Rapidor 6" saw - work in progress

[MattF]

Like a fat hacksaw blade? are they easily available?

Aye, they're easy enough to get hold of. They're still a common thing. If you search on Ebay for power hacksaw blade, it should list a few.

No not figured it out yet, i recon its a pollard as its too similar not to be, but theres NO makers stamps or marks anywhere, the motor is a replacement so nothing from that, the guy i bought it off had it a long time and thought it was an Elliot, but i think that must be from the "progress" name?

That's definitely the maker I'd guess at still. Styling seems so similar to theirs, even accounting for the variations. With the progress tag, I've seen quite a few different machines seemingly with that label, especially with the banks of drills. Seems they class it as a working methodology as much as a model name.

Made a couple more bits for the saw today. The first photo is the adjuster screw for the blade tensioner. The second is a clamp bolt for the blade holder.

Centre drilled that clamp bolt so that I could fit a brass nub in the end. Pretty much every other one of these machines which I've seen photo's of have had a broken or replaced clamping plate, so I'm guessing they have a tendency to have too much pressure applied and crack the plate. That's why I've made it as a knurled head bolt, so that it can only be finger tightened, and with the brass nub so that that should distort before anything else might risk cracking. Plus, that brass tip should prevent the bolt from marking the backplate when it's tightened. This is the bolt with the nub fitted and where it goes on the machine. That plate it's fitted in is the one which generally seems to disappear or become cracked.

Thought it best to err on the side of caution with that clamping assembly, and finger tight should be ample for its purpose.

The end of that tensioner screw has been centre drilled too, same as the little clamp bolt. Need to make up a disc for the end of that so that it doesn't tighten up directly against the casting, so the hole is in the end for the disc to centre against. I'll leave a little protrusion in the centre of the disc for it to seat in the end of that screw.

I think that tensioner block in the first to third photo's might be another of the Herbert on speck moments. These machines should have a cast block there, rather than one machined from a rectangular block of metal as this one is. The general look of it does make me think its original rather than a replacement piece though, so I'm thinking they may have run out of castings for the adjusters at some point and just made some up from what they had to hand.

I'm gonna have to stop arsing about with these little bits and get those bronze bushes out and measured. It's amazing just how much time the finishing touches take. I swear that all these little finishing touches are taking far more time than the main grunt work of the restoration did. Seems quite converse. You'd think it would be the opposite way around.

 

[MattF]

Barring needing to make a disc for the end of the adjuster bolt, the tensioner assembly is all abouts done.

Yes, I know that knurling is naff, btw. That thing just did not want to play ball, so I gave up eventually. The knurling which is on there is plenty enough for the task though, so it'll do for the time being.

Made some studs for that clamping plate too, so that I could ditch those god awful allen bolts which were on there originally.

 

[brewdexta]

Nice work Matt, I too have some knurling to do for a couple of screws missing on the mill. I've never done it before, I think I have some knurling tools in a box of odds and sods of lathe tools that my dad gave me, no idea if they are any good yet, will have to give it a go.
Cheers
Andy

 

[MattF]

Nice work Matt, I too have some knurling to do for a couple of screws missing on the mill. I've never done it before, I think I have some knurling tools in a box of odds and sods of lathe tools that my dad gave me, no idea if they are any good yet, will have to give it a go.

Provided the teeth are sharp, they should be fine. It can be a patience tester though. It's not oft I knurl owt, (hence why my technique needs some work), but it's one of those things which'll either work spot on or cause you to think sod it. It's like parting off, IMHO. Some days you have it, some days you don't.

 

[MattF]

I think I can safely say that I dislike knurling. I'll be damned if I can get the thing to be consistent. Works fine one moment then a dog the next time round. It's more of a roughening the surface tool, IMHO.

Made some new blade pins. The old ones were well knacked. Had to figure a way of working around the fact that the old ones screwed into the blade holders, but due to the fact they've used some fine thread, (I'm guessing likely BSB from the fine pitch and diameter, though I haven't checked the exact TPI of the holder threads), which I don't have a die for, I had to come up with an alternative method of retaining them. This is one of the old pins:

An outer, threaded sleeve which screws into the blade holder, with the centre pin being a sliding fit for retaining the blade:

These are the new ones. Two parts, one is a slide fit into the threaded side of the holder, the other being a slide fit through the pin side of the holder.

