Why the High Table Sides?

[joe_dusel]

I know this must be a dumb question, but why does the ShopBot have the high table sides? They look like they must get in the way when you are loading and unloading panels.

Thanks!

Joe

[thewoodcrafter]

Good question Joe.
I have always wondered myself but never asked.
I think it is the type of rails ShopBot uses on the X axis. It is just sharpened angle iron with V groove rollers. Not something that can be placed under the table. And maybe kept high to keep cleaner.
You can only load from the ends. If the rails are kept greased they do get in the way by keeping you from leaning on them.

[myxpykalix]

I think it has to do with the clearance area under the carriage for Z height. The height of the carriage on the rails along with the lower height of the table surface is what gives you your 6" clearance. If the rails were lower you would have less Z cutting depth.
At least thats what i think it is....

[cwshop]

When I first looked at Shopbot’s from there first beginnings, I never thought much about the rails. Then I bought a PRT one of the first they made. I made a steel table much like they recommended with the sides. Love my machine, but the rails are a defendant change I would like to make. It would be so handy to just side material on and off from the side without going over the rails. Of all the nice improvements Shopbot has made over the years, I think they have over looked this one. If they ever get the X-rails below the table surface, I might just buy me a NEW MACHINE. YE HI.

[dakers]

Joe thanks for your question. i wanted to know the same thing too.

I had a Gerber Sabre router with all the options at $75,000.00 and it was a great router. But the price point of the shopbot is what is drawing me to it plus the forum. It was a servo router. We had a Camtech with stepper motors. We had problems with the steppers and could never solve it. the router just had a mind of it's own about twice a week and destroyed material. We thought it was the static in the dust collection system and we tried everything to fix it but never did. both routers loaded from the sides but we never loaded from the sides for some reason. We always loaded from the end. I always assumed the shopbot had high sides because it was more economical to build and sell but i really do not know what problems the rails impose on others. would like to read more posts about it.

[rb99]

The Y carriage is not stiff enough to be like other CNC machines.

RB

[harryball]

I suspected when I saw the PRS gantry design we were on our way to a machine without rails. Don't know if that's true or not but it would be a welcome change. Dick is right... an extra $25-50k not to have rails would keep me out of the market altogether. I'm very happy with my PRTAlpha96.

I've only found the rails to be a moderate nuisance at times and a black sawtooth pattern is on almost all of my work shirts.

/RB

[knight_toolworks]

I think it would really raise the price. plus the drive may have to go to servo's too that would really increase the price and slow the machine down unless the price jumped quite a bit.

[mims]

I looked hard at Shopbot when buying my router. The final deciding point was the rails. I decided to go with another US built router that did not have rails, because the machine is in a small workshop and is not possible to load from the ends. I have about 3' clearance from the ends of the table, so I am forced to load full sheets from the side.

Shopbot obviously has a good thing going with a good machine, but I just wanted to mention that is why I chose another machine. For reference, the machine did not cost any more than the same sized 'Bot, so I'd think it should be possible for Shopbot to offer such a machine and not increase price much if at all.

[harryball]

I also looked at another machine similarly priced with no side rails. I was having a very difficult time deciding. The friendly people at the IWF and the forums made the difference. I felt more confident about getting support and help from other botters. The other brand I just wasn't so sure. Aat the time, other owners appeared awful scarce and it seemed all support came from one person.

Maybe I'm way off but looking at the PRS style gantry it doesn't look impossible to lower and almost elminate the rails while keeping the same drive system.

/RB

[mims]

R Ball, you make a good point about the confidence in service and support from Shopbot. In my case, I didn't have alot of choice due to my workshop situation, and so the low sides and welded table pretty much were the driving factors in the decision.

[cutitout]

who makes the other machines?

[mims]

I don't want to post about specific other companies on the forum. For one thing, the fact that I went with another machine for one reason doesn't mean they didn't have their own separate issues. The company I went with, as well as several others with similar designs (welded table, low sides) can be seen in the first 10 or so pages on a Yahoo search for cnc routers.

Alright, so moving on.. does anyone with a Shopbot actually find it a nuisance to have the high sides? Even better, are there specific advantages to it?

[harryball]

Email sent. I don't like mentioning other brands on the forum.

[knight_toolworks]

from my research you have a much slower machine. though I don't cut that fast having really slow jogging speeds is not something i would want to sacrifice.

