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[TrickyCNC]

a paste from my build thread on another site ...

the basic layout of the bed and X axis....






I've made the bed in the form of a torsion box out of 1/2" MDF.
Finished bed size is 36" x 27" x 4" - max working area will be about 26" x 26"

I've laid the screw and rails on top roughly in the position they will be in, except it will be the bottom when finished.

The gantry will be torsion box sections too , and fixed to the rails under the bed for a clean look.

The bed will be raised on legs when I figure out how high they need to be !







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anyhoo,, today I spent a couple of hours on my build.

the rails I lined up on a bit of 3/4 ply, using a new ground level as a straight edge.



I drilled through and counter bored underneath, before grinding off the bolts before tightening









I must say, the mixed sets of machine screws / washers / nuts etc . are one of the most usefull buys I ever bought !



I mounted the motor / screw assy on a bit of ply and shimmed it to be parallel



and this is them all layed out .



I now have to fix one to the bed and set the others in place of the 1st fixed bit.

I'm deciding whether to use the screw as the ref , or a rail .. but I don't suppose it matters much.

[TrickyCNC]

Starting the gantry ..........









nothing impressive done

made a bracket from 1/4 plate for one of the bearings as I only had 3 out of 4.

Made the top and bottom gantry torsion boxes





Got to paint a dolls house tomorrow, so prob wont get much done here

Rich


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]got the under gantry mounted. Just bolted at the moment. If it moves at all, I'll glue it.

I added some temporary legs and got it right side up.

Played about with the settings, and upped the amps on the driver, got it upto 168IPM, with the acceleration almost instant

It moves pretty strong too, I can put a lot of force against the direction of movement and it keeps going.

I'm very happy so far.

it's moving about 20" back and forth in this video clip

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[TrickyCNC]

I made the gantry bridge tonight.

the top and bottom are 8 x 4, the uprights are then 9 x 3 .

It's just glued and pinned, so I'll have to wait till the morning to see how stiff it is, but being a bit gentle with it tonight I'm quite impressed !

I also like the video my el cheapo phone can produce ... perfect for this kind of thing !

so, some more :)

<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid121.photobucket.co m%2Falbums%2Fo238%2FRichAAC-UK%2FMOV00005.mp4">

[TrickyCNC]

I'll fix the video links so they work in this forum when I get a chance :)

[TrickyCNC]

Starting the Y movement parts..................







so, I very quickly realised that the clearance will be reduces when the Z assy goes in ! oh well, I'll try and design it to be as thin as poss under the Y.

I had some precision supported rail (without the support ) from the skip (dumpster) stuff.

I cut it in half with an angle grinder, and made some supports from angle iron I have knocking about.

That's about it for today. I bought some M8 threaded rod / bolts / nuts / and washers, so will start on the bearing trucks tomorrow









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[TrickyCNC]

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So, not much done today to show.

I got the Y rails more or less aligned (good enough for now)

Simple setup with a set square and clamp, 1st I got the height from the bed equal along the length of each rail, and both rails equal to each other.

Then I checked the distance from the outer edge rail to rial along the length.











then I got to making some skate bearing trucks.

the rails are 31" long, my travel will be about 25" long, so I cut some angle iron to 7" and drilled the holes 1/2" in for the bolts for the skate bearings. spaced with nuts, and cut to length after with the angle grinder.





next to figure the best way to atatch the trucks to the Z carriage ???

I'll be asking that in another thread :)

[TrickyCNC]

so, today I had to clear the CNC project to one side to do some paid work

I cut this stack of MDF to make 2 house shaped bookcases, which is the kind of thing I make most of my living off

This is the stack



it's one of the things I want to cut by CNC

the finished item looks like this



this one was ordered with rainbows for a children's therapy room.

anyway, I'll assemble them tomorrow.

I got the Y carriage mostly built later today

I dado'd out for the bearing trucks, based on Ger's answer to my other post. Thanks Ger



The bolt head were a little proud, so I ground them on the belt sander





for a nice fit



I made a torsion box at the top, and a removable bottom plate for dissassembly.
A threaded rod just above the bearings for the pre load adjustment
I might make a fitted side plate if it needs stiffening (to stop nodding), will know more tomorrow when the glue has dried



it rolls pretty well

<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid121.photobucket.co m%2Falbums%2Fo238%2FRichAAC-UK%2FMOV00009.mp4">

I'll connect the screw assy tomorrow, then to start on the Z

I hope to make some sort of 1st cut by the end of this week :wee:

[TrickyCNC]

]Spent today beefing up the carriage.

I filled in the sides, and added a mini torsion skin the the front. I'll do that back at a later date. Lined up for the screw to be bolted up.



Now it's just the Z to make and I can test it :D

so, tonight, I'll mostly be looking at everyones Z's and choosing how to do mine.[/

[TrickyCNC]

:) finally got started on the Z today

I'm still making it up as I go along, depending on what I can find to make it out of !

Today, it was 1/2" birch ply.

the bearing trucks and rail are quite wide, and as I dont want to build out any more than I need, towards the front, the Z plate ended up quite a bit narrower than I imagined. It's still 4", so should be ok.

In fact, it ended up just like an idea I had the other day of making your own Hiwin type rails and bearings.

I have it mostly assembled and glued under preload from a clamp. It moves really nicely.

Tomorrow, when the glue is set, I'll be adding more glue block support to the outside edges, behind the bearings. the pipe is not attached yet, so I can shim under it if needed.

Also, not shown in the photos, I block planed the rail housing edges so the pipe fits in it's slot snugly and seats on the bottom.













CLICK TO PLAY

[TrickyCNC]

T

I got a bit done today.

Screw and nuts sorted.

I'm going to mount the motor to the Z plate, and was looking at the space I had to mount the nut(s) for the allthread screw.

I have just enough room for the nut, but not much more. so this ruled out a nut surround.

My 1st thought was to weld the nuts to a small bit of 1" x 1/8" flat bar, but my welder is well packed in under a load of "stuff" in the corner of the shop. So I'm wondering how to hold the nuts in posistion without using any space around them. The nuts are quite meaty, so I had the idea to drill and tap through the side of the nut, and hold it in place with a bolt, through the bottom of the bearing carriage . I didn't know if it would work, or what the nuts were made of ? could I drill them ? would they be too hard ?

Anyway, it seemed to work OK. I tried a bit of spray can to mark the bolt that protruded through, but it didn't stay on when I removed it, so a bit of fussing, and I had the bolt ground down to the correct length where they wont foul the leadscrew, but have maximum purchase on the nuts.
I didn't really take the time to have the nuts alighned, instead, I left them slightly loose, threaded the leadscrew through both, set the leadcrew in the correct posistion and 5 min epoxy'd the nuts in place. once that had set, I tighten the bolts that hold the nut. Time will tell, but I see this as a temporary setup until I get a better screw and antibacklash nut.

So, onto the screw. I wasn't sure how the end should be, so I made it look like pictures I'd seen on here and online CNC shops.

It's the 1st time I've used a lathe, so was happy how it came out.

It's M12 allthread rod, skate bearing, M8 nut, and 1/4" coupling bit on the end.

The lathe cost me about £100 UK pounds and is about 100 yrs+ old !
I think it will pay for itself very quickly :)

So, I still have the bearing blocks and couplings to make, they'll be next.

Still not cutting, but getting there ! It seems to be taking longer to make the Z than the rest put together ...
















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