Holding smaller parts on table
 

I don't want to go with a vacum type table but I am also wondering about holding parts that are smaller than the spoilboard . How are you supposed to clamp the sides opposite the 0,0 edge, or the edges of your materials if they are too small to clamp to the edges of the spoilboard?

I have seen some aluminum track that can be screwed into a routered pocket and has attatchment clamps that slide inside the track.

I didn't know if that is a good idea since the spoil board is continually getting thinner, and eventually the track would have to be removed to keep from getting hit by the cutting tool.

Very common are plain old screws into the spoilboard. More fancy is this one: http://www.raptornails.com/english/firstframe.html

I use the Raptor Nails. I have to say the composite nails work great and will not hurt the tool. I have built a 36' boat with them and they are very strong and forgiving. not bad in price ether I pay around $28 to $30 for a box of 2350pc.
http://i36.photobucket.com/albums/e3...s/P4240001.jpg

Gene,
Those nails look like they can be driven with a pneumatic nailer. Have you used them this way or just driven them in by hand? What type of nailer do they work in if you used one?
Hope you are feeling better. :)

Those look interesting. So you can hammer those into the mdf board and they will go into the board without breaking?


I was thinking of slotting one spot on my support board and spoilboard so that I can do fingerjoints and dovetail joints.

Something simmilar to what this guy did with his table. He has a hobbie size cnc with aluminum table, so it's not the same but I think it would be easy to use the same idea on my table to make box joints.

Anyone doing anything like this yet?

ED,
Check out the shopbot talk forum. They have some links to guys doing all kinds of joints on their bots. They usually clamp the board to the end of the table. Search for Knapp joint and see some really nice joinery that is doable on a cnc. You are not limitied to plain old box joints. :)

The nails are for a pneumatic nailer. I use a 15ga harbor freight nail gun. Raptor sales a gun that they recomend but it cost over $300.00.I told them I would take my chance with the $20.00 HF gun. I have shot over 6000 nails with no problems.

I contacted the LOCAL agent in South Africa. This is his reply:

Price on the mini nail gun up to 38mm is R2200-00

Price on 25mm plastic brads is R77.35 per 1000 (normally 2000 nails in a box
and 20 boxes in a carton)

These prices exclude Vat and valid for 7 days

As I said they are very expensive still and we would need a faxed order and
50% deposit before we import them.

Pity

I used rivnuts with great success on another project. Drill holes in a pattern (say 100mm square) little shy of od of nut push rivnut from bottom so as not to interfere with bit and use normal 6/8/10 bolt to clamp. Wurt sells them.

Are the rivnuts the same as what they call Tee-nuts?

I had forgot about those. I wonder if they will hold in the mdf board okay? I have used these with holes about every 12" apart on 3/4" plywood to make climbing walls before and they work pretty good.

Ed

Mcmaster-carr has them... I have used them for years... countersink the hole a little before you install them and the will be flush...

http://www.mcmaster.com/ search: rivet nut

No, rivnuts are different, insert them from the bottom, no need to countersink or hammer them in, mdf doesn't like hammering. Just drill hole little bit shy so you don't need to buy the riviter, which is expensive.

Woodserts are another option as they can be installed from the top of the board - found a PDF file here.

They are made by Wurth and others

Alan the good thing is these can be bought in brass, so if they are accidentally cut :o it's not the end of the world.

Jan you probably already know this :cool: but others might not ..... rivnuts are designed to have the bolt go in through the flanged end first, therefore the tighter they get the more squeeze they exert on the material they are going through.:)

Here is a picture of rivnuts. When used with a rivnut gun they mushroom in the middle just like a regular rivet. The end opposite the flange is threaded.

festool
 

i saw this and made me a table 24" wide (x) and 96" long (y) for small parts and long fluting, the clamps came from festool (80.00 $ a pair) and have proven them selves flawless
jim mcgrew

I have the Festool clamps and use them frequently; however, they sometimes tend to lift one edge of the material off the table by about 1/16 inch or more. Sometimes a tap with a mallet seats the material, and sometimes it doesn't. Most of the time that "lift" isn't a problem, but when accurate depth of cut is essential, I use traditional C-clamps, Vacuum Clamps, or screws.

