I'm working on a new MM quietly in the corner #5 - Orlando. FL

[Greg J]

Thanks Sean,

A compression bit would have made all the difference. Gotta take the blinders off.

Using 1/4" up-cut spiral for laminate on MDF core. Have to cut with laminate facing up due to pocket within pocket design. Actually, the cut/edge isn't that bad when FR is reduced.

One more cup of coffee and out to the shop.

[smreish]

Well, as promised. A little fun with big, thick, solid wood today.
This was 1 of 12 pieces to form the perimeter of a really big table.
Fun stuff. Especially figuring out how to hold down the part being cut! JR should have his thinking cap on by now

Note: this was a sample cut from the knotty end of the board. This is 8/4 Alder (about 1.8" thick)
alder_sweep.jpg

conf_table.jpg
...big pile of scrap to the right of the machine for Gerald!

...for Greg and others.
1/2 Diameter, Bosch Carbide tipped bit
2.75" cutting length
4" overall length
19,000 R
44 IPM
30 IPM z axis plunge
.4" depth per pass for chip clearance.

[PEU]

But how did you held it down???

[Leko]

Looks like you screwed it up through a piece of luaun and then clamped that down. Yes? Maybe?

Looks good bro!

[Gerald D]

Thanks for the scrap!

Our first choice for holding the thick stuff down? Screw up through the bottom of the table....if the client doesn't mind. Otherwise, screw down from the top outside the cutting area and don't cut right through - stop 1mm short and put parts through thicknesser to release them. Otherwise, screw down from the top outside the cutting area and leave one small tab in the last 2mm - ie. stop cutting just before it wants to break loose. (Reduce the depth of cut (cutting force) before leaving that tiny single tab).

It is for these jobs that you do not want a vacuum table, or for a T-slotted, highly technical, super-finished table top to get in your way!

[J.R. Hatcher]

I learned this little trick about 42 years ago , credit goes to my shop teacher.
Put a small amount of wood glue on the sacrifice board, next lay a paper towel on top of that glue, then put more glue on top of the towel, now the wood to be machined, clamp all of this together. Make sure there is paper between all glue, a little stray glue makes a permanent glue joint . This will make a weak glue joint that can be broken apart at will . Experiment, experiment, experiment. The paper towels we used were those folded brown shop towels. I don't know if the 'quicker picker upper Bounty' will work or not, it would probably be toooo thick.

[smreish]

...Well, I actually used a small section of 1/2" plywood and made a .030 pass on it so I knew the registration of the part to the real wood and registered it to the corner of the table. 3 screws were counter sunk in the registration board from the underside. Worked like a charm. I thought it would be fun to stir up some thought on the forum.

...now - back to work!

[hennie]

Try using the same tape that Kobus got for his small parts ( thin double sided tape).I use it in my shop to hold down items that needs to be hand routered and for jigs works good.

[J.R. Hatcher]

Sean I need help. I need to cut some .25 lexan, any suggestions on parameters, or suggest a clear plastic that will cut better. I will be doing some lettering and also some graphics. thanks

[smreish]

JR,
Lexan is also known as Polycarbonate for those that don't know.
I recommend a onsrud #52-624 or similar 1/4" diameter.
Cut at 15K RPM or so, 35-60ipm, 2 - 1/8" per pass.

[J.R. Hatcher]

Thanks for the info Sean, I'll give it a try.

[smreish]

...JR, a little additional information.
Get a spiral up bit, 1 or 2 flute made for soft plastic.
The real key is get the chips out of the cutting path, otherwise they weld themselves back in the kerf and make for an ugly part.
Acrylic is really known for this, Polycarbonate doesn't weld as much, but it's really soft compared to other cutting materials.

[cncb]

I would recommend cutting most plastics with an o-flute cutter. I cut this with a 1/4" o flute up spiral and as Sean says good to get rid of the chips; up spirals do just that. Leaves a really smooth finish quite minimal chatter/tool marks if any. Not lexan, but cast acrylic. I'm sure it would cut very similar.

[cncb]

http://www.woodcraft.com/family.aspx?familyid=8017 here's the one I use, but onsrud and amana, most companies carry them

[J.R. Hatcher]

Thanks for the help guys Brian that's a nice cut.

[smreish]

Brian.
That is the same quality of cut I getting on my machine as well with Spiral Up Onsrud bits.
Thanks for posting a picture!

