plans for my buddy table

[Ajcoholic]

Well the new table is staying flat, and true across the whole top.

The rollers work well!

[Ajcoholic]

Well, it has been nearly 9 months (if I can add) since I have had the 2X3/4"MDF table on my buddy.

I plan to make a new one tomorrow... as this one has been used so much (and resurfaced down as much as I can go without cutting into the screws) it is full of screw holes from holding down plywood.

On the new table I plan to put in another 4 lengths of the aluminum track so they are closer together.

For what one sheet of 5' by 10' 3/4" MDF costs, even making two tops a year is next to nothing in terms of material costs.

I might also replace the casters with some really nice polyurethane/ball bearing rollers I bought a while back - but the casters have proven to work really well so I might just leave them on as well.

AJC

[Ajcoholic]

So I spent 1/2 the day today getting the new table made and installed.

I left the sheet full width (61") which allowed the wooden spacer blocks that went bewteen my side rails and the angle/wheel hold downs to be discarded. Now the hold down wheels are even more rigid.

I also left the length the full 6' of the buddy aluminum extrusion. And, I added 5 more T tracks for a total of 11, spaced 5" apart. Now I can hold down the edge of a 48" square sheet with my aluminum clamps just catching the outer 1/2".

Bolted down and surfaced, she's ready to go and hopefully last another year

WHile I had the powerstick off, I cleaned and regreased the pinions, oiled the rails, checked the tightness of the spindle bolts and gave everything a good cleaning (it wasnt too bad I am a neat freak). Its good to go I figure for 2013!

AJC

[Simops]

Andrew been following your table layout since beginning of this thread.....

3 quick questions come to mind.....

1. Your 'roller wheel stabilisers' are they on both bottom and top......it seems to be on top only .....what happens if the deck curls down?

2. Notice you use the deck as the spoil board as well....this seems not the usual convention. When you surface the table, 48 x 48 in this case you are pocketing down into the deck. How do you find that with sheet material placement on the deck? Also what allowance are you giving yourself between the alum T track and surface considering future re-surfacing and cut depth.

3. The T track dados are all the way across the table deck.....did you use a hand held router to this as the spindle won't go all the way across to the edge....well not on mine.

Cheers
Mike

[Ajcoholic]

Andrew been following your table layout since beginning of this thread.....

3 quick questions come to mind.....

1. Your 'roller wheel stabilisers' are they on both bottom and top......it seems to be on top only .....what happens if the deck curls down?

2. Notice you use the deck as the spoil board as well....this seems not the usual convention. When you surface the table, 48 x 48 in this case you are pocketing down into the deck. How do you find that with sheet material placement on the deck? Also what allowance are you giving yourself between the alum T track and surface considering future re-surfacing and cut depth.

3. The T track dados are all the way across the table deck.....did you use a hand held router to this as the spindle won't go all the way across to the edge....well not on mine.

Cheers
Mike

Mike, the rollers I put on the top only... The big rollers are already on the underside. The mdf is trapped between them.

I don't cut into the top. When I machine parts I use a half sheet of 1/4mdf as my spoil board. It's cheap here, I use both sides and then dispose of it.

I didn't cut the t tracks, I cut strips of mdf, rabbet the edge and then glue and screw the strips to the base layer of mdf from underneath. I just surface the top lightly every so often to make sure it's still flat. So far it stays very flat, but if it wants to curl, it always seems to want to go up.

[Simops]

Thanks Andrew....

Mike, the rollers I put on the top only... The big rollers are already on the underside. The mdf is trapped between them.

Mmmm...i would of thought the rollers underneath weren't extensive enough to give counter pressure against your stabiliser wheels.....but obviously works for you. I would of thought it would have needed something underneath to oppose the stabilisers....

I don't cut into the top. When I machine parts I use a half sheet of 1/4mdf as my spoil board. It's cheap here, I use both sides and then dispose of it.

Ok makes sense.....

I didn't cut the t tracks, I cut strips of mdf, rabbet the edge and then glue and screw the strips to the base layer of mdf from underneath. I just surface the top lightly every so often to make sure it's still flat. So far it stays very flat, but if it wants to curl, it always seems to want to go up.

Oh ok I see what you have done.....neat. When you say surface the top I gather you mean the 1/4" MDF spoilboard.
I guess it must be north / south hemisphere thing because here I have had the decks curl down always or me

Cheers

[Ajcoholic]

Thanks Andrew....


Mmmm...i would of thought the rollers underneath weren't extensive enough to give counter pressure against your stabiliser wheels.....but obviously works for you. I would of thought it would have needed something underneath to oppose the stabilisers....



Ok makes sense.....



Oh ok I see what you have done.....neat. When you say surface the top I gather you mean the 1/4" MDF spoilboard.
I guess it must be north / south hemisphere thing because here I have had the decks curl down always or me

Cheers

I do surface the laminated MDF top. So it is flat in the 48 by 48" working surface. The 1/4" MDF is uniformly flat so I dont have to do anything to it, just place it under the parts I am machining (if I am cutting all the way through that is, if not I just go directly on the big top).

I cant see how the top would/could curl downwards, if the upper rollers are holding it down onto the 6 buddy rollers, how could it curl further downwards? Also, being 1 1/2" thick it tends to stay pretty flat vs a single sheet of 3/4 or 1" like I tried originally.

Remember on the buddy, the only place the working surface needs to stay "flat" is under the gantry. If the sheet curls up or down as it passes past the rollers, it doesnt matter. When it comes back to the center of the machine and gets stuck again in between the rollers, it remains in the same position.

I check my table often, with a 4 foot aluminum straight edge. Maybe I got lucky, but it stayed flat. And, when I cut parts from a 4 foot by 4 foot sheet, I can see in the 1/4" spoilboard how deep the cutter goes. Its always within a few thousandths and worst case has been out about 0".010

[RhinoFabLab]

Very nice!

[Bob Eustace]

Hi Andrew

Have finally bitten the bullet and about to start building table edge pressure rollers. Totally agree with almost all your logic but would love to hear your reasoning for gluing two chunks of 3/4 together. We can get 32mm MR here at reasonable cost. Could you share your thoughts on this before I buy some tomorrow please if possible. Did you go the glue system because of your tracks and the strip idea? Got some superb ball bearing rollers from Chrissy and I reckon these could well see me out!

How have you faired with regards to clamp collisions. We waste a lot of time keeping Z too high. Probably due to lack of confidence!

[Ajcoholic]

Update on the table..

Firstly, sometime a few months ago I replaced the cheap hardware store casters for my hold down, to polyurethane/ball bearing "scooter" wheels. These are basically like oversize roller-blade wheels. Much smoother and no squeaks.

Next, after a year of use on the table I made this time of year a year ago - and some resurfacing - the MDF started getting thin over the aluminum tracks and was lifting up when I tightened the hold downs.

Rather than replace the entire top - I decided to try something new. I took some 6mm Baltic Birch - and cut it into 5" strips (the width of the table between tracks) and glued it down and tacked it with some plastic brads. I resurfaced the table this morning as I was running a bunch of cabinet gables and shlef pin holes - and found the BB much less "slippery" than MDF and the pressure needed to clamp was much less to avoid slipping. Also, the strength is amazingly strong when clamping and no flexing up of the T tracks occurs.

Time will tell if the BB ont the MDF will cause curling issues, etc.

Pics later..

AJC