Class 22 Diesel (next project)

[Ron LadenParticipant @ronladen17547]

Boring a clearance hole in the two chassis top plates (3mm steel) to allow a 17mm socket access for adjusting the bogie pivot bolt, the plates only just fitted mounted diagonally across the table which allowed a clamp on each corner.

The picture also shows the bogie plates and the pivot bolt, I just kept it simple and shortened a M10 bolt leaving enough plain shoulder to run through both the bogie and chassis plate, the chassis plate is a copy of the bogie plate. I have also produced a 2mm thick x 35mm dia thrust washer but I am going to remake those increasing to 55mm diameter. I have also gone simple by using a nyloc nut to hold the pivot in place, once adjusted and at the moment I am thinking 0.50mm end float the nyloc should hold that position and not work loose.

On one of the plates you may be able to make out a pair of M5 hex heads either side of the M10 head, these are to prevent the bolt from rotating when adjusting the nyloc. When the motors are assembled into the bogie frame there is no access to the bolt head with a spanner or socket as the head is almost hidden. I did think about having the head tack welded or thread the plate and fix with 638 but that would mean losing the plain shoulder and having to make a sleeve/bush. So again I went simple and fitted the M5 Hex heads, when the bogie is assembled I can just get a thin screwdriver between the motors to push the bolt head up between the M5,s until the nyloc pulls it up to the plate.

Not too far away from having a rolling chassis.

 

Edited By Ron Laden on 28/11/2019 10:09:04

[Ron LadenParticipant @ronladen17547]

At long last I have a rolling chassis, more detail to add to the sides and ends but that can come later as I want to make a start on the body.

Still thinking about the best approach for the build of the body, I have considered carving a blue foam plug and laying up a glass shell with laminating epoxy. I have used the method a few times in the past on R/C aircraft but in a small workshop the thought of being knee deep in foam shavings doesnt appeal much.

I built the shunter body from a mix of 6mm MDF, 1mm, 2mm and 3mm ply, ABS and alu sheet and it worked quite well so that is an option but the class 22 body is twice the length so it would mean more in the way of framing.

Anyway pleased the main chassis and bogies are complete.

[Ron LadenParticipant @ronladen17547]

I have the loco body, well not really but I have my original sketch which I offered up for an idea of sizes and how it looks, the sketch is short lengthways by 35mm so needs to grow a tad.

I have decided to go with the MDF, PLY, ABS etc as I did with the 0-4-0 shunter, I,m quite happy working with those materials, the loco length is 48 inches buffer to buffer.

The body main side panels will be 6mm MDF and you can see from the sketch there are a good number of doors and vent panels. I dont fancy cutting all those out and weakening the panels so I am thinking of facing the MDF with 1.5 mm Birch ply and cutting the apertures out of the ply, it will cut well with a good Stanley blade and a steel rule. I can then make and fit the doors/vents into the recesses and only cut through the MDF for the windows. Also a bonus with the Birch ply is that it is easier to achieve a good surface finish plus its a tougher skin and doesnt suffer dings as easily as MDF.

The curved roof will be a skin of 1 mm Birch ply built on a framework, at the moment I plan on having the roof lift off for access.

Anyway thats the plan so will see how I get on with it.

[Ron LadenParticipant @ronladen17547]

The 6mm MDF body side panels will need some 3mm deep recesses and slots and for what I need to do it would be much easier if I can cut them on the mill. I know you can get away with cutting wood and the like with metal working cutters but I have not tried MDF and wonder what type of cutter I should be looking at bearing in mind that I only have 2500 rpm top speed.

I was thinking of trying a 2 or 3mm 2 flute uncoated HSS Al cutter which I would have to get in but before I do wondered if any of you guys have any thoughts on it.

I appreciate that wood cutting bits would be the way to go but they run at much higher speeds than I have available.

Thanks

Ron

[John HaineParticipant @johnhaine32865]

Almost anything will cut MDF! I suggest either what you mention of perhaps better a wood router bit as big as will do the job. If the loco is going to run outside (I assume it will) then take great care to seal the MDF afterwards. At the moment I'm doing quite a lot of work with Valchromat which is like a very high spec MDF, harder/stronger/less toxic/a "solid surface". Also less wear on cutters. It can be used outdoors when properly sealed. I mill pockets etc in it using a 1/4" router cutter at 5000 rpm quite happily. Recommended if you can get some.

[JasonBModerator @jasonb]

Ron you would be best with carbide as MDF is quite abrasive and will quickly wear the cutter. Either a 2-flute carbide milling cutter or router bit both run at top speed.

If you have not bought the MDF yet then get MR MDF (Moisture resistant) not so much for that property but it is almost twice the density of "standard" MDF so does not have such a fluffy edge when cut.

