn't in a hurry just wanted to see if it could be done.
//chopper

I'm amazed!! Good job.

Wow, those look really good. :)

Chopper,
Great stuff! Love you work. I'll be using your 4:1 Belt reduction for my build.
A few stupid questions, hope you can help clear my misery
1) You are using MDF as spoil board while cutting metal (AL & Steel)?
2) You use coolant for your cuts?
3) How to keep the MDF happy while applying coolant?

Excellent Job! The MechMate is certainly versatile.

Ken,
1) yes
2) on aluminum I do not use coolant, just a little air to keep the chips out of the cutting area, on the steel I used some silicone spray lube and air, mostly air, but if I were to cut it all the time I would set up some type of coolant system for the steel.
3) if you were to use coolant while cutting you would need to change out the table top to a substrate that would not be affected by the coolant like a plastic or aluminum, I am sure there are other types of material that could be used, my thought is to set up a tray to put on top of the table to catch the coolant when I need to use coolant, and remove when I do not ( so the MDF would be protected) ...
but I do not see myself using the MM to cut steel to often this was just a test to see if it could be done, so I haven't put a lot of thought into the coolant as of yet..no question is a stupid one.if you have more just ask..
//chopper

thanks Wayne,
I was enjoying your posts on the 4th axes indexer you put on your machine very cool, what type of head are you using for the indexer?
//chopper

Even if it was not the MechMate destiny nor original concept, I’m somehow certain it is a « velour » to Gerald seeing that his DIY, low-cost no frill simple yet robust work horse can “ballet” dance on those metal, alu, and other material than plain sheet goods !
Robert ;)

Chopper, can you confirm that you are still using a router, and not a spindle, for these cuts. There is often talk about a spindle giving a better finish than a router . . . . . I can't see that you can get much better than that! :)

Also, your z-axis is not very much modified, compared to the standard drawings . . . . this is another part where some believe that the basic MM design is weak. Would you think that z-axis mods are essential for basic wood board cutting?

Gerald,
yes I am using a router it is a Milwaukee 5625 the only thing I have done to the the router is put new bearings in it ( much higher quality)
the modifications on the Z are minimal, the only difference on the Z is I welded it instead of bolting it, however, the spider is also modified ( I guess I consider that part of the Z ) and most of the modification on the spider is to make the squaring easier, and the bars that space the V wheels out are welded to the spider ( this really stiffened it up ), I think for some reason the welding makes the parts stiffer since bolts can move and welds cannot, so basically all the parts become one so to speak..

as far as it being necessary for wood board cutting is a good question.
I think the machine is under more stress from wood cutting than metal cutting, with metal I am limited to what the bit can do the machine is way more capable than the bit, on wood the same is true but at much higher speeds and feeds and depth of cut which can cause some to over drive their machine, the mods on the spider were needed to space out the V wheels anyway, so why not do it. so I guess that was a long yes...

I have thought about modifying the spider and Z assembly and I may some day, but what I have works..

I also wanted to add the only reason that I want to go to a spindle is not for cut quality, what I really want is the flexibility of different collet sizes right now I am limited to 1/4 or 1/2 inch size tooling, which so far has not been a big issue, and the er collet system is much better than what Milwaukee uses,
I have designed a collet system for the router but I decided that by the time I finished the proto-type I could have bought a spindle..
//chopper

Hi Chopper,

That was the exact reason I finally went with a spindle - collet size. I do a lot of work with acrylic and flame polishing and I now have a lot more bit selection. I no longer have to use a 3mm 0-flute with a 6mm shank (very expensive). I can just use a 3mm collet with a 3mm bit (very cheap - so cheap, I use a new bit for almost every job.

May I ask about your vacuum hold down system. I'm looking into a 10HP roots blower. You mentioned that you felt your vacuum was too strong? Can you tell me a little more about why do think this is so? I'm in Taiwan and there is a lot of industry here and when people talk about vacuum hold down, they all point point to this particular product. It pulls a staggering 55mm of mercury at a frightening cfm. I'm new to vacuum hold down and you have a pretty good setup. Can you give me some advice as to the plenum material (I'm thinking about using 3/4" PVC, bleeder (MDF) , or whatever else you can advise.

I'm still a little confused about the bleeder board. Why not just put what you cut directly on the plenum grid?

Sorry about so many questions but, if I'm spending almost $2000 for a 10HP roots blower, I just want to make sure I'm making the right decisions and understand what I'm doing.

Also, I've looked into your belt drive design and I can actually make a set very cheaply in Taiwan. Good design, simple and effective.

Thank you and sorry to inundate you with so many questions.

