Plywood Machine table question

[Mac McCaskie]

I just built a table for my grizzly small mill with two layers of 3/4" birch ply for the top. While moving stuff around I found a sheet of "formica" that will fit behind a book shelf (actually it was an empty wine rack). Is putting plastic on the mill table a good idea or not? Currently I'm not planning on bolting the mill down to the bench, and instead use the provided feet to level it. Now I'm beginning to think the mill will skid around on the plastic top (yes/no?).

Or: does anyone have a thought on how to "through bolt" the mill and still be able to level it and keep it level?

TIA, mac

 

[Cogsy]

I'm not certain, but i don't think mill has the same need for 'level' that a lathe does, as the ways are much shorter and less prone to 'twist'. My mill is bolted to a steel bench and I've never checked it for level at all. I do tram my mill though and I believe you could just as easily tram a level mill as one that is not level. If it were me I'd bolt it down securely and keep it in tram and it should be just fine.

 

[Mac McCaskie]

Oh, thanks. That will make life a bit easier.

 

[goldstar31]

Honestly, I don't. see much of a problem having TWO lathes indoors.
One is a ML10 and is bolted onto a cheap Ikea table which is topped with about 3/4" CHIPBOARD top with a patterned vinyl wood effect skin and the little Myford goes on a fairly thin bit of sheet steel which cme from a refuse dump whereas the heavier Sieg C4 and the powered vertical mill/drill attachment lives on an office desk, again with an 1" chipboard/vinyl top and the standard Sieg sheet metal drip tray.

In both cases, I bolted both down and made an attempt to level them.

With both machines, the table tops and the sheet steel 'drip trays' complete an a structural rectangle. For my mill drill( possibly a RF25), I cut up scaffolding steel poles and welded them to plates cut from a new naval ship.

So if you are 'windy', I'd suggest making a structural steel 'box' of your mill or lathe or whatever.
True, one must avoid 'going into twist' but at the end of the day, getting everything 'level' is only to make it easier for setting up work pieces but think carefully, things like submarines and tug boats have mills and lathes which follow the movements of their ships.

I hope that this helps your final decision

Norm

 

[ShopShoe]

My 0.02 cents worth:

Chipboard and its cousins (in the USA) are prone to sagging from weight over time. Some plywood is as well. I have used both of these as a covering over a structure of either steel (angle, channel, or square tube) or dimensional lumber framed-up under the weight-bearing areas like where the feet of the machine rest. I tend to "over-build" for strength and long-term dimension-holding.

I have used formica off-cuts to top my plywood or chipboard for ease of cleaning and because it is softer than the cutting edges of tools I might place or drop. (I got a deal on discontinued colors, too.)

In a "dream shop" I might incorporate a heavy granite or epoxy-concrete top or cover a built-up table with sheet aluminum.

I have bolted my mini-lathe and X3 mill to the table LOOSELY so I don't have to chase them around. I experimented with the lathe on a bench top when I first got it and found that it did move around and I did not like that. To quote an old boss of mine: "It's all temporary." I just figure that upgrades may also call for an upgrade in the stand or table, too.

--ShopShoe

 

[Wizard69]

I just built a table for my grizzly small mill with two layers of 3/4" birch ply for the top. While moving stuff around I found a sheet of "formica" that will fit behind a book shelf (actually it was an empty wine rack). Is putting plastic on the mill table a good idea or not?

I would say yes. The reason though is the same as it’s use in counter tops. That is it prevents direct moisture absorption of the underlying wood product. This can be very important if you are using water based coolants.

Currently I'm not planning on bolting the mill down to the bench, and instead use the provided feet to level it. Now I'm beginning to think the mill will skid around on the plastic top (yes/no?).

I don’t know how you operate your machine so can’t say much about skating around! However I strongly lean towards small machinery that is fastened down in some manner. It just prevents accidents. That can often means a sub-plate that gets clamped to a bench to prevent a grinder from walking for example.

For a mill you don’t want the machine to walk at all. However torquing the mill down isn’t exactly a good idea either. The reason being wood products move which can lead to twisting a cast iron frame.

Leveling is important in my mind. These days a level machine and a digital protector can make for quick setups. At least to the accuracy of the digital protractor. Beyond that I just feel more comfortable with a level machine, it even helps with keeping the coolant flowing in the right direction.

