New from Tennessee

[Bank Walker]

Just wanted to introduce myself. I bought a 4x8 shop bot a week ago yesterday. Might take a while to reassemble and get it back operational. I am sure I will have lots of questions for the group.

[Bank Walker]

30975

First of many pictures

[Brady Watson]

At first glance, this appears to be an early PRT 4G - looking at the AL extrusion on the gantry, CNC bent legs and gussets.

There are several non-factory parts on the machine that I can see - The X rails are Bishop-Wisecarver (BWC) but are tacked on to the AL square tubing in a horizontal configuration. Hardened rails are better than stock, but that wasn't the best way to pull it off.

The stepper motors (at least the one on the Z) is not factory & I cannot tell if it is running gear reduction. It doesn't appear that it is - and that means very coarse movement and not a lot of torque.

The cable carriers are a nice addition - not factory though. Most problems with these machines stem from poor wiring management.

Post more pics - including ones of the control box electronics, and I'll do what I can to help identify.

Welcome to the SBF.

-B

[Bank Walker]

3097630977309783097930980

[Bank Walker]

3098130982309833098430985

[Tim Lucas]

Welcome !!

[Brady Watson]

Hopefully you paid pennies on the dollar or got it for free...Somebody did a LOT of hacking on that machine & I wouldn't say it was for the best. I am not someone to blow sunshine - so I'll tell you the truth. This machine *could* be a decent reliable machine, but you're going to have to put some money into it. You basically have a blue frame with a ShopBot sticker on it. It's a lot like buying a car as a rolling chassis...

The Y acme leadscrew (not even anti-backlash) isn't factory, nor does it belong on any CNC. Neither are the controls - appears that someone pulled all the SB controls and downgraded to a parallel port based control software. What a shame. It doesn't appear that any of the high quality stock Vexta steppers with gear reduction are on the machine. They broke/cut the gantry where the stock X motors would go...so there's some welding to be done too...

You're probably looking at $3k minimum to get the machine in working condition where you could rely on it - on a shoestring...with you doing all the labor. You need a modern control box (maybe could reuse the motor drivers but they're old tech), new motors with gear/belt reduction, or you'll have no torque or resolution, take off the Y screw and replace with rack & pinion. Any less than this & you'll just have a boat anchor and you'll be forever frustrated. You could spend a little more and replace all the junk with real linear bearings...and a spindle instead of that Porter Cable, which may need brushes and bearings as it sits.

Don't want to come off all doom & gloom but I've wrenched on more than my fair share of these machines over the years...

-B

[srwtlc]

All I can add to what Brady has already stated is "Oh My"!

[Bank Walker]

Well, not sure where to start that is best. No need to get angry or frustrated yet. No since in getting upset. No, I did not pay much. Nowhere near a new machine. I realize there are much newer and much higher tech units available. I knew it was older when I bought it. I watched it run. He used it mostly to fabricate cabinets and cases for sound systems. While I was there he used it to turn a 1x12 into a box with predrilled holes, bottom groove and dovetails on the sides. Yes, it is slow but plenty fast for my needs, maybe. I plan to use it to cut 4x8 sheets of material and engrave signs. Considering I am starting from nothing, it is a start and gets me straight up to 4×8 size.

I will need to reassemble, get it wired back up and running. Then see how well it will work for my needs. Then upgrade, change out as needed. No stress.

It has Mach3 and Lazy Cam with it now. So, I will be looking at upgrading that also when I get it all up and going and need more design capability.

[Bank Walker]

30989
This is my weakest mechanical link. If i can replace this welded piece of angle iron with the 2 nuts for proper cnc equipment I feel it will greatly speed up the machines performance. At higher speeds above 100 inches per minute it would flex the 2 away or towards one another causing chatter in the units operation. I have no clue what should be there or why it was replaced with this instead of something factory OEM ? But, it is and we will fight this one battle at a time. Again, no stress. Maybe, this entire ball screw setup will be swapped out instead for a rack and pinion before i change the control system. Time will tell.

[Bank Walker]

3099030991

I thought this control system was the most mismatched part of the unit. Again lots of potential but a huge learning curve to get the bugs worked out. This is another example of needing a replacement but unsure what is needed that will work with the current machine. I am a firm believer if something ain't broke don't fix it. It is never going to be as great as the new machines on the market. Operational is more my objective as opposed to optimization. Thanks for all the help. Your input already has me looking at possible solutions to the known issues.

[chiloquinruss]

As I have followed this forum for some time I find that most of the issues with 'reassembles' is that of grounding. Make sure your machine has really good ground connections as this will help to minimize 'some' of the reassemble gremlins.

Welcome to the forum. It's a great bunch of craftsman. Russ

[Tim Lucas]

Hey when you get it up and running again just take it slow and learn then when you can afford to upgrade or purchase a newer used machine then you will have some more knowledge to put with it.

My machine is an older unit and when I got it running I found the Z plate was wore enough that I could not adjust the rollers tight but I used it and just accepted the fact my accuracy was not as good as I wanted. Saved some money up and purchased a used Z upgrade, much better now but I still run the PC router. Saving some more money up and hope to someday get an alpha with spindle.