Carr-Lane makes many different toggle clamps that people use for fixturing around here:

http://www.carrlane.com/Catalog/inde...173C3B28535241

For the cheap-skates amoung us:

http://www.harborfreight.com/cpi/cta...emnumber=96237
http://www.harborfreight.com/cpi/pho...6299/96237.gif

Others, simular:
http://www.harborfreight.com/cpi/cta...emnumber=96233
http://www.harborfreight.com/cpi/cta...emnumber=96234

An interesting clamp:
http://www.harborfreight.com/cpi/pho...7099/97051.gif
http://www.harborfreight.com/cpi/cta...emnumber=97051

Mike:

Do you use the screw part from underneath the table or just the clamp part on top? I have noticed that there is less deflection of the workpiece with using both parts of the clamp versus when just using the upper portion.

Roman

Roman,

I hadn't thought of using the screw part. My "clamping platform" sits on top of my vacuum platen, so there is no access from below. But, you're right. The using the screw part would keep the clamps from lifting.

(To tell the truth, until I read your post, I'd forgotten all about the screw part. I had to dig through the Festool stuff to find them. At least when I use the Festool Multifunction Table, I'll be able to clamp things down better.)

The t track is what I had originally thought of using, but I didn't want to have to use it within my existing spoilboard, because then you couldn't use the spoilboard for it's intentional use you would cutt into the aluminum track cutting any deeper than the project. It would defeat the design of having a spoilboard table.

I would still like to make a smaller board maybe 30in x 48in that has these t tracks in it. That way I could clamp the outer edges of the 30 x 48 board onto the spoilboard and have the use of the clamps for smaller stuff and remove the board for cutting full sheets.

Does something like this sound like it would be a good idea ??

Ed, it is fairly standard practice to have "pallets" that are equipped with holding fixtures/tools, and then to clamp these pallets to the table.

i'm painted this plain for see this simple system for hold parts in the base table.

we need a Plunge router for long holes in the table.

cutting tabs after machining
 

Hi,

I have a dilema. I want to cut some parts that slot together out of 1/4" or 6MM Baltic Birch (material is thinner than 1/4"). I will nest the parts and use tabs to hold everything together. Here is my problem. I would like to use a flush triming bit in a palm router to cut the tabs after machining. But I can't find a bit smaller than 1/4" to fit my contouring bit that is 7/32.

Has anyone ever heard of a flush trimming bit smaller than 1/4".

Could I some how cut all these small pieces on the mechmate without using tabs? Custom vacume plenum? I don't want to cut all these tabs by hand and then clean them up. I just want to cut the small parts out on the machine.

Any suggestions welcome THANKS!

Justin

Are there any hole in the piece ? If so, drill / cut these first. Put a screw or nail maybe with a washer to hold it down, then cut and trim the outsides.

The most basic method:... Climb on the table with a stick and hold each part down when the cutter does the last part of the breakthrough. (Make sure that the start/end of the cut is on the opposite side to where you stand/kneel)

Justin how thick are the tabs?

Justin have a look at these bits, they work for me.

http://www.amazon.com/Vermont-Americ...959226&sr=1-17

and

http://www.woodworkersworld.net/flush_trim_bits.shtml see bit SC28B on this page

JR,

I found a flush trim bit 3/16" from Amana tool. I cut some parts last night and I think I will have to make a custom vacume plenum. I so want to cut fast with the part coming off the table finished. I think something like a Brady vac will work for large production runs. I have been looking into gasket mask also.

Gerald,

After and hour of leaning over the table my legs were getting so tired.:):eek: