Discussion in 'Project Logs' started by Javerh, 21 Jan 2009.
Looks fine mate.
Even I use a lighter and that's pretty good.
Usually I use the Dremel Versa Flame, with the diffuser, it's million times better than the lighter
Maybe a little crazy, but what about an oven? The heats all around in there, so it won't be concentrated on one place...maybe?
A hot hair dryer works really well.
looks even to me. I wouldn't use a lighter though cause I can see a bit of were it started browning the white sleeve. I used a cheap heat gun for mine.
I like to use a hot air gun but I've misplaced it somewhere.
An oven could be nice but I'd be scared of loosing all control of the sleeving.
Oh, no the sleeving and the heatshrink are still pristine white. The lighting and the camera are playing tricks there.
#36 One step forward, two steps back
Yesterday, a disaster struck.
I was making a housing for the power button. First, I sawed this 30x30x50mm aluminium block and mounted it on the lathe and faced the surfaces. Rectangular parts are hard on the lathe, because they have plenty of discontinuous turning. The constant hammering was too much for the power train. There was a loud bang from the headstock and then the spindle and the intermediate shaft stopped rotating together. The hi-lo - shifter could not engage either. Obviously, I had busted the gear on the intermediate shaft. That's not too bad, but disassembling the headstock is a pain.
Stripping every part from the headstock and then lifting the headstock from the ways reveals what was to be expected. The delrin gear just split at the keyway. While I was there I also noticed that the bearings on the intermediate shaft rattle a little. This could be do to the shock, but I'm guessing it's just the fine chinese workmanship. Both ends of the shaft were fixed and the bearings are cheap CIYU 6001Z's. I'll have to replace them with better ones and modify one of the bearing housings.
LittleMachineShop.com was down for a while, but now it's open again. I ordered a couple of change gears in delrin. The metal gears would have been better but apparently they're discontinued.
I also checked out replacement gears from this side of the pond. The gears on the lathe appear to be MOD 2.25 and standard gears come with MOD 2 or 2.5. Besides, they are a lot wider and would need some work to be made into one gearset.
It'll take a couple of weeks for the replacements to arrive. In the meantime I'll have to work with something else. Perhaps I should finally get the acrylics underway?
Great project you have going here, you got my vote for the MOTM Oh and congrats on the nomination
Congrats on teh MOTM nomination!
Lol! My first thought after reading brinkz0r's comment was "what the f...".
Thank you for your support. Although, I don't really think I have a chance of winning with so many amazing builds.
Well you got my vote too... so maybe you are in the running. You tease too much though, noone quite understands your vision. We just like what we see.
something wasn't right, the key should have broke, not the gear. The key way dose two job's, locks the gear to the shaft, but also acts a stress point in the event of too much torque the key should break.
^^ What you said would hold for standard gears. The key is a standard component, but the gears are made from acetal. Besides, the gears are something like MOD 2.25. They should be at least 25mm thick but they are only 8mm. I'm surprised the teeth didn't shear.
Grats on the MOTM nomination, and feel you on the disaster It really sucks when tools fail.
#37 Another minilathe update
I finally ordered the acrylics. I'll post more about them when I get them.
Meanwhile, here's my lathe again:
So the lathe was busted and I couldn't do anything before I got the spare parts. I decided to strip the lathe into pieces and try to fix some of its shortcomings.
One of the issues was poor mating surface quality. To fix the saddle I ground the bottom of the saddle ways with 180, 240, 600 and 1000 grit wet-sand paper. I glues the wet-sand paper to the ways and used several pieces of plain copy paper to keep the saddle level. After sanding the rear side I sanded the one side of the front vee and then the other side. Finally, I used some sanding paste and rubbed the saddle back and forth on the bed ways.
Now the saddle glides perfectly on the ways. Hopefully this procedure helped to make the saddle alignment better and not worse.
Next, I filed a slight chamfer on the edges of all sliding surfaces in the compound- and cross-slides. Again I used sanding paste to smoothen the gliding surfaces.
Afterwards, I swept all surfaces with acetone and oiled them.
The saddle does not have any kind of indicator to measure its movement. I wanted to add a simple digital readout to it. The easiest way to achieve this is to add a digital caliper to the saddle. Fortunately, on this lathe there is a perfect gap for it between the apron and the saddle bodies. I filed the insides of the gap smooth so that the caliper slide fits nicely in place.
