Saturday 30 March 2013

Well Easter has come upon us and given us a shortened work week. I was hoping to get a fair amount done this week but events conspired against me. The old adage " one step forward and two steps back" seemed to be my mantra this week.

I decided that the first thing I would finish off was fixing my cross feed assembly on the #39 lathe. I finished cleaning up the cross feed assembly from the lathe that was parted out in California the #77 and reassembled it for installation in my #39. After installing it I noticed that there was no change the cross feed assembly was still very stiff to turn. I had originally thought that the repair work I had done was the cause of this stiffness. So since I was still using my original Bronze nut I decided to try the #77's bronze nut. Unfortunately that one would not fit my lathe, it was a little to high to fit in the slot on the carriage. Went back to my nut and with out locking it down ran the handle full out and in and it worked fine. Looked at the nut and realized that there were small grooves down each side on the top. Evidently over time the nut had some how been grooved and therefore when tightened was pulling the thread up and therefore uncentreing it. Placed a few shims on the top of the nut reinserted it and tightened it up and the cross feed assembly worked fine. Decided to reinstall my original assembly and with the shims on the nut this assembly worked as well. Maybe not as smooth as it should be but more than acceptable for me. So at least that was done.

Once this was all fixed used the lathe for the first time to thread by making the bolt that will hold the collet tray up to the spindle. Here are two pictures showing the threading process and the final product.

The treading system works very well just need to be carefully how you set it up being so close to the chuck. Unfortunately I did not measure very well and the bolt was 50thou undersize, so will need to make another one. That was the first 2 steps back but not a real issues since this was giving me good practice in threading on this lathe.

At this time I decided to fix the carriage rack since the original rack with my #39 was worn in the area when you are close to the chuck. This was one reason I bought the carriage rack from the #77. Well I learned a few things installing this carriage rack. Evidently not all Hardinge Cataract QC parts are interchangeable. First I did find out that the carriage rack can be turned end for end and used again. However mine had already be done and there were two wear spots in the same spot from both ends. Evidently sometime previously they had already flipped the carriage rack. This was also confirmed by the lack of pins between the screws that would hold the rack in place. When I went to put the rack from the #77 on it would not fit. The holes would not line up on my lathe body. On careful examination I saw that the new rack was .5" longer and about .125" higher than my original rack. Now the question then is was this an original Haridinge rack or was this a replacement made by some one else. On my rack the serial number was stamped on the new rack there was no serial number stamped. However this rack was installed on the lathe in California so we have a mystery. When placed on top of one another and the holes lined up, which they do, the rack from #77 was approx. .125" higher. Here are some pictures that show this.


However when I inserted the rack without screwing it down the carriage would run up and down and was actually much better than my original rack system in that I had much less backlash. So decided the best thing I could do was elongate the recess for the screw head and the hole itself to allow the new rack to be installed. So since I don't have a milling machine yet I needed to get my old cheap Busy Bee drill press into play and use it as a very crude milling machine. Needless to say being careful and slow it all worked out. Used a 3/8" endmill to elongate the recess and a 1/4" endmill to elongate the hole. Here are two pictures showing setup and the final product.

As mentioned once this was installed the carriage ran up and down quite smoothly and my backlash was significantly reduced.

So that was the second step forward now for the second two steps back. When I had been doing the threading I talked about earlier I was in back gear for the low speed. Once I was finished I took the lathe out of back gear and decided I would run up the speeds and check to see if the headstock was getting too warm yes or no. So ran it up on the low/high speed for a while then moved the belt to med/high also for a while. Everything was going great so moved the belt to max speed and within 30 seconds the headstock came to an abrupt stop and the chuck proceeded to unthread it self. Managed to turn off the machine and catch the chuck before it fell on the floor and luckily no damage to the lathe bed or the chuck. The head stock though was locked solid. Checked it over and no, the back gear did not re-engage nor did any other pins cause this. This left me with having to disassemble the headstock to see what happened. Once I had it all removed the problem was obvious some how the headstock either spalled or a chip was ingested and came between the headstock and the bearing. Approximately .25" in from the end of the rear bearing, on the pulley side there were three distinct grooves and on the headstock shaft there was some spalled metal. Here are two pictures showing this.



So down I went picked up some 400, 1000, and 2000 grit sandpaper to fix this issue. Carefully placed the headstock in the Boley lathe and on slow speed used a fine file to get rid of the spalled bits of metal. Then used 400 grit sandpaper to carefully smooth that area out until just small grooves left. Then used 600, 1000, 1500, and 2000 grit sandpaper to repolish the areas where the bearings would fit. I also went in to the bearing and smoothed it down as well. There is still a groove in the bearing however no loose material or raised area to catch the headstock. I could grind that area down because there is still lots of bearing surface left in the remainder of the bearing however I think this should work and it will maybe help to allow oil to move around the headstock as well. Here is a few pictures of the finished polishing on the headstock. Actually if you look closely on the second picture you can see my hand holding up the camera as I take a picture so essentially mirror like quality.







Well just need to wait a few days for my order of spindle oil to come in and then I can re-assemble everything and put it back together. With keeping it clean and liberal amounts of oil while re-assembling this I hope not to have any more problems with this. I'll also probably be a little more careful in keeping this area clean and ensuring the oil covers stay closed. Still not 100% sure exactly what caused the problems however I hope this will solve them.