To say they're only a simple thing, I spent an inordinate amount of time making that first one, figuring out the design as I went along. The second one obviously took far less time once I had the design and dimensions. They might need a bit of tweaking and alteration if necessary, but theoretically they should work.

Everything in place on the bow:

 

[MattF]

Been sidetracked working on the Major the last few days. That one is more of a refurb that a restore. Not gone to excess getting the old paint off or the like, as this one is purely for functionality over form, but it's looking better than it did, (I hope ). I've got all of the manky blue paint off, but there are still portions of the original Alexander's green and cream paint under there in places.

New pivot pins for the damper and holding arm. The old ones were those horrid split pins, the things which are like sprung tube with a slit down them. Made some new ones up from mild, and left them a tad longer than necessary. Thought the protrusions might come in handy if I ever wanted an extra knock point for some mechanical or electrical addition at a later date.

Sorted the damper adjuster too. The bottom portion of that rod was bent. Spent a while trying to think of how to straighten it without damaging the threads before common sense finally kicked in, and then just turned the end down.

For reference for anyone who might wonder how the damper works:

There are six holes drilled through that ball, top to bottom. The plate merely allows or blocks flow through them.

New shims made. Didn't go overboard shaping these like the last lot. Just cut them roughly semi-circular with the fretsaw then finished them with the file. Made from ply, as BS suggested. Four 3mm and four 6mm. Had 3mm, 6mm and 12mm, but not an ounce of 9mm knocking about, hence the two lots to make up the required thickness.

Got to love the irony of this. A power hacksaw manufactured with rods which have ends cut almost as badly as if they've been done by hand. Skimmed the ends of that bow pivot before I refitted it.

Her current state.

 

[candor]

Thanks for sharing about the shim, just sort the one here soon on that front.

 

[MattF]

Glad I could help. It's a bit of a phaff getting the alignment and pressure set correctly, but if you compress both covers down so that there's a slightly oversize gap to the slides and then work on one cover at a time, that seems to be about the best method. As you adjust the second cover, you might need to back the first one off slightly. Seems that precision alignment wasn't a must with these saws, so alignment may change slightly once both covers are all abouts set. It does need a bit of tweaking as you get closer to finished. I just aimed for the spot where I can't hear or feel binding, (which does leave a bit of play), but so that it jams when the sections at the ends of the slides where they aren't worn reach the covers. The inbetween spot of the worn & unworn sections, so to speak.

Out of leather and ply, the ply is definitely a lot easier to compress. If I hadn't been trying my damnedest to stay original as much as possible with the old one, within reason, the ply is definitely a more workable option. Herbert's then Alexander's must have used that reasoning at some point in time too, as both the Minor and Major had softwood shims.

 

[Fazerruss]

Looks Good, I'm also now in the Rapidor owners club.

 

[MattF]

We're gonna outnumber the non owners soon. Btw, how come everyones metalwork always looks shinier than mine? Really like that colour scheme you've chosen. Those two colours really do compliment each other.

 

[Fazerruss]

Being a tight Yorkshire man I used what ever paint I could get free or cheap. The grey is some hammered finish industrial stuff I scrounged off my brother and the red is left over from a paint job I did on my wife's previous fiesta. Could have gone for the original hammered green but that would have meant me opening my wallet.

 

[brightspark]

Being a tight Yorkshire man I used what ever paint I could get free or cheap. The grey is some hammered finish industrial stuff I scrounged off my brother and the red is left over from a paint job I did on my wife's previous fiesta. Could have gone for the original hammered green but that would have meant me opening my wallet.

theres enough moths flying about without u doin that

 

[MattF]

They've worked well. Think those colours look a lot better than the original colour. Never been a fan of that light green. The Meddings saw had a similar colour on it too, and I detested that with a vengeance.

How've you got on with the blade pins, btw? Have the threads totally stripped, or is there enough meat left to just tidy the threads up? It's a 1/8" BSP thread on those, btw.

theres enough moths flying about without u doin that

How does this look. Filled and smoothed the gap between the suds reservoir and the bed with glazing putty mixed with the paint to colour it. This is before:

and now:

Need to smooth the putty a bit more when it's gone off a bit and become less tacky and soft, but does it look okay'ish or a bit naff?

