I "restored" this Ritter dental drill, there is a detailed thread on another forum, but you'd have to join up to see it so I'll just paraphrase. if you happen to be a member, the direct link is here: OWWM posting about Ritter dental drill
I want this thing out of my life, I'm way behind on projects and I'm also out of room - it is basically fixed and ready to assemble, you need a belt (they are available) and you need to wire it up. The drill is located in the USA, shipping across the pond will be expensive, I'm willing to do it but I'd not recommend it. If you pick it up from me (I'm near Los Angles), $40 for the whole thing. if I have to pack it and ship it, $75 plus whatever shipping costs. I'll part this out on eBay in a few weeks probably as "steam punk" material. note, the belt in the first photo (the blue box) was not for this machine and I put it with the correct machine and it is gone. If you get the machine, I am happy to download the thread for your perusal if you want, I'm not posting it here to preserve board storage space and because it isn't really about making a model engine.
The thread starts out this way: "this thing (a dental drill) went through the famous (or infamous) Devoe Fire, and amazingly enough it seemingly survived because it was knocked down and protected by debris on top. So I cleaned it up and posted in BYOD to a resounding yawn. After the failure with the Cutawl, I figured I needed a success, so let's get started"
The reason it didn't run was that a brush had broken off - this motor has a weird brush holder where the brush is screwed to a spring loaded arm. Falling over and getting hot, in combination (no, no film noir love scene here) was probably the root cause of breaking the brush, though maybe it had been over tightened. Being cheap and impatient I don't want to order a new brush, so I decided to repair the broken one ..... (insane? just follow along)
<several photos of shaping the brush with a razor blade>
you can see the repaired brush on the right side, and the one that didn't require repair on the left bottom side.
<a few more photos>
And here it is reassembled, with the slip ring in the bottom, and it works still - so that is good. I'll need to clean up the foot pedal assembly and then test again, but I am pretty sure (due to its age) that the foot pedal is just a resistive element with a slider. The field and the armature are avaialble seprately, so if I was going to use this for some application where I cared, I could use a modern motor controller and have automatic speed regulation. I'm still not convinced I want it but now that it works it's a lot more tempting to keep...... the more modern little air drills, the 200K RPM type are lighter and much nicer but this would be good for polishing small items
<a photo>
after this post I did look at the foot slider and it is as I expected, resistive, and it works like I would expect (measuring with an ohm meter. But now I've lost interest in this and it needs a new home.
I want this thing out of my life, I'm way behind on projects and I'm also out of room - it is basically fixed and ready to assemble, you need a belt (they are available) and you need to wire it up. The drill is located in the USA, shipping across the pond will be expensive, I'm willing to do it but I'd not recommend it. If you pick it up from me (I'm near Los Angles), $40 for the whole thing. if I have to pack it and ship it, $75 plus whatever shipping costs. I'll part this out on eBay in a few weeks probably as "steam punk" material. note, the belt in the first photo (the blue box) was not for this machine and I put it with the correct machine and it is gone. If you get the machine, I am happy to download the thread for your perusal if you want, I'm not posting it here to preserve board storage space and because it isn't really about making a model engine.
The thread starts out this way: "this thing (a dental drill) went through the famous (or infamous) Devoe Fire, and amazingly enough it seemingly survived because it was knocked down and protected by debris on top. So I cleaned it up and posted in BYOD to a resounding yawn. After the failure with the Cutawl, I figured I needed a success, so let's get started"
The reason it didn't run was that a brush had broken off - this motor has a weird brush holder where the brush is screwed to a spring loaded arm. Falling over and getting hot, in combination (no, no film noir love scene here) was probably the root cause of breaking the brush, though maybe it had been over tightened. Being cheap and impatient I don't want to order a new brush, so I decided to repair the broken one ..... (insane? just follow along)
<several photos of shaping the brush with a razor blade>
you can see the repaired brush on the right side, and the one that didn't require repair on the left bottom side.
<a few more photos>
And here it is reassembled, with the slip ring in the bottom, and it works still - so that is good. I'll need to clean up the foot pedal assembly and then test again, but I am pretty sure (due to its age) that the foot pedal is just a resistive element with a slider. The field and the armature are avaialble seprately, so if I was going to use this for some application where I cared, I could use a modern motor controller and have automatic speed regulation. I'm still not convinced I want it but now that it works it's a lot more tempting to keep...... the more modern little air drills, the 200K RPM type are lighter and much nicer but this would be good for polishing small items
<a photo>
after this post I did look at the foot slider and it is as I expected, resistive, and it works like I would expect (measuring with an ohm meter. But now I've lost interest in this and it needs a new home.