[DalboyParticipant @dalboy]

If you use MDF whether it is the standard or the MR stuff one thing you may find that any cut or routed edges will suck up paint like mad

I made a rocker motorbike and found that the best thing was to apply a coat of PVA glue on any edges this sealed them and made painting a lot easier.

If you need to produce small lines on the surface like I have done on this piece (see the door and bonnet detail) I used a 1.2mm router bit as used in a dolls house router set by Trend. If interested I will post a link to them

Edited By Derek Lane on 12/12/2019 16:16:05

[John HaineParticipant @johnhaine32865]

Derek's suggestion of PVA is good – can apply over the whole surface to seal after milling. Thin down a bit first.

Another suggestion is a product sold by Ronseal for rotten wood. It's a resin dissolved in a volatile liquid that you splash on liberally with a brush and gets soaked up like water in the desert After a couple of hours it has set hard, gluing all the fibres together. May need a couple of applications with MDF, but should help waterproof it as well.

[Ron LadenParticipant @ronladen17547]

Thanks guys thats helpful.

Valchromat and the Ronseal looks interesting also the small router bits thanks for the links.

I would never have thought of MDF as abrasive just goes to show. I will get a 3mm 2 flute carbide from ARC, s premium range and give it a go. For convenience I buy 4ft x 2ft cut sheet I will see if I can find some MR MDF in cut sizes.

[JasonBModerator @jasonb]

Must admit that I never bother to seal the edges of MDF just go straight on with Dulux Trade quick dry Primer/Undercoat, just off to get some more after lunch as I have 850kg of MR MDF to get painted for the current job.

[BazyleParticipant @bazyle]

If speed is important would it be helpful to use a cutter double the diameter then the cutting edge is running at twice the peripheral speed? Does it help to apply some sealer / binder to the cut line before cutting to help hold the edge together for a cleaner line?

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 13/12/2019 13:01:21:

Must admit that I never bother to seal the edges of MDF just go straight on with Dulux Trade quick dry Primer/Undercoat, just off to get some more after lunch as I have 850kg of MR MDF to get painted for the current job.

850 kgs..? hells bells Jason watch your back.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ron Laden on 13/12/2019 13:40:06:

Posted by JasonB on 13/12/2019 13:01:21:

Must admit that I never bother to seal the edges of MDF just go straight on with Dulux Trade quick dry Primer/Undercoat, just off to get some more after lunch as I have 850kg of MR MDF to get painted for the current job.

850 kgs..? hells bells Jason watch your back.

I expect he's making a full-size version of Derek's half-track!

[JasonBModerator @jasonb]

Don't worry Ron, I won't try and lift it all at once and with my brother having had a hernia op on Monday it's not my back I will be thinking of!

[JC54Participant @jc54]

Posted by SillyOldDuffer on 13/12/2019 14:00:09:

Posted by Ron Laden on 13/12/2019 13:40:06:

Posted by JasonB on 13/12/2019 13:01:21:

Must admit that I never bother to seal the edges of MDF just go straight on with Dulux Trade quick dry Primer/Undercoat, just off to get some more after lunch as I have 850kg of MR MDF to get painted for the current job.

850 kgs..? hells bells Jason watch your back.

I expect he's making a full-size version of Derek's half-track!

No not a half track, just making shelving to keep all of his engines on!!

[Ron LadenParticipant @ronladen17547]

I used to use an Evostik water based contact adhesive it came in a flat furniture polish sized tin, it came with a red plastic spreader which had a 50mm round of foam which made it very good for covering large areas at an even thickness.

I dont know if anyone is familiar with it but I suspect it has been discontinued as I cant find it anywhere, I used to buy it at the DIY stores but none of them seem to carry it any more. I would be interested if anyone knows of an equivalent product that comes in smaller sized tins, I know that there is trade size tins of water based contact but that is way more than I would ever need or use.

Ron

[John HaineParticipant @johnhaine32865]

I don't know about contact glue by I've recently started using a clear Gorilla Glue which is available in quite large bottles, and it is amazing!

[Ron LadenParticipant @ronladen17547]

We all know MDF but is anyone familiar with HDF.

Apparently HDF is denser and stronger than MDF, hardboard is a HDF and available in 8ft x 4ft x 1/8" thick. I have read that HDF is produced in a range of thickness but apart from the 1/8" the other sizes don't seem to be stocked in the UK ?

Wondered if anyone knows anything of it.

[JasonBModerator @jasonb]

18mm high density MDF is stocked by the panel specialists such as Spanolux Deep Rout this has a density a bit higher than HDF at 960kg/m3 but its not something you will find in a DIY shed being used more commercially for things like kitchen cabinet doors that would have a decorative panel routed into then before being foil or vinyl covered as it has a smoother surface and cut ends less plecking (fluffynesss).

