MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Personal Build Histories > Construction started, but not cutting yet
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Sun 19 January 2020, 10:37
Panovak
Just call me: Paul
 
St. Paul
United States of America
Frame started

I've finally started on building the mechmate. I am a complete beginner. Never welded or done any metal work but I'm not gonna let that stop me! I joined a local tool share space which gives me access to amazing equipment 24/7. I got lost in the work last night and looked up at the clock and it was 4am! Drilling holes in metal with the nice drill press is actually very calming. This was contrasted with the chaos of me attempting to weld for the first time.

Anyways here's a pic of my progress.
I'm using metal that was nearly free to me so it's a little beefy. The I beam is 12x6.5" (around 30 lbs/ft).
I want to cut 49" x97" inch sheets. Im butting the cross members on the web of I beam. This gives me a height of 8". The beams and cross supports will be welded. The legs will be bolted to the I beams. The x sides will be welded in one piece and then the y sides will bolt to this.

I have a question. The distance from outside to outside of my I beam is 72.15 inches. I've been trying to figure out how long my Gantry tubing needs to be to conform to the plans. Or another way of asking is how far past does the Gantry go past the outside of the main beams?

Also any help or suggestions would be great. As I said this is all new to me. Thanks
Reply With Quote
  #2  
Old Sun 19 January 2020, 11:34
Panovak
Just call me: Paul
 
St. Paul
United States of America
Dry fit

Base table. 49"97"
Attached Images
File Type: jpg IMG_20200118_221848078_10.jpg (62.4 KB, 245 views)
Reply With Quote
  #3  
Old Sun 19 January 2020, 19:06
xraydude
Just call me: Ted #131
 
New Orleans, LA
United States of America
In Gerald's plans, I'm sure you know the gantry tube length is y + 19.7" (500mm). That was dependent on using the plan's formula for the distance between the outer edge of the main beams being y + 17" (430mm). From your post it looks like you actually used y + 23.15" (588mm) to get the 72.15". Assuming you are mounting the x-rails according to the plans, (with them overhanging the outer edge of the main beam enough to mount the rack), I believe you would only have to add the delta between those, 6.17" (156.72mm) (23.15" - 17") to the plan's gantry tube length to make it work for you, so 74.87" (1901mm).

Just my quick thoughts. Someone should check me.

Ted
Reply With Quote
  #4  
Old Mon 20 January 2020, 07:42
MarkRH
Just call me: Mark
 
Maryland
United States of America
Paul the plan calls for 2.75" wide main beams to make all the measurements work I believe. (Ted, im getting a diff measurement)
Yours are 6.5 , so a difference of 3 3/4" each side, so add both those to your 49" cut you want = 56.5" for your y. 56.5+19.7 = 76.2 gantry tubes. If you put those cross bearers inside the beam instead of under it you will have to account for that also, and it will warp in 2 directions when you weld it up. I think this is how i did the measurements for mine but do check and recheck mocking things up. Welding my cross bearers to the beam warped it to a crown very slightly, putting another weld on the tops of the main beams brought it back down straight, and just grind them flat.
Reply With Quote
  #5  
Old Mon 20 January 2020, 09:00
Panovak
Just call me: Paul
 
St. Paul
United States of America
Mark good point regarding the welding warpage in two directions.
I'll read more to verify the Gantry length but Mark your math makes sense to me.
I'll be using linear rails with rack and pinion so this overhang should be designed to Gerald's plans.
Thanks guys
Reply With Quote
  #6  
Old Mon 20 January 2020, 11:03
xraydude
Just call me: Ted #131
 
New Orleans, LA
United States of America
To double check myself, I physically measured on my machine. The gantry tubes overhang the outside edge of my main beams by 1.375 inches per side, so the tubes are 2.75" longer than the outer edge to outer edge measurement across the mains. In your case, that would mean 72.15" + 2.75" = 74.9" gantry tube length, which seems to match with my rushed math based upon the drawings in my other post. The width of your main beams doesn't figure into this, as you have already stated the overall measurement to be 72.15".

Their width will affect the total amount of y travel you have, though. On my machine, with the y-carriage at the stops, I have about 2" of clearance between the inner edge of my main beams and the Z-plate. My main beams are 2.25" wide. If they were 6.5" wide with the same measurement between the outer edges, they would be 8.5" closer to each other, which means I would have to move my y-stops in 4.25" per side to maintain the 2" clearance between the Z-plate and inner edge of the beam (or sacrifice that 2" of clearance and only move the y-stops in 2.25" per side), so I would lose 8.5" or 4.5" of y travel. The only way to maintain the same y-travel, would be to space the main beams further apart.

Now all of this is based upon the v-rail and bearing design. With the linear rails, I couldn't say what difference that would impart. If you are mounting the rack directly to the underside of your I-beams (which could be problematic if the underside is not parallel to the top), rather than on an overhanging rail, that would shorten the needed y-tube beam length by about 1.5".

Again, I would hope that my always suspect math is double checked. It is easy for me to throw around numbers when it is not my machine being built.

