View Full Version : Gantry Router Log

12-04-2005, 06:01 AM
Like most newbies I have been reading the forum for months and have been inspired by the many variations and materials that members are building their routers from.

I have been building for a couple of months and now have something to show for the effort. Don't ask for drawings as they are in my head and change to suit the materials I have available and the problems I encounter as I construct it. :o I know this is a cop out but I would rather be making chips than drawing pictures.

The biggest hurdle was the electronics as I have very little experience other than how to solder. As this was going to be the critical component for me I decided to get the Xylotex board and if I could mount it and get it going the rest should be easier.

The box I got was not big enough to house the transformer and board so I got another one and put the transformer in one and driver board in the other.

Once I was confident I had everything working I got the 269 oz motors.

Here are some photos of the finished driver board and power supply.


Perth, Western Australia

12-04-2005, 06:12 AM
So the electronics, motors and cables have been completed.

I decided to make the base from steel and the gantry from aluminium. My choice for a steel base is that it adds weight and stability and because it is fixed it does not require additional motor power.

I also wanted to have the rail supported laterally and vertically along it's lenght. The rail is 2 inch by 1 inch bright mild steel and is attached to the sides of the frame. The backbone and turnbuckles let me adjust one side without affecting the other side. There are slotted holes in the crossmembers to allow for adjustments.

Rather than waffle on perhaps if I post pictures it will be clear as mud for everyone. :)


Perth, Western Australia.

12-04-2005, 06:21 AM
The bearing carrier contacts three faces of the rail and I will be able to get the fourth face of the rail when the lower gantry crossmember is fixed in place.

The bearing holders are adjustable so that I will be able to plumb the gantry as well as make minor adjustments to each bearing.

There will be a total of twelve bearings on each side.

The first photo shows the bearing carrier on the rail. Second is the bearing carriage and the last is one of the bearing mounts before it was painted. Skateboard bearing have been used.

Well that is about it for the moment. Next I will be making a frame to hold the router and at the same time I will strip down the base and paint.

Just ask if you want more detailed photos or descriptions.


Perth, Western Australia

12-04-2005, 07:53 AM
It's looking great Rod. Your nicely organized and labeled driver box will hopefully encourage me to build one. I currently have my driver board hanging from the wires on my x-axis motor :nono: It's only a matter of time before one of those wires comes loose and fries the driver :eek:

12-04-2005, 08:03 AM
Are you counting on the stiffness of the gantry to keep the baearings tight to the rails? It seems like the bottom bearings may be able to pull away, but if the entire machine is aluminum and / or steel, it might not be a problem.

What's the overal size of the machine, and working area? It looks about 4 ft long? If it ends up as heavy as it looks like it might, I think the Xylotex might be a bit underpowered. But if it is, you can always sell it and upgrade later if you need to. It will certainly run the machine, you just might want to upgrade for higher speeds later.

Looks good, though. Keep us posted.

12-04-2005, 08:58 AM
The labels are for me to remember the details of the unit and where to plug everything in. :)
Apart from my poor memory if you live in a remote part of the world it can be very inconvenient and expensive to send bits off for repair. :(

12-04-2005, 09:48 AM

The dimensions are X 28 inches, Y 39 inches and Z ? at this stage. I have probably got X and Y mixed up but these are the base dimensions. Base is steel and gantry will be aluminium.

As you have pointed out I too have pondered over the lower bearings maintaining contact.

Tests today seem to work OK with just two ali flats clamped between the bearing carriers. The bearing rails are 1 inch square and the plate they are attached to is 3/8 inch. The sides of the gantry will be 3/8 ali and will be fixed to this plate so there will be 3/4 inch ali over the bearing carrier. Fingers crossed at this stage. I plan on fixing 40mm (I gave up on the conversion to inches on that one :D ) ali angle iron to the gantry sides as well.

It would be better to have the gantry cross rail below the lower bearings and if needed I can do this as a major modification later.

My lead screws are 1/2 inch single start 6TPI acme threads. This was the only acme thread I could get locally after days of enquiries. The 6 TPI doesn't convert to linear very well but it will do for starters. It has a double bearing at the motor and single on the other end and I have turned up my own version of AB nut. Half of it is sitting on the photo of the base unit but it is not tested yet so more later. I agree the Xylotex might be a bit light but it gets me started and at over $AUS600 shipped it was all I was willing to pay at this stage.

It is expensive over here with low conversion rates and shipping costs. I got burnt for $AUS300 on ebay for a set of supposedly new Z axis linear rails so I am still recovering from that mistake. Description was new but no warranty and I blame myself for not being wiser. :frown:

A feature I forgot to mention is that with this design the the bearing rails will be fully covered by the table so I should not be getting bumps from the bearings running over sawdust.

I have a long way to go and appreciate any suggestions offered.