Same panel specialists will also have nominal 6mm hardboard/HDF but mostly only smooth on one face as well as 6mm melamine faced MDF which is quite a high density., I often use the later for knocking up quick templates.

[Ron LadenParticipant @ronladen17547]

Thanks Jason that's helpful.

[Mark EasingwoodParticipant @markeasingwood33578]

Happy New Year,

 

Just seen your build thread, looking good.

 

I have been in joinery manufacture for about 40 years, and had my own business for about 30 years, so this is my opinion on MDF etc.

 

MDF is available in standard, moisture resistant, exterior and fire resistant grades.

There is no noticeable difference in density in any of these grades. The moisture resistant, (mr), grade is always dyed green, either right through, or just the core for identification purposes. The standard and mr version soon swell and disintegrate if they get wet for any prolonged time. The more expensive exterior grade also requires all edges to be sealed if it is to survive prolonged exposure to water. There is a new kid on the block, which is described as extremely durable, and sold as Tricoya, not cheap but with a claimed durability, guaranteed for 50 years.

 

I have only ever seen HDF sold in 3mm thick sheets with a white/black or cream coloured finish on one face, it is used as a replacement for white faced hardboard. The denser deep rout MDF is, I think, only available in thicker boards. It is used because the “normal” thicker MDF boards can have an inner core made up of larger fibres, which don't leave a good finish when routered into.

 

All MDF is abrasive and blunts hand tools and HSS type spindle moulder tooling very quickly, TCT or even diamond coated tooling is required. TCT router cutters are ok to use, but do blunt quicker than when used on timber.

 

Thin Birch plywood is nice to use, but I think it is interior grade only, in thin sheets, and not moisture resistant or exterior grade.

 

Lawcris, Arnold Laver, Timbmet and Lathams are all good suppliers of MDF and Ply, depending where you live.

 

Solvent based contact adhesive is still available, not seen the really small tins or tubes for years, I think shops stopped selling them during the glue sniffing era in the 80's.

 

I have been using this solvent based, Link , own brand from, “Construction Chemicals”, the big name EVO-STICK is also available, but I am not convinced it is the same formulation as it used to be. It all goes off in the tin after its been opened, but sometimes it's still ok after a year or so! Water based is also available, but I haven't tried it. The red plastic spreaders are also a thing of the past.

 

Polyurethane glues, such as Gorilla glue, stick well, they don't care about a freezing cold workshop, (unlike PVA types), and are waterproof, but also messy, and possibly carcinogenic, via prolonged skin contact.

Hope some of this may be of interest. I am in East Yorkshire, if I can help by ordering anything for you, or cutting anything.

Mark.

 

 

Edited By Mark Easingwood on 05/01/2020 17:53:38

[Ron LadenParticipant @ronladen17547]

Thanks Mark, information appreciated.

We have a couple of local firms which make bespoke kitchens so I will pop in and see what material they carry and if suitable if I can purchase some.

Ron

[Ron LadenParticipant @ronladen17547]

I took a gamble and bought a cheap Chinese set of 4 radius edge cutters, cost £8 for the set 1/8, 1/4, 3/8 and 1/2 inch rads.

The 20mm thick loco body cab/end plates have radiused edges which I was planning to cut and shape by hand but then thought it better and more accurate if I could machine to the basic shape and then hand finish. I didnt want anything expensive as the cutters will be seldom used if at all.

I know router cutters are run at high speed and I only have a top speed on the mill of 2500 so that was the main worry, would they work at the lower speed..? Need not have worried as they work and cut just fine, tried some test cuts on a piece of Pine, unknown hardwood and MDF and they left a very clean finish even on the MDF which surprised me. So in this instance £8 well spent.

1/2 inch cutter below.

[Ron LadenParticipant @ronladen17547]

Our club track is open again (with restrictions and limited numbers) so I thought I would put a few hours in and make a start on the body. A picture below of one of the side panels in its early stages, base material 6mm MDF faced with 1.5mm birch ply. The top third of the panel is angled inboard by 5 degrees and the apertures cut for the numerous louvered vent panels and doors, 20 vent panels, 4 double engine bay doors and 4 cab doors on a class 22.

I considered fitting the 1.5mm facing as a one piece but went with cutting it into three and added one at a time, used 4 parts PVA / 1 part water to allow it to spread a bit easier when clamped and weighted down.

I found an old tin of cellulose sanding sealer which I tried on some MDF off cuts, 2 or 3 coats with a light sanding in between seems to work really well especially on the edges it soaks well in and seals the surface.

Edited By Ron Laden on 10/09/2020 13:41:02

[Ron LadenParticipant @ronladen17547]

The body slowly coming together, the sides, base plate, bulkheads and cab end plates all connected and aligned.

Click twice to enlarge.

Edited By Ron Laden on 18/09/2020 19:42:27

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