Both saws are side by side now, btw. Been rearranging, so this is where they're staying for the moment.

The blue one is a damned sight easier to move than the big one.

 

[Fazerruss]

The original blade pins were fine but the thread in the blocks were stripped. I drilled out the thread hole to about 8.5 mm then tapped the pin hole to M6.
I then turned a small sleeve to 6mm id and ~8mm od. The bolt now holds the tension on the blade and the sleeve centralises the bolt and also nips the blade against the block so to hold it square. The first sleeves I made were slightly shorter which didn't hold the blade secure enough resulting in it flexing and so not cutting square.

 

[Fazerruss]

Your blue Rapidor looks to be the exact same model as mine with the fabricated cabinet. Was your blue cabinet also in need of some fettling? Mine was crap to say the least. Nothing on it was cut square.
What is the bolt stuck up vertically that is screwed into the bed to the left of the blade for?

 

[MattF]

The original blade pins were fine but the thread in the blocks were stripped. I drilled out the thread hole to about 8.5 mm then tapped the pin hole to M6.
I then turned a small sleeve to 6mm id and ~8mm od. The bolt now holds the tension on the blade and the sleeve centralises the bolt and also nips the blade against the block so to hold it square. The first sleeves I made were slightly shorter which didn't hold the blade secure enough resulting in it flexing and so not cutting square.

Sounds just the job. Nice one.

Had been wondering about the blade floating point, with regards to whether it should be snugged up against the clamp else left to centralise on the pin on its own.

Your blue Rapidor looks to be the exact same model as mine with the fabricated cabinet. Was your blue cabinet also in need of some fettling? Mine was crap to say the least. Nothing on it was cut square.

This one ain't great either. Holes etc. look like they've been cut with an oxy torch, and the middle strut running widthways, where the beds centre bolts are supposed to go, is around 1/8" lower on the frame than it should be. Plus, looks like they never heard of deburring or the like.

What is the bolt stuck up vertically that is screwed into the bed to the left of the blade for?

That bolt's just a temporary plug to stop crap getting into there. That spot in the bed is where the upright rod for the coolant feed goes. I haven't put it there yet though as it sticks up about 18", and last time I was working on the machine with it in place I smacked my forehead on the top of it when leaning over. It stung somewhat, so I err on the side of safety now.

 

[Fazerruss]

Had been wondering about the blade floating point, with regards to whether it should be snugged up against the clamp else left to centralise on the pin on its own.

Me too. I was beginning to think I may have to shim the clamps on the bow but then thought back to a similar problem I had with my band saw. I made new roller guides for that which sorted the blade wondering.
The sleeves seem to hold the blade nice and tight with no deflection and it cuts nice and square. The main test will be when I put some flat bar upright in the vice and see how good it cuts.

One thing I do love about this saw which is the main reason I got it is that it's so quiet compared to my TCT saw.

 

[MattF]

The main test will be when I put some flat bar upright in the vice and see how good it cuts.

Let us know how that goes, so I know which way to go with the pins.

One thing I do love about this saw which is the main reason I got it is that it's so quiet compared to my TCT saw.

Likely a lot less mess too? Never used a TCT myself, but I know I always see a shower of sparks/filings when anyone else is using one.

 

[NickyG]

Rapidor Mechanical Saw

Hi I'm not sure if this is the right place to ask but I'm sure one of you nice guys will point me in the right direction! (hopefully!)

I work in a secondary school as the tech in the D & T department. We have a Rapidor Mechanical saw which up until today has run beautifully.
It has now stopped sawing through anything (it isn't jamming in the work) and isn't as smooth as usual. The blade has been changed but I think it is more mechanical rather than the blade being an issue. I have taken the cover off to look at the belt. It's a bit loose but when the saw is running and it stops, the belt isn't slipping on the drive wheels.
If it need a new belt, where do you get your parts from?

Can anyone help me and give me some ideas to try please?? This machine is the best thing in the workshop and I need it working!

Thanks in advance,

Nicky

 

[Robotstar5]

Can you watch the pulley on the end of the motor when it stops cutting?, does the motor stop turning (stalling) - take usual precautions when running with covers removed!