[jason75]

I figured out I had assembled the couplings wrong. I believe this is the correct way.

[cncrr]

Nice start Jason. I'm following your build with great anticipation.

I currently own a 5' x10' CNC Router that I am selling. Bought for my cabinet business 3 years ago then got sick and had to close the business, but I still want a small CNC Router for my shop to do small hobby things.

So far so good!!!!!

Chuck

[jason75]

Thanks Chuck.

Seems I don't get to play much now. Seems the kids soccer and t-ball takes all the play time. Seems I just get a little time here and there now that spring is here.

[cncrr]

Hi Jason,

Thought I'd drop a line and see if there is any progress yet. I noticed from the begining of this build that you bought your frame material from Automation4less.com. Did you also get the hardware from them?

Hopefully my 80/20 catalog will be here soon so I can start designing my 3' x 4' CNC router. So far I think I'll be able to get almost everything I need from CNCRouterparts.com.

Have a good Easter.

Chuck

[jason75]

I got a little bit more done with the gantry. I put the bearing blocks together and assembled the uprights to the cross bar.

I made some end plates at work to help keep the uprights straight.

I'm not happy with the the small amount of "slop" in the gantry. I can rack it just a little bit to the left and right. I am going to try to adjust the bearings or add some shims.

You can see I forgot the t nuts to bolt the Screw bracket to! Oh well......it comes apart easy.

[Drools]

A quick question on the mounting of the extended CNCRP carriages. You have used 2 bolts to mount attach them to the 1530 running horizontal. I checked into it and you could use (there is clearance) Socket-Cap-Screws to attach them to the gantry upright. This would allow 3 anchor points instead of 2. Has anyone ever tried this? These screws can also be purchased in a low head profile.

[jason75]

Drools

Im not sure what you mean. There are only 2 t slots in the peice the bearing truck rest on. There are 4 bolt holes in the truck. Two bolts go through the truck and into the the t slot and then a corner gusset bracket attaches to the 1530 and truck from the outside bolt holes.

I've come to the conclusion that I do not like these bearings. I am considering changing over to linear ball bearings.

Jason

[jason75]

Drools

Do you mean to the Vertical peice of 8020? There are 3 t slots in it that the trucks could bolt to. But again.................I hate these bearings...............I think they were meant to be cost effective!!

[CNC Lurker]

2 things I did to overcome racking is first I used 2 linear carriages to on each end, one long one on the outside and one short one on the inside. Of course, you'd need a wider flatbar so the inside ones could ride on. The second thing I did was when attaching the linear carriages I used a clamp to snug it up tight against the flatbar as shown in the attached pic.

You might want to try clamping the linear carriages before replacing all the bearings. I will say that there have been several builds on here using the CNCRP linear carriages and I don't recall the bearings ever being an issue.

That said, if you do want to switch then you ought to try VXB. I bought ABEC 7 bearings from them that I was going to use for a Joe's 2006 CNC router before I found the 80/20 one we built. VXB Bearings LINK

[jason75]

Paul

I will try clamping this way. I have been using one clamp in the center of the upright pusing against the bearing. I will try one clam at each end. I like the inside bearing but I think if I had to replace the flat bar I would rather go with linear bearings. Sometimes I like trying to "reinvent". I think I get more enjoyment out of figuring things out then acutally using the thing!!! I am sure there is nothing wrong with the bearing set up. Just me and wanting to change things!

Jason

[Drools]

Yes into the vertical piece of 8020, it looks like 1545 from the picture. I to mounted mine to the bottom piece of 8020 (1530) with 2 bolts and if you think about it this is a weak point. I looked at it and it came to me that I could mount the carriage to the vertical upright if the heads of the bolts did not interfere with the CRS. Normal hex head bolts will not work but bolts like I mentioned will. You could also use 2 x 4332 corner gussets on the horizontal piece (1530) to allow 4 bolts to be used. I have seen this method used on the forum in several builds. My point is to get more strength into that mount point, either by mounting to the vertical piece with 3 bolts and a corner gusset or to the horizontal piece with 2 bolts and 2 corner gussets.
I had my doubts on these carriages as well until I purchased the Aluminum cutting blade for my chop saw. I did not purchase my 8020 cut to length so I had to get it cut or cut it myself. With my chop saw and the Ali blade I was able to cut each cross member of my frame to be exactly the same length which made the frame exactly the same width at all points which is so important when using these carriages.

[jason75]

I think having the extrusion cut the exact length is the key. I ordered mine cut to the the specs but have noticed a gap between the bearing block and up rights if I keep the uprights and cross beam flush at the ends. I'm trying Paul's idea of using four clamps instead of using two as I was earlier.

I think I prefer the idea of linear rails!

Jason

[Drools]

I actually cut my lower horizontal piece a tad shorter than needed so I could use shims to get the exact length needed. I use Ali end plates on my uprights as reinforcements. Tightening down these end plates moves the carriages in and loosing them moves the carriages out. If the table is the exact same width all the way along then the carriages just work. The hardest problem I had was getting the chopsaw to cut square!
I will see if I can find the build log where I got my ideas from.

[Drools]

This thread shows the use of end plates as reinforcement. He uses his own DIY LM bearings attaching them to the gantry vertical uprights.
http://www.cnczone.com/forums/diy-cn...nded_post.html
Look at the 3rd picture in this post. He uses L brackets to strenghten the joint.
http://www.cnczone.com/forums/777708-post244.html
I could not find the thread showing the corner gusset, so I took some pictures of my rebuild using the corner gusset to strenghten the carriage mount.