So yeah level the machine and also bolt it down to keep it from walking. Just don’t torque the living hell out of the bolts holding the machine down. The idea is to keep the machine in position and avoid accidents.

Or: does anyone have a thought on how to "through bolt" the mill and still be able to level it and keep it level?

TIA, mac

I’m not sure what you are asking there. You run the bolt through and shim or adjust for level. If the machine doesn’t have the option of an adjustable screw for level you can use shims. In fact you can buy shim packs specifically designed for leveling machine tools. You have other options like toe clamps but they take up space.

Another option worth considering are machine leveling pads which have rubber feet and an associated jack screw. These can prevent some walking but have no additional safety offerings. They are likely more suitable for machinery heavy enough that the average person can’t easily knock over.

I know I’ve focused a bit more on safety here than the other aspects of bolting things down but in the home shop I believe it is an important aspect when considering fastening down machinery.

There are limits though, our safety department at work requires that Bridgeport mills be bolted down. For the life of me I can’t see a reasonable person turning one of those over. Drill presses yes but I have a hard time imagining a Bridgeport roll over. In the home though you have to worry about kids, teenagers, and the idiot next door that might not know better. You even need to consider what might happen loosing your balance, slipping or struggling with something heavy and you end up crashing into the machine. A small mill rolling over can easily do additional damage.

I e literally see examples of guys using surplus rotary tables and indexers that weigh more than the mill the are sitting on. It is great that such iron can be picked up for a song but you know have a machine that potentially isn’t as stable as intended. There are many ways that machine stability can be impacted by the materials on the table. So any thing that prevents rolling is a good thing in my mind.

 

[kquiggle]

Wizard69 - Recently "Joe Pie" did a youtube video on work holding safety when drilling. He told an anecdote in which a work-piece held in a heavy vise on a Bridgeport was being drilled with a large drill. The vise was not fastened down, the drill caught in the work and started spinning the heavy vise around until eventually the Bridgeport fell over! Maybe those safety guys are on to something . . .

 

[rmd55]

In the Workshop series of books #15 Work Holding in the Lathe right at the end of the book the author gives a design for holding a lathe to a wooden bench. It takes in account the movement of the wood and also levels the lathe to remove twist. The design is simple. A carriage bolt is inserted from the underside of the top in a sightly oversized hole, you want some movement here. A washer and nut are placed on the bolts. You want these just finger tight. A shop made threaded leveler is made from about 2" (50mm) round 1/4 to 3/8" thick (6-10mm). The leveler is placed on the bolt the machine then goes on the levelers. Once the machine is level it is securely fixed with nuts as the last item in the stack.
The machine is secure to the table allows for wood movement because the nuts holding directly to the table are only finger tight and the machine is level. If you are concerned that the finger tight nuts might vibrate loose and change the level use nylocks. Check out the book if you need more info.
Richard

 

[goldstar31]

As far as I recall, Tom D Walshaw as Tubal Cain actually moved from Darlington, County Durham and retired to near Kendal in the English Lake District.

His retirement home and workshop were on the side of a hill- which was constantly moving and this necessitated constant review of the various lathes.

Moving to plywood, I recall that we Brits were making rather sophisticated de Havilland Mosquito aircraft primarily out of balsa wood and -- seaweed. This was the time that 'we'. got plywood which was no longer stuck together with animal glues- to feed woodworm and onto water and boil proof resins. I recall that there was a British Standard BS 1088 and the standard for Marine Ply was AX100.
Digressing ever so slightly, Thomas De La Rue made Formica on the Coast Road between Newcastle and Tynemouth and the stink of phenol formaldehydes was appalling. Slightly to the east, there were timber yards peeling veneers from imported hardwoods for ply.
Further to the West was Resinous Chemicals a subsidiary then of British Paints at Dunston and this was also the start of things like polyester and epoxy resins and modified resins for abrasive wheels as well as having the chemist that moved to Stocksfield to make Hammerite in his own rite.

I suspect that I am a shareholder of some bit of it.

Norm

 

[kquiggle]

Richard - your description of the jacking screw was excellent, but here's an illustration for additional clarity:

 

[goldstar31]

Kqiggle, this is more or less of how Myford adjusted their ML7 series lathes.

