Hey Folks:

I've had a long and arduous trip with my PP ///, but I've finally gotten things to the point where I'm getting utility out of it.

I'm currently trying to get my shop back up and running well enough to produce model kits again. What I make is not flat foam kits (although I plan on adding a couple here before long), but rather machined EPP models.

My intention with the PP /// was to use it to make flat stock parts where possible in balsa and ply and then use it to cut out fuselage profiles that would be further machined with a router using templates (faster than CNC). I'm finally to that point.

The picture attached is my first successful use of the PP /// to make a part of the router tooling. The part shown is the alignment plate for the forward Push-E Cat fuselage. There are two more plates that have to be cut: the one that lets me make the interior bays and the one that lets me cut the wiring and cooling channels.

It took a while to get here. The X-axis debacle, of course, was the most damning thing to go through. That said, it has been a 1001 little things that all have to go right before the system works, often with "let's try this" causing more grief than anything.

For reference, I replaced my X-axis motor with 260 ounce-inch hybrid unit from Probotix. All of the set screws in my pulleys have now been replaced with longer socket head screws. I'm using a set of the refined rollers that have the HDPE end caps (one of which I had to re-set with JB Weld per Mark's suggestion.) For cutting in 1/4" MDF as shown in the picture, I used the original Harbor Freight jeweler's motor set with the Tile Cutter "Phlatbit". Feed rate was 5" per minute, including plunge. I set the transition speeds down to 25" per minute to keep from inducing axis error when moving from cut group to cut group. Kerf was set in the Sketchucam box as .125. I obtained between .125 and .155 in cut width in the end. The largest variances occurred at the nose where the X-axis was working simultaneously with the Y, which leads me to believe that it's related to backlash. That said, There really wasn't any drift in the X overall for which I'm very thankful. The green foam carrier is what I use to make sure the rollers have something to hold onto.

I'll probably post pictures of the other two parts I'm going to cut for my router tool and then a final one of the finished tool for reference. When I get to cutting the fuselage parts in production, I'll show those, too.

Bests,

Darwin Attached files

 

Thanks for the encouragement, Mark.

I reviewed the piece in the picture a bit more closely last night. It looks like the X was drifting negative with each cut on the order of .005". The two profiles are off in the X-axis by about 1/16" (10 passes total, five per outline.) I still think this is a lot less variation than what I would have achieved using a scroll saw or a Rotozip.

The goal for the Phlatprinter is to have it cutting the materials it was designed for on the whole. I'm only doing MDF because of a burning need to avoid having to use a scroll saw and deal with the slop from that.

I do want to have a router attachment. My first attempt at cutting a variation on Flash's file ended horrifically. I'm hoping that by creating a file whole-cloth in my separate CAD system and then importing it like I did for the profiles shown above, that I can achieve a much better cut file. Also, I'm implementing your new settings and re-calibrating today. That may deal with the X-axis drift.

The system is close to usable now. If I can deal with the X-axis drift in such a manner that I can depend on it to reliably stay within 1/32" after no less than 20 x 24" transitions, I will call this project complete and move on to actively using the tool to make kits.