The key is you have to start somewhere and I have seen some purchase a brand new machine, get frustrated trying to learn and just give up so its not the machine that drives your use but your knowledge.

Have fun
Tim

[bleeth]

It's OK if your machine is not ShopBot Standard. Many over the years have modified their mills for various reasons in ways that SB didn't. Sometimes, SB liked those mods so much they adopted them. Regardless-Welcome to the fold. We who have lived with and love the epitome of Tinker Toy CNC's welcome you.

[Bank Walker]

Thanks for the kind welcome , it ain't all gloom and doom. I have lots of help. A friend within minutes drive that has built several. Another member here has offered advice before I ever joined. The seller, who moved 4 or 5 times and moved this machine and reassembled it each time, has offered to advise as needed. We talked today for a hour about the y axis leadscrew swap to a rack and pinion. My middle son is a computer tech guru and my baby boy is an electrical engineer with computer code experience.

I am off for a week. I plan to assemble, test and trouble shoot as needed. I saw it in service. I plan to see what I can live with and what I can not. The control system is my weakest link as far as having a plan. Replacing the router or setting up a spindle comes in a distant third behind the y axis and the control boards. The Lazy Cam software is my final piece of the puzzle that will be upgraded after it is at a good operating level. This is just a hobby type deal. Maybe use a few days a month. We have a small mom and pop type business only open 5-6 months a year. Once I build the stores inventory with some signs and stuff it will just be used to fill orders or inventory sells. Nothing major.

Thanks again. I am sure I will have tons of stupid questions.

[srwtlc]

On the toolpath/design software, if you can swing it, you would be miles ahead by getting at least Vectric's VCP (you need a Christmas present ;)). LazyCam is part of Mach3 and is not a design program, but is an importer of .dxf files for toolpath generation. This will lead to much frustration and only hinder your road ahead. Besides that, it's deadware. I see that your Mach3 install is set to use the good screen set by Gerry (Ger21), that will help with using Mach3 by limiting much of Mach3's clutter.

If you need to stay with the controller as is for the time being, an upgrade to it would be to drop Mach3 and the parallel port and update it to Ethernet and UCCNC (Gerry has a good screenset for it also). You can then run up to windows 10 with it if desired. I've been running it on a small machine with a previously Mach3 setup controller and the motion is better than Mach3 due to better trajectory planning in the constant velocity settings. Mach3 was always a struggle to get it set right to run the machine well without rounding corners of parts. Since your tool is slower, it may not be as much of an issue.

[Brady Watson]

^^^^^^^
Solid gold advice right there kids...

-B

[Bank Walker]

Thanks for the info. I do not understand what some of it means yet but I am learning. I know it important and I plan to write all these ideas down. My big issue is I do not know what it was like new. I only know the now but even unsure what is good or bad. It's like learning a new language from a text book. I've been reading about updates they had for this system and how much of the tech over the years has progressed so quickly that the company had to stop supporting the systems so they could concentrate on newer technology.

As I understand it it has a 32 bit system. So, this in itself limits my upgrades without totally gutting it. Time w I'll tell.

I have been looking at getting v carve pro as a design program.

[otlkirk]

First welcome.
Second where in TN I'm in cookeville and have 3 shopbots.
Last if I can help feel free to reach out.

[Brady Watson]

The machine looked similar to this when new:

30993 (click to expand)


and the control box, if the 4G version, would have looked like an ATX case, with toroid power supply (like your box has now) guts like the attached pic. This is circa 2005 tech or older so...keep that in mind.

32 bit/64-bit doesn't really matter...

-B

[Bank Walker]

Ok, Camden Tn. About 3 hours from Cookeville. I am about as far away from Nashville as you are but on the other side. I bought this out of Nashville last week. I had been doing a bunch of internet searches on the Google about cnc and laser machines and this popped up on my news feed on Facebook. I got it and the dust collection system that was attached. Good or bad deal, time will tell. But I think it will not be a bad deal as long as i keep a positive attitude and do my best to get it to work.

Great news about the 32 bit. I thought that was part of my restrictions I had to deal with. Just shows my lack of knowledge.

[Bank Walker]

Jerry, I tried to reply but your in box is full.

[jerry_stanek]

I just emptied some messages.

[otlkirk]

Ok, Camden Tn. About 3 hours from Cookeville. I am about as far away from Nashville as you are but on the other side. I bought this out of Nashville last week. I had been doing a bunch of internet searches on the Google about cnc and laser machines and this popped up on my news feed on Facebook. I got it and the dust collection system that was attached. Good or bad deal, time will tell. But I think it will not be a bad deal as long as i keep a positive attitude and do my best to get it to work.

Great news about the 32 bit. I thought that was part of my restrictions I had to deal with. Just shows my lack of knowledge.

I'm familiar with the area I grew up in Palmersville. They are great machines for the price point and as you will learn the support here is unbeatable.

