Better carriage?

Yes I'm still working on my Ormerod printer. I was ready to do a test print and I have a broken piece of filament in the tube leading to the hot end. So I stopped and then life got in the way again. I have now removed that and had to take the hot end off to do it. While putting it back on I noticed how much my hot end would rock side to side. I have the carriage that has a bearing that rolls on the bottom of the arm. I have adjusted it up but I either have a little play or it slides like crap.
Does anyone have a better design that can be printer and that holds the dc42 sensor board?

There is a better design of the x-carriage which runs the bearing upon the back edge. Don't think it supports dc42's sensor board.

Running the bearing upon the back with the original x-rib might also cause problems with too much yaw as it moves up and down the x-axis.

Upon my set-up I have a bolt pushing in towards the rib from the side placing pressure upon the bearing bolt so giving some adjustment

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Supporting 3D Printers with Parts and Build services.
Printer: Ormerod 2 (528.4) Duel extruder set-up with Aluminium X-Rib, RRPro Firmware v1.11-ch (2016-04-08)

My sensor board is best mounted on the hot end, not the carriage. This is so that the trigger height does not vary so much with the amount that the head rolls about the X rod.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Do you have a picture of this or is that the while printed parts on your instruction page I need.
And just my luck while messing with the print head 3 of the six wires came out of the connector plug. I should just rewire now and install your board but have no way to get the parts.

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dc42
My sensor board is best mounted on the hot end, not the carriage. This is so that the trigger height does not vary so much with the amount that the head rolls about the X rod.

This thread may help [forums.reprap.org].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Note that the hotend stays down by gravity and is supposed to be able to rock so that it is free to lift up and ride over the inevitable bumps in a print. If you make the hotend solid the nozzle will catch the print at frequent intervals and cause the X or Y axis to slip, or will knock the print off the plate.

Dave

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dmould
Note that the hotend stays down by gravity and is supposed to be able to rock so that it is free to lift up and ride over the inevitable bumps in a print. If you make the hotend solid the nozzle will catch the print at frequent intervals and cause the X or Y axis to slip, or will knock the print off the plate.

Dave

I agree that is the intention, but my experience is that a lot of the prints that I produce with the Ormerod have a slight curve at the bottom because it's so difficult to get a perfect distance from the bed, so the over or under extrusion causes the head to be at a different position to the ideal, and because of the hinging mechanism against the carriage, you have a curve that carries through to other layers (albeit less and less each layer).

Example:

The upper layers are affected by the nozzle being a little too close to the bed, slowly but surely the effect goes away, but because of the hinge effect, there's a curve. A similar effect occurs if the part lifts from the bed.

Other printers I've work with have the height of the head locked in place, so it can't 'ride the bumps' which produces (IMO) a better result on the lower layers.
Example:

This part was printed upside down - The lowest layer is quite squished on the bed for good adhesion (or because I didn't get it quite right), but the subsequent layers aren't much affected.

The head doesn't ride over the bumps so much as through them, which can cause missed steps in extreme cases, or high speeds. When z-dist and extrusion multiplier are properly set up and with effective cooling of the part, there aren't many bumps to ride out though.

Edited 1 time(s). Last edit at 08/16/2016 08:47AM by VortyZA.

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brlowe
While putting it back on I noticed how much my hot end would rock side to side. I have the carriage that has a bearing that rolls on the bottom of the arm. I have adjusted it up but I either have a little play or it slides like crap.
Does anyone have a better design that can be printer and that holds the dc42 sensor board?

There are a few of things to watch out for with a bottom mounted bearing.

Firstly with the stock carriage it's very difficult to tighten the bearing as the bearing nut tends to slip and if not tight enough the bearing slowly moves during printing allowing the carriage to roll.

With the bearing running on the bottom on the arm it's critical the rod is parallel to the arm. I had to re-seat the idler bracket to get it spot on. Of course the same applies with a side mount bearing but at 90^o.

With my original PLA printed parts the belt fixing point on the carriage was not perfectly in line with the belt as it exited the idler bracket and motor mount. This could be made worse when adjusting the motor as there is enough play allow it to move vertically. The impact of this is that the carriage has a tendency to roll towards the end of travel. I thought I had a dip in the middle of the bed till I realised what was happening. Try lifting the carriage and letting it drop back against the bearing in the middle and at the two extremes of travel. If you notice any difference then that may be causing the carriage to roll.

It's a faff getting everything perfectly in line but perseverance pays off.

I mounted my sensor board on the carriage as I wanted to be able to easily change the head as in the thread above. However I am contemplating getting another sensor board for my 0.3mm head and mounting both on the print heads to bring them closer to the nozzle. I use a thin printed fan spacer (Quickset hot end) and will probably add a 90^o lug and use that as the mounting point.