My 8020 router build

[Bear5k]

Nice videos!

[RicknBeachcrest]

It's a little strange talking into a camera. I can see why people on Youtube just shoot the video and don't say anything, but I think it really looses a lot without a little talk. I wasn't too sure how people would like these videos. I will post more if you all find them helpful.

Rick

PS. I have been able to work on the router the last couple of days. Feels really good to put some serious time into it.

[RicknBeachcrest]

I got the 2nd half of the table joined together this weekend. In putting together this half, I noticed that the two joined pieces of 1530,were twisted. That is one of the things I like about this 8020, it can be taken apart and put back together. So I took apart number 2 side and making sure it was all sitting flat carefully joined them together. Nice to have a flat surface to assemble on.

I checked number 1 side and it too was twisted, so that came apart. I had used locktite on it, so I had to clean all the locktite out of the nuts and bolts. So my new plan is to wait til completion and then locktite everything then.

[Senna]

Rick... MORE CNC and LESS RC...!!!

Just checkin in. You're doing a bang up job which should pay dividends once finished...!!! I'm still blown away with my machine. It continues to impress. I'll be embarking on a new carving path as soon as my 30 deg engraving v-bits arrive. Going to attempt some LITHOPHANES...

Here's a pic for inspiration... and seriously... give those thumbs a rest...!!!

Steve

[RicknBeachcrest]

It's hard to work on CNC when the weather is so good. It's been a long and cold winter. It feels so good to be outside in just a shirt. Weekend is suppose to be rainy, so it looks like CNC time. But tomorrow should be good, so I'll get out and do a little flying.

Next up is the interface between the linear bearing truck and the 1530 extrusion. I plan on making it out of 3/8" aluminum bar stock. I think I will make a test piece out of some ply to make sure everything works out.



Pics to follow.

Rick

[Senna]

Atta boy... but you're still protracting MY pleasure...! Commencing rain dance...

I'll check back on the weekend and see if that dance worked...!

Steve

[RicknBeachcrest]

Well it was a rainy, cloudy, windy weekend in the great Pacific Northwest, a great time to work on a CNC project.

My plan was to make a test interface piece (from a 3/8 in. piece of plywood) that will hold the linear bearing trucks to the extrusion. The final piece will be made from a piece of 3/8 in. aluminum bar (3X7 1/2 in.) The trucks are Hiwin AG15's. I'm sure glade that they (the trucks) were not bigger. As you can see from the pics, the two center SHCS were a real squeeze.

I guess this could also be called use the tools you have and be happy (there are many who have less).

For machine tools, I have a Sherline mill and lathe. The mill has a digital readout(DRO). To really appreciate a DRO, you need to go years with just counting hand cranks. I would have gone nuts with out the DRO, for sure. Sherline tools are great value for the price, but size of work is a real limitation and challenges a person to be creative.

It would be nice to have had a bigger milling machine, but I just don't have room for a tool that size that would get used occasionally. The throat on my mill is only 2 3/16 inches, so this forced me to take the work piece out and then re indicate it. At first I was going to indicate it to opposite corners, then got to thinking this would rely too much on the squareness and exact size of the work piece. Then I got the great idea to drill a hole in the center and indicate to this. The DRO made this so nice to do.

The bolts for the truck are 5mm and I drilled 5.5 mm holes, so they needed to be placed fairly accurately. Also these holes needed to be counter bored, so they would not interfere with the extrusion. I used a 3/8 in. end mill to counter bore for the 5mm screws. The SHCS that bolt to the extrusion are 5/16 in. and I drilled 21/64 in. holes. These could be off a little more since the slots in the extrusions are not exactly 5/16 in.

Only drilled one wrong hole. Next up will be to put this onto the rail and see how that works out. I am going to fine tune the placement of one truck and the two center 5/16 SHCS.