David

David,

If you use a vacuum mask between the plenum and the part being cut, you don't need a bleeder board. There are times when I use that method, but it requires the time, effort and expense of making a mask. (The mask is cut so that any through-cuts on the specific part do not have a direct "hole" to the plenum, which would cause the vacuum seal to immediately fail. When I cut a vacuum mask, I usually add AllStar gasket tape around the holes in the mask to give a little extra insurance against vacuum leaks.)

By using a mask and a GAST vacuum pump, I've cut parts as small as 2-1/2 inches square. With a normal bleeder board and two FEIN vacuums, I hesitate to cut anything smaller that 24-inches square without leaving a "skin". Others have had better results than I have, but they are usually at a lower altitude. (The Salt Lake City, area is about 4,500 feet above sea-level.)

"I also wanted to add the only reason that I want to go to a spindle is not for cut quality, what I really want is the flexibility of different collet sizes right now I am limited to 1/4 or 1/2 inch size tooling, which so far has not been a big issue, and the er collet system is much better than what Milwaukee uses,
I have designed a collet system for the router but I decided that by the time I finished the proto-type I could have bought a spindle..
//chopper"

Chopper

Milwaukee makes a collet for 3/8" tooling. P# 48-66-1000. I use one in my 5625-20 router. It's not listed for that router but it looks identical, and as far as I can tell it measures the same. I use regular milling tooling in wood, that allows me more flexibility.

Dave

If you get that collet, you will need a collet nut as well. p# 44-40-0095.

You can get both from Milwaukee tools and Amazon.

M.T. collet $26.45, nut $3.60 total $30.05

Amazon collet $24.04, nut $16.26 total $40.30.

Amazon probably has free shipping on these items.

Unless you live close to a Milwaukee distribution center, you'll have to pay shipping. So it'll be close to the same.

Dave

Thanks Dave, I will check into this it, do they have the same taper as the 5625 collets?
thanks//chopper

David,
I am no expert with vacuum hold down, my reason for saying to much vacuum is more a limitation of my blower than there really being to much vacuum, my blower is an old army surplus air defense siren, and the duty cycle is really short about 15 minutes, and at that point it will blow the thermal protection on the motor, I need to upgrade it to a motor with a 100% duty cycle, also it depends on how I use my table if I have a small part to hold down and I only apply vacuum to one zone I will blow the thermal protection much faster since the blower has to work a lot harder, so when I do this I bleed off the vacuum through some of the non covered zones, so in reality I do not think there is to much vacuum..( I believe at the time I meant it sarcastically)

I use mdf for the plenum material on mine but in doing so you need to seal it to prevent vacuum loss, I have seen them made from pvc and aluminum,
the pvc I believe would be a great choice since it is impervious to moisture
and easy to machine, now my understanding of the purpose of the bleeder board (mine is trupan, light mdf ) is it acts as a spoil board so you do not cut up your expensive pvc plenum, but more importantly it spreads out the pull of the vacuum more evenly over the entire area of the zones being used, and if you cut all the way through your material down to the spoil board it slows down the leakage of vacuum so your parts are less likely to fly off, if you were directly on the plenum and you cut all the way through
it would be hard to produce enough vacuum to hold the parts in place since the vacuum loss would be great.(unless you did like Mike Richards suggested)

I also want you to know that the roots blowers are great for this application
but they are also very noisy so be prepared for the noise and the harder they pull the louder they get, so you can tell how good your vacuum is by the sound of your blower..
and thanks for the compliment on the belt drives, if this does not answer your questions, or raises new ones please ask I will answer to the best of my ability..
//chopper

Chopper

All three collets appear to be the same. They all fit the same collet nut, they are all the same height ( length ) and they are all the same diameter at the top end and they all hold the tool securely. For my money, they are the same.

On the CNC Zone others are using them as well with success.

Changing tools, sometimes three maybe four times during the job is a real pain, and once the MM starts to make an income, I'll try to justify an ATC set up.

I slid the MechMate through the funding officer, but to ask for $4000 to $9000 to make life easier on me won't be as easy until I have some real work.

Dave

Dave thanks for the info....
by chance do you know what model router the collets are for?
I am also looking for an 1/8 inch collet
//chopper

The 3/8" collet is for model # 5660 and 5680, I haven't looked for an 1/8" collet.

If you are going to drill, then you might consider a Jacobs drill chuck for a milling machine. You could find one with a 1/2" straight arbor and use your 1/2" collet. You would have to turn you router to it's slowest speed.

Dave

Here's another suggestion on the 1/8" collets. Here's a link to a shopbot guy that might have a solution for you if you are using engraving tooling. Scroll to the bottom, it's the last article.

http://www.shopbottools.com/BradysTricks.htm

Here's another option.

http://www.rlspellmanmfg.com/index_bushings.html

Dave

Dave, thanks again
//chopper