Unheated Shop - PRT Alpha Control Box protection?

[Einsiedler]

Dear All -

As the cold weather returns, maintaining a uniformly warm PRT Alpha environment becomes increasingly expensive, especially w/ intermittent shop use.

A few questions:

1) Any suggestions for appropriate control box temp control, as opposed to "whole shop" heating?

2) With some alternative solutions in mind, what is the "official" allowable ambient temperature range or the control box electronics? (+33 to 95 degrees F ?)

3) Could a control box "jacket" and an "in-box", thermostatically regulated heat source do the trick? (Assume that the control computer and display are not part of this discussion.)

4) Should I worry about the steppers?

Condensing atmospheres are always a potential problem, I realize.


TIA, Einsiedler

[gene]

what part of the country do you live in? I am in Ga and do not worry about the cold . I have a prt alpha and i do nothing to keep it warm in the winter . I heat the shop with a torpedo heater when i need to but at night i dont leave any heat on . If it makes you feel better you could get a electric blanket and pillows for yours. Just do not tell mine , it would probably want one too!

[stump]

I run mine in an unheated garage in Minnesota. The shopbot has never had an issue. Can't say the same for the operator. :D

[gene]

I am going to guess Stephenstown NY:eek:

[Einsiedler]

Dear Responders, All --

Minnesota sounds closet to this climate in this part of NY state, though the cold/winter here is perhaps less consistent and more given to frequent fluctuations into condensing conditions. -20 F isn't unusual, but the quick rate at which exposed, untreated steel/iron can develop a bloom of rust is surprising. (I keep the bot "rails" lightly greased between sessions.) I'm guessing that you, Miles, rely on the control box gasketing to ward off condensation (inside the box). I know that LCD displays are ruined by cold temps, while CRTs seem to hold up better over time.

Just wondering if anyone has had problems (that I can avoid with advance action) and what they may have been.

Thanks!

[Xray]

My LCD did fine in an unheated garage last winter, though of course last winter was fairly mild.
I do have a propane forced air heater to take the chill off when I'm in the garage, but its unheated 90% of the time, and I had no issues with computer/control box or machine. [I live in MI].

[jerry_stanek]

Here just outside of Cleveland No heat in shop and PR and PRS runs fine

[tlempicke]

You got it kinda backwards there! When it comes to computers cold=good, hot=bad. That is why supercomputers have elaborate cooling systems.

What your REAL enemy is is moisture. A dehumidifier can take care of this.

If you want to warm up the machine before using it. remember that the motors get their hottest when not moving. So just turn it on for a bit. Your spindle has it's own special routine, use it once ot maybe twice.

Figure out how to use a keyboard with mittens or gloves on.

[chiloquinruss]

If I haven't been in the shop for awhile I run my surfacing routine without a bit in with the spindle running. I do the spindle warm routine first though then the surfacing routine. So far no issues that I am aware of. If I can't see my breath then the shop is ok for temp, if I can see my breath then I run the shop heater for a bit to bring the air up to temp. Shop is heated with propane and around here that is expensive these days $4.09 gal delivered! Temp at the moment a very balmy 34 and windy! Russ

[jerry_stanek]

There is a fellow shopbotter in the Toledo area that has his shopbot in a freezer to do ice sculpturing.

[Brady Watson]

As others have pointed out - Cold is not a problem, but moisture can be. Watch the condensation.

Also - you'll need to take extra care when warming up your spindle. If it is really cold, I'll start mine spinning at 500-1000 RPM, and creep it up slowly. I realize that many of you are pegged at 5000 RPM as your lowest possible speed you can turn your spindle, so that is where I would start. The VFD is capable of spinning it down to 60 RPM (1 Hz) but many of the newer VFDs are programmed to go no lower than 5000 RPM...you can program it to go lower if you are inclined to do so.

For those that want to know, the colder it gets, the thicker and harder the grease in the spindle becomes. It can get like candle wax...to prevent skidding the bearings, I always spin the nut first by hand a few times and then start it out at a really low RPM, like 1,000. You certainly don't HAVE to do this, it's just what I do on those really cold days.

-B

[Einsiedler]

Many thanks to Brady and everyone else! With so many affirming experiences with cold conditions, let's switch to the issue of condensation. What's a conservative/practical approach to protecting the box electronics? Perhaps put a pouch of desiccant* inside and tape all the seams with something like aluminum duct tape? (Annoying for quick box access, but better than trouble?) *Such as: http://www.uline.com/BL_1005/Container-Dri-II-Desiccants

~E

[curtiss]

Would a small light bulb and/ or a fan that runs off a simple thermostat work ?

I know they make some small heaters they use under grand pianos when they turn the temps down at the church.

[gene]

i think that if you were to put a heating device in the control box you would be asking for trouble . The temp difference between the outside and the inside of the box would cause condensation. if it were in a small heated room then it wouldn't because the inside the box and outside the box would be the same temp . What do you all think?

[myxpykalix]

I am in Virginia and some days it is very cold, not Minnesota cold, but cold and lots of days i leave my laptop out there (I forget it) and i's ok.
I asked this very question when i fist got my shopbot too because i was concerned but was assured here it would be ok and in 6 winters i've never had a problem!

I've never had a problem with condensation but if you just leave the power to your control box on all the time (I don't do it) then all the electronics will stay warm.

[stump]

I'll step out on a limb here and tell you that condensation will not be an issue in a cold shop. Both from experience and because for condensation to form you have to have one of two sets of conditions.

First one would be a surface colder than the surrounding air. This occurs in the summer with a cold drink on a hot day, or in the winter it occurs whenever a guy with glasses walks into a warm building. (personal experience :D) Your control box will be the same temp. as everything else in the shop or even warmer if it has been running so no problems there.

The other scenario is that the air has to cool and become saturated in which case frost (dew in the summer) forms on all surfaces. The outside air will cool before your shop does, so it should not be a problem. That's why I put my car in the garage at night, no condensation (frost). Now if you have frost forming in your garage you have bigger problems, however even if you did the gasket will keep the electronics clean and happy. After all, frost forms on the outside of the car, not on the inside.

Condensation is a problem with electronics when you take them from a cold place into a warm place. That's when you can have issues. An example would be taking your laptop that was left out in the car overnight into the office and firing it up before it warms up.

I agree with the other posts about the spindle. If you are fortunate enough to have one (I'm a router guy) I would run a warm up program. I know the CNC's where I work will not even let you run a program unless they are warmed up. They are larger, metal working machines, but the concept is the same. Spindle bearings are a precision item and need to be taken care of.

[rb99]

My old controller has been in an unheated garage for years, no problems. I have a brand new 4g box I am hooking up soon and I was thinking about bringing it into the house when not in use, which could be most of the time.

Would all the plugging and unplugging be worse than it just sitting in a cold cement floor garage?

[jerry_stanek]

My old controller has been in an unheated garage for years, no problems. I have a brand new 4g box I am hooking up soon and I was thinking about bringing it into the house when not in use, which could be most of the time.

Would all the plugging and unplugging be worse than it just sitting in a cold cement floor garage?


I would not bring it into the house the. change in temp could cause more problems. I have an unheated shop and have had no problems keeping the 4g box and computer out there and just starting them up when I need them. I have done this with 2 tables at the same time. A PR and a PRS both with the 4g.