Steve... Is there any trick on putting the trucks onto the rail? I know with ball screws you need to worry about having the balls fall out. My plan is to put each truck (two on each rail) on the rail and then to attach them to the interface piece, then attach the extrusion to that. I think this should insure that both are in the same line.

Rick

[Senna]

Is there any trick on putting the trucks onto the rail? I know with ball screws you need to worry about having the balls fall out. My plan is to put each truck (two on each rail) on the rail and then to attach them to the interface piece, then attach the extrusion to that. I think this should insure that both are in the same line.

Rick

Rick... the way I went about it was to complete the 'skates' (the 8020/interface plate/bearings) then I loosely attached them to the gantry. By loose I mean that things can shift a bit BUT not flop around. Then with the BASE FRAME bolted together BUT lacking the stub feet I propped up the frame high enough for the gantry to be slipped on one end. If your feet are already bolted on another way you can do it is to leave the bottom cross tie of your gantry off and bolt it on after you slip the gantry onto the rails. By the pics you posted you also have the non-caged bearings. So those white plastic keepers NEED to stay in place and ONLY get displaced as the rail moves into the truck. DO NOT take them out by hand... let the rails push them out...!!!

NOW... as far as alignment goes... I cut a shallow alignment channel into my interface plate that perfectly fit my bearing trucks. That way I was assured that the two trucks were aligned to one another. Can you incorporate an alignment channel in your plate design?

I see you have your rails mounted. Unless you are absolutely certain your rails are perpendicular it's better to leave them loose on the extrusion. Also this all has to take place on a frame that is perfectly squared.

With the gantry on the rails...run the gantry to one end of your machine base. Tighten the rail screw at that end slightly. Run the gantry to the opposite end of the base. Tighten that end screw slightly. Run the gantry back and forth feeling for any resistance. If none felt tighten the remaining rail attach screws. Once the rails are aligned to the bearing trucks... start to tighten the screw or bolts that attach the skate to the gantry. First run the gantry to one end of the base. Sight the gantry to a frame end rail to insure squareness. Bump adjust it if needed. Tighten the screws slightly. Run the gantry to the other end being careful to not rack it at all. Sight the gantry to that frame end rail. If your base is absolutely square AND you didn't rack the gantry during the move... it should align with both end rails. Tighten down the screws a bit more. Once you are certain of proper alignment and squareness... torque all rail and skate attach hardware to you specs.

Let me know if anything doesn't make sense. It's not the only way to go about things... just how I did it.

Steve

[RicknBeachcrest]

Thanks for the very complete explanation. It all make sense.

Good to know about those plastic keepers. I suspected that is what they were, but was not really sure. Sounds like once the trucks are on the rails, it is best to leave them there. This changes things a little for my methodology of assembly. With the trucks on the rail and tightened to the interface plate, there is no room to screw the extrusion to the interface plate.

So the two trucks need to be aligned to each other and attached to the interface plate. Then this sub-assembly needs to be attached to the 7 1/2" extrusion to form the skate. This skate then can be slide onto the rail. My thinking now is that it would be easier to attach the gantry to the two skates (after they are on the rails), then to try and slide the trucks (four) onto the rail with the gantry attached.

Ref the rails attached to the 1530 extrusion; I am sure that the rails are dead center on the extrusion within a couple of thou. Worst case is that I can loosen the bolts holding the rail to the extrusion and realign per your sequence of steps.

Steve, Thank you so much for taking the time and explain in copious detail how you built your machine. Your help has been invaluable.

Rick

[Senna]

Rick... I'm glad I can help!

The caveat about those white plastic keepers is from experience...! I discovered that the ONLY thing retaining the ball bearings without the keepers there is grease... AND that doesn't do all that good a job...!!! DOH!!! It took me hours to find all the bearings, clean them, and replace them in a thicker layer of grease. I was so happy to get that keeper back in place and hoped I got all the balls back...! It all worked out but I wouldn't want to repeat it!

