If I was to do it all over again I would go with the Grizzly bladed style over the abrasive cut off saw anyday.

@Travis; I have seen both machines cut and I could agree with you, I think for me however because I dot plan on cutting that much steel that paying 2.5 times the price for an blade vs abrasive was not justified. IF I needed to cut a lot of steel or build another MM I would certainly do it. This next project I am working on only requires about a dozen cuts to 3x3" (.125") square tubing.

Here are a few shots from the shop today. I took a break from welding and machining while I recovered from being sick for a spell. One side is done minus the holes for the cross members and top rails. I hope to start on the other side shortly. I've been rearranging the shop this weekend so that I can start to assemble it pretty much in place.

Attachment 13129Attachment 13130
Attachment 13131

Coming along nice Herb.. Good Job.. You will be making dust before you know it.

I want to know how you guys keep your shops so neat and purdy :D !!!

@Mike, thats because they don't have a MM yet making dust :)

Maybe Hennie with (on) his broom visits every night.

When my shop is not dirty thats when I know Im not making much money :(

Why ... ?
 

does every one making steel machines do solid welds....I have been a structural welder for 45 years and never do we weld solid...to much waste. Not even bulldozers are welded solid... ; ) Nothing could convince me it will hold better. Also for those that want nice cuts, you can buy 40, 60 and 100 tooth cold cut blades for chop saws....I will try to post a link...

Well I think we weld solid becuase we figure that if we get half of it to hold we did good ..... :D !!!

:D:D.... I make a lot of money because I charge $50 an hr and it hardly ever takes me more that an hour to weld up anything....Say on a leg ...tack each corner and 1 " down each side then weld around each corner in 1/2 " welds.....never top or bottom or it will pull on the top frame piece....all ways let it normalize at air temp...use jigs when possible and use a big rosebud tip to normalize joints that have pulled and they will usually go back to position.

Great to know we have a professional welder among us.



Would you mind elaborate on the procedure. If all possible a tutorial is most appriciated. I'm about to make a 28ft square hollow section beam from a 20ft & 8 ft 2"x3" square hollow section. Really don't wiant to end up with a crocket & twisted beam.

You need a table and supports for the section that overhang the ends....clamp a section of 2-2.5 " angle, at least 4 ft to the table and center it ....use a string and push or pul it till it is perfectly straight. Prep you tube by grinding your ends to be joined, to a 45 degree bevel, leaving an edge where they touch, the thickness of the wire or rod you are using to weld with...leave a gap of the same thinkness...this will insure pentatration.... i like to do big spot welds one over lapping the other !
Clamp to the table against the angle and place another piece of angle on the other side ....use at least 4 clamps ...one on each side of the break and one on each end. if you can, clamp the second angle to the table too !
Make sure the weld method can do the job..... test with scrap plate ! Tack the tube on all 4 corners, turn the tube to get to bottom....grind tacks if they are not flush..... if your machine is having trouble doing the weld in one pass , heat tube, with torch and make multiple pases. , but do one side at a time...make a root pass and clean all welds, then make the next series, till the groove is filled slightly above surface , then grind for finish.
If you take your time , you can have a tube, that when painted no one can tell were it is joined! The string is your best friend for straightness.....you can use a torch and heat the high sides and rapid cool to straighten ....only practice will make you good at it ....after 45 years , I almost got it down ... ; ))))

Metalsmith,
Thanks for the run through. Clears some doubts as I read.


Like is in particular, this method never sprung in my mind ever. Will definately have a go.

Another question.
I do worry when weld solid on one side at a time, the heat will pull the tubes. Do you mean that the tack will hold them from pulling? or I'm am just over worrying?

Ken
 

The spot welds need to be hot enough to melt into both parts .... if the heta is not high enough .... holding the trigger (mig) will only make it worse..... What method (Type of machine) do you use /

Lately, I bought an economical Chinese MIG, The manufacturer's manual & specs are useless, so I measured the max. Voltage range to be about 14~32V. Max current is about 200~220Amp lowest about 80~100Amp.
So far, I had success welding upto 1/4" (6mm) which is thickest I need to weld to ate. using 003" (0.8mm) wire with the voltage & wire speed dial set about the middle of the full range. I am using pure CO2 gas for now.

Before the MIG, I use my portable 160A inverter stick welder.

Ken
 

Use the CO2, cheapest and gives a hotter burn.... the spot should lay down flat if you have the right heat & feed....should sound like frying bacon(Meat)...we have cowboyed the thread long enough, send me questions in PM.... ; )) Thanks

Herb
 

Any updates ..... ?

Both sides are welded up and the feet are installed. The cross members should be done soon and then I can begin to bolt them on to the sides. I'll take some photos when the beams have all been drilled and the cross members are bolted on. I've been dreading grinding the rails but that's next for me after the cross members.

A little progress. I am 1 cross member short so it'll have to wait a bit more. I also had to stop because I bent the only bit I had in that size. How many bits did you all go through on your projects? This will be the 3rd in that size. Anyway, three more cross members to drill and attach and then that'll wrap up the majority of the table. Only minor fabrication left on the table and then onto the rail grinding.