Till next time

Harold





Sunday 24 March 2013

Well this week I was a little bit all over the map in working on things. I had planned to find a piece of steel to make the big thick washer that holds the collet tray up to the spindle. Unfortunately when I got to my local scrap yard they were closed for the afternoon. So needed to work on something else.
I decided to take the new to me crossfeed  threading handle apart that I purchased from California. Upon closer inspection it looks like this crossfeed extension support was also repaired at one time. The gear for auto crossfeed was a later Boston gear part that was pinned onto the shaft as well it looks like "JB weld" on the back of the crossfeed extension support. Here is a picture of the repair job  as well as a picture of the all handle pieces. The threaded shaft is in Evapo rust as i type cleaning off the small bit of rust there was.


While these parts are soaking away decided to start some work on the wooden pattern I will build to allow a foundry to cast more some more tray support brackets. Here is a picture of the original bracket that will be the template for the new pattern.


Decided the first thing I will build will be the lower shelf support. Glued up a few boards for the project and then planned them down to a little over 1/2" thick for the parts I will need. Picked up one piece and cut a groove in it to allow the support bracket to be glued in. Here is a picture of the wood pieces and the bottom of the bracket so you can see where the pieces would go.



 I then cut that piece in half down the centre of the support bracket and then transferred the shape of the tray support over to the wood pieces and cut them out. Once rough cut, I sanded up to the line with the oscillating drum sander I have. Here is a picture of the two pieces rough cut prior to sanding down to size. I still need to carefully sand a taper on some of the sides to allow smooth release from the green sand casting material when at the foundry.

One of the other pieces I started on was the curved bracket you can see in the third picture. I had a thick piece of maple that worked perfectly for this. I carefully drew out the curve a best as possible and then removed the majority of the wood with the table saw. I then went back to the Drum sander and carefully sanded it down to the thickness and shape required. Here are two pictures showing the rough cut out and the finished piece.




I still need to make the back brace for this part and then fit it into the pattern as needed. Being as I am not going to work this week I hope to have a fair amount done over the next 3 days before the Easter weekend.
Until next time

Harold



Saturday 16 March 2013

Hello again. This Saturday we finished up the Collet trays. A couple weeks ago I purchased the metal flat bar that was required and since I wanted it to be more durable decided to use Stainless steel. Well I may not have to worry about rust or painting it however took twice as long as regular steel to work. I knew it was harder to work just didn't know how hard. First thing I did was make up the band that goes around the collet tray. This was reasonably simple quickly made up a template of the circle from scrap plywood and then carefully bent the 1.25"wide flat bar around the form. Once I had the metal shaped carefully measured and cut the hoop to the right length and then with the Tig welder joined the two ends together.  Needed to do a little sanding on the collet tray to get it to fit however we soon had the hoop around the collet tray. Here are two picture showing the Tray with the hoop and the weld joint.

I then proceeded to make the two washers/gussets that go around the central pivoting hole. There are two needed one on either side. After cutting them down as much as possible with the portaband I then ground them down into a circle on the grinder before going to the lathe to turn them down to 4" dia. Once this was done we drilled and then bored a hole to 1.25" for the spindle shaft. Once this was done drilled and countersunk 4 holes on each washer and then carefully installed them on the collet tray using the spindle extension as the support to ensure both washer were mounted in the right spot. Here are two pictures showing the top washer/gusset installed as well as a picture showing the screws that hold the ring to the tray.
 
 Now the only thing to do is make the large Shoulder bolt that holds the tray to the spindle. As well I need to make one more wheel bearing for the spindle tray and I need to make the runners that the tray rolls in. Will need to disassemble the one I have to get measurements for that. That will be next week's project.
Have a nice week
Harold

Sunday 3 March 2013

Well here's another look at the project. Week and a half ago picked up some metal to use to band the collet tray and make washers as well picked up some sheet stock to make the trays. Picked up enough metal to make two sets of trays one for the #39 and one set for the #86. Had the metal store cut the sheet stock down to 9by19 and 13by19 for the two different sizes. Then proceeded to mark out he 1/2" line for bending the edges and cut out the corners and marked them up for radius corner. Luckily we have a small metal shop at work which had a bending brake so spent 15min with the techs setting up the brake and then bending the 4 sides per piece. Here's a pictures showing the resultant product.
Then on this past Saturday used a 1" piece of pipe in the vise to carefully hammer over the two tabs to make a rounded corner. Needed to use the Dremel tool to cut off some of the tab so that we had a close fit.  Here's  a close up of the corner once hammered over prior to welding and then a picture of the welded corner as well. A professional welder I am not however by the end the welds were looking a lot better then the first ones I did.
 

Once they were all welded up I carefully ground the outside's and insides to give a smoother surface cleaned them with acetone and then gave them a coat of primer on both sides. I'll them just let them sit until I'm ready to install them. This will be down the road sometime as I need to use the tray bracket as a template to make a pattern so that I can get some more brackets cast up. I'll be talking about the pattern making in some future blogs. I did not get around to making the collet tray edging or washers since I bought the wrong size stock so need to get some correct sized material for this work. I also received the first of the parts from California to fix my #39 second parcel comes this week and the overhead drive assembly I hope will be shipped to my cousins in the US within the week. I'll be able to pick this up in May when I visit thereby saving me border charges and higher shipping costs.

Till next time

Harold