At this point it's a good thing to think things through... turning it every which way... looking for warts and gotchas. My many mistakes were mostly forgetting to place t-nuts in the slots of extrusions that were captured and had no way to get the nut in there without dis-assembly. Those drop in nuts 8020 offers would of really helped in a goodly number of instances!

I'm attaching a pic and PDF of that sight picture alignment technique for squaring the gantry to the base.

Steve

[RicknBeachcrest]

Steve,

Speaking of squaring, how did you go about squaring the table?

In my cabinet work, I measure the diagonals and make sure they are the same.

Rick

[Senna]

Rick,

I used machinist squares... LittleMachineShop.com - Machinist Square Set, PEC only because I have them and I'm familiar with their use. I checked my frame with the diagonal measurement as a way to confirm. One problem I found was the extrusions have a rounded edge and it was somewhat difficult to get a precise corner to measure off. I also don't trust a tape measure as drape and droop can effect the outcome. I used a story stick... BUT... with your cabinet experience I'm certain you are familiar and comfortable going the diagonal measurement route as your primary. I'd just use a secondary technique to insure you have perfect 90 deg corners.

OH... a little tip... if you don't have a square that you are confident of... in a pinch I've used the plastic CD jewel cases as a way to check corners...

Steve

[RicknBeachcrest]

Well as most will probably attest, building a CNC router is a series of hurdles to overcome. My latest hurdle is the fabrication of the interface between the 8020 skate that will support the gantry and the linear bearing trucks. I had planned on using some bar stock (3/8" X 3" X 7.5"). I've got the methodology for accurately drilling the attachment holes in this piece down.

When I placed these pieces on a flat surface (table saw top) I noticed that each piece was slightly cupped. Using feeler gauge I measured a gap of about 7.5 thou. in each. When I placed them together (cup side to cup side (see pic), there was a 15 thou gap. I would have settled for 2 to 3 thou. on each. So I have been putting lots of thought into flattening these pieces with my limited machining equipment. With a larger milling machine and fly cutter this would be pretty straight forward, but no so with what I have. Then I got to wondering if there was another material that just came flat (or pretty close to flat).

I posted the question on another subforum here on CNCzone and thanks to Gerry found out about Mic6, or cast tooling plate.

http://www.cnczone.com/forums/genera...tml#post963754

Ebay didn't have any sizes small enough for what I was looking for. A little Googling and I found this place.
https://www.midweststeelsupply.com/s...FQFubAodLy3rZw

I placed my order this morning.
I really like that I can order just what I need and the price seems reasonable.

Rick

[Senna]

Hey Rick,

We've all run into snags of this sort. Delays are never something to look forward to... they always tend to pull at the fabric of enthusiasm... especially the closer you get to completion!

I myself was all set to see some real progress... but alas... a snag! I share in your disappointment.

My Hitachi router burned up the lower bearing a couple days ago... I'm waiting on a bearing purchase to arrive.

Steve

[louieatienza]

Rick... I'm glad I can help!

The caveat about those white plastic keepers is from experience...! I discovered that the ONLY thing retaining the ball bearings without the keepers there is grease... AND that doesn't do all that good a job...!!! DOH!!! It took me hours to find all the bearings, clean them, and replace them in a thicker layer of grease. I was so happy to get that keeper back in place and hoped I got all the balls back...! It all worked out but I wouldn't want to repeat it!

At this point it's a good thing to think things through... turning it every which way... looking for warts and gotchas. My many mistakes were mostly forgetting to place t-nuts in the slots of extrusions that were captured and had no way to get the nut in there without dis-assembly. Those drop in nuts 8020 offers would of really helped in a goodly number of instances!

I'm attaching a pic and PDF of that sight picture alignment technique for squaring the gantry to the base.