Here is another photo of the base adjusting thingo.

12-04-2005, 10:55 AM
40mm = ~1-9/16" :)

$600 for a Xylotex :eek: I'm using a Xylotex for cost reasons as well, even though I'd rather be using Gecko's.

Don't worry about the 6tpi. Once you set up the software, it doesn't matter what the lead is. How long does it take to adjust all those bearings?

12-04-2005, 11:38 AM
The bearings are very easy to adjust and have the added advantage of allowing me to square things up. I have tapped the bearing holders so it is simply a matter of holding the bearing against the rail and tightening the bolt.

Before we converted to metric I was brought up on imperial measurement. My rules and tapes have both measurements and I work in both units. I visualise imperial for most things even though it has been forty years in metric for us.

The conversion was strange because for a long time they still made imperial sizes and just nominated the nearest mertic equivalent.

I just realised I have just highjacked my own thread. :D

Thanks for the heads up on the 6TPI.

12-13-2005, 11:11 AM
I have taken up your advice on the support for the bottom bearings. What I have done is flip the ends so that I now have 2 inches clearance under the base. This will let me extend the gantry sides below the base and I can fix another cross piece between the gantry sides. This means one cross piece above the bearing carrier and one below.

I have also had a look at using screws to push the bearing pivots to make adjusting easier. I will include this when I rebuild it this weekend. Last weekend I built the bench to mount it on and I will paint all the bits and re-assemble it on the new bench. I got my X axis rails and bearings yesterday and are very pleased with them. 20mm shaft and four slide bearings and mounting blocks. I have a complete Z axis assembly with ballscrew in transit. With these components once I build the gantry it should progress much quicker than I had anticipated. I will post some more pictures after this weekend.

What I would like is some advice on a method to allign both rails during assembly. With all the adjustments I have incorporated I have the potential to make this machine very accurate but I can't think of a foolproof way to make both rails parallel and on the same plane. It would be very easy to build a machine with a twist in it.

Any suggestions would be really appreciated?

12-19-2005, 10:21 AM
Progress is slow but moving forward. I built a bench to mount it on and have pulled it apart and painted the steel.

I modified it by reversing the ends to lift the base off the table so I could attach a lower cross member. The gantry is finished and after a bit of adjustment it rolls very well. To make it perfect I need to adjust the rails slightly to make them parallel but I ran out of time tonight.

We are now into our summer and it is becoming too hot for daytime work so it has started to become a bit of a chore. I am hoping I will spark up after I attach a motor and see some movement.

A few pictures to update the thread.

12-30-2005, 04:41 AM
I pulled the gantry apart again and bored a couple of holes to reduce the weight.

I finished the adjusters for the bearing which has made it very easy to align and adjust the gantry. I am pleased with the gantry - smooth and no play or racking along the entire travel.

AB nuts are now finished and seem to work well. I machined two flanges and welded the stock nuts inside the flange. Springs between the plates keep the set screws tensioned.

Next step is to mount the acme thread and attach a motor for some movement.

01-04-2006, 08:39 PM
I finished the framework for the cutting table. 50mm by 3mm ali angle in a sort of torson box design. MDF will cover the table and threaded inserts used for hold down clamps.

01-11-2006, 10:40 AM
Still ticking along and learning heaps. I have very kindly been given acme thread and delrin nuts so a slight change of plans. I finished the table and will mount it next. I worked on the lathe and mill all day making the bearing mounts for the X axis and motor mounts. The shoulder on the bearing holder is to locate it in the frame to help allign the motor to the axis. Photos should show you how it goes together.
Here are the results.

01-14-2006, 09:40 AM
Hello :wave:

Not much to show for a couple of days work but I have done the final adjustments on the X axis and leadscrew. Installed the table and fitted the Y axis rails.

The table is good and the gantry is solid as a rock and rolls easily. I think having so many bearings around the rails has helped quite a bit.

The 20 mm linear rails are good on the 700mm Y axis but I don't know how they would go over longer spans. I think on anything over this span I would go 25mm or linear rails with trucks.

More photos and starting to look like a CNC gantry router now. :)

01-16-2006, 08:54 AM
Finished fitting the Z axis tonight. The finished work area is :
X - 760mm or ~30 inches
Y - 550mm or ~21.5 inches
Z - 150mm or ~6 inches (clearance between bottom of Z axis and table).

Z will be reduced to 120mm or ~4.7 inches when the router is fitted.

I still have to make and fit the Y axis leadscrew and the router plate. In two weeks it should be making a noise and if it works I will be making a louder noise. :)

01-23-2006, 11:17 AM
It is finally finished and is ready to go. The dirver board and wiring harness was done before I started making the machine so this weekend it should be making a noise. Well not a loud noise as I am going to use a spring loaded pencil to make patterns on paper until I iron out any bugs and learn to use the software.