[mims]

Hi Steve, my rapid is set at 1000ipm. I don't pretend I cut at that speed though, just rapid moves. I don't think I've tried cutting over 400. I get pretty conservative when it comes to feeds/speeds.

btw, I like your work and look forward to seeing your posts here.

[dakers]

I was also looking at another brand with comparable costs and they offer servos and low sides and future flexibility. it was all aluminum. the software was comparable. You would have to ask for them to build the table with low sides. The other companies did not have a forum like this. Shopbot seems to have a cult following like the Grateful Dead that is amazing to me. I am sure that is a huge advantage for them. But they must be doing some other things right with customer experience too.
I am sure Shopbot will diversify their products in the future and offer lower sides as an option. it seems to be a natural evolution of their products to go in that direction eventually. The shopbot forum has given me a level of trust i would not have if they did not have the forum. So alot of it is about trusting the mfg and hoping they will be around for future service. Plus if you can get a router for $20,000. that will do the job why spend $50,000 or more. There are routers i would rather buy than Shopbot but for me i need to spend money on other things too.

[knight_toolworks]

yours is not servo based? when I looked at most of the welded table designs (that's something I would have loved to have) they were servo based and speed was something you paid out the nose for.
but I seldom cut fast my first production job this weekend i thought I would have to cut fast to make money but i found rounding over the parts took lover then cutting so I slowed down cutting to match that speed.

[ted]

Well ... actually there are a couple of reasons.

The first is historical and practical. As noted above, the way our earlier gantries worked, it was the best structural way to get clearance height. On our earliest tools, these sides were actually 2x8 lumber which was readily available for building tables.

Second, over time, we came to appreciate the safety advantages of the high sides. While it does not happen frequently, a small part breaking loose or a cutter fracturing can send debris flying. Because of the nature of the tangential forces of cutting, the debris tends to come out horizontally and is captured by the high table sides. Thus, we've come to think of them as safety sides.

Given that you should be using the guard/dustskirt which retains most flying debris, the actual need for additional horizontal protection may be minimal. Nonetheless, it still offers an extension of protection.

We do appreciate that the high sides do make side-loading awkward -- though end-loading is pretty natural if space is available. [Have a look at Rob Bell's ShopBot salute if you haven't seen it; ummm... I say this with a little bit of tongue in cheek: http://www.shopbottools.com/robsmagic.htm#Loading_Heavy_Sheet ].

We are planning on offering a "raised-deck" table option later this year. It will basically be the same table except the cross supports will be bracketed higher inside the table sides. This should serve the needs of those wanting deck-top loading. For those interested in Buddies, note that a PowerStick with outfeeds basically allows unobstructed loading directly onto the deck when at either side of the tool.

Ted Hall, ShopBot Tools

[mims]

Steve, no it uses steppers. You can get it with servos, but I passed on that option. My main upgrade was a Colombo spindle, which I haven't regretted for 1 second.

It's really pretty cool that there is so much competition in this level of cncs. Keeps prices in check and innovation up.

edit: thanks Ted, excellent explanation.

[cutitout]

Thanks for the info -- looks like the Z is short so a "raised deck" would have the same effect.

[joe_dusel]

Thanks all for the great responses! I will be anxiously awaiting the debut of the new machine. So Ted, any hints on what the new machine will go for?

Joe

[ken_rychlik]

Joe, I was wondering if they were going to make a hybrid therm/bot.

One other thing the high sides are good for is keeping the sawdust in check. Thanks to visiting another bot friend, (thanks james) I put some filler pieces in between the spoil board and frame and it does help.

Kenneth

[joe_dusel]

I wonder if the new ShopBot RaD will be shown at AWFS in Vegas this summer. That would give me a good reason to go to the show. Hey Ted, bring one along with the auto tool changer.

Thanks!

Joe

[thewoodcrafter]

Joe,

ShopBot had a booth last show.
Hopefully they will be back this year also.
I have heard vendor attendance is down this year.

I will go anyway and wonder the isle drolling over what I can't have.

[bcondon]

ZZZZZZING Clink


The sound of a cutter hitting the head of a
sheet rock screw (zing) and then the screw head flys and hit the table side (Clink)

It is those words afterwards that can't be put on the forum!

8-)

[joe_dusel]

Bob,

Why are you processing parts with sheet rock screws in them? That reminds me of the sound I made when I used my brand new Festool saw to trim an inch off the top of a door only to find out that an alarm company had inserted a steel rod in it. I was suddenly fluent in French.