Steve

Of course thos would only work if you got all four corners absolutely square. You could have a parallelogram or trapeziod and still get your gantry parallel to both endplates. So trust... but verify! Even a good rafter/framing square can be inaccurate, and must be checked before using as a reference. Machinist or enngineer's squares are very accurate, but expensive, especially at the lengths we'd normally need.

[striperman36]

Rick... MORE CNC and LESS RC...!!!

Just checkin in. You're doing a bang up job which should pay dividends once finished...!!! I'm still blown away with my machine. It continues to impress. I'll be embarking on a new carving path as soon as my 30 deg engraving v-bits arrive. Going to attempt some LITHOPHANES...

Here's a pic for inspiration... and seriously... give those thumbs a rest...!!!

Steve

Who's kit or plans is that machine? I am definitely interested in that layout with 8020

Bill

[Drools]

I had the same problem with my 8" wide .75" thick ali. Fortunately I have a machine shop when I can have my plates fly cut, flat. However I'm considering using Baltic Birch as Gerry does on his Z axis. He seems to have good results with it.

[RicknBeachcrest]

Who's kit or plans is that machine? I am definitely interested in that layout with 8020

Bill

Hi Bill,

It sure isn't a kit. And as far as plans there really aren't any in the conventional definition of plans. I am shamelessly using Senna's (Steve's) design as the basis of my design. I linked Senna's build thread in the first part of this thread. And Steve has been very forthcoming with answering all my questions. Thanks Steve.

My dimensions are different and the linear rails and trucks are a different size. I still don't have all the details worked out yet. I need a finished frame in front of me. My biggest unknown is the drive mechanism. I would like to use ball screws. It would be a heck of a lot easier to use ACME threads, but i really like the benefits of ball screws.

There is a lot to this CNC router stuff. It certainly is not for the faint of heart and requires a bit of a commitment. Most of the answers are in this forum and there are many generous people who will try and answer your questions.
Rick

[RicknBeachcrest]

Well it has been a great summer here in the pacific Northwest. Most weekends were out at the RC field and the others were house projects and family obligations. Fall is here along with the bad weather, so it's time to get back to building this machine.

First an observation or two. 8020 is a great building material, but the biggest hurtle for building a CNC machine with it, is coming up with the interface (means of connection) between the 8020 and the pieces integral to a CNC machine.

When we last left this build, I was working on a means of attaching the trucks to the skate of the gantry. I wasn't happy using bar alu, so I ordered a piece of cast tooling plate.

I got the cast tooling plate and it is nice and flat. I ordered enough to make three pieces just in case I screwed one up. I highly recommend this material. The only draw-back is that it needs to be milled on four sides. Having a machine shop or knowing someone who does is very helpful.

Suggestion 1. When making a piece you are unfamiliar with, use a piece of wood as a test piece. For this piece, I ended up doing 2 test pieces.

The details : The dimensions of each piece were 7 1/2 in X 3 in X 3/8 in. The SHCS for attaching the trucks were M5 X (I need to check on this) and the SHCS to attach the alu to the 8020 were 5/16 in. I drilled the metric holes a 1/2 mm oversize and the SAE a 1/64" (21/64") oversize. This gave me ample wiggle room but not too much. I counter-bored the metric holes with a 3/8" endmill.

Design consideration: It was a tight squeeze to get two trucks mounted on this piece of aluminum and have room the 5/16" SHCS. I got lucky on this one, but I'll take it.

More to follow.
Rick

[Senna]

Whooeee! That's some nice work! Good to see you back at it!

I made my interface plates out of 1/2" HDMW plastic. It was something I had on hand and intended for them to only be prototypes... just to proof the design... but they are performing yeoman duty... no need to change them out.

I went with 1/2" 5 start Acme for both the X & Y... Dumpster nuts, radial thrust bearings, along with Ahren's bearing blocks. Couldn't be happier with the performance. I did manage to snag a sweet 570mm THK ballscrew for the Z though! It came with the bearing blocks and that really helped ease the design for that axis.

Steve