[How-To] Build wooden skids for milling machines

[vista_joe]

I've decided to put my milling machines on skids so I can move them around the shop. I looked at lots of different pallets and skids. Most were either too light weight or only provided access from one direction. I decided to build my own.

I created models for each of the three classes of mills: Lagun FT-1, Bridgeport BOSS 5 CNC, Bridgeport Series II (I have two of these). They are the same design with only slightly different measurements. The driving factor was to have access from both the front/back and the sides with a standard 27" pallet jack. The width of the pallet jack became the limit on the minimum width for all three at 36".

I use
9 ea. 4" x 4" x <some_length> as the base, then
3 ea. 1" x 4" slats on top of those to tie them together and finally
3(or 4) ea. 2" x 12" x 36" for the top as you can see here.


Lagun: 42" x 36"
With the base


BOSS 5: 38" x 36"
With the base


Series II: 48" x 36"
With the base

I'll assemble these using #9 2 1/2 or 3" Star Flat Head Wood Deck Screws.

The bolt holes in the base of each mill will go through the 2"x12" with room for nuts to be attached underneath. I plan to use 1/2" x 13 x 8" bolts, nuts and washers to hold the skids in place under the mill. One of the Series II does not have bolt down holes in the base. The Lagun only has bolt down holes in the front (unless there are some inside the housing - I haven't looked there yet). This means I've only identified a requirement for 10 bolts so far.

The lumber cost is expected to be ~$150.00
The deck screws are ~$30 for 5#
The bolts are ~$3.00 ea.
Total estimated cost to build 4 skids: ~$210.00


I acquired a heavy duty pallet jack rated for 11,000 lbs due to the weight (~5200 lb) of the Series II machines.

Any comments or suggested improvements on this approach are welcome.

 

[vtcnc]

What a good idea!

I would be concerned about:

a) where does the cast iron base actually make contact with the skid? I'm skeptical that they are perfectly flat and will sit that way on the skid. More likely that they will sit with pressure on three and hopefully four contact points. I am not very familiar with any of the base casting features of any of those machines, but I would be wary of high pressure contact points that create bending moments around some of your skid structure, especially when picking up from the side. You are only using 1"x4" so on the Lagun skid for example, if you pickup on that large space and the contact points are to the left and right of that pressure point, you could see the 1"x4" crack or fail.

b) beef up the stringers (1"x4") to 2"x4" or 2"x6". You may be able to use thinner material for the top pieces.

I don't know if that makes sense, but that is what I see - opinions and experience with these matters vary greatly.

 

[tq60]

Use plywood for top as cleaning is a pain...we know this!

Plytainum is a brand of product at Lowe's that is very good.

We used the 1.125 subfloor as our second floor material and it came out great.

It is 48 inch span rating meaning normal floor loads only needs support on 48 inch centers instead of 16.

Ours are at about 15 and you can not cause floor to give.

Leave your base as is but add the 1.125 layer on top to both insure nothing falls into the middle but also spreads the loads.

That is plan for ours but it smacks of too much effort to redo...

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[vista_joe]

Use plywood for top as cleaning is a pain...we know this!

Plytainum is a brand of product at Lowe's that is very good.

We used the 1.125 subfloor as our second floor material and it came out great.

It is 48 inch span rating meaning normal floor loads only needs support on 48 inch centers instead of 16.

Ours are at about 15 and you can not cause floor to give.

Leave your base as is but add the 1.125 layer on top to both insure nothing falls into the middle but also spreads the loads.

That is plan for ours but it smacks of too much effort to redo...

Sent from my SAMSUNG-SM-G930A using Tapatalk

The Plytainum is an interesting approach. I hate to think of handling a 4x8 sheet of this - knowing how difficult of a time I have with 3/4" sheets. I assume you mean to replace the 2x12 with the Plytainum - not add an additional layer on top of the 2x12's.

My local Lowes does not carry this - but I found a Lowes about 20mi away that claims to have it in stock.
Current price here in TX is $52.46 for the 4x8 sheet.

 

[vista_joe]

What a good idea!

I would be concerned about:

a) where does the cast iron base actually make contact with the skid? I'm skeptical that they are perfectly flat and will sit that way on the skid. More likely that they will sit with pressure on three and hopefully four contact points. I am not very familiar with any of the base casting features of any of those machines, but I would be wary of high pressure contact points that create bending moments around some of your skid structure, especially when picking up from the side. You are only using 1"x4" so on the Lagun skid for example, if you pickup on that large space and the contact points are to the left and right of that pressure point, you could see the 1"x4" crack or fail.

b) beef up the stringers (1"x4") to 2"x4" or 2"x6". You may be able to use thinner material for the top pieces.

I don't know if that makes sense, but that is what I see - opinions and experience with these matters vary greatly.

I just looked at the machines and your concern is valid for the Series II - the base only only contacts for ~6" at each corner. However for the other two, it appears the base is essentially flat all the way around. The BOSS 5 does have some pry bar access points but that is a very small area for each one.

I was concerned about the space on the Lagun but it is much lighter than the other machines and the pallet jack has 7" fork width on each side - wider than the gap so I sort of skipped over this.

Perhaps I can combine your suggestion (use 2"x4" instead of 1"x4") and tq60's suggestion of using the Plytainum plywood instead of the 2x12's.

 

[tq60]

Have them cut in 1/2

We place a straight edge such as cut plywood or other wood on ply with clamps to guide saw.

For us 1.5 inches from blade, cutsheet while on floor resting on scrap wood with blade set to just made than thickness.

Price went up in 15 years...was 32 a sheet when we got ours.



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[tq60]

Duplicate deleted

 

[hman]

I'm about to get a "baby" Bridgeport-style mill. Gonna be generating a whole bunchalot of dandruff, scratching my head and thinking about your plan (and subsequent comments) for machines on skids. Thanks to all for the ideas!