I just plan on milling sheet materials, so I should be safe if I buy one of the new RD machines.

Joe

[pro70z28]

My first CNC had a table with no sides. I have to load from the end regardless of CNC design because of the space limitations of my shop. The sides have never been a problem. For what the ShopBot costs (compared to my first table) I am a happy camper. I'd like to be running the Bot this afternoon, but we are having bad storms. I don't know if it's because there is a transformer on a pole not far from the shop , but any hint of a storm and I have to unplug the bot (and anything else electronic out there) or risk it getting fried.

[frank134]

Gary why don't you get a good tvss for you panel and a good ups for your computer. then put in some very good grounding. As for the high side I like them. I am new to cnc so every time I set a new part to cut I get nervous as hell. I rest on the high side and feel like I am sitting at a craps table and some how I relax. I don't know why I don't gamble , but I relax.

[joe]

Frank,

Good for you in liking the the high sides, but they won't be around for long. The reason being they are no longer needed and for many CNC production shops, they pose lots of limitations.

All the CNC manufacturers I've seen are becoming more sophisticated and accurate, offering very advanced options. None of these have raised sides on the new models. It won't be long before the TC is a standard option also.

Joe
www.normansignco.com (http://www.normansignco.com)

[mikek]

Ted mentioned "safety sides". My friend cuts mostly aluminum with her Bot. Last week a small part got picked up by the bit, was spinning very fast immediately, bit broke, and the part and bit went sailing. They hit a pail full of paintbrushes, cutting off a few handles on the way. This missle went down the open end of the table and not into the "safety sides" that would have stopped the missile possibly. She couldn't find the missile and gave up looking for it. That afternoon, 50 feet out in the parking lot, her manager found it. They don't use the dust boot on aluminum because it gets gummed up with the cutting fluid they use. I think the high sides are fine.

[rb99]

I don't understand how the high sides helped.

RB

[joe]

Mike,

This isn't another one of those Longhorn Texas tales is it?

Tell your friend about Belin O Bits. With these there isn't any need for cutting fluids. And the edges of the aluminum will be mirror glossy. We completed 77@ 4" letters a couple of weeks ago. They were from 1/4'aluminum. The Belin not only finished up this job, it's still in use. Be sure to order the up spiral O.

Your right about protection, she should be wearing some kind of armor plate clothes with that 50' slinging metal.

Joe Crumley
www.normansignco.com (http://www.normansignco.com)

[bleeth]

Richard, If you are prepared for a gun fight and wear a bulletproof vest you still might get shot somewhere else. But if it does come at your chest you are protected. There may not be any guarentees but protection of a sort all the way along the x is better than none at all.
That being said, now that SB is actually getting close to a value priced totally stiff gantry moving the guide and drive under the table is probably a couple of updates away. (would that be the PRWOW?) The key is not just a design that has the x rails under the table, it's doing it and still keeping the price well under the big iron and improving speed and smoothness at the same time.

[rb99]

I cannot understand how that is difficult to do...

They need to manufacture the gantry ends out of heavy material. This cannot cost very much more than what they make now.

Just look at CNC from China...

RB

[joe]

I think Richard is correct. It's just a matter of changing the concept. Once you see how simple and clean it all works, you will want one.

Both of my neighbors have units with rails beneath the table and it solves some problems aside from operator convenience of loading materials.

One that comes to mind is the stability of the gantry. There isn't any way it can come off track.

[pro70z28]

frank
Gary why don't you get a good tvss for you panel and a good ups for your computer. then put in some very good grounding.

I could do that but unplugging it is cheap & effective. I do the same with my TIG welder out there. Many years ago I had my first CNC get hit by lightning. It fried it so bad I could smell it when I opened the shop door. The Bot got zapped once even though it was unplugged. It came through the com cable. Didn't hurt the computer but did knock out the board on the Bot. I've since got in the habit of unplugging both the Bot & the computer. That has been the end of my problems with storms.

[servant74]

There is a DIY router that was initially based on an old SB design. www.mechmate.com (http://www.mechmate.com) ... It too has the 'high rails'. After looking at their design pretty closely, I get the feeling that the reason is to keep from having to make the gantry 'to tall' or having to extend the 'base' of the gantry to far to add stability without adding cutting surface area. ... Still, just conjecture on my part.

If I did a DIY version, I would think about making a 'back' high rail, and 'lower' the front to below the bottom of the spoil board. That way it could be loaded/unloaded from one side.