Frankenmill: Bridgeport J head onto Victoria U2

[Pete O]

(04-30-2019, 11:29 PM)Highpower Wrote: I use way oil on mine but I don't have all that extra stuff hanging off the front of the ram. That's got to be putting some serious pressure on the dovetails at the back of the ram (I would think) when run out that far. Lot of leverage there, no?

Yep that's my thought, it's a lot of weight and the further out it gets the harder the ram is to move. I have no concern about the dovetails being damaged as the forces involved in horizontal milling would undoubtedly be much greater than the force here- also the user manual shows the whole machine slung from the overarm when moving it- but I'm also not totally happy with using the Y-feed to move it as I did here. I'll go with Tom's suggestion of grease when I reassemble it after painting, will be interesting to see the result.
A counterweight is also an intriguing idea, I don't think I'd have room behind the machine when the ram is retracted though to hang anything far enough out to counter the weight of the new bits when it's extended.

[SteveG]

Looks awesome Pete.
To make it easier to move, how about some sort of temporary support down to the table with a bearing on the end.
If there's a flat area on the underside of the ram something along the lines of a cheap axle stand with a bearing on the top would do. Incorporating a heavy spring would allow you to load it up slightly by cranking the knee up without fear of damage due to jamming a solid strut in there.
Over-thinking it even more, you could do a few tests to see how much compression worked best, then mark the spring to be able to repeat it next time.


Steve

[Pete O]

I've been doing a few bits and pieces in preparation for painting the conversion parts. The motor cowl was beaten up and in need of some TLC, looks like it has received a blow from something that has not only put a hole in it but also broken the four screw holes out of the bottom rim.
   
I had some fibreglass offcuts and leftover epoxy from my canoe build 10 years ago, probably pushing the shelf-life envelope but it was expensive stuff. Also some release agent from a forgotten project that pre-dates the canoe build by several years. I cleaned up a good section of the cowl on the side opposite the damage, coated it with release agent and then laid a few layers of fibreglass cloth over it and brushed the epoxy in. Let it set up overnight.
   
I was a bit worried about the stale release agent, it was quite a bit more viscous than when I last used it and I have no idea what to thin it with so used it as-is. The repair mould came away nicely.
   
I cut out the damaged section and taped the negative over the hole after coating it with the release agent
   
and patched the hole from inside. Left it for a couple of days. Seems to have got the shape into the repair pretty well, the imperfections should respond to spray-putty during the painting process.
   
I also cut out the broken sections around the rim where the four mounting screws go, repaired them one at a time as the epoxy is very runny, can't rotate the job until the previous patch has set up. Today I cut off the excess, marked and drilled the holes and smoothed the bottom edge.
   

The top cowl piece is missing, parts suppliers want about $80+ for it which is out of the question. I'm thinking I might see if I can pick up some kind of vintage chrome hubcap of a suitable diameter.


I spent a few hours with some flap wheels, blending the sharp edges and corners on all the mounting pieces. I think they should look acceptable once painted and re-mounted. For interest sake I weighed the new parts, 61.5kg or 135.3lbs. add to that the 200lb head and it's little wonder the ram is hard to move.
   

I checked the flatness of the front plate as promised; I was expecting it to be a bit convex but there was zero rocking with the face down
   
so I decided to blue it. The result was interesting. For the record, I don't plan to scrape it. I have neither the skills nor the equipment and I don't think it's necessary.
   

Getting things ready for painting, I've stripped the overarm and applied a new skim of body filler, it's ready for primer and spray-putty
   

Still need to do the prep work on the arbor supports, I stripped the paint and filler off one of them ages ago but didn't get any further.
   

The weather looks promising for painting on my days off next week.

[Dr Stan]

Just a thought.  As long as you have the ram off the mill what about drilling & taping for some grease zerts to shoot some grease on the bearing surface of the ram?  Give it a shot in each zert fitting before moving it.  Probably should use a high pressure grease.

[Pete O]

(05-19-2019, 12:24 PM)Dr Stan Wrote: Just a thought.  As long as you have the ram off the mill what about drilling & taping for some grease zerts to shoot some grease on the bearing surface of the ram?  Give it a shot in each zert fitting before moving it.  Probably should use a high pressure grease.

That's a good thought Stan, I'll have a look at the possibility of doing that before painting. Do you think that grease might have a detrimental effect on the ability of the dovetails to hold securely when clamped?

[Pete O]

I had a look and it would be simple enough to drill a few grease passages into the dovetails on the top of the column, a horizontal hole from the side of the machine into the internal angle, then a vertical hole from the top surface to intersect it and a grease 'zerk' (we call them grease nipples here, don't laugh) threaded into the outside. I could sort that out while the paint dries.
   

That aside, I've just done something really annoying; tapping a hole to attach the tilt azimuth / scale, I've broken an M5 tap in the nosepiece.  

   

[Pete O]

Got some painting done.
   
   
   

I decided to leave the arbor supports for this round as they need a fair bit of preparation work and I didn't want to miss what might well be our last run of good weather for the season. Just as well I left them cos it looks like I'll be re-doing the cowl as well.
\    

I don't like painting at the best of times, the toxic stink, the mess, the hours and hours of sanding, filling, sanding, sanding, the cleanup, the stink...to stuff it up like this at the last hurdle makes me want to kick the thing across the yard.
Oh well, at least it's the easiest part to remove, so I can get the machine together and re-paint the cowl later when I paint the other bits.

Just got to resist the temptation to fiddle with things before the paint is dry.

Oh yeah I dealt with the broken tap...
   
   

The perfect crime.

[Dr Stan]

Yes painting can be less than fun.  For smaller items I purchased a powder coating system and use an old oven for curing.  It limits me on the colors, but that's OK.

BTW, with the mass and the amount of contact between clamping surfaces I don't think the little amount of grease will cause any movement of the ram once clamped in place.

BTW, I quickly learned not to use the word "fanny" in England in mixed company and assume it has the same meaning down under.

[Pete O]

Yep the 'fanny' here is located somewhat anterior to where it is in the U.S. and is restricted by gender. I think the term is outdated now though.

Would powder coating work on fibreglass? I know very little about it. And don't tempt me to buy even more stuff!

I've been ruminating over the ram dovetails issue and I think I will leave it be and just apply some EP grease on assembly. I think that moving it all the way out will be very infrequent and can be dealt with when the need arises. Hopefully at a future time (?retirement) I'll be stripping the base machine down and if needs be I'll make modifications then. The work I've done here is enough for a while I think, I've got a few details to paint and then basically put it together and use it. None too soon!

[Dr Stan]

No power coating only works on metallic items as the powder uses electricity in the process. I've never tried it, but using a heavy copper spray paint such as copper spray on gasket material may lay down enough copper to make the process work. I know this is how plastic is chrome plated.