I suspect that this probably was in one or more of Tom Walshaw's books.

My stand for one of my Myfords has a pair of steel raising blocks whilst another -the ML10 has wooden hardwood ones. I didn't make the frame for the Super7B, it certainly is not Myford- Myford and the tray is not Myford either but one bright remark comes to mind and that is the balance of the 7 series is certainly poorly designed nd tends to tip away from the operator.

I put a strut between the lathe and my wooden shed. Others might disagree but the shed is on a concrete float- as is my bungalow.

 

[taeright]

When you talk about the table for a lathe and making it level are you just talking about a CNC lathe?
I just have a manual lathe and have just started into this world of lathes.

 

[goldstar31]

When you talk about the table for a lathe and making it level are you just talking about a CNC lathe?
I just have a manual lathe and have just started into this world of lathes.

This was on page 102 of Workholding in the Lathe by Tubal Cain and was written long before CNC made its appearance in the home workshop.
If you plough your way through the Tubal Cain books you will find that Tom Walshaw designed ALL of his models for construction mainly using a 7" swing lathe with a vertical slide.
Walshaw, if you read his history, was a Senior Lecturer in Engineering = amongst his many other qualifications and wrote for ordinary people to learn and enjoy. Like me, I suppose

Cheers

Norman

 

[taeright]

I am sorry that being new is not good for this Forum and I always thought.

"The only stupid question is the question that is never asked."

 

[Cogsy]

taeright - we welcome those new to machining and you shouldn't feel afraid to ask any question. No member should make you feel bad because you haven't gained knowledge yet. Limited esoteric knowledge is not an indicator of worth and some members would do well to remember that.

 

[taeright]

taeright - we welcome those new to machining and you shouldn't feel afraid to ask any question. No member should make you feel bad because you haven't gained knowledge yet. Limited esoteric knowledge is not an indicator of worth and some members would do well to remember that.

Thanks for your reply and your kind words. I looked at this Forum and see all the great thinks make by the members and I wish I could do. It's hard to ask questions when you are new and not a good writer. I am handy with my hands and repair all the things that I can and have made many repair parts without a lathe. I just trying to learn from people that know machines and how to use them.

 

[ShopShoe]

I stumbled accross this video Saturday night that provides relevant information about bolting down lightweight lathes.

This Old Tony (On YouTube) revisited the MiniLathes and posted the following video:



At about 28:18, he uses his example without, then with mounting to a rigid surface.

Food For Thought,

--ShopShoe

 

[Wizard69]

I think I watched the same video last night. I’m surprised that the bit didn’t shatter in that case.

In any event I really believe that home shop machinery should be fastened down in some manner. The last thing you want is a fast sounding spindle rolling about where you are working. That is easy to happen on top heavy machinery.

Wizard69 - Recently "Joe Pie" did a youtube video on work holding safety when drilling. He told an anecdote in which a work-piece held in a heavy vise on a Bridgeport was being drilled with a large drill. The vise was not fastened down, the drill caught in the work and started spinning the heavy vise around until eventually the Bridgeport fell over! Maybe those safety guys are on to something . . .

 

[Wizard69]

Welcome aboard!

I’m not sure what has frustrated you here but don’t be afraid to ask questions. There are guys with decades of experience here (not me) that can provide great insight with respect to model making.

By the way references to books and magazine articles is a good thing in my book as it can put people on the same page so to speak when discussing a problem of project. So finding these old articles or books can go a long ways towards learning about your machinery.

In any event there are many theories about leveling machinery that pop up in these forums. Personally I look at it as mandatory on a mill as it can make some types of setups easier to achieve.

Is it important to setup a bench grinder to a high degree of level? Probably not but even so i like to have the bench they sit on level to some degree. Maybe that is a force of habit but if I move a bench I will level it afterwards.

Now understand that leveling doesn’t mean bolting things down until they twist in place. This is something that you need to watch out for because it is easy to twist the casting of some of these smaller bench top tools.

Thanks for your reply and your kind words. I looked at this Forum and see all the great thinks make by the members and I wish I could do. It's hard to ask questions when you are new and not a good writer. I am handy with my hands and repair all the things that I can and have made many repair parts without a lathe. I just trying to learn from people that know machines and how to use them.