Ted
Reply With Quote
  #7  
Old Mon 20 January 2020, 11:28
TheDave
Just call me: dave
 
Toledo (Ohio)
United States of America
Paul,

Nice job on your table, it's always nice to see someone saving a little money by using what's readily available to them!
I've been building custom trailers for about 15 years now and I just want to offer a little tip on welding up your cross supports. I would suggest tacking them all in place first, and checking everything for square and level as you do this.
Once you start welding them in place - if you skip around a lot you can eliminate the warping to the main beams. For example, start on the upper right side and make one weld on a cross member. Then skip to the lower left side and add a weld to a cross member there. Keep going back and forth, making only small welds on cross members that aren't right next to each other. Mix it up, and go to the middle once in a while - you don't want to follow a regular pattern. By doing this you shouldn't have problems with the main beams warping.
Good luck!
Reply With Quote
  #8  
Old Mon 20 January 2020, 17:10
Panovak
Just call me: Paul
 
St. Paul
United States of America
Thanks for the tip Dave! The saved money on iron will get gobbled up by the linear rails I plan on using instead of the v rails. Don't tell my wife there is a cheaper option ��
Reply With Quote
  #9  
Old Sun 26 January 2020, 12:03
Panovak
Just call me: Paul
 
St. Paul
United States of America
So I have the base frame entirely built and grinded down! My last task is to weld the cross members to the main beam. The grinding of the old rusty steel was a job I'll never do again!! But the results are very nice, at least for my novice eyes. I'll try to post some pictures soon.

I've been trying to find out how people with automatic tool changers have designed their system. I'm wondering at this stage because my main beams aren't cut to length yet. It seems I made need some extra length for the Gantry to access the bits. Is this the way to do it? The beams are 127". The plans for my size table call for 120". Would this be enough extra length if it was the way to do it? Thanks again for everyone's help. I'll continue to read through this forum to minimize questions already asked.
Reply With Quote
  #10  
Old Mon 27 January 2020, 14:14
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Hi Paul. As you've surmised, for ATC you need an area that the spindle can get to that does not conflict with the work area. With the MechMate design, that's likely easiest to do with extra space at the end of the beams, as opposed to spacing the beams farther apart.

There are, in theory, two other possibilities I can think of: a moving tool rack that can slide in and out of the work area under computer control ( solenoid or motor ), or simply giving up some cutting area in one corner, if you don't often cut out to all four max edges.

Seven additional inches sounds like enough to me, if the tool rack is on the correct end of the table, meaning the same as the end of the Y car with the spindle, and not the side with any dust collection or other mechanisms that might crash into the tool rack during cutting. That's based on the back-of-the-envelope assumptions that all tools will be 2" or smaller in diameter, and that 5" is reasonable clearance for any assemblies that move in the Z direction.

While I'm on this, though, have you given consideration to the interaction between ATC and dust collection?
Reply With Quote
  #11  
Old Fri 07 February 2020, 14:25
Panovak
Just call me: Paul
 
St. Paul
United States of America
Finally taken time to upload an image of my table. Very excited for next phase... so is my back! Everything came out very good from what I can tell. My plan now is to grind some more, then paint. After that I'll be pouring epoxy on my main beams to get them flat and in perfect plane. In process of ordering my linear rails from automation overstock.
To anyone worried about welding if they never have. Don't be. I think drilling and bolting is actually more challenging.
Attached Files
File Type: pdf Paul.pdf (657.3 KB, 46 views)
Reply With Quote
  #12  
Old Fri 07 February 2020, 14:32
Panovak
Just call me: Paul
 
St. Paul
United States of America
Here's a pic of me moving the table out of shop and onto my trailer.
Attached Files
File Type: pdf table2.pdf (955.5 KB, 53 views)
Reply With Quote
  #13  
Old Thu 13 February 2020, 05:17
xraydude
Just call me: Ted #131
 
New Orleans, LA
United States of America
Now that is the way to move a MechMate! Everytime I have moved mine, I have had to hoodwink a bunch of friends with vague promises of free beer and food!

Ted
Reply With Quote
  #14  
Old Wed 26 February 2020, 10:07
Panovak
Just call me: Paul
 
St. Paul
United States of America
Got it painted. Working on electrical components right now. Acorn + Dyn4 motors. Way in over my head.
I will epoxy level the i beams prior to placing down the linear rails.
Attached Files
File Type: pdf painted mechmate-converted.pdf (1,007.0 KB, 37 views)
Reply With Quote
  #15  
Old Wed 26 February 2020, 15:14
Panovak
Just call me: Paul
 
St. Paul
United States of America
Ive started a google photo bucket for simplicity

https://photos.app.goo.gl/th6rUqavMVn2GkNa9
Reply With Quote
  #16  
Old Thu 27 February 2020, 05:47
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Good progress. I notice your x-rails are sitting on top of the bottom I-beam flange. Are they mounted there or just sitting there while the paint dries?
Reply With Quote
  #17  
Old Thu 27 February 2020, 07:43
Panovak
Just call me: Paul
 
St. Paul
United States of America
They are welded like that. My I beam was 12 inches tall so this way I have an effective height of 8 inches.
Reply With Quote
  #18  
Old Sun 30 August 2020, 23:00
Aviyo1
Just call me: Aviyo1
 
INDIA
India
Excellent thread! Thank you!
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Mechmate Frame For Sale maxman The Market Place 2 Wed 18 July 2018 05:02
Mirror frame javeria The Show Room 12 Fri 14 December 2012 17:10
Sacrificial wood on base frame? giggler 10. Base Table 18 Thu 07 July 2011 08:34
Frame for Oil Painting Khalid Archives 2 Sat 18 July 2009 10:55
Same torque, different sized frame chrisd7306 Motors & their mountings 5 Wed 19 November 2008 02:25


All times are GMT -6. The time now is 08:52.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.