Last photos of the machine building is the Y axis leadscrew. Not much to show but it took three days to finish this bit. A lot of lathe work and milling.
I won't bore you with details as the photos should show how I did it.

I have really enjoyed making this and I think I am addicted to building these as I have parts ready for number two and three machines. These will be ballscrew and linear rails and I am looking forward to improving on this one.

I hope that this thread provided some interest even though I think I might have broken the record for consequetive posts. :) It has been good to put something back to the forum that has given me the inspiration and courage to finally have a go.

01-23-2006, 04:30 PM
very nice. one of the cleanest I've seen. please post your results when you get it running.

01-23-2006, 05:42 PM
Your machine looks very nice! Keep us posted

01-24-2006, 10:16 AM
Thanks for the comments. I will post the results but it will be a few weeks because I have to learn CAD as well as TurboCNC.

Does anyone have something interesting, either Gcode or Drawing that I can use to do some trials. I am going to use a spring loaded pencil until I work out how to use the software and iron out any bugs in the machine.

01-24-2006, 12:35 PM
You could try this.
it's an Eagle stting on a globe (interlocking parts)

01-24-2006, 01:03 PM
Sorry that's just the globe,but it should get you started.
Let me know if you want the Eagle,I'll see if I can find it...Jim

01-24-2006, 01:20 PM
I found the whole file, it fits on a panel about 16" x 21" x 1/8".

01-24-2006, 05:24 PM
I found the whole file, it fits on a panel about 16" x 21" x 1/8".
any pictures of it already cut and assembled?

01-24-2006, 07:17 PM
Thanks Jimini

I appreciate the code and will use it for a test this weekend.

01-26-2006, 08:04 AM

Would you post the dxf for this file i get an error at line 19080?


Vaughan Sage
01-26-2006, 12:15 PM
I'm in South OZ on 'STRALA DAY, good to see another ozzie who is interested in CNC!
I reckon your machine is looking great! Looks solid as rock BUT... I'm wondering what will happen with ally & steel mixed on large widths like this, different thermal expansion of steel & ally means your bearings will try to leave the sides? or I guess you'll have em preloaded a bit. Aside from all that I think you should have more bearings on the INside of the flat rails at the top, so that when you get offset loads from the spindle at max Y+ &Y- posi. that the whole gantry doesn't skew or rattle >> more rigid footings of your whole gantry. Instead of the gantry hugging the base from the OUT side you would get double close-tied grips from BOTH siderails. Try testing your rigidity that you have got so far... put a dial indicator on your gantry on one side (off centre)& just pull/push with a spring balance with a force of what your cutter might require say 10lbs.force, this show you what "specific rigidity" you have.... in any machine! You dont need the cutter to be running. I you can apply the force to the end of the cutter & clock the deflection in X Y or Z you get the summation of ALL the deflections in ALL the compenents, beams, screws, rails, bearings... this what goes boing every time a cutter tooth lets go of your workpiece. Deflections shown on the dial indicator will be different depending if the cutter is at full height, low down, left/right on the Y travel, etc. You should really apply spring-force the between the workpiece mounted on the suspended platform table and your cutter tip. Then you can add stuff to reduce deflections to immediate effect/improvements. Sounds complex BUT it's dead easy!

01-26-2006, 06:38 PM
Hi Vaughan

I had intended to put bearings on the inside of the rails but found it didn't need it. There are nine bearings on each rail (total 18 on X axis) and the gantry has a cross brace above and below the bearing assembly. The gantry is very rigid with no play on the bearings and no flexing. At this stage I am going to run the machine and see what happens. I can always add them later or swap out the bearing assemblies for linear bearings later. If it performs well I will swap out the acme thread for ballscrews.

The aluminum was used to reduce the weight of the gantry. Steel was used on the base to keep costs down and also to add weight to the machine. The bearings are slightly preloaded but not enough to cause drag.
I have no idea about the different thermal expansions of the materials. This is a hobby and I have no engineering background so it is likely that I have created a problem by my choice of materials.

Thanks for the feedback.

01-27-2006, 04:11 AM
Well done Rod,
very neat machine you've built there. I wouldn't be worried about thermal expansion differential between the steel and alloy componants as the overall dimensional change will be negligable.


01-27-2006, 12:50 PM
Thanks Splint
Thanks for the heads up on that as I was a bit worried about it and there is not much I can do about it now. I have just run the machine in jog mode in TurboCNC. I have a full day tomorrow visiting (got to keep the boss happy) and I know what I will be thinking about all day. :D
Roll on Sunday.

01-27-2006, 08:00 PM
Rodm, did you draw your machine in CAD?

If so, would you consider putting the plans up on the site for others to download (ala Jgro?)

01-27-2006, 08:47 PM
Hi Whirlybomber

Sorry this machine evolved as much as it was designed. I don't know how to use CAD software yet and are trying to fast track the learning process.