[cncb]

Np; but I def noticed a huge improvement in quality of cut in plastics when I went to the O-Flute. It just ejects chips nicer and leaves a cleaner finish. Onsrud, whatever company you use o-flute for plastics seems to be the way to go.

[Leko]

OK I'll bite. What does O-flute denote? Does that mean spiral?

[smreish]

THE ONE TOOL that is capable of slicing through the toughest materials... Plastic, Wood, Aluminum, Solid Surface
The highly polished open flute not only allows for easier chip formation and evacuation, but also provides for a sharper cutting edge that delivers a better edge finish on a variety of materials. Our premium micro grain carbide allows for superb wear resistance and tool strength. Special point geometry contributes to improved bottom finish and plunging capabilities. Tools are available in upcut and downcut versions from 1/16” through 3/8” diameters.
.
Brochure List 65-000 Single Edge, Solid Carbide Upcut Spiral O Flute Plastic, Wood, Aluminum & Solid Surface PART #CEDCELSHK DIAOAL 65-0001/161/41/82 65-0101/81/41/42 65-0131/81/21/82 65-0121/81/21/42 65-0193/165/83/162 65-0183/165/81/42 65-0203/161-1/41/43 65-0231/45/81/42 65-0251/47/81/42-1/2 65-0261/41-1/41/43 65-0271/41-1/21/43 65-0333/81-1/83/83 64-000Single Edge, Solid Carbide Downcut Spiral O Flute Plastic, Wood, Aluminum & Solid Surface PART #CEDCELSHK DIAOAL 64-0001/161/41/82 64-0121/81/21/42 64-0163/163/83/162 64-0183/165/81/42 64-0241/43/81/42 64-0251/43/41/42 64-0251/41-1/41/43 64-0313/83/43/83 64-0333/81-1/83/83

[Gerald D]

Open flute, meaning open "groove", meaning a lighter weight bit, meaning more chance of breaking and less chance of re-sharpening. They do cut darn well, but treat them nicely - we have broken them simply by dropping them on the floor.

[smreish]

Today I moved the machine to it's new home.
Upgrades and pictures coming soon!
Over the holiday I will install the new 36" long slide and spider tower

[domino11]

Sean,
Really looking forward to the pics of the long tower.

[smreish]

Move done! Machine back in service. Only took about 8 hours to disconnect what needed to be, then moved 20 miles. Releveling, connections, motors remounted, etc. All done in one day!
I moved the entire machine assembled with the exception of taking the x motors off and putting the gantry on the table. A few ratchet straps and one forklift easily moved the machine on the flatbed quickly.

Pictures next week.

Sean

[smreish]

I have the last bits of indexer gear showing up this week.
The modification is in 2 parts. The indexer and the slide.
Indexer:
Camco 40:1 indexing head with hollow bore mounting shaft
(small black handle will be replaced with big crank handle for easy set up. Motor you see is will be replaced by the OM stepper)
Oriental Motor PK299-F4.5A

Slide:
48" slide w/ premanufacture V rail
custom 8 roller spider plate

[Gerald D]

Aah, it's nice to see a REAL indexer for a change!

Something curious about their sales pitch though, the concept of backlash gets no mention in their definitions? Maybe those cams are loaded to be backlash-free?

[Gerald D]

Is your power supply voltage a good match for the PK299-F4.5A?

[smreish]

Gerald,
I played back in forth on the voltage when selecting this motor. The OM Engineer I was working with really helped me dial in this motor based on the speed/torque curves and my 56V power supply.
Hopefully, I made the right choice. If not, it's only a couple hundred dollars to try another one!

Indexer.
As far as I can tell, the indexer is preloaded in the +/- direction and appears to be very - very tight. I picked this model up at the surplus house for 95 dollars. It sells new for 3450.00. Not a bad for a quick find.
Based on my input voltage, speed and gear reduction - I should be able to comfortably spin 185# @ 50RPM. Fast enough for now.

[Gerald D]

I googled that Camco's backlash, apparently it is pre-loaded and does have zero backlash. At $95 you scored big time!

[smreish]

Okay,
I found 2 more indexers like the one above, but 60:1 and come with a 90vdc motor. Almost new condition. They are not nearly as cheap, and in better condition than mine. The cost is 500 dollars at the machinery depot I frequent.

If interested, I put them on 3 day hold and would be glad to buy them and ship for 2 lucky folks.

PM me if interested.

Sean

[smreish]

Update on the indexer.
Live end and dead end of indexing bed complete.
indexer_back.jpg

indexer_frt.jpg