Attachment 13212Attachment 13213

Hi Herb.

Try drilling at slower RPM . About 60 rpm.

And lube the bit while drilling to keep the heat down.

I only used one set of drill bits in my build. None bent or snapped. Lots of cutting oil. Frequent sharpening (I use a Drill Doctor - a worth while investment that's paid for itself and given me a new "skill"). A drill press is key so the pressure is directly down. All my drilling was at 100rpm. Probably slow for some people, but I did get nice curls coming off the bit.
Here's a post that helped me http://w3.uwyo.edu/~metal/drilling.html

Drill Doctor rules, and I never see anyone else talk about it.

Buy the few bits you are going to use a lot in Cobalt.

They last 6-8 times longer than normal, and when you resharpen them, the cobalt is not ground away.

I have one!!! 750X rules :D !!! Use it all the time.

Made by Darex - Drill Doctor is there domestic brand. Real toyz here:

http://www.darex.com/

Nowadays, hand grinding drill bit is a lost skill.

I have the darex XT3000, but my preferred method is by hand and a drill gage. I like to simpleness looking at the drill doctors.

Well I'm back at it and working on the record for longest build. I think I have it squarely in hand if I ever get there. I have a quick double check I want to throw past everyone. I'm getting back to the kitchen table project. I plan on running a 110V router initially and eventually a spindle with a VFD. I would also like to run a 110V dust collector and have it turn on automatically. I found the following solid state relay (CRYDOM CKRD2430) and just wanted to run it by everyone before I ordered two of them. One for the router and one for the dust collector.

http://www.crydom.com/en/products/catalog/c_kr24.pdf

Another follow-up question. If I eventually go to a VFD with a spindle, should I consider wiring up the panel with 220 volts or leave it at 110 volts as I have it now?

I'd run 220 in anyway, gives you the spindle option and its just one more wire in and a few minor differences in contactor, etc. I asked the very same question about setting up the dust collector to turn on automatically, it was suggested by several not to and just do it manually, but to each his own.

I personally prefer to turn on the dust collection manually.
I have found, that I always had at least a few cutting operations that dust collection hurt the process, than helped it.

Good luck with your choices.

Kitchen Table Project
 

Updating you quickly during my work lunch. The heat sink is mounted with all the tapped holes ready for mounting the Geckos (will put in temporarily and wait until the end for the heat sink compound), the BOB stand-offs are in, and expecting the SSRs today or tomorrow. I hate parting with the money but love having gifts at my door when I get home from work. Tonight's short list, mounting the control panel vent, mounting the muffin fan, prepping and cutting wire to connect the Geckos to the BOB.

I'm doing some last minute calculations and just want to run it by the electronic experts...which I am definitely not.

Using the following:
PS5N30R5R12
Gecko G203Vs
PK296A2A-SG2.7 Unipolar (half coil) equating to 3A/Phase

47 x 3 / (7 - 3) = 35.25

I need (4) 35K resistors. Do I have that correct?

By the way, I upgraded to a larger panel. One of the other forum members graciously traded me for my smaller panel so I had to do some rework. Please disregard the earlier photos of the control panel.

They only had 33K resistors at Radio Shack. Will I have any problems using those as opposed to the 35K resistors?

Those will be fine!

Well, it's a major milestone for me. I was able to get everything talking to each other. Very exciting since I'm not an electronics wizard like some of you out there in MechMate Land. I'm looking forward to finishing up the rest of the panel but it was nice to take time out to get things moving for the first time.

http://youtu.be/b3qS8uHoFpA

Excellent, that's a big step. Keep on a roll.:)

On Its Feet!
 

The table is finally on its feet. I was able to squeeze a little work in on the table and control panel.

Started the dreaded rail grinding. Won't get much time with it during the week but at least it's started.

Just wanted to update everyone on my status and pass along my solution to the cross angle brace. Don't look too closely at my Frankenstein welds because it was definitely a challenge for me to figure out the angles. I used the holes at the bottom of the channel that will be used for drilling out the support board. I simply made a bracket that spanned two holes on the channel and then welded the cross angle brace to the single cross bearer on the bottom. I still have the other side to do but I wanted to make sure it was going to work out.

All of the grinding is finished but I haven't drilled the holes out for either the table or the gantry. I will tackle that after I finish the other cross angle brace.

Wiring and Paint
 

I figured it's time for an update. I was able to get quite a bit done over the past couple weeks. I'm happy to say that there are only very minor items left on the build checklist excluding wiring. I made a few minor mistakes along the way but nothing that should impair the operation of the machine.

I ended up with a broken tap (see photo) in one of the main beam holes but other than that, it's ready for wiring and paint. So question to the group. Would you stop now and paint the whole thing first before wiring or would you finish mocking it up in case there are additional brackets to add, etc? I was thinking I would do a test run with it before paint due to the lack of warm weather here. I probably won't see temps appropriate for paint for another 3-6 weeks anyway. Suggestions?

Some don't even paint it for awhile, personally, cold weather or not I'd paint it first. Adding things to it later may require touch up, that's about all. If you don't paint it now you may never paint it.