[Bank Walker]

Yea, been thru there many times. My son's all graduated with their bachelors degrees from the University of Tn. there in Martin. Small world.

[Bank Walker]

31002

The reassembly process is complete. Next thing is to hook all the wiring up and attempt to test. Maybe by Thursday.

[Bank Walker]

31400
First project from v-carve pro trial edition. Me and one of my son's spent a few hours wiring the cnc back up on a warm day the first week of January. Then months of cold weather and my regular job kept me out of the shop. Tested it last weekend. Found 2 loose wire connections then tested the operation by programming a square path with Mach3. Today, Hooked up laptop with Windows 10, downloaded V-carve and tested it with this open sign program after we closed up for the day at our store.

Next step is to purchase V-carve, buy some different size bits and resurface the top sheet. Then get to work on orders we have received. Ran this program at 100 inches per minute with a 1/4" upspiral mill bit and a 90 v-bit. Total time to machine was 20 minutes.

[scottp55]

Congrats!
BUT I notice your end mill was Z-Zeroed considerably lower than the VBit was...VERY important to ZZero at the same exact spot on the material at the bit change!
It will dramatically change your finishing/sanding time.
Welcome:)
scott

[Bank Walker]

Yes, when I ran the endmill program I raised it up to exactly +1.000 after I zeroed the bit, then after that program finished it returned to +.800. I was unsure why it had returned to that position but figured it was part of the program. I also noticed the vbit was shorter than the end mill bit. I positioned the vbit a little lower in the collet to kind of compensate for the fact it was shorter. I just eyeballed the length of the two side by side, one in the collet and the endmill as my guide. I was unsure how exactly to deal with this issue in a two bit project. The vbit could have went a little lower into the cut but I guess I was positioning the vbit wrong or the program should have returned to +1.000. The fact it did not shows preprogrammed points. After the vbit program finished it also returned to +.800. It was getting late so I did not take the time to search the setting to check for possible causes. My lack of knowledge is the 3rd issue. Considering it was my first project it turned out as well as could be expected. It was not a fail, but still a learning experience. I am already trying to decide if I should retry that same project again to try and learn from my experiences this time or move on to another. Any advice is greatly appreciated

[coryatjohn]

Each time you change a bit, you zero the bit to either the table surface or some predesignated place on your work that isn't going to be machined down. That way, you always get consistent depth regardless of the physical difference in length of any two bits.

There are several ways to do this. Most use the zeroing plate and the zeroing procedure. I use the "eyeball" method and have given up on the zeroing plate. The way I do it is to get the bit close to the table with the K (keyboard), then go into the fixed (D) step and use 0.01". By using a light mounted on the side wall, I can judge precisely when the bit touches the work or table within 0.01" which is usually good enough. Sometimes I go to 0.005" steps if it's something like aluminum.

It is impossible to get two bits at the same length or even close by just chucking them up. If you can get within 0.1", you are lucky. Most jobs require better precision than that. As you get used to the machine, all of this will become second nature.

(John from Memphis)

[tlempicke]

Your decision to go with VCarve is a good one. You will eventually wind up with the full version of Aspire, and getting V Carve now will save a lot of time re-learning things down the line. I have bought VCarve and all of the upgrades as they have come along. You might think about getting the full version as a money saver down the line. You can use it, as it comes to you, to drive just about any CNC machine in the marketplace today.
One thing you have to be able to do with precision is return the bit to the 0,0 position and to zero the Z axis reliably.
I am a user of the Shopbot SB3 setup and so I can.t help with control inputs. What I can tell you is that there should be limit switches on your machine. There is a routine native to the SB3 software that will use those switches to send the carriage to 0,0 with good accuracy. You need something like that so that you can always get the tool to a known point quickly.
As a for instance - I want to cut 20 "No Parking" signs.
I would set up a couple of rails on my table so that I can put the piece of stock in the same place every time and use clamps to hold it in position. I would then issue the command to zero the bit to the table coordinates for 0,0. Then move the bit to the 0,0 position FOR THE MATERIAL I AM GOING TO CUT. Record the x and y coordinates and then set the cutting program to 0,0.
Now I can return the bit to the zero position for the sign, by using those X and Y coordinates, quickly and with good accuracy.
This turns out to be more important than you think it might be. The same holds true for the Z axis.

[Bank Walker]

Yes, I think that is a huge hole in my knowledge base. Like how to get the machine back to home, with one button push. Mach3 is my program and I am still learning. I need to watch lots of videos. i did not get any instruction manuals with the cnc. Plus it has so much that has been changed.

[Bank Walker]

31452

Practice attempts # 2 and 3. I did run the programs on a 1×12 also but I gave it away to a friend that is tutoring me on how to use the programs and the machine. Not like he needs it or anything but at least I have some results. Might try it one more time before I move on to a different practice project. We created 3 more yesterday and each requires a tool change or two. I figured out how the system remembers positioning of x, y and z.

[Bank Walker]

Project # 2. 31461

[Bank Walker]

31463

Stained and poly