I bought a 300mm caliper from eBay. It is of nice quality so it's a bit of shame to chop it. I used a dremel to cut one of the inside measurement prongs off. Now the screen can be put right next to the saddle. I think I should cut the othe prong too. I tried drilling mounting holes in the main prongs, but the hardened stainless steel is just too hard for my hand drill. I'll have to try with a drill press during the weekend.
On Tuesday, I finally got my spare parts. The new gears are made from white delrin. I also bought two new SKF explorer 6001-2Z - bearings and mounted them on the auxiliary shaft. Before that, the shaft and the bearing ways were ground to size. Now one end of the shaft is fixed and the other one floats. SKF bearings were pricey but luckily they had a 50% discount!
One of the problems with saddle has been that the gib plates keep on getting too loose. It's really a hassle to tighten them, so I wanted to make it easier. I drilled the gib mounting holes through the saddle and tapped them all the way. (I hate all the carbon scrap from cast iron on the floor!) Then I used simple M6 bolts and ground flats at the end of the threads. Now if and when the gibs get loose, I can retighten them from the top.
I also drilled holes in the saddle for a saddle-lock. I'll get to it when I have some time. For now it's not important.
All that's left is to put everything in place and make sure the lathe is in alignment. It's slow and tedious. Hopefully, I can get back to modding soon.
Again he mods his tools
Tool modding, the best of both worlds .
machine failure isn't fun, nice to see it was an easy fix though. I like your digital read out mod on the lathe, will be nice to see how it turns out since I'm planing on doing the same with my lathe.
Sorry about the long wait. Lately, I've been content with just waiting for the acrylics to arrive. The good news is that they're finally here!
I got these pieces from Tampereen Liikeacryl for 35€. According to the owner, the pieces are made out of extruded acrylic. I'll have to consider annealing them before bolting them in place to prevent any cracks.
Two of the pieces will form the proper bottom of the PSU. They will be bolted together. The plates have holes for the power connector, power button and slots for the cabling to pass through.
The PSU will be mounted to the rest of the case with these 20x20mm alu tubes.
The psu bottom plate has 3 mounting holes so they should be sturdy enough. Two of the holes will need a spacer block to mate against the alu profile. The narrow gap below the profile will allow the acrylic to move more freely to reduce the possibility of cracking.
One of the holes is really close to the gap. However, it won't be subjected to large stresses as it's only used for mounting the PSU fan.
There are some schorch marks left from the bending. I'll have to see if they're bad once I peel off the plastic cover.
The reservoir plate fits the reservoir and the pump nicely. The teflon pump top piece extends couple mm's above the res plate. If it would sit lower, you could see through the acrylic to the bottom side. The acrylic height is perfect when it is sitting on the pump top bolts.
I also tested the res top with an o-ring. The seal is nice and tight. One interesting side effect of the o-ring is this optical illusion. The acrylic tube and the o-ring create this black band that looks like it's on the outer surface of the reservoir.
The res plate fits in place like it should. There is a ~4mm gap around the res plate to allow another acrylic to be placed there. To make the res plate level with bent alu edge, the pump bottom will have to be lifted by about 10mm. That should be enough space to allow for enough vibration padding below the pump.
Unfortunately, I cant test wether the other acrylic plate fits in place without disassembling the whole case. It would sit between the res plate and the HDD shell.
I love how the white acrylic reflects the innards.
Here you can see how the res plate and the hdd plate fit together. There should be plenty of space for the cables to pass through.
In other news, I tried drilling through the digital calipers. I bought a few 3mm and 5mm carbide drillbits meant for stainless steel.
The hardened stainless is the most horrible material I've ever worked with. First, I tried drilling a pilot hole using the 3mm bit, slowest possible drill press speed and flood cooling of Rocol RTD drill spray and lots of pressure. The bit didn't even make a dent. At some point the bit simply shattered.
I had better luck with the 5mm bit. The bit slowly sank into the material producing lots of smoke even though I kept spraying the cutting fluid. I'm guessing the fluid burnt off.After the first hole succeeded, I tried drilling more. Apparently, the bit was now so dull it could only penetrate for about 1mm before work hardening the hole so much it was impossible to proceed.
Next, I tried resharpening the bit with a diamond hone. It just failed just as miserably. No luck with peck drilling either.
On the back side I tried the difference with using a center punch and drilling raw. The centerpunched holes are on the right and the raw holes are on the left. Centerpunching made the material work harden enough to make it impossible to penetrate. On the left, one of the holes wandered too close to the edge and cracked as it went through.
Plan b is to use the semispherical dimples to mount the caliper between blocks of alu and grind the broken tip off.
If some of you are going to try this, I'd suggest you try to grind slots in the caliper jaws instead of drilling.
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