I should have done full drawings before I started becuase it is much easier to fix with an eraser than remake parts.

Making these machines is addictive and I am thinking as much about making the next one as I am about using this one. Those first steps (pun intended) are a big high.

01-31-2006, 08:33 AM
Well I am pumped. The machine turned out better than I expected and with the trusty pencil attached as a makeshift router I am getting good results.
Speed is 900mm (about 35 inches) per minute which is not bad for first setup and having such a heavy gantry. I am running Mach3 and I am very impressed with it.

I hope to improve the speed as I learn a bit more and develop the machine.
Photo of finished machine and a sample of work. I have added knurled wheels to the motors, wiring, limit and home switches. I need to make a switch box with E stop and a mount for the monitor and ............

Mike F
01-31-2006, 08:37 AM

That is one neat, clean machine you have there and you should be proud of your efforts. I just don't know how you guys find the time to complete projects so quickly - I'm envious!


01-31-2006, 11:09 AM
Thanks Mike,
I appreciate the feedback. I am beginning to think these machines are never finished as I keep thinking of things to do to it. :)

02-02-2006, 08:26 AM
Mounted the router last night and did a test run tonight.

Did a quick and dirty graphic in Corel Draw and then imported it to Mach3. Didn’t worry too much about correct spacing and I have the depth of cut a bit low for these characters so excuse the result. It cut both sides of each letter and cleaned up the curves. It is cut into a piece of white faced masonite (compressed fibre board). I can recommend Mach3 to anyone starting off in this hobby.

I hope you get a laugh at the wording.

02-02-2006, 09:12 AM
That is a great machine you have put together.

The explanations & photos here in your build log are excellent! Thanks for sharing your experiences.

Congratulations on the first cut. You do seem to like turnbuckles. :)

What format did you use for the Corel Draw file into Mach3 ?

02-02-2006, 09:38 AM

Thanks for your comments.

I saved Corel drawing as DXF Autocad release 9 with curves. I read this on the forum a while ago and it worked fine for me. Just altered feed and depth of cut in edit gcode in Mach3 but I think this can be done during the import process. I have a lot to learn yet.

02-22-2006, 12:47 AM
Sorry I just now noticed your request.
I hope this file will help you.

02-22-2006, 01:09 AM
Whoops you asked for the dxf files, try these, again, sorry for the delay.Jim

02-25-2006, 07:39 PM
I thought I would update this thread. A couple of weeks ago I built a compartment for the computer and an electrical panel. All recycled material so this explains the additional holes you can see.

The cabinet that houses the computer and driver board has a large 12 volt fan at the back connected through a manifold to pressurize the compartment. The idea is to keep dust out of these components.

The switch panel in the middle has an E stop button plus individual switches for computer, driver board, etc. There is a spare waiting for a vacuum of some sort.

The drawer houses the monitor, keyboard and mouse.

Prior to making this I had the computer, etc on a separate bench and there was a mass of tangled cords around the machine. Now the only cord coming out of the machine is the power cord - but I still manage to trip over it occasionally. :)

The router is going well and I am getting some good results in aluminum and wood. Mostly practice pieces while I learn how to use the software.

I swapped out the X and Y leadscrews with rolled ballscrews as I couldn't get the speed I wanted with the acme threads. I got the Home Shop CNC ones and now have 47 inches per minute cutting speed and 71 inches/minute on rapids. I am very pleased with that so I can stop tinkering with this machine and start the next one. I enjoy building these as much as I do using them. :)

11-21-2006, 08:13 PM
Hey Rod, how did u make thoose really large holes on the aluminium? what tool did you use? was it easy? do you think it could make a hole on 1 inch alluminium?

11-21-2006, 10:01 PM
Hi Brenck

I cut the holes with a bimetal holesaw on a drill press. It was a slow process and chattered a bit and the aluminum squealed even though I used cutting fluid. It gums up with swarf pretty quick while you are cutting and I would not be in a hurry to do any more of these.

I would think one inch thick aluminum would be a job for a mill and a boring bar but I am not a machinist so maybe somebody more experienced than me could suggest a method for you.

12-30-2006, 01:09 AM
I have just finished a major rebuild of this machine. I have over 600 hours of cutting on the machine and it has performed flawlessly but I had some improvements I wanted to do.
I have rebuilt a new steel base and done away with the skate bearing rails and fitted THK25 linear rails. I moved the ballscrew under the base which reduced the machine height and meant the table had a lot more support. New motor mounts, dust covers for the linear rails, and steel rails to enable lateral clamping of the workpiece to the table.
I have a 25% increase in rapids and the machine is more compact and therefore hopefully more rigid.
The first two photos are the new base during construction and the last two are of it completed.
Sadly all the turnbuckles are gone so I will have to think of a new name. :)